JP2017045704A - LED lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device which does not need to use LED light emitting elements having different color temperatures to attain various color temperatures needed by use application and eliminates a burden caused thereby.SOLUTION: An LED lighting device comprises at least one LED light emitting element 2 and an insulating substrate 1 having light reflectivity. The LED light emitting element 2 is disposed on one surface of the substrate 1. At least part of the LED light emitting element 2 is provided with a coating body 3 comprising a transparent solid body and metal particles dispersed on the transparent solid body. The metal particles are composed of aluminium particles, copper, or copper alloy.SELECTED DRAWING: Figure 2

Description

Detailed Description of the Invention

  The present invention relates to an LED lighting device, and more particularly to an LED lighting device that can obtain a desired color temperature simply and at a low cost.

  In recent years, an LED lighting device having an LED light emitting element on one surface of an insulating and white substrate has been widely used for indoor lighting and the like. Conventionally, in order to obtain a desired color temperature in such an LED lighting device, the structure of the LED light-emitting element, the composition of the LED semiconductor, the composition of the phosphor to be used in combination are adjusted to emit light at the desired color temperature. ing.

  The lighting device has various uses, and the color temperature required varies depending on the use. Since the color temperatures required for the light source are diverse, it is necessary to prepare LED light emitting elements having color temperatures suitable for each application. This is a burden of production and distribution in various aspects such as design, manufacture, and inventory management of LED light emitting elements (hereinafter abbreviated as LED).

  Often, a desired color temperature is obtained by combining two or more types of LEDs having different color temperatures, but this also does not greatly change the burden of production and distribution. A method for obtaining a desired color temperature by combining an LED that emits colored light with a white light LED has also been proposed in Utility Model Registration 3132253 (Patent Document 1) and Patent Publication 2009-176692 (Patent Document 2). The problem is the same in that the necessary types and number of colored light emitting LEDs need to be prepared along with the light LEDs.

  In order to obtain a desired color temperature, a method for providing a color temperature conversion filter on the front surface of a light source is disclosed in, for example, Japanese Patent Application Laid-Open No. 2013-4365 (Patent Document 3), but an optical filter having an accurate conversion performance is generally used. Expensive. Japanese Patent Publication No. 2009-200021 (Patent Document 4) and Patent Publication No. 2015-18612 (Patent Document 5) have also been proposed in which a color filter layer is provided on the front surface of each LED to adjust the color temperature. Accurate management of concentration and thickness is not easy. A major drawback of the color filter layer is that when the use of the LED light source is continued, the pigments and the like fade and the spectral absorption characteristics change. Even when a pigment is used as the absorber, it is difficult to prevent fading because the luminous flux from the LED is strong ("LED" abbreviated so far).

  Utility model registration 3132253   Patent Publication 2009-176692   Patent Publication 2013-4365   Patent Publication 2009-200021   Patent Publication 2015-18612

  Therefore, in order to obtain various color temperatures required by the use of the lighting device, it is not necessary to prepare various LED light emitting elements having different color temperatures, and it is possible to realize a lighting device that eliminates the burden for that. It is an object of the present invention.

  Another object of the present invention is to obtain a white light source having a desired color temperature without using a color filter layer that causes fading.

  An LED illumination device that achieves the above object of the present invention is an LED illumination device comprising at least one LED light emitting element and an insulating and light reflecting substrate, wherein the LED light emitting element is arranged on one surface of the substrate. At least a part of the light-emitting element has a covering made of a transparent solid and metal particles dispersed therein.

  In the present invention, an easily available LED light emitting element that emits white light having a predetermined color temperature is used as the LED light emitting element. This predetermined color temperature may be different from the (desired) color temperature required for the lighting device, which is a major feature of the present invention.

  The LED light emitting elements are often arranged along a predetermined straight line, but may be arranged along a curved line. It may be arranged along a plurality of columns.

  As the transparent solid, a synthetic resin such as a silicon resin is suitable. However, glass or other inorganic materials may be used. Silicone resin is advantageous because it can be peeled off from the LED light emitting element as required.

  As the metal particles, metal particles such as aluminum, copper, copper alloy, gold, nickel, and stainless steel can be used.

  When aluminum is used as the metal particles, an illumination device having a higher color temperature than the light emitted from the LED light-emitting element can be provided. A suitable aluminum alloy such as duralumin can also be used.

  When particles of copper or an appropriate alloy thereof are used as the metal particles, a lighting device having a color temperature lower than that of light emitted from the LED light emitting element can be provided. For example, an alloy of copper and zinc (brass) is advantageous because it has corrosion resistance. An alloy of copper and tin (bronze), an alloy of copper and silver, an alloy of copper and gold, or the like can also be used.

