CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent

Application No. 61/287,936 filed on December 18, 2009.

FIELD OF THE INVENTION

[0002] The present invention relates generally to illumination systems, and more specifically to lamp assemblies employing light emitting diodes (LEDs) as light sources.

BACKGROUND

[0003] Conventional light emitting diodes are capable of producing radiation in the visible spectrum of wavelengths. It is desirable to design lamp assemblies from such conventional light emitting diodes.

SUMMARY

[0004] The present invention may comprise one or more of the features recited in the attached claims, and/or one or more of the following features and combinations thereof. In one illustrative embodiment, a lamp assembly may comprise a frustum, a plurality of light emitting diodes positioned at least partially about the frustum, and a driver circuit configured to electrically drive the plurality of light emitting diodes from a source of voltage.

[0005] The frustum may define a lower base, an opposite upper base, at least one wall extending between the lower base and the upper base and a longitudinal axis between the lower base and the upper base. The plurality of light emitting diodes may be mounted to the at least one wall of the frustum such that radiation produced by the plurality of light emitting diodes is directed away from the frustum generally at an angle relative to the longitudinal axis. Illustratively, the plurality of light emitting diodes may be mounted to the at least one wall of the frustum such that radiation produced by the plurality of light emitting diodes is directed away from the frustum generally at a non-zero angle relative to the longitudinal axis. The plurality of light emitting diodes may be mounted to the at least one wall of the frustum such that radiation produced by the plurality of light emitting diodes is directed away from the frustum generally normal to the longitudinal axis. Each of the plurality of light emitting diodes may be mounted to the at least one wall of the frustum such that radiation produced thereby is directed away from the frustum generally normal to the at least one wall, and the at least one wall may define the angle relative to the longitudinal axis.

[0006] The frustum may define a lower base, an opposite upper base and a plurality of side-by-side walls each extending between the lower base and the upper base. Each of the plurality of side-by-side walls may define an outer wall surface and an opposite inner wall surface. The plurality of light emitting diodes may be mounted to the outer wall surface of one or more of the plurality of side-by-side walls. Alternatively or additionally, the plurality of light emitting diodes may be mounted to the inner wall surface of one or more of the plurality of side-by-side walls.

[0007] The frustum may define a lower base, an opposite upper base and a single, unitary wall extending between the lower base and the upper base such that the frustum defines a truncated cone. The single, unitary wall may define an outer wall surface and an opposite inner wall surface. The plurality of light emitting diodes may be mounted to the outer wall surface at least partially about an outer periphery of the truncated cone. Alternatively or additionally, the plurality of light emitting diodes may be mounted to the inner wall surface at least partially about an inner periphery of the truncated cone.

[0008] The source of voltage may comprise a source of AC voltage and the driver circuit may be configured to be responsive to an AC voltage signal supplied by the source of AC voltage to activate a number of the plurality of light emitting diodes while maintaining a remainder of the plurality light emitting diodes in an off state during portions of the AC voltage signal having positive voltage values, and to activate the remainder of the plurality of light emitting diodes while maintaining the number of the plurality of light emitting diodes in the off state during portions of the AC voltage signal having negative voltage values. The driver circuit may comprise a parallel connected resistor and capacitor with one end of the parallel connection defining a first connection to the source of AC voltage, an opposite end of the parallel connection of the resistor and capacitor electrically connected to an anode of a first diode having a cathode electrically connected in forward bias relationship to the number of the plurality of light emitting diodes, the opposite end of the parallel connection of the resistor and capacitor also electrically connected to a cathode of a second diode having an anode electrically connected in forward bias relationship to the remainder of the plurality of light emitting diodes. The number of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The cathode of the first diode may be electrically connected to an anode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the number of the plurality of light emitting diodes. A cathode of a last light emitting diode in the at least one string of two or more series connected diodes of the number of the plurality of light emitting diodes may define a second electrical connection to the source of AC voltage. The remainder of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The anode of the second diode may be electrically connected to a cathode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the remainder of the plurality of light emitting diodes. An anode of a last light emitting diode in the at least one string of two or more series connected diodes of the remainder of the plurality of light emitting diodes may also define the second electrical connection to the source of AC voltage. Either or both of the number of the plurality of light emitting diodes and the remainder of the plurality of light emitting diodes may comprise two or more parallel connected strings of two or more series connected light emitting diodes.

[0009] The source of voltage may alternatively comprise a source of DC voltage.

[0010] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the plurality of light emitting diodes, the thermally conductive medium configured to control an operating temperature of the plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the plurality of light emitting diodes in response to current flow therethrough. Each of the plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions, wherein current flow across the semiconductor junction of each of the plurality of light emitting diodes in response to a voltage supplied by the driver circuit causes the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive medium may be positioned at least partially about the semiconductor junction of each of the plurality of light emitting diodes such that the thermally conductive medium receives the thermal energy radiated outwardly from the semiconductor of each of the plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the plurality of light emitting diodes. The thermally conductive medium may be positioned completely about the periphery of the semiconductor junction of each of the plurality of light emitting diodes. Each of the plurality of light emitting diodes may comprise an encapsulating material encapsulating the semiconductor die, and the thermally conductive medium may be positioned about an outer periphery of the encapsulating material of each of the plurality of light emitting diodes.

[0011] The lamp assembly may further comprise a lamp base carrying an electrical connection to the source of voltage. The assembly of the frustum, the plurality of light emitting diodes, the driver circuit and the thermally conductive medium may be mounted to the lamp base with the source of AC voltage electrically connected to the driver circuit. The lamp assembly may further comprise a transparent or translucent cover mounted to the lamp base with the assembly of the frustum, the plurality of light emitting diodes, the driver circuit and the thermally conductive medium positioned between the transparent or translucent cover and the lamp base. The combination of the lamp base, the transparent or translucent cover and the assembly of the frustum, the plurality of light emitting diodes, the driver circuit and the thermally conductive medium may together comprise a street lamp.

[0012] The frustum may comprise a first frustum and a second frustum juxtaposed with the first frustum. The plurality of light emitting diodes may comprise a first plurality of light emitting diodes and a second plurality of light emitting diodes with the first plurality of light emitting diodes positioned at least partially about the first frustum and the second plurality of light emitting diodes positioned at least partially about the second frustum. The driver circuit may be configured to electrically drive the first and second plurality of light emitting diodes from the source of voltage. The second frustum may define a lower base, an opposite upper base, at least one wall extending between the lower base and the upper base and a longitudinal axis between the lower base and the upper base that is collinear with the longitudinal axis of the first frustum. The second plurality of light emitting diodes may be mounted to the at least one wall of the second frustum such that radiation produced by the second plurality of light emitting diodes is directed away from the second frustum generally at an angle relative to the longitudinal axis of the second frustum. The angle relative to the longitudinal axis of the first frustum may be substantially equal to the angle relative to the second frustum. The angle relative to the longitudinal axis of the first frustum and the angle relative to the second frustum may both be acute angles relative to a common end of the longitudinal axes such that radiation produced by the first and second plurality of light emitting diodes is directed generally in a common direction away from a plane normal to the

longitudinal axes. Alternatively, the angle relative to the longitudinal axis of the first frustum may be an acute angle relative to one common end of the longitudinal axes and the angle relative to the second frustum may be an acute angle relative to an opposite common end of the longitudinal axes such that radiation produced by the first plurality of light emitting diodes is directed in one direction away from a plane normal to the longitudinal axes and radiation produced by the second plurality of light emitting diodes is directed in a generally opposite direction away from the plane normal to the longitudinal axes.

[0013] The angle relative to the longitudinal axis of the first frustum may be different from the angle relative to the longitudinal axis of the second frustum. The angle relative to the longitudinal axis of the first frustum and the angle relative to the second frustum may both be acute angles relative to a common end of the longitudinal axes such that radiation produced by the first and second plurality of light emitting diodes is directed generally in a common direction away from a plane normal to the longitudinal axes. Alternatively, the angle relative to the longitudinal axis of the first frustum may be an acute angle relative to one common end of the longitudinal axes and the angle relative to the second frustum may be an acute angle relative to an opposite common end of the longitudinal axes such that radiation produced by the first plurality of light emitting diodes is directed in one direction away from a plane normal to the longitudinal axes and radiation produced by the second plurality of light emitting diodes is directed in a generally opposite direction away from the plane normal to the longitudinal axes.

[0014] The second plurality of light emitting diodes may be mounted to the at least one wall of the second frustum such that radiation produced by the second plurality of light emitting diodes is directed away from the second frustum generally at a non-zero angle relative to the longitudinal axis of the second frustum.

[0015] The second plurality of light emitting diodes may be mounted to the at least one wall of the second frustum such that radiation produced by the second plurality of light emitting diodes is directed away from the second frustum generally normal to the longitudinal axis of the second frustum.

[0016] Each of the second plurality of light emitting diodes may be mounted to the at least one wall of the second frustum such that radiation produced thereby is directed away from the second frustum generally normal to the at least one wall of the second frustum, and the at least one wall of the second frustum may define the angle relative to the longitudinal axis of the second frustum.

[0017] The second frustum may define a lower base, an opposite upper base and a plurality of side-by-side walls each extending between the lower base and the upper base of the second frustum. Each of the plurality of side-by-side walls of the second frustum may define an outer wall surface and an opposite inner wall surface. The second plurality of light emitting diodes may be mounted to the outer wall surface of one or more of the plurality of side-by-side walls of the second frustum. Alternatively or additionally, the second plurality of light emitting diodes may be mounted to the inner wall surface of one or more of the plurality of side-by-side walls of the second frustum.

[0018] The second frustum may define a lower base, an opposite upper base and a single, unitary wall extending between the lower base and the upper base of the second frustum such that the second frustum defines a truncated cone. The single, unitary wall of the second frustum may define an outer wall surface and an opposite inner wall surface. The second plurality of light emitting diodes may be mounted to the outer wall surface of the second frustum at least partially about an outer periphery of the truncated cone. Alternatively or additionally, the second plurality of light emitting diodes may be mounted to the inner wall surface of the second frustum at least partially about an inner periphery of the truncated cone.

[0019] The source of voltage may comprise a source of AC voltage and the driver circuit may be configured to be responsive to the AC voltage signal supplied by the source of AC voltage to activate a first number of the first plurality of light emitting diodes while maintaining a remainder of the first plurality light emitting diodes in an off state during portions of the AC voltage signal having positive voltage values, and to activate the remainder of the first plurality of light emitting diodes while maintaining the first number of the first plurality of light emitting diodes in the off state during portions of the AC voltage signal having negative voltage values, and to activate a second number of the second plurality of light emitting diodes while maintaining a remainder of the second plurality light emitting diodes in an off state during portions of the AC voltage signal having positive voltage values, and to activate the remainder of the second plurality of light emitting diodes while maintaining the second number of the second plurality of light emitting diodes in the off state during portions of the AC voltage signal having negative voltage values. Alternatively, the source of voltage may comprise a source of DC voltage.

[0020] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the second plurality of light emitting diodes. The thermally conductive medium may be configured to control an operating temperature of the second plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the second plurality of light emitting diodes in response to current flow therethrough. Each of the second plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions. Current flow across the semiconductor junction of each of the second plurality of light emitting diodes in response to a voltage supplied by the driver circuit may cause the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive medium may be positioned at least partially about the semiconductor junction of each of the second plurality of light emitting diodes such that the thermally conductive medium receives the thermal energy radiated outwardly from the semiconductor of each of the second plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the second plurality of light emitting diodes. The thermally conductive medium may be positioned completely about the periphery of the semiconductor junction of each of the second plurality of light emitting diodes. Each of the second plurality of light emitting diodes may comprise an encapsulating material encapsulating the semiconductor die. The thermally conductive medium may be positioned about an outer periphery of the encapsulating material of each of the second plurality of light emitting diodes.

[0021] The lamp assembly may further comprise a lamp base carrying an electrical connection to the source of voltage. The assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit and the thermally conductive medium may be mounted to the lamp base with the source of voltage electrically connected to the driver circuit. The lamp assembly may further comprise a transparent or translucent cover mounted to the lamp base with the assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit and the thermally conductive medium positioned between the transparent or translucent cover and the lamp base. The combination of the lamp base, the transparent or translucent cover and the assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit and the thermally conductive medium may together comprise a street lamp.

