LED ILLUMINATION APPARATUS

Technical Field

[1] The present invention relates to a light emitting diode (LED) illumination apparatus, and in particular, to a transparent electrode structure formed on a transparent panel. Background Art

[2] When fluorescent lights are used to implement an illumination apparatus, power consumption is high due to use of a large number of fluorescent lights, the life span of the fluorescent lights is short and maintenance is difficult, and the size of the fluorescent lights is an obstacle to making the apparatus compact.

[3] Further, when a neon tube or a cathode tube is used to implement an illumination apparatus, power consumption is high due to use of a high- voltage power supply, there is danger of electric shock, and wiring is not easy so that it is difficult to realize an elegant illumination apparatus.

[4] Moreover, when an incandescent or halogen lamp is used to implement an illumination apparatus, the size or shape of the incandescent or halogen lamp has an influence on the appearance of the illumination apparatus and places numerous limitations on its design.

[5] Because of such limitations, illumination apparatuses using LEDs, which have the advantages of enabling various designs, brightness, sizes, and colors at low power, are currently being researched.

[6] Following this trend, a transparent electrode structure of an LED illumination apparatus that is capable of obtaining uniform brightness and operating at low voltage has come to be researched. Disclosure of Invention Technical Problem

[7] The present invention is directed to a light emitting diode (LED) illumination apparatus that is capable of obtaining uniform brightness since a transparent electrode is implemented by forming a plurality of electrode patterns having the same sheet resistance on a transparent panel.

[8] The present invention is also directed to an LED illumination apparatus that has an elegant appearance since a positive (+) terminal and a negative (-) terminal of a power supply terminal are formed on the same one of four outer portions of a transparent panel.

[9] The present invention is further directed to an LED illumination apparatus that can be driven at a low voltage since it includes a plurality of transparent electrodes including a plurality of electrode patterns having the same sheet resistance and electrical power is selectively supplied to the electrodes. Technical Solution

[10] One aspect of the present invention provides a light emitting diode (LED) illumination apparatus in which plurality of electrode patterns having the same sheet resistance are formed using a transparent electrode formed on a transparent panel.

[11] Another aspect of the present invention provides an LED illumination apparatus in which a positive (+) terminal and a negative (-) terminal of a power supply terminal supplying electrical power to a transparent electrode are formed on the same one of four outer portions pf a transparent panel.

[12] Still another aspect of the present invention provides an LED illumination apparatus in which electrical power is selectively supplied to each of a plurality of transparent electrodes including a plurality of electrode patterns disposed on a transparent panel to be spaced apart from each other and having the same sheet resistance.

Advantageous Effects

[13] In a light emitting diode (LED) illumination apparatus according to the present invention, a plurality of electrode patterns having the same sheet resistance are formed on a transparent panel to implement a transparent electrode, so that uniform brightness can be obtained.

[14] Also, a positive (+) terminal and a negative (-) terminal of a power supply terminal are formed on the same one of four outer portions of a transparent panel, so that a structure hiding the power supply terminal can be minimized to achieve an elegant appearance.

[15] In addition, in the present invention, a plurality of transparent electrodes including a plurality of electrode patterns having the same sheet resistance are formed, and electrical power is supplied to each of them to drive the apparatus at a low voltage. Brief Description of Drawings

[16] The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which:

[17] FIG. 1 is a cross-sectional view of a light emitting diode (LED) illumination apparatus according to the present invention;

[18] FIG. 2 is a plan view of a transparent electrode structure of an LED illumination apparatus according to an example embodiment of the present invention;

[19] FIG. 3 is an example of the shape of an electrode pattern;

[20] FIG. 4 is a plan view of a transparent electrode structure of an LED illumination apparatus according to another example embodiment of the present invention; [21] FIG. 5 shows a transparent electrode of an LED illumination apparatus according to one example embodiment of the present invention;

[22] FIG. 6 shows a transparent electrode of an LED illumination apparatus according to another example embodiment of the present invention;

[23] FIG. 7 shows a transparent electrode of an LED illumination apparatus according to still another example embodiment of the present invention;

[24] FIG. 8 shows a transparent electrode of an LED illumination apparatus according to yet another example embodiment of the present invention;

