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Patent Searching and Data


Title:
LED LAMP
Document Type and Number:
WIPO Patent Application WO/2010/018426
Kind Code:
A2
Abstract:
The invention discloses a LED lamp apparatus that has individually replaceable LEDs for easy repair and maintenance. The LED lamp apparatus comprises a lamp base, LED holders and LEDs. LEDs can be inserted into the LED holders without soldering. The LED holders provide mechanical grip and electrical contact for the LEDs. The LED lamp apparatus can be mounted onto ceiling and illuminate areas that are near and relatively far away. This is achieved by using the viewing angle of LEDs and the direction that they point. The LEDs with smaller viewing angles point to and illuminate areas further away while LEDs with larger viewing angles point to and illuminate areas nearer the LED lamp apparatus.

Inventors:
LEE, Song (2 Surin Lane, Singapore 3, 53554, SG)
Application Number:
IB2008/053265
Publication Date:
February 18, 2010
Filing Date:
August 14, 2008
Export Citation:
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Assignee:
YIPI PTE LTD (30 Kallang Place, #07 - 07, Singapore 9, 33915, SG)
LEE, Song (2 Surin Lane, Singapore 3, 53554, SG)
International Classes:
F21V19/00; F21V19/04
Domestic Patent References:
WO1996013866A11996-05-09
Foreign References:
US20070091604A12007-04-26
US6386733B12002-05-14
DE202008001026U12008-03-27
US20050239342A12005-10-27
US20080130275A12008-06-05
CN2758588Y2006-02-15
Attorney, Agent or Firm:
LEE, Song (30 Kallang Place #07 - 07, Singapore 9, 33915, SG)
Download PDF:
Claims:
Claims

[ 1 ] What is claimed is :

1. A LED lamp comprising: a lamp base; one or more LED holders; one or more LEDs; said LED holders attached to lamp base; and said LEDs attached to LED holders. [2] 2. The LED lamp of claim 1 further comprising one or more electrical components such as adaptor, transformer, diode, resistor and electrical wiring. [3] 3. The LED lamp of claim 1 further comprising a lamp cover.

[4] 4. The LED lamp of claim 1, wherein said LED holder comprises: an electrical non-conducting casing; and at least first and second electrical conductors; said electrical conductors are not in electrical contact with each other. [5] 5. The LED holder of claim 4, wherein said electrical conductors are shaped to provide good contact and hold in place the legs of LEDs.

[6] 6. The LED lamp of claim 1, wherein said LEDs are through-hole LEDs.

[7] 7. The LED lamp of claim 1, wherein said LEDs are Piranha LEDs.

[8] 8. The LED lamp of claim 1, wherein said LEDs are surface mount LEDs.

[9] 9. The lamp of claim 8, further comprising LED focusing lens.

[10] 10. A LED lamp comprising: a lamp base; plurality of substrates; at least two groups of LEDs; said substrates attached to said lamp base; said groups of LEDs attached to said substrates; said groups of LEDs point in at least two directions.

[11] 11. The LED lamp of claim 10, wherein said substrate is printed circuit board.

[12] 12. The LED lamp of claim 10, wherein said substrate is LED holder.

[13] 13. The LED lamp of claim 10, further comprising one or more electrical components such as adaptor, transformer, diode, resistor and electrical wiring. [14] 14. The LED lamp of claim 10, wherein said directions of the LEDs are below horizontal plane of said lamp base.

[15] 15. The LED lamp of claim 14, wherein said groups of LEDs having different viewing angles, and said groups of LEDs having LEDs with larger viewing angles point in the direction at or nearer the vertical, said groups of LEDs with smaller viewing angles point in the direction at or nearer the horizontal.

Description:
Description

LED LAMP

Technical Field

[1] The present invention relates to light emitting diode (LED) lamp , more particularly,

LED lamp with individually replaceable LEDs, and more specifically, although of course not solely limited to, a LED lamp suitable for mounting on ceiling and illuminating near and far away areas at the same time. Background Art

[2] LED lamps are made up of many discrete LEDs. Each LED produces a little light and many LEDs together produce the desired amount of light. LEDs operate on low voltages, commonly between two and four volts. Traditional LEDs, like through-hole LEDs, are directional and can have narrow viewing angles such as fifteen degrees, thirty degrees, sixty degrees, and so on. Through-hole white LEDs can produce up to about three lumens each. Surface mount LEDs produce more light and can be as high as more than fifty lumens each. The light produced is often diffused or the viewing angle is wide, such as one hundred and forty degrees or higher. Other types of LEDs exist.