  When the surface of the metal particles has a spectral characteristic that absorbs the long wavelength component of white light (selectively reflects the short wavelength component), a higher color temperature than the light emitted from the LED light emitting element can be obtained. On the contrary, when the surface of the metal particles has a spectral characteristic of absorbing the short wavelength component of white light (selectively reflecting the long wavelength component), a higher color temperature than the light emitted from the LED light emitting element can be obtained.

  The size of the metal particles (usually expressed as an equivalent volume sphere equivalent diameter) is preferably such that it can be easily dispersed in a transparent solid, and is usually selected to be less than about 1 mm (equivalent diameter), but 0.02 A thickness of 0.5 to 0.5 mm is advantageous.

  If the ratio of the amount of the metal particles to the transparent solid is too high, the illumination light is attenuated due to light shielding by the metal particles, which is not preferable. On the other hand, if it is too low, it becomes difficult to obtain a desired color temperature. Therefore, the ratio is selected so that the desired effect of increasing or decreasing the color temperature can be obtained within the allowable limit of the attenuation of the illumination light by the metal particles. Such a ratio is much lower than the density covering the entire surface of the LED light emitting element, and the effect of changing the color temperature is sufficiently obtained at such a density.

  The same applies to the thickness of the cover on the LED light-emitting element, and the thickness is selected so that the desired effect of increasing or decreasing the color temperature is obtained within a range in which the attenuation of the illumination light is acceptable. The thickness of the covering on the individual LED light emitting elements may be uniform or may vary depending on the location. That is, the covering may have a top surface that is a plane parallel to the substrate, or the top surface of the covering may be a convex curved surface (for example, a spherical surface).

  In order to provide a cover with a desired thickness on the LED light emitting element, the LED light emitting element may be covered with a liquid phase dispersion system in which metal particles are dispersed to solidify the liquid phase. The solvent may be evaporated from the polymer solution, or the liquid polymer may be thermally cured or photocured. A solvent such as alcohol may be added to a synthetic polymer such as an uncured or semi-cured silicone resin to form a solution, which may be applied or spotted on the LED light-emitting element, and the solvent may be evaporated.

  Depending on the thickness of the covering and the content of the dispersed metal particles, the degree of conversion of the color temperature of each LED light-emitting element can be adjusted.

  The illuminating device of the present invention is provided with a covering in which metal particles that absorb either a long wavelength component or a short wavelength component of white light are dispersed only in some of the LED light emitting elements in the array of LED light emitting elements, and the remainder It is good also as a structure which does not provide a coating body in this LED light emitting element. The color temperature of the entire lighting device can be adjusted to a desired value by the ratio of the LED light emitting element provided with the covering to the LED light emitting element not provided.

  In the LED light-emitting element array, some of the LED light-emitting element covers use metal particles that absorb the long-wavelength component of white light, and the remaining LED light-emitting element cover absorbs the short-wavelength component of white light. Metal particles may be used. Each of the former and latter portions may be continuous or discontinuous in the sequence. Any part may be discontinuous.

  Two or more kinds of metal particles may be dispersed in the covering (for example, copper and copper alloy, copper and gold).

  A covering may also be present on the periphery of the LED light emitting element on the substrate. The LED light emitting element and the surrounding covering may be integrated, or a continuous layer may be formed.

  According to the illuminating device of the present invention, at least a part of the LED light emitting element is provided with a covering made of a transparent solid and metal particles dispersed therein, so that the color temperature of the light source is different from that of the LED light emitting element. Can be easily adjusted to the value. Therefore, it is not necessary to prepare various LED light-emitting elements with different color temperatures in order to obtain the color temperature required according to the application, thereby eliminating the burden in terms of design, manufacturing, inventory management, etc. A lighting device having color rendering properties can be provided simply and at a low cost. Further, according to the lighting device of the present invention, a light source having a desired color temperature can be obtained easily and stably without using an expensive or difficult-to-manage color filter layer. Furthermore, the problem of fading (fading) of the color filter layer can be avoided.

  When the surface of the metal particles has a spectral characteristic that absorbs the long wavelength component of white light, a higher color temperature than the light emitted from the LED light emitting element can be obtained. On the contrary, when the surface of the metal particles has a spectral characteristic that absorbs the short wavelength component of white light, it is possible to obtain a lower color temperature than the light emitted from the LED light emitting element. Therefore, a desired color temperature that is higher or lower than the color temperature of the LED light emitting element to be used can be easily obtained by selecting the metal particles to be dispersed. According to the lighting device of the present invention, when the effect is particularly great, it is possible to obtain a color temperature increase of up to 3000 K compared to the color temperature of the LED light emitting element itself used.