[25] FIG. 9 shows an example in which a power supply terminal is formed on the same one of four outer portions of a transparent panel;

[26] FIG. 10 shows an example in which a power supply terminal is formed and condensed on the same one of four outer portions of a transparent panel;

[27] FIG. 11 is a plan view of a transparent electrode of an LED illumination apparatus according to yet another example embodiment of the present invention;

[28] FIG. 12 is a plan view of a transparent electrode of an LED illumination apparatus according to yet another example embodiment of the present invention;

[29] FIG. 13 is a plan view of a transparent electrode of an LED illumination apparatus according to yet another example embodiment of the present invention; and

[30] FIG. 14 illustrates an LED illumination apparatus installed in a car according to the present invention. Mode for the Invention

[31] Example embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[32] FIG. 1 is a cross-sectional view of a light emitting diode (LED) illumination apparatus according to the present invention. As illustrated in the drawing, the LED illumination apparatus 100 includes a transparent panel 110, a transparent electrode 120, a power supply terminal 130, and one or more LEDs 140.

[33] The transparent panel 110 is formed of a transparent insulator such as glass or a polymer. The transparent electrode 120 is formed of a conductive material such as carbon nanotubes (CNTs), a conductive polymer, etc., on the transparent panel 110, and includes a plurality of electrode patterns 121 electrically insulated from other elements by a chemical process such as etching or a physical process such as scratching.

[34] The power supply terminal 130 is connected to a power input means (not shown) applying electrical power to the transparent electrode 120, and includes a positive (+) terminal and a negative (-) terminal. The LEDs 140 are formed on the plurality of electrode patterns 121 formed on the transparent electrode 120, and are installed such that two adjacent electrode patterns are electrically connected to each other, i.e., such that the two adjacent electrode patterns are in contact with each other simultaneously.

[35] When the electrical power is input through the power supply terminal 130, current flows through the electrode pattern 121 connected to the positive (+) terminal of the power supply terminal 130, and the current flows through the LED 140 that is installed such that the electrode pattern 121 and an adjacent electrode pattern are in contact with each other simultaneously. Finally, the current flows through the negative (-) terminal of the power supply terminal 130, so that a closed circuit is constituted. Accordingly, since the LED 140 is turned on, the LED illumination apparatus 100 operates.

[36] FIG. 2 is a plan view of a transparent electrode structure of an LED illumination apparatus according to an example embodiment of the present invention. According to an example embodiment, the transparent electrode 120 includes a plurality of electrode patterns 121 having the same sheet resistance. Here, in order for the sheet resistance to be the same, the electrode patterns 121 should all have the same shape.

[37] For example, the electrode patterns 121 may be patterned in the same quadrangular shape (square or rectangle) or in the same polygonal shape (circle, arc, oval, triangle, pentagon, or trapezoid). Here, the size of the electrode patterns 121 in each shape may be different from each other or the same.

[38] FIG. 5 shows a transparent electrode of an LED illumination apparatus in which all electrode patterns are implemented as the same square according to one example embodiment of the present invention. FIG. 6 shows a transparent electrode of an LED illumination apparatus in which all electrode patterns are implemented as the same rectangle according to another example embodiment of the present invention.

[39] FIG. 7 shows a transparent electrode of an LED illumination apparatus in which all electrode patterns are implemented as the same rectangle and trapezoid according to still another example embodiment of the present invention

[40] FIG. 8 shows a transparent electrode of an LED illumination apparatus in which all electrode patterns are implemented in the same arc and oval according to yet another example embodiment of the present invention.

[41] For example, in an electrode pattern having the shape of a square, in order for each electrode pattern 121 to have the same shape, the ratio of the width to the length of each electrode pattern should be the same.

[42] For example, in order for the ratio of the width to the length of each electrode pattern

121 to be the same, the electrode pattern 121 should be patterned in the shape of a square, as illustrated in FIG. 2. Here, the electrode patterns in the shape of a square may have different sizes or have the same size. In the drawing, in order to be connected to the power supply terminal 130, the size of a lead portion should be minimized so that a sheet resistance of the lead portion of the electrode pattern 121 is negligible.