[0022] A lamp assembly may comprise a first frustum defining a first longitudinal axis therethrough, a first plurality of light emitting diodes positioned at least partially about the first frustum, a second frustum defining a second longitudinal axis therethrough, the second frustum juxtaposed with the first frustum such that the first and second longitudinal axes are collinear, a second plurality of light emitting diodes positioned at least partially about the second frustum, a plurality of support members positioned between the first and second frusta and configured to support the first and second frusta relative to each other, and a driver circuit configured to electrically drive the first and second plurality of light emitting diodes from a source of voltage.

[0023] The plurality of support members may be attached to the first frusta and to the second frusta. The plurality of support members may be electrically connected to the first frusta, the second frusta and to the driver circuit. The lamp assembly may further comprise a base member mounted to at least one of the plurality of support members. The lamp assembly may further comprise a lamp base carrying an electrical connection to the source of voltage, and the assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit and the plurality of support members may be mounted by the base member to the lamp base with the source of voltage electrically connected to the driver circuit. The lamp assembly may further comprise a transparent or translucent cover mounted to the lamp base with the assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit, the plurality of support members and the base member positioned between the transparent or translucent cover and the lamp base. The combination of the lamp base, the transparent or translucent cover and the assembly of the first and second frusta, the first and second plurality of light emitting diodes, the driver circuit, the plurality of support members and the base member may together comprise a street lamp. [0024] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the first plurality of light emitting diodes and at least partially about the second plurality of light emitting diodes. The thermally conductive medium may be configured to control an operating temperature of the first and second plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the first and second plurality of light emitting diodes in response to current flow therethrough.

[0025] A lamp assembly may comprise an arcuate panel, a plurality of light emitting diodes mounted to the arcuate panel, and a driver circuit configured to electrically drive the plurality of light emitting diodes from a source of voltage.

[0026] The arcuate panel may have a first end and a second end opposite the first end. The arcuate panel may define an angle between planes normal to the first and second ends thereof. The angle defined between planes normal to the first and second ends of the arcuate panel may be an acute angle. Alternatively, the angle defined between planes normal to the first and second ends of the arcuate panel may be an obtuse angle. The angle defined between planes normal to the first and second ends of the arcuate panel may be approximately 180 degrees.

[0027] The arcuate panel may define an inner concave surface and an outer convex surface opposite to the inner concave surface. The plurality of light emitting diodes may be mounted to the inner concave surface of the arcuate panel such that radiation produced by the plurality of light emitting diodes is directed away from the inner surface of the arcuate panel toward a focal point defined by the inner concave surface. Alternatively or additionally, the plurality of light emitting diodes may be mounted to the outer convex surface of the arcuate panel such that radiation produced by the plurality of light emitting diodes is directed outwardly away from the outer surface of the arcuate panel.

[0028] The arcuate panel may have a first end and a second end opposite the first end. The arcuate panel may comprise a plurality of side-by-side walls extending between the first and second ends. Alternatively, the arcuate panel may comprise a single, unitary panel extending between the first and second ends.

[0029] The source of voltage may comprise a source of AC voltage and the driver circuit may be configured to be responsive to an AC voltage signal supplied by the source of AC voltage to activate a number of the plurality of light emitting diodes while maintaining a remainder of the plurality light emitting diodes in an off state during portions of the AC voltage signal having positive voltage values, and to activate the remainder of the plurality of light emitting diodes while maintaining the number of the plurality of light emitting diodes in the off state during portions of the AC voltage signal having negative voltage values. The driver circuit may comprise a parallel connected resistor and capacitor with one end of the parallel connection defining a first connection to the source of AC voltage, an opposite end of the parallel connection of the resistor and capacitor electrically connected to an anode of a first diode having a cathode electrically connected in forward bias relationship to the number of the plurality of light emitting diodes, the opposite end of the parallel connection of the resistor and capacitor also electrically connected to a cathode of a second diode having an anode electrically connected in forward bias relationship to the remainder of the plurality of light emitting diodes. The number of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The cathode of the first diode may be electrically connected to an anode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the number of the plurality of light emitting diodes, and a cathode of a last light emitting diode in the at least one string of two or more series connected diodes of the number of the plurality of light emitting diodes may define a second electrical connection to the source of AC voltage. The remainder of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The anode of the second diode may be electrically connected to a cathode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the remainder of the plurality of light emitting diodes, and an anode of a last light emitting diode in the at least one string of two or more series connected diodes of the remainder of the plurality of light emitting diodes may also define the second electrical connection to the source of AC voltage. Either or both of the number of the plurality of light emitting diodes and the remainder of the plurality of light emitting diodes may comprise two or more parallel connected strings of two or more series connected light emitting diodes.

[0030] The source of voltage may alternatively comprise a source of DC voltage.

[0031] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the plurality of light emitting diodes. The thermally conductive medium may be configured to control an operating temperature of the plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the plurality of light emitting diodes in response to current flow therethrough. Each of the plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions, and current flow across the semiconductor junction of each of the plurality of light emitting diodes in response to a voltage supplied by the driver circuit may cause the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive medium may be positioned at least partially about the semiconductor junction of each of the plurality of light emitting diodes such that the thermally conductive medium receives the thermal energy radiated outwardly from the semiconductor of each of the plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the plurality of light emitting diodes. The thermally conductive medium may be positioned completely about the periphery of the semiconductor junction of each of the plurality of light emitting diodes. Each of the plurality of light emitting diodes may comprise an encapsulating material encapsulating the semiconductor die, and the thermally conductive medium may be positioned about an outer periphery of the encapsulating material of each of the plurality of light emitting diodes.

[0032] The lamp assembly may further comprise a lamp base carrying an electrical connection to the source of voltage. The assembly of the arcuate panel, the plurality of light emitting diodes, the driver circuit and the thermally conductive medium may be mounted to the lamp base with the source of voltage electrically connected to the driver circuit. The lamp assembly may further comprise a transparent or translucent cover mounted to the lamp base with the assembly of the arcuate panel, the plurality of light emitting diodes, the driver circuit and the thermally conductive medium positioned between the transparent or translucent cover and the lamp base. The lamp base may be configured to mount to at least one of a ceiling, a wall and a floor of a structure. Alternatively or additionally, the lamp base may be configured to mount to at least a door or gate of the structure.

[0033] A lamp assembly may comprise a first arcuate panel, a first plurality of light emitting diodes positioned at least partially about the first arcuate panel, a second arcuate panel separate from the first arcuate panel, a second plurality of light emitting diodes positioned at least partially about the second arcuate panel, a support structure positioned between the first and second arcuate panels and configured to support the first and second arcuate panels relative to each other, and a driver circuit configured to electrically drive the first and second plurality of light emitting diodes from a source of voltage.

[0034] A lamp assembly may comprise a substantially flat panel, a plurality of light emitting diodes mounted to the flat panel, and a driver circuit configured to electrically drive the plurality of light emitting diodes from a source of voltage.

[0035] The flat panel may have a first end and a second end opposite the first end, and the flat panel may comprise a plurality of side-by-side walls extending between the first and second ends. Alternatively, the flat panel may comprise a single, unitary panel extending between the first and second ends.

[0036] The source of voltage may comprise a source of AC voltage and the driver circuit may be configured to be responsive to an AC voltage signal supplied by the source of AC voltage to activate a number of the plurality of light emitting diodes while maintaining a remainder of the plurality light emitting diodes in an off state during portions of the AC voltage signal having positive voltage values, and to activate the remainder of the plurality of light emitting diodes while maintaining the number of the plurality of light emitting diodes in the off state during portions of the AC voltage signal having negative voltage values.

[0037] The driver circuit may comprise a parallel connected resistor and capacitor with one end of the parallel connection defining a first connection to the source of AC voltage, an opposite end of the parallel connection of the resistor and capacitor electrically connected to an anode of a first diode having a cathode electrically connected in forward bias relationship to the number of the plurality of light emitting diodes, the opposite end of the parallel connection of the resistor and capacitor also electrically connected to a cathode of a second diode having an anode electrically connected in forward bias relationship to the remainder of the plurality of light emitting diodes. The number of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The cathode of the first diode may be electrically connected to an anode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the number of the plurality of light emitting diodes. A cathode of a last light emitting diode in the at least one string of two or more series connected diodes of the number of the plurality of light emitting diodes may define a second electrical connection to the source of AC voltage. The remainder of the plurality of light emitting diodes may comprise at least one string of two or more series connected light emitting diodes. The anode of the second diode may be electrically connected to a cathode of a first light emitting diode in the at least one string of two or more series connected light emitting diodes of the remainder of the plurality of light emitting diodes, and an anode of a last light emitting diode in the at least one string of two or more series connected diodes of the remainder of the plurality of light emitting diodes may also define the second electrical connection to the source of AC voltage. Either or both of the number of the plurality of light emitting diodes and the remainder of the plurality of light emitting diodes may comprise two or more parallel connected strings of two or more series connected light emitting diodes.

[0038] The source of voltage may alternatively comprise a source of DC voltage.

[0039] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the plurality of light emitting diodes. The thermally conductive medium may be configured to control an operating temperature of the plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the plurality of light emitting diodes in response to current flow therethrough. Each of the plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions, and current flow across the semiconductor junction of each of the plurality of light emitting diodes in response to a voltage supplied by the driver circuit may cause the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive medium may be positioned at least partially about the semiconductor junction of each of the plurality of light emitting diodes such that the thermally conductive medium receives the thermal energy radiated outwardly from the semiconductor of each of the plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the plurality of light emitting diodes. The thermally conductive medium may be positioned completely about the periphery of the semiconductor junction of each of the plurality of light emitting diodes. Each of the plurality of light emitting diodes may comprise an encapsulating material encapsulating the semiconductor die, and the thermally conductive medium may be positioned about an outer periphery of the encapsulating material of each of the plurality of light emitting diodes.

[0040] A lamp assembly may comprise a driver circuit configured to be electrically connected to a source of voltage, a thermally conductive sheet defining a number of openings therethrough, and a plurality of light emitting diodes each mounted to the thermally conductive sheet and extending through a different one of the number of openings defined therethrough such that the thermally conductive sheet is positioned about each of the plurality of light emitting diodes. The thermally conductive sheet may be configured to control an operating temperature of the plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the plurality of light emitting diodes in response to current flow through each of the plurality of light emitting diodes from the source of voltage.

[0041] Each of the plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions. Current flow across the semiconductor junction of each of the plurality of light emitting diodes in response to a voltage supplied by the driver circuit may cause the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive sheet may be positioned about the semiconductor junction of each of the plurality of light emitting diodes such that the thermally conductive sheet receives the thermal energy radiated outwardly from the semiconductor of each of the plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the plurality of light emitting diodes.

[0042] The thermally conductive sheet may be rigid and may be shaped to form a substantially flat, polygonal sheet. Alternatively, the thermally conductive sheet may be flexible, and the flexible, thermally conductive sheet may be elastically or non-elastically deformed into a specified shape after the plurality of light emitting diodes are mounted thereto. The flexible, thermally conductive sheet may be modified to form a plurality of interconnected, thermally conductive sub-sections, and the specified shape may be formed by one or more portions of one or more of the plurality of interconnected, thermally conductive sub-sections.

[0043] The specified shape may be one of a frustum, a sphere, a truncated sphere, an annular band and an arcuate panel. The specified shape may be, for example, a frustum, and the frustum may define a truncated cone. [0044] A lamp assembly may comprise a flexible substrate, a plurality of light emitting diodes each mounted to the flexible substrate, with the flexible substrate being elastically or non-elastically deformed into a specified shape after the plurality of light emitting diodes are mounted thereto, and a driver circuit configured to electrically drive the plurality of light emitting diodes from a source of voltage.