[3] Different LED lamps were invented to meet different needs and are used in different areas.

[4] One such invention is disclosed in US Patent No. 6, 499 , 860 . The LED lamp is able to provide continuous uniform high intensity lighting using standard bulb socket. Referring to FIG. 1, the LED lamp 101 is shaped like a bulb and comprises a regular polyhedron substrate and in this example a tetrahedron substrate 102 within the bulb with LEDs 103 mounted on each of the substrate's surfaces 102. The tetrahedron substrate 102 is connected to a tubular hollow gear column 104, which in turn is connected to the lamp cap 105. The LED lamp 101 also includes a fan 106 incorporated in the gear column 104, which generates air flow to cool the LEDs 103. The electronic gear (not shown) necessary to control the lamp is accommodated within the gear column 104. Such a LED lamp is able to provide high luminous flux by using LEDs that provide more than five lumens each. High luminous LEDs also produce a lot of heat. The invention overcomes the problem of the LEDs overheating by using the fan to actively cool the LEDs. Better all round illumination is achieved by having a polyhedron with more faces, such as a hexahedron or octahedron.

[5] Another invention is disclosed in US Patent No. 6,860,628. The invention provides a

'drop-in' replacement for fluorescent tubes. Referring to FIG. 2, the LED lamp 111 comprises an elongated hollow tube 112 with end caps 113 and connectors 114 similar in size to conventional fluorescent tubes, containing a plurality of LEDs 115 and ap- propriate electrical components (not shown). The LEDs 115 are connected in series and point vertically downwards. Such a LED light tube is able to illuminate the area under the light tube.

[6] In the market there exist LED lamps which are box-like in shape. Referring to FIG. 3

, the LED lamp 121 comprises of a box-like structure 122 with LEDs 123 mounted on printed circuit board (PCB) in series with their lighting ends exposed on the bottom face 124 of the box-like structure 122. Such a LED lamp is able to illuminate the area under it.

Disclosure of Invention Technical Problem

[7] A LED lamp comprises of many LEDs. Some LED lamps have more than a hundred

LEDs in them. All LEDs have a lifespan. Some LEDs last longer and some shorter than their expected life spans. Some LEDs fail prematurely. When a LED in the LED lamp fails, all the LEDs in the same group, which are connected in series in the circuit, will not light up. As the LEDs are soldered onto a PCB, it is difficult to determine which LED in the whole group has failed. It requires special tools to replace the failed LED. It is especially difficult to repair the LED lamp on site. Often, the PCB with its mounted LEDs, or the whole LED lamp is replaced in order to fix the problem. This is wasteful and environmentally unfriendly.

[8] A second problem is that current LED lamps are not well suited to provide lighting for both near and far away areas at the same time. The LED lamp will need to comply with design codes or client's requirements and this often has two technical requirements. The first requirement is that the illuminance (brightness) level directly under the lamp at floor level needs to meet a certain minimum, such as 30 lux. The second requirement is that the ratio of the minimum illuminance (brightness) level divided by the maximum illuminance (brightness) level at floor level, also commonly known as uniformity level, needs to meet a certain minimum value, such as 0.3.

[9] Take an example of a long corridor in a multistory building. The ceiling height is fixed and the corridor is long. Using current LED lamps, the spacing between LED lamps need to be very close, such as two meters apart. This is not economical or acceptable in some situations. If the LED lamps are placed further apart, the mid-point area between two LED lamps will not be bright enough. By adding more LEDs into LED lamp, it will not solve the problem. Most of the light from the additional LEDs will illuminate the area directly under the LED lamp and very little of the light will illuminate the areas far away. This is because LEDs have viewing angles. Also, luminous flux density from the LEDs will decrease according to the square of the distance. As a result, the uniformity level will never be satisfied. Technical Solution

[10] In consideration of the first problem, a LED holder is incorporated into the LED lamp. So instead of soldering the LEDs onto PCB or some substrate, the legs of the LEDs are inserted into the LED holder, which forms part of the circuit. The legs of the LEDs are held in place in the LED holder by mechanical means and the LEDs can be removed or replaced easily without the need for soldering.