[43] Sheet resistance refers to the unique resistance per unit area that is characteristic of a material. As illustrated in FIG. 3, the sheet resistance of an electrode pattern 121 in the shape of a rectangle having a thickness T, a width W, and a length L can be represented by the following equation:

[44] p = Λ » «-£- - -L .-L s ⁹ A T-W T W

[45] where RS denotes sheet resistance and denotes resistivity which is constant When the thickness T is fixed and the value of L/W (the ratio of the width to the length) is held constant, the sheet resistance is the same regardless of the size of the electrode pattern 121.

[46] For example, when the width is the same as the length, i.e., when the shape is a square, L/W is always 1, so that the sheet resistance of the electrode pattern 121 is always the same regardless of the size of the square.

[47] If the electrode patterns 121 all have the same sheet resistance, it means that when the same voltage is applied to a plurality of LEDs 140 installed to be in contact with two adjacent electrode patterns, all of the LFJDs have the same brightness.

[48] Therefore, advantages of an LED illumination apparatus such as the ability to realize various designs, brightness, sizes and colors can be gained, and drawbacks such as non-uniform LED brightness caused by .a non-uniformly changed voltage according to non-uniform electrode pattern sheet resistance can be overcome. Thus, an LED illumination apparatus having uniform brightness can be obtained and thereby an object of the present invention can be accomplished.

[49] In the meantime, according to another aspect of the present invention, as illustrated in

FIG. 2 of the present invention, the positive (+) and the negative (-) terminal of the power supply terminal 130 can be formed on the same one of four outer portions of the transparent panel 110.

[50] Furthermore, as illustrated in FIG. 4, the positive (+) and the negative (-) terminal of the power supply terminal 130 can be implemented to be formed and condensed on one same portion of the outer portions.

[51] That is, in the present example embodiment, a configuration (not shown) of the power supply terminal 130 supplying electrical power to the transparent electrode 120 is not visible. That is, an installation portion including an outer case covering an outer wall of the transparent panel 110 and hiding the power supply terminal 130 is minimized to the point of invisibility. As a result, the design of the apparatus can be varied and it can be given an elegant appearance. [52] As described above, the positive (+) and the negative (-) terminals of the power supply terminal 130 are formed on the same one of the four outer portions and condensed to enhance their invisibility. As a result, the design of the LED apparatus 100 can be varied, it can be given an elegant appearance, and thereby an object of the present invention can be accomplished.

[53] FIG. 9 shows a power supply terminal formed on the same one of four outer portions of a transparent panel, and FIG. 10 shows a power supply terminal formed and condensed on the same one of four outer portions of a transparent panel.

[54] Other example embodiments of the LED illumination apparatus according to the present invention will be described with reference to FIGS. 11 to 14. FIG. 11 is a plan view of a transparent electrode structure of an LED illumination apparatus according to yet another example embodiment of the present invention, FIG. 12 is a plan view of a transparent electrode structure of an LED illumination apparatus according to yet another example embodiment of the present invention, FIG. 13 is a plan view of a transparent electrode structure of an LED illumination apparatus according to yet another example embodiment of the present invention, and FIG. 14 illustrates an LED illumination apparatus installed in a car according to the present invention.

[55] The LED illumination apparatus according to one example embodiment includes a transparent panel 110, a plurality of transparent electrodes 120, a plurality of power supply terminals 130, an LED 140, and a controller 150.

[56] The transparent panel 110 is formed of a transparent insulator such as glass or a polymer. The transparent electrodes 120 are formed of a conductive material such as carbon nanotubes (CNTs), Indium Tin Oxide (ITO), a conductive polymer, etc., on the transparent panel 110, and includes a plurality of electrode patterns 121 electrically insulated by a chemical process such as etching or a physical process such as scratching.

[57] The transparent electrodes 120 are disposed on the transparent panel 110 to be spaced apart from each other, and include a plurality of electrode patterns having the same sheet resistance. The electrode patterns having the same sheet resistance are described above and there description will not be repeated here.

[58] The power supply terminal 130 is connected to a power input means (not shown) that applies electrical power to the transparent electrodes 120 and includes a positive (+) terminal and a negative (-) terminal. The LEDs 140 are formed on the plurality of electrode patterns 121 formed on the transparent electrode 120, and are installed such that two adjacent electrode patterns are electrically connected to each other, i.e., such that the two adjacent electrode patterns are in contact with each other simultaneously.