[0045] The lamp assembly may further comprise a thermally conductive medium positioned at least partially about each of the plurality of light emitting diodes. The thermally conductive medium may be configured to control an operating temperature of the plurality of light emitting diodes by dissipating thermal energy radiated outwardly by each of the plurality of light emitting diodes in response to current flow therethrough. Each of the plurality of light emitting diodes may comprise a semiconductor die defining semiconductor junction defined between two dissimilar semiconductor regions, and current flow across the semiconductor junction of each of the plurality of light emitting diodes in response to a voltage supplied by the driver circuit may cause the thermal energy to radiate outwardly from the semiconductor junction about a periphery of the semiconductor junction. The thermally conductive medium may be positioned at least partially about the semiconductor junction of each of the plurality of light emitting diodes such that the thermally conductive medium receives the thermal energy radiated outwardly from the semiconductor of each of the plurality of light emitting diodes and dissipates the thermal energy to thereby control the operating temperature of the plurality of light emitting diodes. The thermally conductive medium may be positioned completely about the periphery of the semiconductor junction of each of the plurality of light emitting diodes. Each of the plurality of light emitting diodes may comprise an encapsulating material encapsulating the semiconductor die, and the thermally conductive medium may be positioned about an outer periphery of the encapsulating material of each of the plurality of light emitting diodes.

[0046] The specified shape may be one of a frustum, a sphere, a truncated sphere, an annular band and an arcuate panel. The specified shape may be, for example, a frustum, and the frustum may define a truncated cone.

[0047] The thermally conductive medium may comprise one or more thermally conductive sheets each defining a number of openings therethrough, and each of the plurality of light emitting diodes may extend through a different one of the number of openings defined through the one or more thermally conductive sheets. The one or more thermally conductive sheets may comprise at least one flexible, thermally conductive sheet. Alternatively or additionally, the one or more thermally conductive sheets may comprise at least one rigid or semi-rigid thermally conductive sheet.

[0048] In any of the embodiments, each of the plurality of light emitting diodes may comprise an encapsulating material encapsulating a semiconductor die defining a semiconductor junction through which the current flows, wherein the

semiconductor die of each of the plurality of light emitting diodes generates heat in response to current flow therethrough and the encapsulating material conducts the generated heat away from the semiconductor die in each of the plurality of light emitting diodes. The thermally conductive medium may be configured to further control the operating temperature of the plurality of light emitting diodes by dissipating the heat generated by the semiconductor die and conducted away from the semiconductor die to the thermally conductive medium via the encapsulating material of each of the plurality of light emitting diodes. The thermally conductive medium may be positioned relative to each of the plurality of light emitting diodes such that a plane defined by the semiconductor junction of each of the plurality of light emitting diodes intersects the thermally conductive medium.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 A is a front elevational view of a light-producing portion of one illustrative embodiment of an LED-based lamp assembly.

[0050] FIG. 1 B is a perspective view of the LED-based lamp assembly embodiment illustrated in FIG. 1 A as viewed upwardly from beneath the light- producing portion of the lamp assembly.

[0051] FIG. 2 is an electrical component-level schematic diagram of the embodiment of the LED-based lamp assembly illustrated in FIGS. 1A and 1 B.

[0052] FIG. 3 is a cross-sectional view of the LED-based lamp assembly embodiment of FIG. 1A viewed along section lines 3-3 thereof.

[0053] FIG. 4 is a top plan view of one illustrative embodiment of an electrically conductive pattern formed on a top surface of the main circuit board of the LED-based lamp assembly embodiment illustrated in FIGS. 1A-3.

[0054] FIG. 5 is a top plan view of one illustrative embodiment of an electrically conductive pattern formed on a bottom surface of the main circuit board of the LED-based lamp assembly embodiment illustrated in FIGS. 1A-4. [0055] FIG. 6 is a front elevational view of one illustrative embodiment of one of the plurality of LED mounting sections of the upper frustum of the LED-based lamp assembly embodiment illustrated in FIGS. 1A-5.

[0056] FIG. 7 is a front elevational view of one illustrative embodiment of one of the plurality of LED mounting sections of the lower frustum of the LED-based lamp assembly embodiment illustrated in FIGS. 1 -6.

[0057] FIG. 8 is a cross-sectional view of the LED-based lamp assembly embodiment of FIG. 3 viewed along section lines 8-8 thereof.

[0058] FIG. 9 is a front elevational view of one illustrative embodiment of one of the plurality of frustum interconnection and support members of the LED-based lamp assembly embodiment illustrated in FIGS. 1A-8.

[0059] FIG. 10 is a top plan view of the LED-based lamp assembly embodiment illustrated in FIGS. 1 -9 with the main circuit board omitted to illustrate the arrangement of the plurality of frustum interconnection and support members relative to the upper and lower frusta.

[0060] FIG. 1 1 is a cross-sectional view of a portion of one of the plurality of LED mounting sections of the upper frustum of the LED-based lamp assembly embodiment illustrated in FIG. 1 B viewed along section lines 1 1-1 1 thereof.

[0061] FIG. 12 is a schematic diagram, shown partially in cross-section, of the LED die and thermal energy dissipation arrangement illustrated in FIG. 1 1 , demonstrating operation of the thermal energy dissipation medium in response to current flow across the junction of the LED die.

[0062] FIG. 13 is a cross-sectional view of one illustrative application of the LED-based lamp assembly embodiment illustrated in FIGS. 1 -12, implemented in a conventional street lamp fixture.

[0063] FIG. 14 is a diagram of one alternative embodiment of the LED-based lamp assembly implemented in a conventional street lamp fixture.

[0064] FIG. 15 is a diagram of another alternative embodiment of the LED- based lamp assembly implemented in a conventional street lamp fixture.

[0065] FIG. 16 is a cross-sectional view of another illustrative embodiment of an LED-based lamp assembly.

[0066] FIG. 17 is a cross-sectional view of yet another illustrative embodiment of an LED-based lamp assembly. DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0067] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to a number of illustrative embodiments shown in the attached drawings and specific language will be used to describe the same.

[0068] Referring now to FIGS. 1 A and 1 B, one illustrative embodiment of a light emitting diode (LED)-based lamp assembly 10 is shown. In the illustrated embodiment, the lamp assembly 10 includes an upper frustum 12 juxtaposed with a lower frustum 14. The upper and lower frusta 12, 14 are joined together and supported by a frusta interconnection and support structure 16, and a base member 18 is attached to the frusta interconnection and support structure 16. In the illustrated embodiment a first plurality of light emitting diodes, Du, is positioned and distributed completely about the upper frustum 12 and a second plurality of light emitting diodes, D _L , is positioned and distributed completely about the lower frustum 14. It will be understood, however, that while the first plurality of light emitting diodes, Du, is illustrated in the drawings as being positioned completely about the periphery of the upper frustum 12, and the second plurality of light emitting diodes, D _L , is illustrated in the drawings as being positioned completely about the periphery of the lower frustum 14, this disclosure contemplates embodiments in which the first plurality of light emitting diodes, Du, is positioned only partially about the periphery of the upper frustum 12 and/or in which the second plurality of light emitting diodes, D _L , is positioned only partially about the periphery of the lower frustum 14. It will further be understood that while the lamp assembly 10 is illustrated in the drawings as having the first plurality of light emitting diodes, Du, positioned about an outer periphery of the upper frustum 14 and has having the second plurality of light emitting diodes, D _L , positioned about an outer periphery of the lower frustum 14, this disclosure contemplates embodiments in which some or all of the first plurality of light emitting diodes, Du, are positioned partially or completely about an inner periphery of the upper frustum 12 in addition to or alternatively to the light emitting diodes positioned partially or completely about the outer periphery of the upper frustum 12, and/or in which some or all of the second plurality of light emitting diodes, D _L , are positioned partially or completely about an inner periphery of the lower frustum 14 in addition to or alternatively to the light emitting diodes positioned partially or completely about the outer periphery of the lower frustum 14. It will further still be understood that while the lamp assembly 10 is illustrated in the drawings as including an upper frustum 12 and a lower frustum 14, this disclosure contemplates embodiments in which the lamp assembly includes only one frustum 12, 14 or the other, or in which the lamp assembly includes one or more frusta in addition to the two illustrated frusta 12, 14. It will further still be understood that while the lamp assembly 10 is illustrated in the drawings with both frusta 12 and 14 oriented such that radiation produced by both the first and second plurality of light emitting diodes Du and D _L respectively is directed downwardly, this disclosure contemplates embodiments in which one or the other, or both, of the frusta 12 and 14 is/are oriented such that radiation produced by the first or second plurality of light emitting diodes Du and D _L respectively, or both, is respectively directed upwardly or other directions.

[0069] As used herein, the term "frustum" will be understood to mean an N- sided hollow structure defining a first base at one end, a second base at its opposite end that is generally juxtaposed with the first base and defining a longitudinal axis that extends centrally through the first and second bases, wherein the first base has a cross-sectional area that is greater than or equal to that of the second base, and wherein N may be any positive integer. In some embodiments, the cross-sectional areas of the first and second bases may be normal to the longitudinal axis, although in other embodiments the cross-sectional area one and/or the other of the first and second bases may be non-perpendicular, e.g., oblique or other linear, piecewise linear or non-linear shape, relative to the longitudinal axis. In the case of N=1 , and with the cross-sectional areas of the first and second base both circular and normal to the longitudinal axis, for example, the resulting frustum is partially conical and may typically be referred to as frusto-conical or a truncated cone. In cases where N>1 , and the cross-sectional areas of the first and second bases are both normal to the longitudinal axis, in contrast, the frustum may typically be referred to as piece-wise frusto-conical or truncated cone, and generally includes N walls positioned in side- by-side relationship generally about the longitudinal axis to define the frustum shape. In cases where N=1 and the cross-sectional areas of the first and second bases are circular, equal and normal to the longitudinal axis, the frustum will generally be cylindrical, and if N>1 it will be piecewise cylindrical. In some embodiments, the first and second bases are both symmetrical about the longitudinal axis, although in other embodiments one or the other of the first and second bases may be asymmetrical about the longitudinal axis.

[0070] In the example embodiment illustrated in FIGS. 1 A and 1 B, the upper and lower frusta are illustratively piece-wise frusto-conical with N=12 for the upper frustum 12 and N=14 for the lower frustum 14. More specifically, the upper frustum 12 is illustratively a 12-sided structure constructed of 12 equally sized walls U1 - U12 (only walls U6, U7 and U8 are specifically identified in FIG. 1A), the top ends of which are each attached to an adjacent wall via a fixation element 15, such as a clip or a wire or the like, for example, to form a piece-wise frusto-conical structure, and the lower frustum 14 is illustratively a 14-sided structure constructed of 14 equally sized walls L1 - L14 (only walls L7, L8 and L9 specifically identified in FIGS. 1A and 1 B), the top ends of which are each attached to an adjacent wall via a fixation element 17, such as a clip or a wire or the like, to form another piece-wise frusto- conical structure.

[0071] The upper base of the upper frustum 12, which corresponds to the top ends of the walls U1 - U12, has the larger cross-sectional area and is illustratively open, and the lower base of the upper frustum 12, which corresponds to the bottom ends of the walls U1 - U12, has a comparatively smaller cross-sectional area and is illustratively mounted to and electrically connected to a main circuit board 20 sized slightly larger than the lower base to allow the bottom ends of the walls U1 - U12 to be mounted thereto. The upper base of the lower frustum 14, which corresponds to the top ends of the walls L1 - L14, has the larger cross-sectional area and is illustratively open, and the lower base of the lower frustum 14, which corresponds to the bottom ends of the walls L1 - L14, has a comparatively smaller cross-sectional area and is also illustratively open. The frusta interconnection and support structure 16 is illustratively formed of a plurality of individual interconnection and support members each having a top end and a bottom end. The top end of each of the plurality of frusta interconnection and support members of the frusta interconnection and support structured is illustratively mounted to and electrically connected to the main circuit board 20, and the bottom end of each of the plurality of frusta interconnection and support members of the frusta interconnection and support structure 16 is illustratively mounted to and electrically connected to the bottom end of a different one of the walls L1 - L14 of the lower frustum 14. The frusta interconnection and support structure 16 thus mounts, i.e., mechanically attaches, the upper frusta 12 to the lower frusta 14 via the main circuit board 20, and further provides for electrical interconnection between each of the walls L1 - L14 of the lower frustum 14 and the main circuit board 20.