[11] In consideration of the second problem, the need to illuminate near and relatively far areas at the same time is solved by making use of the directional and viewing angle properties of LEDs. The LEDs are grouped together according to their viewing angles. Those with large viewing angles point to and illuminate the areas near the LED lamp. Those with small viewing angles, which are brighter and more focused, point to and illuminate the areas relatively further away from the LED lamp. This keeps the lighting flux focused in the areas required, achieving the required lighting levels and uniformity levels. Advantageous Effects

[12] This invention overcomes the disadvantages and limitations of prior art. When a single LED fails, it is easy to replace the failed LED on site. This invention can also be used to illuminate both near and far away areas at the same time. Description of Drawings

[13] The accompanying drawings are solely for purposes of illustrating the concepts of the invention and are not drawn to scale. The embodiments shown in the accompany drawings, and described in the accompanying detailed description, are used as illustrative embodiments and should not be construed as the only manner of practicing the invention. Also, the same reference numerals, possibly supplemented with reference characters where appropriate, have been used to identify similar parts. The '+' and '-' signs used in the drawings refer to the positive and negative voltage polarities. These and other objects and features of this invention will be clear and apparent to those skilled in the art upon reading the detailed description together with the drawings, wherein:

[14] FIG. 1 shows a prior art of a bulb-shape LED lamp;

[15] FIG. 2 shows a prior art of a tubular-shape LED lamp;

[16] FIG. 3 shows a prior art of a panel-shape LED lamp;

[17] FIG. 4 shows a front view of a LED holder with a through-hole LED inserted;

[18] FIG. 5 shows cross-section 1-1 of the LED holder in FIG. 4;

[19] FIG. 6 shows cross-section 2-2 of the LED holder in FIG. 4;

[20] FIG. 7 shows a cross-section of a LED lamp;

[21] FIG. 8 shows cross-section of two LED lamps operating along a corridor; [22] FIG. 9 shows a Piranha LED and a surface mount LED;

[23] FIG. 10 shows the front view of a Piranha LED holder with Piranha LEDs;

[24] FIG. 11 shows a perspective view of another LED lamp.

Best Mode

[25] Referring to FIG. 4, it shows the front view of a LED holder 4 with a through-hole

LED 10. The LED holder 4 has a row 41 of holes 42, which are connected internally electrically by electrical conductors 43. The LED holder 4 has another row 51 of holes 52, which are also connected internally electrically by electrical conductors 53. Voltage potential difference can be supplied to the two rows 41 and 51, such as connecting the positive voltage to row 41 and ground voltage to row 51. The LED 10 will light up when the right voltage is applied. Each pair of holes 42 and 52 can accept one through-hole LED 10. The shape of the LED holder 4 is not restricted to what is described here. For example, it could be longer and wider and encompass many pairs of rows 41 and 51 like a panel, and allow for rows of LEDs 10 to be attached. The LED holder can also be of similar design to breadboard or electrical connectors whereby the electrical conductors provide electrical contact as well as physical grip on the legs of electrical components and the electrical conductors are enclosed within a plastic casing.

[26] Referring to FIG. 5, it shows the cross-section view 1-1 in FIG. 4. The LED holder 4 comprises electrical conductors 43 and 53, which are held in place and insolated from each other within a non-conducting casing 4O.The electrical conductors 43 and 53 can be made of copper or aluminum or other suitable materials. The casing can be made of plastic material or other suitable materials. A non-conductor backing 48 is used to complete the enclosure of the casing 40 in isolating the electrical conductors 43 and 53 from contact with other unwanted electrical conductors. The electrical conductors 43 and 53 are shaped such that they also provide the mechanical grip required to hold in place the legs of LEDs. The mouth of the electrical conductors 43 and 53 can open up slightly to receive the legs of the LED through holes 42 and 52. Referring to FIG. 6, it shows the cross-section view 2-2 in FIG. 4. The through-hole LED 10 is inserted through holes 42 and 52 and its legs 12 and 13 are held tightly by the electrical conductors 43 and 53. Only one LED 10 is shown here for simplicity. Depending on the lighting design requirements, more LEDs 10 can be inserted into the LED holder 4.