[59] Here, the LED 140 may be a Light Emitting Diode (LED), a Laser Diode (EL), an organic EL, a Liquid Crystal Device (LCD), or a Field Emission Device (FED). Any kind of LED capable of emitting light can be employed.

[60] The controller 150 selectively supplies electrical power to the plurality of power supply terminals 130. Here, one of the positive (+) and the negative (-) terminals of the power supply terminal 130 is divided, and the other may be divided as illustrated in FIG. 12 or formed as an integral unit as illustrated in FIG. 11.

[61] Meanwhile, the controller 150 may be implemented to sequentially supply electrical power to the plurality of power supply terminals 130. In the meantime, the controller 150 may be implemented to supply electrical power to the plurality of power supply terminals 130 according to a time interval fixed in advance. Alternatively, the controller 150 may be implemented to selectively supply electrical power to the plurality of power supply terminals 130 according to a mode set in advance.

[62] When the electrical power is selectively supplied to the plurality of power supply terminals 130 by the controller 150, current flows through an electrode pattern connected to the positive (+) terminal of the power supply terminal 130 of each transparent electrode 120. Also, the current flows through the LED 140 installed to be in contact with the electrode pattern and an electrode pattern adjacent thereto simultaneously. Finally, the current flows through the negative (-) terminal of the power supply terminal 130 to constitute a closed circuit, so that the LED 140 is turned on. Here, since electrical power is selectively supplied to each transparent electrode 120 by the controller 150, the LED can be driven at low voltage.

[63] For example, when the controller 150 supplies electrical power in a short time interval that people cannot easily observe, users looking toward the LED illumination apparatus 100 may feel that LEDs 140 are emitting light simultaneously.

[64] Meanwhile, the LED illumination apparatus 100 according to the present example embodiment of the present invention is not influenced by the size of the transparent panel 110. Generally, an LED illumination apparatus that temporarily emits light as a whole requires a large voltage in proportion to its size. This is because the larger the size of the LED illumination apparatus, the more LEDs it has, and thus the greater the driving voltage.

[65] However, the LED illumination apparatus 100 according to the present example embodiment can be divided into a plurality of regions which are then sequentially supplied with electrical power. Therefore, low voltage can be implemented regardless of the size of LED illumination apparatus 100.

[66] In the meantime, the controller 150 may supply electrical power to the power supply terminal 130 at a time interval set in advance. Here, the time interval set in advance may be short, within a second, such that people cannot easily detect it. Alternatively, it may be within 1.5 seconds to 4 seconds such that people can feel secure, cozy, or pleasant for visual effects or within 2 seconds to 4 seconds close to a breath interval. Various embodiments are possible.

[67] Moreover, the controller 150 may differentially supply electrical power to the power supply terminal 130. That is, for example, the electrical power may be sequentially supplied from the left side of the divided transparent panel 110 region to the right side. Alternatively, the electrical power may be supplied at random. Furthermore, the electrical power may be differentially supplied in a fixed sequence. When the LEDs 140 are arranged in a circle, the electrical power of the power supply terminal 130 may be differentially supplied such that from one LED 140 is replaced in a clockwise direction or an anti-clockwise direction, and this process is repeated. Accordingly, an effect of a moving picture can be obtained.

[68] In addition, the controller 150 may selectively supply electrical power according to a mode set in advance. For example, in order to interrupt the supply of electrical power, the electrical power may be selectively supplied depending on a low-power mode such as a normal mode, a suspend mode or a standby mode.

[69] Also, the brightness of the LED 140 is adjustable. During supplying electrical power, it can be controlled to gradually increases in brightness. The brightness of the LED can be adjusted according to a uniformly repeated cycle. Moreover, an RTC circuit capable of identifying time is added to selectively supply electrical power. For example, the electrical power may be differentially supplied depending on whether it is day or night. The example embodiments can be implemented since the electrical power of the power supply terminal 130 can be selectively controlled.

[70] Meanwhile, according to the present invention, the LED illumination apparatus 100 may further include an auxiliary transparent panel (not shown) disposed to face the transparent panel 110, and a packed layer (not shown) installed between the transparent panel 110 and the auxiliary transparent panel to cover the LED 140. The auxiliary transparent panel is formed of the same transparent material as the transparent panel 110, and functions to form a space between the transparent panel 110.