[0072] Generally, the N sides of the frustum will be defined by N walls of uniform thickness, although this disclosure contemplates embodiments in which one or more of the N walls may have different thickness relative to one or more other of the N walls and/or embodiments in which one or more of the N walls varies in thickness. It will further be understood that one or more, or all, of the N walls of the frustum may be made up of M wall layers, juxtaposed or otherwise, wherein M may be any positive integer. In the embodiment illustrated in FIGS.1 A and 1 B, for example, each of the walls L1 - L14 of the lower frustum 14 includes a circuit board, e.g., LC7, LC9 and LC 9 identified in FIG. 1 A, to which a number of the light emitting diodes, D _L , is mounted, and a thermal energy dissipation structure 80 mounted over each of the light emitting diodes D _L , e.g., such that each of the light emitting diodes D|_ extends through a different opening defined through the thermal energy dissipation structure 80, and each of the walls U1 - U12 of the upper frustum 12 includes a circuit board, e.g., UC6, UC7 and UC 8 identified in FIG. 1A, to which a number of the light emitting diodes, D _u , is mounted, and a thermal energy dissipation structure 82 mounted over each of the light emitting diodes Du, e.g., such that each of the light emitting diodes Du extends through a different opening defined through the thermal energy dissipation structure 82. Further details relating to the thermal energy dissipation structures 80 and 82 will be described hereinafter.

[0073] Referring now to FIG. 2, an electrical component-level schematic diagram 21 is shown of the embodiment of the LED-based lamp assembly 10 illustrated in FIGS. 1 A and 1 B. In the illustrated embodiment, the schematic diagram 21 includes a driver circuit 28 that is configured to electrically connect to an AC voltage source, V _AC , and to drive the plurality of light emitting diodes Du and D _L , mounted to the various walls U1 - U12 of the upper frustum 12 and the various walls L1 - L14 of the lower frustum 14 respectively, from the AC voltage source, V _A c- In one embodiment, the driver circuit 28 is generally configured to be responsive to the AC voltage signal supplied by the AC source, V _A c, to activate a number of the light emitting diodes Du and/or D _L , i.e., a subset of the light emitting diodes Du and/or D _L , while maintaining the remaining number of the light emitting diodes Du and/or D _L deactivated, i.e., in an off state, during portions of the AC voltage signal having positive voltage values, i.e., during positive-voltage half-cycles of the AC voltage signal, and to activate the remaining ones of the light emitting diodes Du and/or D _L while maintaining the number (i.e., the subset) of the light emitting diodes Du and/or D|_ deactivated, i.e., in an off state, during portions of the AC voltage signal having negative voltage values, i.e., during negative-voltage half-cycles of the AC voltage signal. Illustratively, the number of light emitting diodes activated by the driver circuit 28 during the positive-voltage half-cycles of the AC voltage signal is approximately equal to the remaining number of light emitting diodes that are activated by the driver circuit 28 during the negative-voltage half-cycles of the AC voltage signal, although this disclosure contemplates embodiments in which the number of light emitting diodes activated by the driver circuit 28 during positive-voltage half-cycles of the AC voltage signal is not equal to the remaining number of light emitting diodes that are activated by the driver circuit 28 during negative-voltage half-cycles of the AC voltage signal.

[0074] In the embodiment illustrated in FIG. 2, the driver circuit 28 includes a resistor, R1 , and a capacitor, C1 , electrically connected in parallel with one end of this combination electrically connected to one terminal, e.g., terminal 1 , of an electrical terminal block, TB, through a series connected fuse, F1 . The opposite end of the parallel combination of the resistor and capacitor, R1 and C1 , is electrically connected to an anode of one diode, D1 , and to a cathode of another diode, D2. The capacitor, C1 , is illustratively a non-polarized capacitor.

[0075] Another terminal, e.g., terminal 2, of the electrical terminal block, TB, is electrically connected to a signal line 26, and the terminal block, TB, is configured to be electrically connectable to the AC voltage source, V _AC . More specifically, terminal 1 of the electrical terminal block, TB, is electrically connectable to a so-called hot wire or terminal, T1 , of the AC voltage source, VAC, via an electrical conductor, e.g., wire, 25, and terminal 2 of the electrical terminal block, TB, is electrically connectable to a so-called common wire or terminal, T2, of the AC voltage source, V _A c, via an electrical conductor, e.g., wire, 27. The AC voltage source, V _A c, is illustratively a conventional voltage source for commercial or residential use, and in the United States the voltage source, V _AC , may typically be an electrical utility company that supplies sinusoidal AC power to residential homes and businesses typically between 1 10 and 480 Volts AC and at approximately 60 Hz. In many other countries, the AC voltage source, V _AC , supplies similar voltage signals but at approximately 50 Hz. It will be understood, however, that the AC voltage source, V _A c, may alternatively be any AC voltage source configured to supply any voltage/current, i.e., any voltage waveform shape with any peak voltage value and any corresponding current, at any frequency above a minimum frequency as will be discussed hereinafter, that is capable of driving light emitting diodes as described herein.

[0076] As briefly described above, the light emitting diodes, Du and D _L are illustratively partitioned into two separate groups or sub-circuits of approximately equal numbers of light emitting diodes; one group that is activated only during the positive-voltage half cycle of the AC voltage signal, V _AC , and the other that is activated only during the negative-voltage half-cycle of the AC voltage signal, V _A c- In the illustrated embodiment, for example, positive voltage inputs of light emitting diode groups mounted to each of the frustum walls L1 , U1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13 are electrically connected to a cathode of the diode, D1 , via a signal path 22, and negative voltage inputs of each of these groups of light emitting diodes is electrically connected via the signal path 26 to the second terminal (terminal 2) of the electrical terminal block, TB, such that when the diode, D1 , becomes forward biased during positive-voltage half-cycles of the AC voltage source, V _AC , the light emitting diode groups mounted to the frustum walls L1 , U1 , L3, U3, L5, U5, 11, U7, L9, U9, L1 1 , U1 1 and L13 likewise become forward biased and thereby become activated to produce radiation. Similarly, the negative voltage inputs of light emitting diode groups mounted to each of the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14 are electrically connected to an anode of the diode, D2, via a signal path 24, and positive voltage inputs of each of these groups of light emitting diodes is electrically connected via the signal path 26 to the second terminal (terminal 2) of the electrical terminal block, TB, such that when the diode, D2, becomes forward biased during negative-voltage half-cycles of the AC voltage source, V _AC , the light emitting diode groups mounted to the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14 likewise become forward biased and thereby become activated to produce radiation. In the illustrated embodiment, the light emitting diodes may generally be configured to emit radiation in any frequency range and be configured to emit radiation within any desired range of angles relative to the light emitting diode devices. In one illustrative embodiment, for example, the light emitting diodes Du and D _L are all selected to emit radiation in the visible white frequency spectrum, although this disclosure contemplates that the color of light produced by the lamp assembly 10 as a whole may be tuned by selectively substituting any number of different color light emitting diodes in either or both of the diode groups Du and D _L .

[0077] Illustratively, the light emitting diodes in each of the light emitting diode groups mounted to each of the frustum walls U1 - U12 and L1 - L14 are electrically connected together in series such that the positive (+) voltage inputs of each of the frustum walls L1 , U1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13 are electrically connected to an anode of a first light emitting diode in the corresponding string of series-connected light emitting diodes mounted to the wall, and the negative (-) voltage inputs of each of the frustum walls L1 , U1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13 are electrically connected to a cathode of a last light emitting diode in the corresponding string of series-connected light emitting diodes mounted to the wall. Similarly, the negative (-) voltage inputs of each of the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14 are electrically connected to a cathode of a first light emitting diode in the corresponding string of series- connected light emitting diodes mounted to the wall, and the positive (+) voltage inputs of each of the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14are electrically connected to an anode of a last light emitting diode in the corresponding string of series-connected light emitting diodes mounted to the wall. In one illustrative embodiment, as will be described in greater detail hereinafter with respect to FIGS. 6 and 7, each frustum wall U1 - U12 and L1 - L14 has a total of 32 light emitting diodes mounted thereto and electrically connected in series such that 13 parallel-connected groups of 32 series-connected light emitting diodes are activated during the positive-voltage half-cycle of the AC voltage source, V _A c, and 13 parallel-connected groups of 32 series-connected light emitting diodes are activated during the negative-voltage half-cycle of the AC voltage source, VAC- The upper frustum 12, in this illustrative embodiment, thus has 416 light emitting diodes mounted thereto, as does the lower frustum 14, for a total of 832 light emitting diodes mounted to the light assembly 10. In this exemplary embodiment, R is illustratively a 60 kQ, ½ watt resistor, C is illustratively a 6.7 F, 250 volt capacitor (e.g., two 3.35 pF, 250 volt capacitors connected in parallel), and the diodes D1 and D2 have reverse breakdown potentials of at least 250 volts. It will be understood that these component values are provided only by way of example, and that other component values may alternatively be used. [0078] It will be further understood, that the embodiment illustrated herein represents only one example embodiment, and that this disclosure contemplates embodiments in which only a single series connection of two or more light emitting diodes or any number of parallel-connected groups of any number of series- connected light emitting diodes may be connected to the cathode of the diode, D1 , and likewise to the anode of the diode, D2. It will further be understood that the diodes D1 and D2 are required in embodiments in which the total voltage drop across each group of light emitting diodes electrically connected to the signal path 22 and to the signal path 24 exceeds the reverse breakdown voltage of the various light emitting diodes to ensure that none of the light emitting diodes is harmed or destroyed. Illustratively, the diodes D1 and D2 in the embodiment illustrated in FIG. 2 each have a reverse breakdown voltage of at least a few hundred volts in applications in which V _A c = 1 10 volts peak-to-peak, and higher reverse breakdown voltages in applications in which V _A c is greater than 1 10 volts peak-to-peak .

[0079] During operation of the driver circuit 28 as just described, the light emitting diodes electrically connected to the cathode of D1 are activated for the positive-voltage portion of each cycle of the operating frequency of the AC voltage source, V _AC , while the light emitting diodes electrically connected to the anode of D2 are deactivated, and the light emitting diodes electrically connected to the anode of D2 are activated for the negative-voltage portion of each cycle of the operating frequency of the AC voltage source, V _AC , while the light emitting diodes electrically connected to the cathode of D1 are deactivated. With the embodiment of the driver circuit 28 illustrated in FIG. 2, it is desirable for the operating frequency of the AC source to be sufficiently high such that the two separate light emitting diode groups, i.e., those mounted to the frustum walls L1 , U 1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13 and the others mounted to the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14, appear to be activated, i.e., "on," continuously. Because each group of light emitting diodes is activated only for one half of each cycle of the operating frequency of the AC voltage source V _A c, the switching rate, SR, between activations of the two groups of light emitting diodes is given by the equation SR = 21 f _AC . It is generally known that the human eye can detect switching rates between two light sources up to about 16 Hz (0.0625 seconds), and at switching rates faster than this the two light sources appear to humans to both be on continuously. Substituting this value for SR in the above equation thus leads to a minimum operating frequency, f _A c, of the AC voltage source, V _A c, of about 32 Hz. Below this value, the human eye could detect switching of activation between the two groups of light emitting diodes _, whereas fAc > 32 Hz ensures that the two groups of light emitting diodes will appear to the human eye to be activated, i.e., "on," continuously when operated by the driver circuit 28 illustrated in FIG. 2.

[0080] It will be understood that the driver circuit 28 illustrated in the schematic diagram 21 represents only one illustrative embodiment of a driver circuit that may be used to drive the light emitting diodes mounted to the frusta 12 and 14, and that other conventional circuits for driving light emitting diodes may alternatively be used to drive the light emitting diodes mounted to the frustum 12 and/or the frustum 14. Any such other conventional light emitting diode driver circuits may, but need not, include any one or combination of one or more conventional transformers, one or more full-wave bridge rectifier circuits, one or more half-wave bridge rectifier circuits, and the like. Moreover, any such other conventional light emitting diode driver circuit may be configured to simultaneously and continually drive all of the light emitting diodes mounted to the frusta 12 and 14, or may alternatively be configured to intermittently drive sub-groups of the light emitting diodes. Further details relating to the driver circuit 28 are described in co-pending U.S. Patent application Ser. No. 61/224,247, the disclosure of which is incorporated herein by reference.