[27] Having addressed the first object in having replaceable LEDs, we now move on to explain the LED lamp in addressing the second object. Referring to FIG. 7, it shows the cross-section of a LED lamp 1. The LED lamp 1 comprises a lamp base 2, LED holders 4, LEDs 10 (10a, 10b or 10c) and a lamp cover 5. The length of LED lamp 1 (into the page) can vary (such as 600 mm or 1200 mm), depending on the number of LEDs required to provide the required illumination or the width of the area required to be illuminated. The lamp base 2 can be made of aluminum or other suitable materials. The other components of the LED lamp 1, such as the transformer (not shown), rectifier (not shown), end caps of lamp (not shown), lamp cover 5, and LED holders 4 can be attached to the lamp base 2. Electrical components such as transformers, rectifiers, voltage source, resistors and wires and circuits are not shown here so as to make the main points clearer; and in any case, they are also obvious to those skilled in the art. While it is simplest to have a direct current source to power the LED lamp 1, it probably is more common to have an alternating current source to power the LED lamp 1. In such an instance, the alternating current source is stepped down by transformer to the appropriate voltage and rectified to direct current to power the LED lamp 1. Alternatively, an AC-to-DC adaptor can be used to convert the AC source to a DC output with the required voltage. The lamp cover 5 can be either transparent or translucent. The lamp cover 5 is also optional as the LED lamp 1 can function without one.

[28] The LED holders 4 can be attached to the lamp base 2 and in this example the lamp base 2 is shaped with profiles 3 that allow for the LED holders 4 to be slotted in. There are many other ways to attach the LED holders 4 to the lamp base 2 and they will be obvious to those skilled in the art. Another example is to have a simple flat lamp base and a separate mounting apparatus. The mounting apparatus is attached to the lamp base and holds in place the LED holders.

[29] The LEDs 10 are through-hole LEDs (traditional LED with two legs). LED 10a has the largest viewing 15a angle of 60 degrees and the smallest luminous intensity of 4 candelas. LED 10b has a viewing angle 15b of 30 degrees and a luminous intensity of 12 candelas. LED 10c has the smallest viewing angle 15c of 15 degrees and the largest luminous intensity of 25 candelas. It should be noted here that as the viewing angle of the LEDs decrease, their luminous intensity increases. This LED property is made use of by this invention. The directions of the LEDs are 16a, 16b and 16c for LEDs 10a, 10b and 10c respectively. The LED 10a, which has the widest viewing angle 15a, is used to illuminate the area directly under the LED lamp 1. The LED 10c, which has the narrowest viewing angle 15c, is used to illuminate the area furthest away from the LED lamp 1. The areas within the viewing angles 15a, 15b and 15c receive most of the light emitted by the LEDs 10a, 10b and 10c respectively. The angles 17a (not shown, zero degrees), 17b, and 17c are the angles between the directions 16a, 16b and 16c and the verticals 14a (not shown, vertical and same line as 16a), 14b and 14c for LEDs 10a , 10b and 10c respectively. In this example, 17a (not shown, zero degrees) is the smallest and is zero degrees. The angle 17b is 40 degrees while 17c is 60 degrees and is the biggest.

[30] Referring to FIG. 8, it shows cross-section of two LED lamps 1 mounted on the ceiling 25 of a corridor 26. The height of the ceiling is about 2.5m high, and the width of the corridor is about 1.5m wide. The two LED lamps 1 are installed about 10m apart and illuminate the floor 27 of the corridor 26.

[31] The LEDs 10a, 10b and 10c represent groups of LEDs with the same viewing angles

15a, 15b and 15c respectively. The number of LEDs in each group can be varied according to the lighting conditions required. Each group does not need to have the same number of LEDs as other groups. The LED group 10a, which has largest viewing angle 15a illuminates the area 21, which is directly under the LED lamp 1. The LED group 10c, which has the smallest viewing angle 15c, illuminates the area 23, which is furthest away from LED lamps 1. The LED group 10b, which has a viewing angle 15b which is between those of 10a and 10c, illuminates the area 22, which is between areas 21 and 23.

[32] In this example, the LED lamp is able to meet both the illuminance (brightness) requirement (such as 30 lux) and the uniformity level (such as 0.3). The areas from near to far are well illuminated.

[33] The LEDs 10a, 10b and 10c are explained to have different viewing angles 15a, 15b and 15c. This is to minimize the use of power to illuminate the area required. It should be appreciated that there might be other over-riding considerations, such as the desire to use only one type of LED for the LED lamp so as to minimize logistics issues. This is also possible. This means that the LEDs 10a, 10b and 10c can have the same viewing angle, say 30 degrees. The directions 16a, 16b and 16c of the LEDs 10a, 10b and 10c can be adjusted accordingly to meet lighting requirements. Also, the number of LEDs in each LED groups 10a, 10b and 10c can be adjusted. The number of groups of LEDs can differ from the five explained in this embodiment. For example if there are eight groups of LEDs, they could point in eight directions. Also, while we have explained here using narrow angle through-hole LEDs, LEDs that produce diffused lighting can also be used. And if necessary, LED lens can be used in conjunction with such LEDs to focus the diffused light.