  The top view of the light source part of the LED lighting apparatus equivalent to the 1st form for implementing this invention   Sectional drawing of the light source part of the LED lighting apparatus of a 1st form   The top view of the light source part of the LED lighting apparatus equivalent to the 2nd form for implementing this invention   Sectional drawing of the light source part of the LED lighting apparatus of a 2nd form   The top view of the light source part of the LED lighting apparatus equivalent to the 3rd form for implementing this invention   Sectional drawing of the light source part of the LED lighting apparatus of a 3rd form   The top view of the light source part of the LED lighting apparatus equivalent to the 4th form for implementing this invention   Sectional drawing of the light source part of the LED lighting apparatus of a 4th form   Sectional drawing of the LED illuminating device corresponded to the form for implementing this invention

(First embodiment)
1 and 2 show a light source unit of an LED lighting device corresponding to a first embodiment for carrying out the present invention. The light source unit 10 includes a substrate 1, a white light emitting diode 2, and a covering 3. The white light emitting diodes 2 are arranged along a straight line on the surface 1a of the substrate 1, and the surface 1a is white and light-reflective. A covering 3 is provided so as to cover the white light emitting diode 2.

  FIG. 2 shows a cross section of the light source unit 10 of the first embodiment along the line XX of FIG. The white light emitting diode 2 has a covering 3 thereon (may be separable in some cases). The covering 3 has a lens shape, and aluminum particles are dispersed in a transparent silicon resin. On the surface 1b (back surface) of the substrate 1, electrical components and wiring for supplying electric power suitable for the white light emitting diode 2 are installed, but are not shown for simplicity.

  Due to the presence of the covering 3 in which the aluminum particles are dispersed in the silicon resin, a color temperature higher than the light emitted from the LED light emitting element 2 itself can be obtained on the front surface of the light source unit 10. The width of the color temperature rise depends on the density of aluminum particles per unit area of the white light emitting diode 2.

  In the illuminating device of the present invention, the light source unit 10 is housed in an appropriate case, and in order to supply power to the light emitting diode, the light emitting diode is connected to an external power source or a driving circuit via an electric component disposed on the back surface of the substrate. It is constituted by.

(Second embodiment)
3 and 4 show a light source unit of an LED lighting device corresponding to a second embodiment for carrying out the present invention. The light source unit 20 includes a substrate 1, a white light emitting diode 2, and a covering body 23, and the covering body 23 is provided so as to cover the white light emitting diode 2. Description of the other components that are the same as those of the light source unit 10 is omitted.

  FIG. 4 shows a cross section of the light source unit 20 of the second form. 4 is a cross-sectional view taken along line YY in FIG. The white light emitting diode 2 has a covering 23 thereon. The covering body 23 is made by dispersing brass particles in a silicon resin.

  Due to the presence of the covering body 23 in which the brass particles are dispersed in the silicon resin, a color temperature lower than the light emitted from the LED light emitting element 2 can be obtained on the front surface of the light source unit 20. The width of the color temperature decrease depends on the density of the brass particles per unit area of the white light emitting diode 2.

(Third embodiment)
5 and 6 show a light source unit of an LED lighting device corresponding to a third embodiment for carrying out the present invention. The light source unit 30 includes a substrate 1, a white light emitting diode 2 (including a white light emitting diode 2 C having the same electro-optical performance), and a cover 3. Of the white light emitting diodes 2, the white light emitting diode 2 </ b> C is provided with a covering 3 so as to cover it, but the remaining white light emitting diodes 2 are not provided with the covering 3. Similar to the light source unit 10, the covering 3 has a lens shape, and aluminum particles are dispersed in a transparent silicon resin. 6 is a cross-sectional view taken along line ZZ in FIG. A description of the same components as the light source unit 10 is omitted. The number of white light emitting diodes 2C can be increased or decreased depending on a desired color temperature.

  Due to the presence of the cover 3, a color temperature higher than the light emitted from the LED light emitting element 2 on the front surface of the light source unit 30 but slightly lower than that of the light source unit 10 can be obtained.

  The illumination device of the present invention includes the light source unit described in each of the above embodiments, for example, the above-described light source unit 30 in an appropriate case and supplies electric power to the light-emitting diode via an electrical component disposed on the back surface of the substrate. Thus, the light emitting diode is connected to an external power source or a driving circuit by wiring.