[0081] It will be further understood that while the light emitting diodes Du and D _L are illustrated in FIG. 2 as being driven by the driver circuit 28 from a source of AC voltage, the voltage source used to drive the light emitting diodes Du and D _L may alternatively be a DC voltage source, such as one or more batteries or other DC voltage source. In such embodiments, the driver circuit 28 may be omitted or modified for use with DC voltage, and those skilled in the art will recognize that the alternating operation of the light emitting diodes Du and D _L described above will generally not be possible when driven with such a DC voltage unless the driver circuit 28 is supplemented with additional circuit components.

[0082] Referring now to FIG. 3, a cross-sectional view of the LED-based lamp assembly embodiment 10 of FIGS. 1A and 1 B is shown as viewed along section lines 3-3 of FIG. 1 A. In the illustrated embodiment, the various electrical

components of the driver circuit are shown mounted to the main circuit board 20 which is illustrative provided in the form of a conventional circuit board. More specifically, the terminal base, TB, the fuse, F1 , the capacitor, C1 , the resistor, R1 , and the diodes, D1 and D2, are mounted to a top surface of the main circuit board 20. A series of space-apart, plated-through hole pairs, L1 - L14, are illustratively distributed circumferentially about the components of the driver circuit 28. Each of these hole pairs L1 - L14 represents a mechanical attachment to a different one of the frusta interconnection and support members of the frusta interconnection and support structure 16, as well as an electrical connection between a corresponding one of the frustum walls L1 - L14 of the lower frustum 14 and the main circuit board 20 via a corresponding one of the frusta interconnection and support members of the frusta interconnection and support structure 16. Another series of space-apart, plated-through hole pairs, e.g., U 1 _P and U1 _N , are illustratively distributed about the outer periphery of the main circuit board 20. Each of these hole pairs a mechanical attachment and an electrical connection to a different one of the frustum walls U1 - U12 of the upper frustum 12. In the embodiment illustrated in FIG. 3, each of the various walls U1 - U12 of the upper frustum 12 are shown mounted to the main circuit board 20 and electrically to the main circuit board 20 at a corresponding one of the outer hole pairs.

[0083] The main circuit board 20 illustrated in FIG. 3 defines an alignment mark, AM, that is illustratively used to align a number of masks that define electrically conductive circuit traces to be formed on the main circuit board 20 during fabrication thereof, and examples of two such sets of electrically conductive traces or patterns are shown in FIGS. 4 and 5. FIG. 4 is a top plan view of one illustrative embodiment of an electrically conductive pattern formed on the top surface of the main circuit board 20. The electrically conductive pattern illustrated in FIG. 4 includes, for example, the signal path 22 that electrically connects the cathode of the diode D1 to the positive inputs of the frustum walls L1 , U1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13, and the signal path 26 that electrically connects terminal 2 of the terminal block, TB, to the negative inputs of the frustum walls L1 , U1 , L3, U3, L5, U5, L7, U7, L9, U9, L1 1 , U1 1 and L13 and to the positive inputs of the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14. FIG. 5 is a top plan view of one illustrative embodiment of an electrically conductive pattern formed on the bottom surface of the main circuit board 20. The electrically conductive pattern illustrated in FIG. 5 includes, for example, the signal path 24 that electrically connects the anode of the diode D2 to the negative inputs of the frustum walls L2, U2, L4, U4, L6, U6, L8, U8, L10, U10, L12, U12 and L14. It will be understood that all of the holes in the main circuit board 20 that are illustrated in FIGS. 3-5 are generally plated-through holes such that when the components of the driver circuit 28 are mounted and electrically connected to the main circuit board 20 as illustrated in FIG. 3, the electrically conductive traces illustrated in FIGS. 4 and 5 electrically connect the various circuit components together as illustrated in the schematic of FIG. 2. In other embodiments (not illustrated), at least some of the components of the driver circuit 28 include surface mount components and, therefore, the circuit board would define surface mount pads instead of or in addition to plated through- holes.

[0084] Referring now to FIG. 6, a front elevational view is shown of one illustrative embodiment of one of the plurality of frustum walls, Ux, of the upper frustum 12 of the LED-based lamp assembly 10. In the illustrated embodiment, the frustum wall Ux is provided in the form of a conventional circuit board that defines a plurality plated-through hole pairs through which electrically conductive leads of a plurality of the light emitting diodes, Du, extend to thereby mount the plurality of the light emitting diodes, Du, to the frustum wall Ux such that radiation produced by the light emitting diodes is directed outwardly from a plane defined by the illustrated top surface of the frustum wall Ux. In other embodiments (not illustrated), at least some of the light emitting diodes, Du, include surface mount diodes and, therefore, the circuit board would define surface mount pads instead of or in addition to through hole pairs. In the embodiment illustrated in FIG. 6, the frustum wall Ux is configured to have 32 light emitting diodes, D1 - D32, mounted thereto, although it will be understood that the frustum wall Ux may alternatively be configured to have more or fewer light emitting diodes mounted thereto. In any case, the holes for each light emitting diode that are outlined with a circle are illustratively configured to receive and electrically connect to an anode, AN, of a corresponding light emitting diode, and the holes that are outlined with a square are illustratively configured to receive and electrically connect to a cathode, CA, of a corresponding light emitting diode.

Although not shown in the drawings, the back side of the frustum wall Ux is patterned with electrically conductive traces in a conventional manner that electrically connects the light emitting diodes D1 - D32 in series when the light emitting diodes D1 - D32 are mounted and electrically connected to the frustum wall Ux as just described. More specifically, the electrically conductive pattern is formed such that the cathode of D1 is electrically connected to the anode of D2, the cathode of D2 is electrically connected to the anode of D3, and so on. In one embodiment, the frustum wall Ux is configured such that the light emitting diodes mount substantially flush to the illustrated top surface of the frustum wall so that radiation produced by the light emitting diodes is directed generally normal to a plane defined by the illustrated top surface of the frustum wall Ux. Alternatively, the frustum wall Ux may be configured such that the light emitting diodes mount at an angle, or at various angles, relative to the illustrated top surface of the frustum wall Ux.

[0085] The frustum wall Ux further defines a pair of electrically conductive tabs or terminals 30 and 32 that are sized to be received within a corresponding pair of plated-through holes formed about the outer periphery of the main circuit board 20, e.g., holes U1 _P and U1 N illustrated in FIG. 3. The frustum wall Ux and the main circuit board 20 are oriented such that the electrically conductive tab or terminal 32, e.g., marked with a "+," is received within a plated-through hole defined near the outer periphery of the main circuit board 20 that is also marked with a "+," e.g., U1 p, and the electrically conductive tab or terminal 30, e.g., marked with a is received within an adjacent plated-through hole on the main circuit board 20 that is also marked with a e.g., U1 N- In this orientation, the top surface of the frustum wall Ux illustrated in FIG. 6 thus faces outwardly away from the center of the main circuit board 20 such that radiation produced by the light emitting diodes mounted to the upper frustum walls U1— U12 is directed outwardly away from the main circuit board 20.

[0086] The electrically conductive pattern formed on the frustum wall Ux also electrically connects the "+" tab or terminal to the anode of the first light emitting diode, D1 , in the string of series-connected light emitting diodes, and electrically connects the "-" tab or terminal to the cathode of last light emitting diode, D32, in the string of series-connected light emitting diodes. The holes 34 and 36 adjacent to the respective top corners of the upper frustum wall Ux provide anchor points for securing the frustum wall Ux to adjacent frustum walls via a suitable fixation structure 15 as illustrated and described hereinabove with respect to FIG. 1A.

[0087] Referring now to FIG. 7, a front elevational view is shown of one illustrative embodiment of one of the plurality of frustum walls, Ly, of the lower frustum 14 of the LED-based lamp assembly 10. In the illustrated embodiment, the frustum wall Ly is provided in the form of a conventional circuit board that defines a plurality plated-through hole pairs through which electrically conductive leads of a plurality of the light emitting diodes, D _L , extend to thereby mount the plurality of the light emitting diodes, D _L , to the frustum wall Ly such that radiation produced by the light emitting diodes is directed outwardly from a plane defined by the illustrated top surface of the frustum wall Ly. In the embodiment illustrated in FIG. 7, the frustum wall Ly is configured to have 32 light emitting diodes, D1 - D32, mounted thereto, although it will be understood that the frustum wall Ly may alternatively be configured to have more or fewer light emitting diodes mounted thereto. In any case, the holes for each light emitting diode that are outlined with a circle are illustratively configured to receive and electrically connect to an anode, AN, of a corresponding light emitting diode, and the holes that are outlined with a square are illustratively configured to receive and electrically connect to a cathode, CA, of a corresponding light emitting diode. Although not shown in the drawings, the back side of the frustum wall Ly is patterned with electrically conductive traces in a conventional manner that electrically connects the light emitting diodes D1 - D32 in series when the light emitting diodes D1 - D32 are mounted and electrically connected to the frustum wall Ly as just described. More specifically, the electrically conductive pattern is formed such that the cathode of D1 is electrically connected to the anode of D2, the cathode of D2 is electrically connected to the anode of D3, and so on. In one embodiment, the frustum wall Ly is configured such that the light emitting diodes mount substantially flush to the illustrated top surface of the frustum wall so that radiation produced by the light emitting diodes is directed generally normal to a plane defined by the illustrated top surface of the frustum wall Ly. Alternatively, the frustum wall Ly may be configured such that the light emitting diodes mount at an angle, or at various angles, relative to the illustrated top surface of the frustum wall Ly-

[0088] The frustum wall Ly further defines a pair of plated-through holes 40 and 42 that are sized to receive corresponding electrically conductive tabs or terminals of a corresponding one of the plurality of frusta interconnection and support members of the frusta interconnection and support structure 16 that electrically connects and mechanically attaches the frustum walls Ly to the main circuit board 20. The frustum wall Ly and the plurality of frusta interconnection and support members of the frusta interconnection and support structure 16 are oriented such that the plated-through hole 42, e.g., marked with a "+," is electrically connected via a corresponding one of the plurality of frusta interconnection and support member to a corresponding Ly plated-through hole defined on the main circuit board 20 that is also marked with a "+," e.g., L8 _P , and the plated-through hole 40, e.g., marked with a "-,"is electrically connected via a corresponding one of the plurality of frusta interconnection and support member to a corresponding adjacent Ly plated-through hole defined on the main circuit board 20 that is also marked with a e.g., L8N. In this orientation, the top surface of the frustum wall Ly illustrated in FIG. 7 thus faces outwardly away from the frusta interconnection and support structure 16 such that radiation produced by the light emitting diodes mounted to the lower frustum walls L1 - L14 is directed outwardly away from the frusta interconnection and support structure 16.

[0089] The electrically conductive pattern formed on the frustum wall Ly also electrically connects the "+" plated-through hole 42 to the anode of the first light emitting diode, D1 , in the string of series-connected light emitting diodes, and electrically connects the "-" plated-through hole 40 to the cathode of last light emitting diode, D32, in the string of series-connected light emitting diodes. The holes 44 and 46 adjacent to the respective top corners of the upper frustum wall Ly provide anchor points for securing the frustum wall Ly to adjacent frustum walls via a suitable fixation structure 17 as illustrated and described hereinabove with respect to FIG. 1 B.

[0090] Referring now to FIGS. 8-10, details of one illustrative embodiment of the frusta interconnection and support structure 16 are illustrated and will be described. Referring specifically to FIG. 9, one illustrative embodiment of one of the plurality of frusta interconnection and support members 16i of the frusta

interconnection and support structure 16 is shown. The frusta interconnection and support member 16i is, in one embodiment, formed from conventional circuit board material, and in any case illustratively defines a pair of adjacent, electrically conductive tabs or terminals 60 and 62 extending from top of the member 16i adjacent to opposite outer edges of the member 16i , and another pair of adjacent, electrically conductive tabs or terminals 64 and 66 extending from a bottom of the member 161 adjacent to opposite inner edges of the member 161. The electrically conductive tab or terminal 60 is electrically connected to the electrically conductive tab or terminal 64 via an electrically conductive trace 68 formed on the member 16i, and the electrically conductive tab or terminal 62 is likewise electrically connected to the electrically conductive tab or terminal 66 via an electrically conductive trace 70 formed on the member 16i. The frusta interconnection and support member 16i generally defines a vertical outer wall that extends downwardly away from the tabs 60 and 62 to an angled portion that extends inwardly toward the tabs 64 and 66 at a specified angle. On the angled portion adjacent to the transition from the vertically extending wall to the angled portion, the frusta interconnection and support member 16i defines another tab 72 that is illustratively not electrically conductive.