[34] It should be appreciated that while the described LED lamp has replaceable LEDs and can illuminate near and far areas at the same time, these two functions are not mutually inclusive. That is to say, we can have traditional LED lamps, such as panel- shaped lamps, but using LED holders so that the LEDs can be easily replaced when they fail. Also, the substrates the LEDs attach to need not be LED holders. Instead, the substrates can be PCBs. The LEDs, although soldered onto the PCBs, can still point in directions like those above. In such a situation, the LED lamp will be able to illuminate areas near and far away at the same time, although it will be difficult to replace the individual LEDs on site when they fail. Mode for Invention [35] Other modes of invention exist. The concept explained above can be used with other types of LEDs as well. Different circuit designs are also possible and will be obvious to those skilled in the art.

[36] Referring to FIG. 9, it shows a Piranha LED 18 with four legs (two positive and two negative) and a surface mount LED 19 with six legs (three positive and three negative). The Piranha LED 18 is brighter than a through-hole LED as it contains more than one light emitting diode within the Piranha LED 18. The surface mount LED 19 is even brighter as it contains even more light emitting diodes within itself 19.

[37] In any case, the concept of using a LED holder instead of soldering the LEDs directly onto a PCB can be used. This allows for easy attachment and replacement of LEDs. Slightly different LED holders need to be designed to take into account the number and shape of the LED legs, but this will be obvious for those skilled in the art and there are many possibilities. Basically, the LED holders need to provide electrical connections and a means of holding the LEDs securely. The LED holders can comprise of an electrical non-conducting casing and at least two electrical conductors (one for positive and the other for negative or ground), although the shape and form can vary.

[38] Referring to FIG. 10, it shows the front view of a suitable Piranha LED holder 60 for

Piranha LEDs 18. The internal physical electrical connection depends on the circuit design. In this example, the design is for four Piranha LEDs to be connected in series to a direct current voltage source. So the Piranha LED holder 60 is designed as such. The Piranha LED holder 60 comprises a non-conducting casing 61 with holes 62a and 62b for the positive and negative legs of the Piranha LED 18 to be inserted into. The negative holes 62b for one Piranha LED 18 are electrically connected to the positive holes 62a for the next Piranha LED 18 internally by electrical conductors 63.

[39] Other than illuminating corridors, this invention can be modified to help illuminate landing areas or large rectangular areas. Referring to FIG. 11, the LED lamp Ia has LEDs 10a, 10b, and 10c which point from near to far directions 16a, 16b and 16c respectively. The LED lamp lights up areas in multiple main directions 71, 72, 73, 74, 75 , 76, 77 and 78. This is superior to existing products such as the LED lamp shaped like a bulb (FIG. 1), LED lamp shaped like a fluorescent tube (FIG. 2) or the LED lamp in the shape of a panel (FIG. 3) as it can increase the lighting area and reducing the spacing between LED lamps and the number of LED lamps required for a fixed area. So instead of needing to place LED lamps at say 2 meter spacing, the new invention allows for greater spacing, such as 5 meter spacing.

[40] While the present invention has been explained by reference to the preferred embodiments described above, it will be appreciated that the embodiments are only illustrated as examples to assist understanding of the present invention and are not meant to be restrictive on its scope. In particular, the scope, ambit and spirit of this invention are meant to include the general principles of the invention as inferred or exemplified by the embodiments described above. More particularly, variations or modifications which are obvious or trivial to persons skilled in the art, as well as improvements made on the basis of the present invention, should be considered as falling within the scope and boundary of the present invention.

[41] Furthermore, while the present invention has been explained by reference to LEDs, it should be appreciated that the invention can apply, whether with or without modifications, to other types of lights without loss of generality. Industrial Applicability

[42] This invention improves the maintainability of LED lamps on site. Each LED in the

LED lamp can be replaced easily on site without special tools when it fails. There is also no need to replace the whole LED lamp when only one LED fails.

[43] The invention can also be used to light up near and far areas at the same time. This allows the use of LED lamps for areas such as corridors and walkways, and at the same time keeping the number of LED lamps required to the minimal.