[71] Further, according to the present invention, the packed layer may be formed between the transparent panel 110 and the auxiliary transparent panel, and since it is disposed to cover the transparent electrode 120 and the LED 140, it can protect the transparent electrode 120 and the LED 140 from the external environment including moisture, and can absorb shock to protect electronic parts from external impact.

[72] Also, the packed layer is formed of a transparent material, and since it should be attached to the transparent panel 110 and the auxiliary transparent panel, it may be formed of a polymer-based material having an adhesive property. Moreover, it may be formed of a PVB film, an EVA film or a resin-type liquid filler. According to the present invention, the packed layer is formed between the transparent panel 110 and the auxiliary transparent panel, and thus is can safely protect the electrode pattern and the LED 140 from external impact.

[73] An LED illumination apparatus 100 according to an example embodiment illustrated in FIG. 13 groups a plurality of transparent electrodes 120 to control them. In the example embodiment, the plurality of transparent electrodes 120 are grouped and the groups are selectively supplied with electrical power to be controlled.

[74] As described above, the LED illumination apparatus 100 according to example embodiments of the present invention is driven at low voltage, and thus can be applied to various fields or products. For example, as illustrated in FIG. 14, it can be applied to a car.

[75] For example, the apparatus may be installed in the rear of a car. In particular, the

LED illumination apparatus 100 may be installed on the rear window of the car, i.e., at a position where a car behind can see it. Thus, the LED illumination apparatus 100 can be used to inform a car behind of directions or of an internal status of the car. For example, a stoplight, a U-turn, a direction, application of brakes, etc., can be displayed on the LED illumination apparatus 100.

[76] In a car, in order to drive the LED illumination apparatus according to the present invention, a voltage of 12V or 132 V is required. However, the general LED illumination apparatus 100 requires a high voltage of 1130V or higher. Therefore, it is not simple to apply the general LED illumination apparatus to a car. However, the LED illumination apparatus 100 according to the example embodiment of the present invention sequentially supplies electrical power to disperse a driving voltage. Since the LED illumination apparatus 100 can be sequentially driven at a voltage of, for example, 10V or lower, it can be applied to a car.

[77] Here, electrical power is supplied at a time interval set in advance, in particular, at a time interval people cannot easily detect, so that those looking toward the LED illumination apparatus may feel that contents of the LED illumination apparatus 100 are turned on and off in an instant.

[78] For example, when a driver of a car makes a right turn, the driver operates a turn signal lever so that a turn signal light outputs a right turn signal. At the same time, the LED illumination apparatus 100 on the front or rear window of the car indicates the right turn.

[79] Here, in the LED illumination apparatus 100, the power supply terminal is divided into a plurality of terminals so that electrical power is selectively supplied per divided power supply terminal. In particular, when the electrical power is supplied per power supply terminal, it is supplied at a time interval that people cannot detect, so that an observing user may think that electrical power is supplied in a moment.

[80] Moreover, the LED illumination apparatus 100 used for a car according to the example embodiment of the present invention can be driven at low voltage and there is no limit to its size. As the size of the general transparent illumination apparatus increases, the number of LEDs increases, and thus driving voltage increases. However, the LED illumination apparatus 100 according to the example embodiment of the present invention uses a circuit that is sequentially turned on/off so that the effect of size is minimized.

[81] In summary, in the LED illumination apparatus according to one example embodiment of the present invention, electrical power is selectively supplied to the LED illumination apparatus to turn LEDs on/off, so that a driving voltage can be lowered. Also, when electrical power is separately and sequentially supplied at a time interval that people cannot easily detect, a low voltage can be implemented and a user looking toward the LED illumination apparatus may feel that the LEDs simultaneously emit light. Furthermore, the LED illumination apparatus driven at a low voltage can be applied to various fields and products including cars. In addition, since the apparatus is not affected by the size of a transparent panel, a low voltage can be implemented regardless of the size of the transparent panel.

[82] While the invention has been shown and described with reference to certain example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Industrial Applicability

[83] The present invention may be industrially used in the field of illumination techniques using light emitting diodes (LEDs) and in its applied technical field.