[0091] Referring now to FIGS. 8 and 9, the frusta interconnection and support member 16i is sized such that the electrically conductive tabs or terminals 60 and 62 on opposite sides of the member 16i extend through corresponding pairs of plated- through Ly holes of the main circuit board 20, e.g., through hole pairs L4 and L1 1 respectively, or hole pairs L3 and L10 respectively, etc. (see FIG. 3). The frusta interconnection and support member 16i is further sized such that the electrically conductive tabs or terminals 64 and 66 on opposite sides of the member 16i extend through corresponding pairs of plated-through holes 40 and 42 of corresponding ones of the lower frustum walls Ly. The electrically non-conductive tab 72 illustratively contacts and supports the lower frustum walls Ly between the two ends thereof.

[0092] As illustrated in FIG. 8, the base member 18 illustratively includes a coupling member 54 that is configured to attach to the frusta interconnection and support member 16-| . The coupling member 54 illustratively includes a tab member 54A that is integral with, or attached to, a coupling plate 54B that is sized and configured to attach to the frusta interconnection and support member 16i via a number of conventional fixation elements, e.g., screws, rivets, or the like, as illustrated in FIG. 8. The base member 18 further illustratively includes a post 52 having one end that is attached via a conventional fixation element to the tab member 54A of the coupling member 54, and an opposite end that is attached via a conventional fixation element to a base plate 50.

[0093] Referring now specifically to FIG. 10, the frusta interconnection and support member 16i illustrated and described with respect to FIGS. 8 and 9 represents only two of a total of 14 such interconnection and support members that make up the frusta interconnection and support structure 16 in the illustrated embodiment. The remaining frusta interconnection and support members 16 ₂ - 16i ₃ are distributed radially about the frusta interconnection and support member 16i as illustrated in FIG. 10, and each connect, and each electrically interconnects and mechanically attaches a corresponding one of the frustum walls Ly of the lower frustum 14 to the main circuit board 20 as just described with respect to the frusta interconnection and support member 'I Q . It will be understood, however, that the remaining frusta interconnection and support members 162 - 1613 illustratively comprise only one-half of the frusta interconnection and support member 161 , e.g., one of the halves on either side of the bisection line 75 illustrated in FIG. 9.

[0094] As illustrated in FIG. 8, the walls Ux of the upper frustum 12 generally define an angle, A, relative to a horizontal plane defined by the top of the upper frustum 12, and the walls Ly of the lower frustum 14 likewise generally define an angle, B, relative to a horizontal plane defined by the top of the lower frustum 14, and the lamp assembly 10 defines a longitudinal axis, L, therethrough. In the illustrated embodiment, the angle, A, of the upper frustum 12 is illustratively defined by the angles of the plated-through hole pairs that extend about the outer periphery of the main circuit board 20 relative to the plane defined by the main circuit board 20. As the tabs or terminals 30 and 32 of the various frustum walls Ux are inserted into the plated-through hole pairs about the outer periphery of the main circuit board 20, the angles of these plated-through holes define the pitch of the walls Ux of the upper frustum 12 relative to the main circuit board 20, and thereby defines the angle, A, of the walls Ux of the upper frustum. The angle, B, of the lower frustum 14 is illustratively defined by the angle of the angled portions of each of the frusta interconnection and support members that form the frusta interconnection and support structure 16. The angles A and B may thus be selected by respectively selecting the angle of the plated-through holes that extend about the outer periphery of the main circuit board 20 relative to the plane defined by the top surface of the main circuit board 20, and the angle of the angled portions of each of the frusta interconnection and support members 161 - 1613 relative to the vertical outer walls of thereof.

[0095] Radiation produced by the light emitting diodes, D _U; mounted to the upper frustum 12 is thus generally directed downwardly away from the frustum 12 at the angle, A, relative to the longitudinal axis, L, and radiation produced by the light emitting diodes, D _L , mounted to the lower frustum 14 is thus generally directed downwardly away from the frustum 14 at the angle, B, relative to the longitudinal axis. In some embodiments, the angles A and B are different as generally illustrated in FIG. 8, although in other embodiments the angles A and B may be identical. In any case, it will be understood that either or both of the angles A and B may be selected such that the radiation produced by the light emitting diodes Du and/or D _L is directed away from the respective frustum 12, 14 at any desired angle. In some embodiments, for example, the angles A and B are both generally non-zero relative to the longitudinal axis, L, as illustrated by example in FIG. 8, while in other embodiments, either or both the angles A and B may be selected such that radiation produced by the corresponding light emitting diodes, Du and D _L is directed away from the respective frustum 12, 14 generally normal to the longitudinal axis, L.

[0096] Referring now to FIGS. 1 1 and 12, details relating to the thermal energy dissipation structures 80 are shown and described hereinabove with respect to FIGS. 1 A and 1 B are illustrated and will be described. It will be understood at the outset that the following description of the thermal energy dissipation material 80 applies equally to the thermal energy dissipation medium 82 of shown and described with respect to the upper frustum 12.

[0097] Referring specifically to FIG. 1 1 , a cross-sectional view of a portion of one of the plurality of light emitting diode mounting sections of the upper frustum 12 of the LED-based lamp assembly 10 is shown as viewed along section lines 1 1 -1 1 of FIG. 1 B. In the illustrated embodiment, two of the light emitting diodes D19 and D21 are shown mounted to the frustum wall L8 as described hereinabove with respect to FIG. 7. In the illustrated embodiment, the light emitting diodes D19 and D21 are conventional and each include a semiconductor light emitting diode die 90 mounted to and in electrical contact with a surface of one electrically conductive leads 96 that extends through and is mechanically attached and electrically connected to the frustum wall L8, e.g., via a conventional wave soldering process. The semiconductor light emitting diode die 90 is also electrically connected via a conventional bond wire 92 to another electrically conductive lead 94 that extends through and is

mechanically attached and electrically connected to the frustum wall L8. The semiconductor light emitting diode die 90, the bond wire 92 and portions of the electrically conductive leads 94 and 96 are encapsulated in a conventional light emitting diode encapsulating or potting material 95 that is illustrative a conventional transparent or translucent material. In other embodiments (not shown), the light emitting diodes are high intensity light emitting diodes, organic light emitting diodes, surface mount light emitting diodes, high power light emitting diodes, and so on. [0098] In the embodiment illustrated in FIG. 1 1 , the thermally conductive medium 80 is provided in the form of a sheet defining a number of passageways therethrough that are each sized to receive a light emitting diode, e.g., D19, D21 , therein as illustrated in FIG. 1 1 . The thermally conductive medium 80, in the illustrated embodiment, thus extends completely about an outer periphery of the encapsulating or potting material 95 of each of the light emitting diodes mounted to the frustum wall L8. Optimally, the passageways defined through the thermally conductive medium 80 are further sized such that the edge of the thermally conductive medium 80 that extends about the outer periphery of each of the light emitting diodes is positioned directly across from, e.g., coplanar with, the

semiconductor light emitting diode die 90. In alternative embodiments, the edge of the thermally conductive medium 80 that extends about the outer periphery of each light emitting diode may be positioned above or below the plane defined by the semiconductor light emitting diode die 90. In such embodiments, however, the mass and/or surface area of the thermally conductive medium 80 may need to be increased over that of the embodiment illustrated in FIG. 1 1 in which the edges of the thermally conductive medium 80 that extend about the outer periphery of each of the light emitting diodes are coplanar with the semiconductor light emitting diode die 90 to achieve equivalent thermal energy dissipation performance. In still other embodiments, the light emitting diode mounting structures, e.g. the frustum walls Ux and/or Ly, may be omitted and the thermal energy dissipation sheet 80 may acts not only as a thermal energy dissipating medium as described herein, but may also act as the light emitting diode mounting arrangement such that the frustum 12 and/or 14 consists only of one or more sheets of the thermal energy dissipation material 80.

[0099] In alternative embodiments, the sheet of thermal energy dissipation medium 80 may be provided in the form of individual rings or bands of thermal energy dissipation material that are sized and configured to fit over each individual light emitting diode and/or that are embedded within the encapsulating or potting material 95 of each light emitting diode. In still other alternative embodiments, the thermal energy dissipation medium 80 may be configured to extend only partially around the outer periphery of each light emitting diode and/or only partially around the outer periphery of each semiconductor light emitting diode die 90. In any embodiment, it will be understood that the thermal energy dissipation performance of the thermal energy dissipation material 80 will depend upon several factors. Examples of such factors include, but are not necessarily limited to, the chemical makeup, the mass and the surface area of the thermal energy dissipation material 80, proximity of the thermal energy dissipation material relative to the semiconductor light emitting diode die 90, and the like.

[00100] Referring now specifically to FIG. 12, a cross-sectional, schematic diagram is shown, partially in cross-section, of the light emitting diode die 90 and thermal energy dissipation 80, 82 arrangement illustrated in FIG. 1 1 . The semiconductor light emitting diode die 90 is illustrated in FIG. 12 in a simple form comprising a semiconductor junction defined between two dissimilar semiconductor materials 90 _P and 90 _N . The term "two dissimilar semiconductor materials" is defined for purposes of this disclosure as two semiconductors which differ in their concentration of electrons and/or holes. For example, so-called "P-type" and "N- type" semiconductor materials are, for purposes of this disclosure, two dissimilar semiconductor materials, the semiconductor material 90p is illustratively a P-type semiconductor material, i.e., that which has an excess concentration of holes as compared with a pure, i.e., so-called intrinsic, form of the semiconductor material, and the semiconductor material 90N is illustratively and N-type semiconductor material, i.e., that which has an excess concentration of electrons as compared with a pure, i.e., intrinsic, form of the semiconductor material. The semiconductor material itself may by any known semiconductor element conventionally used to fabricate light emitting diodes, common examples of which include, but should not be limited to, Silicon, Gallium Arsenide, and the like. In any case the two dissimilar semiconductor materials 90 _P and 90 _N form a conventional P-N junction 91 therebetween.

[00101] In the illustrated example, a driver circuit, e.g., the driver circuit 28 illustrated and described herein or other conventional driver circuit is electrically connected across the semiconductor light emitting diode die 90, e.g., between the P- type region 90p and the N-type region 90N, such that current flow, I, through the semiconductor light emitting diode die 90 and across the semiconductor junction 91 is generally normal to a plane defined by the semiconductor junction 91 .

[00102] The thermal energy dissipating medium 80, 82 is shown positioned substantially opposite to the plane defined by the semiconductor junction 91 , and spaced apart from the semiconductor light emitting diode die 90 by a distance di , such that the thermal energy dissipation medium 80, 82 is substantially coplanar with the semiconductor junction 91 , i.e., such that the plane defined by the semiconductor junction 91 intersects the thermal energy dissipation medium 80, 82. In the illustrated example, the thermally conductive medium 80, 82 illustratively extends completely about the periphery of the semiconductor light emitting diode die 90 substantially opposite to the plane defined by the semiconductor junction 91 , although this disclosure contemplates that the thermally conductive medium 80, 82 may in some embodiments only partially surround the semiconductor light emitting diode die 90 as described hereinabove.

[00103] Semiconductor materials are generally understood to comprise crystalline structures that form crystal lattices. When current flows across a semiconductor junction formed between two dissimilar semiconductor materials, thermal energy is transferred to the crystal lattice via various processes including, but not necessarily limited to, electron-hole pair generation and recombination, photon emission in the case of light emitting diodes (LEDs), Peltier heating, electron- hole scattering and the like. At least some of these energy transfer processes result in localized heating of the crystal lattice which, after time, increases the temperature of the entire semiconductor circuit. Thermal energy resulting from current flow across a semiconductor junction thus generally results in heating of the

semiconductor circuit and its surrounding environment.