  7 and 8 show a light source unit of an LED lighting device corresponding to a fourth embodiment for carrying out the present invention. The light source unit 40 includes a substrate 1, white light emitting diodes 2A and 2B, a covering body 3A, and a covering body 3B. The white light emitting diodes 2A and 2B are light emitting diodes having exactly the same electrical and optical performance except for the difference in the covering. The white light emitting diode 2A has a lens-shaped covering 3A, and the white light emitting diode 2B has a lens-like shape. Each of the covering bodies 3B is provided. Description of the other components that are the same as those of the light source unit 10 is omitted.

  FIG. 8 is a sectional view taken along line WW in FIG. The covering 3A is obtained by dispersing copper particles in silicon resin, and the covering 3B is obtained by dispersing brass particles in silicon resin.

  Due to the presence of the covering 3A in which the copper particles are dispersed in the silicon resin, a lower color temperature than the light emitted from the LED light emitting element can be obtained on the front surface of the white light emitting diode 2A. Due to the presence of the covering 3B in which the brass particles are dispersed in the silicon resin, the front surface of the white light emitting diode 2B is lower than the light emitted from the LED light emitting element, but can have a higher color temperature than the front surface of the white light emitting diode 2A. In front of the light source unit 40, these lights are mixed to obtain illumination light having an intermediate color temperature as a whole.

  FIG. 9 is a cross-sectional view showing a typical configuration of the illumination device of the present invention. FIG. 9 shows an example of the third embodiment. A light source unit 30 including a substrate 1, white light emitting diodes 2 and 2 </ b> C (LED light emitting elements), a covering 3, and an electrical component 4 is accommodated in a case 5. The electric component 4 connected to the LED light emitting element 2 by the electric wiring 6 is connected to an external power source or a driving circuit (not shown) through the electric wiring 6a. The other embodiments are similarly configured.

In the first embodiment, an LED light-emitting element having a color temperature of 4200 K is used as the white light-emitting diode 2, and aluminum powder having a particle size distribution in the range of 0.03 to 0.1 mm is dispersed in silicon resin, thereby covering It was set to 3. The aluminum particle / silicone resin dispersion was prepared by the following method.
Add 100 mg of aluminum powder (manufactured by Taiho Trading Co., Ltd.) to 0.5 mL of ethanol, and stir well to disperse the aluminum powder. Add 25 g of uncured silicone resin to the dispersion, mix well and mix. The droplets of the mixed solution fill the depressions at the top of each LED light emitting element (chip), and are dried and cured at room temperature for one day. As a silicone resin, TDSSEAL manufactured by Momentive Performance Materials Japan (go) was used.

  The light source unit 10 incorporating the electrical component 4 was accommodated in the case 5 as shown in FIG. 9, and the electrical wiring 6a was connected to manufacture the lighting device. The color temperature of the light emitted from the lighting device of the example was about 6500K. That is, a color temperature increase of about 2300 K was obtained as compared with the case of the LED light emitting element without the covering.

DESCRIPTION OF SYMBOLS 1 Board | substrate 1a, 1b Surface 2 White light emitting diode 2A, 2B, 2C White light emitting diode 3, 3A, 3B Cover body 4 Electrical component 5 Case 5a Step 6, 6a Electric wiring 10, 20 Light source part 23 Cover body 30, 40 Light source part

Claims (9)

Comprising at least one LED light emitting element and an insulating and light reflecting substrate;
In the LED lighting device in which the LED light emitting element is disposed on one surface of the substrate,
At least a part of the LED light emitting element has a covering made of a transparent solid and metal particles dispersed therein, and the LED lighting device.   The LED lighting device according to claim 1, wherein the metal particles are aluminum particles.   The LED lighting device according to claim 1, wherein the metal particles are made of copper or a copper alloy.   The LED lighting device according to claim 3, wherein the copper alloy is an alloy of copper and zinc.   The LED lighting device according to claim 1, wherein the transparent solid is made of a synthetic resin.   The LED lighting device according to claim 5, wherein the synthetic resin is a silicon resin.   The LED lighting device according to claim 1, wherein the LED light emitting element emits white light having a predetermined color temperature, and emits light having a color temperature higher than the predetermined color temperature.   The LED lighting device according to claim 1, wherein the LED light emitting element emits white light having a predetermined color temperature, and emits light having a color temperature lower than the predetermined color temperature.   The LED lighting device according to claim 1, wherein the covering has a top surface formed of a plane parallel to the substrate.

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