[00104] As used in this disclosure, the term "thermal energy" is defined in the context of a semiconductor light emitting diode die 90 as energy that is transferred to the semiconductor lattice when current flows across the semiconductor junction 91 defined between the two dissimilar semiconductor materials 90 _P and 90 _N . Generally, such thermal energy is transferred from the semiconductor diode 90 to its

environment via the conventional heat transfer processes of conduction and radiation. In the former case, the encapsulating material 95 is in physical contact with the semiconductor die 90 and accordingly conducts at least some of the heat generated within the die 90 by the thermal energy away from the semiconductor die 90 to the periphery of the encapsulating material 95. The thermally conductive medium 80, 82 is illustratively positioned in physical contact with the encapsulating material 95 at least partially about its periphery, and accordingly conducts at least some of heat away from the encapsulating material 95. The thermal energy dissipation medium 80, 82 is thus configured to control, at least in part, the operating temperature of the light emitting diode, e.g., D19, D21 , by dissipating some of the heat generated by the semiconductor die 90 and conducted away from the semiconductor die 90 to the thermally conductive medium 80, 82 via the

encapsulating material 95 of each of the light emitting diode. Illustratively, the thermally conductive medium 80, 82 is positioned relative to the light emitting diode such that the plane defined by the semiconductor junction 91 of the semiconductor die 90 bisects, or at least intersects, the thermally conductive medium 80, 82 as illustrated in FIG. 12. With most commercially available light emitting diodes of the dome configuration, such as illustrated in FIG. 1 1 , this position of the thermally conductive medium 80, 82 generally minimizes the distance d1 between the semiconductor die 90, i.e., the heat source, and the thermally conductive medium 80, 82, and thereby minimizes the distance of heat travel between the semiconductor die 90 and the thermally conductive medium 80, 82. However, this disclosure contemplates that the thermally conductive medium 80, 82 may be alternatively positioned relative to the semiconductor die 90.

[00105] When thermal energy is transferred to the semiconductor lattice as a result of current flow through the semiconductor die 90, some of this thermal energy is radiated outwardly from and parallel to the semiconductor junction 91 . In the example embodiment illustrated in FIG. 12, this radiated thermal energy, E _R , is depicted as being radiated outwardly away from the semiconductor junction 91 in all directions about the periphery of the semiconductor light emitting diode die 90. The thermally conductive medium 80, 82 absorbs and dissipates the radiated thermal energy that would otherwise result in heating of the surrounding encapsulating material 95. Thus, the thermally conductive medium 80, 82 is configured to control the operating temperature of the light emitting diodes as disclosed herein by dissipating thermal energy radiated outwardly by the light emitting diodes in response to current flow therethrough.

[00106] The thermal energy, E _R , radiated from the semiconductor light emitting diode die 90 is absorbed by the thermally conductive medium 80, 82 as briefly described above. In this energy absorption process, the thermal energy dissipation medium 80, 82 acts as a conventional radiating body that radiates a thermal energy which effectively opposes the thermal energy, E _R , radiated by and from the semiconductor die 90. The net thermal energy that is transferred through the encapsulating material 95 to, and absorbed by, the structure of the thermally conductive medium 80, 82 is thus less than the thermal energy, E _R , which would have been transferred to the encapsulating material 95 in the absence of the thermally conductive medium 80, 82. The material used for the thermally conductive medium 80, 82 is illustratively selected such that net thermal energy is transferred to the molecular structure of the thermally conductive medium 80, 82. The resultant increase in temperature of the thermally conductive medium 80, 82 resulting from the absorption of the net thermal energy is then dissipated by conductive, convective, and radiative heat transfer from the exposed surface(s) of the thermally conductive medium 80, 82 to the environment surrounding the thermally conductive medium 80, 82.

[00107] The temperature increase in the thermally conductive medium 80, 82 resulting from the thermal energy conduction and radiation processes just described can be effectively controlled, e.g., decreased and/or maintained, through appropriate selection of the type of material and/or the total surface area and/or total volume and/or total mass of the thermally conductive medium 80, 82. Generally, if sufficient surface area and/or total volume and/or total mass of the thermally conductive medium 80, 82 are provided, the resulting temperature increase in the thermally conductive medium 80, 82 can be effectively controlled. Thus, by appropriate choice of the material used for the thermally conductive medium 80, 82, the placement of the thermally conductive medium 80, 82 relative to the semiconductor light emitting diode die 90 and the total surface area and/or volume and/or mass of thermally conductive medium material 80, 82, the thermally conductive medium 80, 82 may be used to control and maintain the operating temperature of the light emitting diodes mounted to the lamp assembly 10 by dissipating at least some of the thermal energy conducted and radiated outwardly from the semiconductor dice 90 of the various light emitting diodes when current flows therethrough.

[00108] Ideally, the thermally conductive medium 80, 82 should have high thermal conductivity, i.e., should have a high ability to conduct heat. It is known that metals having high electrical conductivity also generally have high thermal conductivity, and in this regard materials that work well for the thermally conductive medium 80, 82 include, but should not be limited to, in order of highest to lowest thermal conductivity, Silver (Ag), Copper (Cu), Gold (Au) and Aluminum (Al). Non- metals having high thermal conductivity, such as diamond, may also be used.

However, practical considerations including, for example, but not limited to, cost and availability, will typically influence the choice of material(s) used for the thermally conductive medium 80, 82. In some embodiments it may also be desirable for the thermally conductive medium 80, 82 to have a low coefficient of thermal expansion such that linear and/or volumetric expansion or movement of the thermally conductive material over the range of operating and environmental temperatures is low. Relatively high thermally conductive materials that also have relatively low coefficients of thermal expansion include, but should not be limited to, Silver (Ag), Gold (Au), Copper (Cu), Aluminum (Al) and diamond.

[00109] Generally, the distance di should be chosen such that the thermally conductive medium 80, 82 is far enough away from the semiconductor light emitting diode die 90 to ensure that the thermally conductive medium 80, 82 will not interfere with the electrical operation of the semiconductor light emitting diode die 90, yet is close enough to the semiconductor light emitting diode die 90 to ensure adequate absorption of the thermal energy radiated by and conducted from the semiconductor light emitting diode die 90. The thermally conductive medium 80, 82 should also be positioned sufficiently close to, and optimally contacting the outer periphery of the encapsulating material 95 opposite to, e.g., coplanar with, the plane defined by the semiconductor junction 91 to ensure adequate absorption of the thermal energy radiated by and conducted from the semiconductor light emitting diode die 90, and should be provided with sufficient surface area and/or total material volume and/or total mass to ensure acceptable temperature rise and subsequent temperature dissipation. It will be understood that the further the thermal energy dissipation medium 80, 82 is displaced, e.g., vertically in FIGS. 12 and 1 1 , from a coplanar position relative to the semiconductor junction 91 of the semiconductor light emitting diode die 90, the lesser will be the effectiveness and efficiency of the thermal energy dissipation medium 80, 82. While this disclosure contemplates embodiments in which the thermal energy dissipation medium 80, 82 may be displaced from the coplanar position relative to the semiconductor junction 91 of the semiconductor light emitting diode die 90, doing so will generally require the total surface area and/or the total volume and/or the total mass of the thermal energy dissipation material 80, 82 to be increased in order to achieve the same overall temperature control

performance as embodiments in which the thermal energy dissipation medium 80, 82 is positioned to be coplanar with the semiconductor junction 91 of the

semiconductor light emitting diode die 90. Further details relating to the thermal energy dissipation medium 80, 82 are described in co-pending U.S. Patent application Ser. No. 61/161 ,61 1 , the disclosure of which is incorporated herein by reference.

[00110] Referring now to FIG. 13, a diagram is shown in which the lamp assembly 10 illustrated and described herein is implemented in an otherwise conventional street lamp 100. In the illustrated embodiment, the street lamp 100 includes a conventional street lamp base or pole 102 having one end (not shown) that is configured to be mounted to a support structure and/or suitably buried in the ground. As is conventional, the lamp base or pole 102 carries electrical wiring 106 that is electrically connected to a source of AC voltage. The lamp assembly 10 is illustratively mounted to, or is otherwise positioned relative to, an opposite end, E, of the street lamp base or pole 102. In the illustrated embodiment, for example, the base plate 50 of the lamp assembly 10 is secured via a number of conventional fixation elements to the street lamp base or pole 102. The electrical wiring 106 is electrically connected to the terminal base, TB, illustrated in FIG. 3 to electrically connect the electrical wiring 106 carrying the AC voltage signal to the lamp assembly 10. A transparent or translucent cover 104 is mounted to the street lamp base or pole 102 with the lamp assembly 10 positioned between the street lamp base or pole 102 and the transparent or translucent cover 104.

[00111] In the embodiment illustrated in FIG. 13, the lamp assembly 10 includes both the upper frustum 12, with the plurality of light emitting diodes, Du, mounted thereto as illustrated and described hereinabove, and the lower frustum 14 with the plurality of light emitting diodes, D _L , mounted thereto also as illustrated and described hereinabove. In the illustrated embodiment, the frustum 12 defines an angle, A, relative to the longitudinal axis, L, of the lamp assembly 10, and the frustum 14 defines another angle, B, relative to the longitudinal axis, L, such that radiation produced by the light emitting diodes Du and D _L is directed generally downwardly. In one example embodiment, the light emitting diodes Du and D _L are selected to produce radiation between zero and 30 degrees relative to a longitudinal axis defined centrally through each light emitting diode. In this embodiment, the radiation produced by the light emitting diodes, Du, mounted to the upper frustum 12 generally follows a radiation projection path bounded by the dashed lines 1 10 and 1 12 in FIG. 13, and radiation produced by the light emitting diodes, D _L , mounted to the lower frustum 14 generally follows a radiation projection path bounded by the dashed lines 1 14 and 1 16. As some of the radiation produced by the light emitting diodes, D _L , strikes a portion of the end, E, of the base 102 of the street lamp, the effective projection path of the radiation produced by the light emitting diodes, D _L , i.e., that which passes downwardly past the street lamp base 102, is bounded by the dashed lines 1 14 and 1 18. Illustratively, the spacing between the frustum 12 and the frustum 14 is selected such that the boundary 1 12 of the radiation projection path produced by the light emitting diodes, D _U; crosses, or is sufficiently proximate to, the boundary 1 14 of the radiation projection path produced by the light emitting diodes, D _L , such that radiation produced by the light emitting diodes, Du and D _L , is perceived by humans as forming a substantially continuous radiation projection path between the boundaries 1 10 and 1 16.

[00112] In one illustrative embodiment of the example street lamp

implementation described in the preceding paragraph, the main circuit board 20 of the lamp assembly 10 is positioned approximately 25 feet above ground. The angle A is illustratively selected such that the radiation projection path at the ground level by the light emitting diodes, Du, mounted to the upper frustum 12, i.e., that bounded by the dashed lines 1 10 and 1 12, spans a ring of between approximately 41 feet and 130 feet from the longitudinal axis, L, of the lamp assembly 10, which, in the illustrated embodiment, is also the longitudinal axis of the street lamp 100. The angle B is illustratively selected such that the radiation projection path at the ground level by the light emitting diodes, D _L , mounted to the lower frustum 14, i.e., that bounded by the dashed lines 1 14 and 1 18, spans a ring of between approximately 18 feet and 50 feet from the longitudinal axis, L, of the lamp assembly 10 and the street lamp 100. The boundaries 1 12 and 1 14, in this example embodiment, overlap by approximately 9 feet, and the radiation produced by the light emitting diodes D _L and Du is thus perceived by humans as together illuminating a substantially solid, i.e., uninterrupted, ring of light at the ground level about the base 102 of the street lamp 100 of between 18 and 130 feet.

[00113] It will be understood that this disclosure contemplates alternate embodiments in which the upper frustum 12 is spaced sufficiently distant from the lower frustum 14, or vice versa, such that the boundaries 1 12 and 1 14 do not cross or are not sufficiently proximate to each other to result in a perceived blending or overlap of radiation produced thereby. One such embodiment 10' of the lamp assembly is illustrated, for example, in FIG. 14. In the illustrated embodiment, the frusta 12 and 14 are sufficiently space apart such that radiation produced by the light emitting diodes mounted to the upper frustum 12 defines a projection path, e.g., bounded by the dashed lines 1 10 and 1 12 in FIG. 14, that is perceived by humans as being separate and distinct from that produced by the light emitting diodes mounted to the lower frustum 14; namely the projection path bounded by the dashed lines 1 14 and 1 16. It will further be understood that in any embodiment illustrated and described herein, light emitting diodes may be selected for use as the light emitting diodes, Du and/or D _L , that are configured to produce radiation generally between zero and G degrees relative to the longitudinal axis defined centrally through each light emitting diode, wherein G is any desired angle, common examples of which include, but should not be limited to, 10, 15, 30, 45 and 60 degrees. It will further still be understood that the lamp assembly 10 illustrated in FIG. 13 represents only one illustrative embodiment of a street lamp implementation, and that in alternate street lamp or other lamp implementations the lamp assembly 10 may include only one or the other frusta 12, 14.

[00114] It will also be understood that this disclosure contemplates alternate embodiments in which the upper frustum 12 and/or the lower frustum 14 is oriented to generally project radiation upwardly, downwardly or normal to the longitudinal axis, L. One such embodiment 10" of the lamp assembly is illustrated, for example, in FIG. 15, wherein the frustum 12 is oriented to generally project radiation upwardly and the lower frustum 14 is oriented to generally project radiation downwardly. In embodiments in which the lamp assembly 10 includes only a single frustum 12 or 14, this results in the foregoing three possible orientations. In other embodiments that include both frusta 12 and 14, this results in nine possible orientations of the two frusta 12, 14; namely, frusta 12 oriented upwardly and frusta 12 oriented upwardly, normal to L or downwardly, frusta 12 oriented normal to L and frusta 12 oriented upwardly, normal to L or downwardly, and frusta 12 oriented downwardly and frusta 12 oriented upwardly, normal to L or downwardly.

[00115] Referring now to FIG. 16, another illustrative embodiment of a lamp assembly 10"' is shown. The lamp assembly 10"' is identical in many respects to the lamp assembly 10, 10' and/or 10" illustrated and described herein, including any and all alternate embodiments thereof, and like numbers are therefore used to identify like components. The lamp assembly 10"' differs from the lamp assemblies 10, 10' and 10" primarily in the overall shape of the lamp assembly 10"'. In particular, the lamp assembly 10"' defines a generally arcuate-shaped panel 120 to which a plurality of light emitting diodes (not shown in FIG. 16) is mounted. As used herein, the term "arcuate panel" shall mean a generally curved panel that may be any desired height and/or width, and that generally has a cross-sectional area that defines a generally truncated, symmetrical or asymmetrical, polygon or circle. In the embodiment illustrated in FIG. 16, for example, the actuate panel 120 generally defines a piece-wise semi-circle of a number of panel walls U1 A, U1 B and U2-U6. The panel walls U1A, U 1 B and U2-U6 are illustratively square or rectangular in shape, although in alternate embodiments the panel walls U1A, U1 B and U2-U6 may be any desired shape. In still other alternate embodiments, the panel walls U1 A, U1 B and U2-U6 may be replaced with a single unitary wall, or with any number of discrete panel walls. It will be appreciated that the arcuate panel 120 may be configured, as described hereinabove with respect to the lamp assembly 10, such that radiation produced by the plurality of light emitting diode mounted thereto is directed generally downwardly, generally upwardly or generally normal to a plane defined by a wall or other surface 124 to which the lamp assembly 10"' is mounted via one or more conventional mounting brackets, e.g., 126A and 126B.

[00116] In the illustrated embodiment, the arcuate panel 120 is mounted to a generally semi-circular main circuit board 130 defining a planar rear surface 130 that faces the wall or other mounting surface 124. The main circuit board 128 may illustratively be formed as described hereinabove with respect to the main circuit board 20 of the lamp assembly 10, or may alternative be provided in one or more other conventional forms. The various components of the driver circuit 28 are shown mounted to the main circuit board 120, although this disclosure contemplates alternate embodiments in which other conventional electrical circuitry is used to drive the light emitting diodes mounted to the arcuate panel 120. The main circuit board 128 is shown in FIG. 16 as including a series of plated-through hole pairs, L1 -L7, and in this regard the lamp assembly 10"' may include one or more additional generally arcuate panels juxtaposed with, attached to and electrically connected to the arcuate panel 120 similarly as described hereinabove with respect to the lamp assembly 10.

[00117] Although not specifically illustrated in FIG. 16, the lamp assembly 10"' further illustratively includes the thermal energy dissipation medium 80, 82 positioned proximate and generally opposite to the semiconductor light emitting diode die 90 of each of the plurality of light emitting diodes mounted to the arcuate panel 120. Illustratively the thermal energy dissipation medium 80, 82 extends completely, i.e., circumferentially, about each of the plurality of light emitting diodes that are mounted to the arcuate panel 120, as described hereinabove with respect to the lamp assembly 10, although this disclosure contemplates alternate embodiments in which the thermal energy dissipation medium 80, 82 extends only partially about one or more of the light emitting diodes.

[00118] Generally, it will be understood that the arcuate panel 120 may be any shape having a cross-sectional area that represents a truncated polygon or circle extending in the horizontal direction, the vertical direction or any direction in between. In the embodiment illustrated in FIG. 16, for example, the arcuate panel 120 has a cross-sectional area that defines a truncated circle, i.e., a semi-circle such that the arcuate or curved portion of the panel 120 spans 180 degrees. In other embodiments, the arcuate panel 120 may alternatively have a cross-sectional area that spans more or less than 180 degrees. As one example, an arcuate panel 120 that is formed specifically for an inside corner of a wall, or for an inside corner between a wall and a ceiling or floor, may define a curved portion that spans approximately 45 degrees such that the arcuate panel 120 is received within the inside corner and extends from one wall to the other, from the wall to the ceiling or from the wall to the floor. As another example, an arcuate panel 120 that is formed specifically for an outside corner of a wall may define a curved portion that spans approximately 270 degrees such that the arcuate panel 120 extends about the outside corner from one wall to the other. Other generally truncated polygon or truncated circle cross-sectional shapes will occur to those skilled in the art, and such other shapes are contemplated by this disclosure.

[00119] Referring now to FIG. 17, yet another illustrative embodiment of a lamp assembly 10 ^IV is shown. The lamp assembly 10 ^IV is identical in many respects to the lamp assembly 10, 10', 10" and 10"' illustrated and described herein, including any and all alternate embodiments thereof, and like numbers are therefore used to identify like components. The lamp assembly 10 ^IV differs from the lamp assemblies 10, 10', 10" and 10"' primarily in the overall shape of the lamp assembly 10 ^IV . In particular, the lamp assembly 10 ^IV defines a generally flat panel 140 to which a plurality of light emitting diodes, D _F , is mounted. As used herein, the term "flat panel" shall mean a generally flat panel that may be any desired height and/or width, and that may be formed from any number of panel walls or a single, unitary wall. In the embodiment illustrated in FIG. 17, for example, the flat panel 140 generally defines a single panel wall 142 that is illustratively square or rectangular in shape.

Alternatively, the flat panel 140 may have any desired linear or non-linear shape. It will be appreciated that the flat panel 140 may be configured, as described hereinabove with respect to the lamp assembly 10, such that radiation produced by the plurality of light emitting diode mounted thereto is directed generally downwardly, generally upwardly or generally normal to a plane defined by a wall or other surface 144 to which the lamp assembly 10 ^IV is mounted via one or more conventional mounting brackets, e.g., 146A and 146B.

[00120] In the illustrated embodiment, a main circuit board 150 is mounted to a rear surface of the flat panel 140 that faces the wall or other mounting surface 144. The main circuit board 150 may illustratively be formed generally as described hereinabove with respect to the main circuit board 20 of the lamp assembly 10, or may alternative be provided in one or more other conventional forms. The various components of the driver circuit 28 are illustratively mounted to the main circuit board 150, although this disclosure contemplates alternate embodiments in which other conventional electrical circuitry is used to drive the light emitting diodes mounted to the flat panel 140. In alternative embodiments, the various components of the driver circuit 28 are mounted directly to the back of the flat panel 140.

[00121 ] The lamp assembly 10 ^IV further illustratively includes the thermal energy dissipation medium 80, 82 positioned proximate and generally opposite to the semiconductor light emitting diode die 90 of each of the plurality of light emitting diodes, D _F , mounted to the flat panel 140. Illustratively the thermal energy dissipation medium 80, 82 extends completely, i.e., circumferentially, about each of the plurality of light emitting diodes, D _F , as described hereinabove with respect to the lamp assembly 10, although this disclosure contemplates alternate embodiments in which the thermal energy dissipation medium 80, 82 extends only partially about one or more of the light emitting diodes, D _F . In some alternative embodiments, the panel 140 may be omitted and the thermal energy dissipation medium 80, 82 may serve both as a thermal energy dissipation medium as described hereinabove and also as the flat panel to which the light emitting diodes, D _F , are mounted and supported. In such embodiments, the main circuit board 150 may be mounted directly to a back side of the thermal energy dissipation medium 80, 82, or the main circuit board 150 may be omitted and the various components of the driver circuit 28 may be mounted directly to the back side of the thermal energy dissipation medium 80, 82 and/or to the terminals 94, 96 of the light emitting diodes, D _F .

[00122] Generally, it will be understood that one or more flat panels 150 may be joined horizontally, vertically or otherwise, to form a multiple-panel lamp assembly. One or more such joined flat panels may, for example, be positioned adjacent to, e.g., in contact with or in close proximity to, one or more nearest neighbor panels, or may alternatively be spaced apart from one or more nearest neighbor panels. It will further be understood that one or more flat panels 150 may be joined, in contact with, in close proximity to or spaced apart from one or more arcuate panels 120 to form a resulting lamp assembly.

[00123] It will be understood that while the various lamp embodiments have been illustrated and described herein as being constructed from a combination of rigid or semi-rigid circuit boards and one or more separate thermal energy dissipation structures, such embodiments have been provided only by way of example and should not be considered to be limiting in any way. This disclosure contemplates other embodiments in which, for example, all or some the light emitting diodes are mounted directly to one or more rigid or flexible thermal energy dissipation media, or in which all or some of the light emitting diodes are mounted to a flexible circuit board. In the former case, the circuit board can be omitted altogether, and in the latter case one or more flexible or semi-flexible thermal energy dissipation structures may be mounted to the light emitting diodes as described hereinabove.

[00124] In one specific example embodiment, some or all of the plurality of light emitting diodes are mounted directly to the thermally conductive medium in the form of a thermally conductive sheet. In this embodiment, the circuit board(s) is/are omitted and the thermally conductive sheet defines a number of openings therethrough. The light emitting diodes are each mounted to the thermally conductive sheet and extend through a different one of the number of openings defined therethrough such that the thermally conductive sheet is positioned about each of the plurality of light emitting diodes. The thermally conductive sheet may be, for example, a rigid thermally conductive sheet that is shaped to form a substantially flat, polygonal sheet. Alternatively, the thermally conductive sheet is flexible or semi- flexible. In this embodiment, the flexible, thermally conductive sheet may be, for example, elastically or non-elastically deformed into a specified shape after the light emitting diodes are mounted thereto. Illustratively, the specified shape may be, but should not be limited to, one of a frustum, e.g., such as a truncated cone, a sphere, a truncated sphere, an annular band and an arcuate panel. Alternatively still, the flexible, thermally conductive sheet may be modified, e.g., by cutting or machining, to form a plurality of interconnected, thermally conductive sub-sections. In this example, the specified shape is formed by one or more portions of one or more of the plurality of interconnected, thermally conductive sub-sections. The specified shape in this embodiment, may illustratively be, but should not be limited to, an approximated one of a frustum, e.g., such as a truncated cone, a sphere, a truncated sphere, an annular band and an arcuate panel.

[00125] In another specific example embodiment, some or all of the light emitting diodes may be mounted directly to a flexible substrate, e.g., a flexible circuit board. A thermally conductive medium is then positioned at least partially about each of the light emitting diodes as described hereinabove. The thermally conductive medium may be provided in the form of one or any number of thermally conductive sheets or other structures, some or all of which may be rigid, semi-rigid or flexible. In this embodiment, the flexible substrate may be, for example, elastically or non-elastically deformed into a specified shape, e.g., any of the specified shapes described above, after the light emitting diodes are mounted thereto. The thermally conductive medium may illustratively be mounted to the light emitting diodes prior to or after such deformation into the specified shape.

[00126] While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.