Lighting device

Abstract

To realize a highly efficient lighting system with excellent color mixing capabilities. [Solution] An illumination device 300 has a light source 320 comprising a first light-emitting element 323R that emits light in a first emission color, a second light-emitting element 323L that emits light in a second emission color different from the first emission color, and a third light-emitting element 323B that emits light in a third emission color different from the first and second emission colors, and controls the light intensity ratio of the light emitted from each light-emitting element to emit illumination light 362 of a specific chromaticity, wherein the planar size 323RA of the first light-emitting element is larger than the planar size 323LA of the second light-emitting element and the planar size 323BA of the third light-emitting element.

Description

[Technical Field]

[0001] The present invention relates to a color-adjustable lighting device, and more specifically to a lighting device that makes objects such as food and clothing appear attractive, as well as a general lighting device for illuminating indoor and outdoor spaces. [Background technology]

[0002] The appearance of colors in objects such as food, clothing, and car bodies changes depending on the lighting. Since the appearance of product colors is extremely important in terms of customer appeal, lighting devices have been proposed to make products appear more attractive. For example, Patent Document 1 describes a lighting device that makes meat appear more vibrant.

[0003] Typically, lighting devices are selected for each product to emit light suitable for that product. In this case, users had to replace the lighting device when changing products. In contrast, Patent Document 2 discloses a lighting device using a first warm-colored light source in which the spectral components of blue, red, and green light are mixed in predetermined ratios, a second high-color-temperature light source in which the spectral components of blue, red, and green light are mixed in a different ratio than the first light source, and a third light source having only the spectral component of blue light. This lighting device is said to eliminate the need to change the light source for each food item and can irradiate each food item with the optimal light.

[0004] Patent Document 3 discloses a lighting device that uses a light source in which three colors of LEDs are arranged in close proximity in equal numbers. This lighting device is advantageous because it can effectively mix the three colors of light emission to reduce color unevenness in the illuminated area, and because the same power supply can be used for each color. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-127855 [Patent Document 2] Japanese Patent Publication No. 2011-040241 [Patent Document 3] Japanese Patent Publication No. 2022-123541 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The three colored light-emitting elements used in Patent Document 3 each have different luminous efficiency. The luminous efficiency with respect to wavelength is high for green and low for blue and red. Furthermore, the energy conversion efficiency of the LED itself that constitutes the light-emitting element is high for blue, which uses an InGaN-based LED chip. Therefore, if the other colored light-emitting elements are arranged to match the red light-emitting element, which has low luminous efficiency and poor energy conversion efficiency as an LED, it was necessary to arrange more light-emitting elements than necessary for the total luminous flux obtained.

[0007] Therefore, the present invention aims to provide a lighting device that can illuminate with relatively efficient and good color mixing capabilities using a light source that combines multiple light-emitting elements of different colors. [Means for solving the problem]

[0008] The present invention relates to an illumination device having a light source comprising a first light-emitting element that emits light in a first emission color, a second light-emitting element that emits light in a second emission color different from the first emission color, and a third light-emitting element that emits light in a third emission color different from the first and second emission colors, and controlling the light intensity ratio of the emission from the first light-emitting element, the second light-emitting element, and the third light-emitting element to emit illumination light of a specific chromaticity. The lighting device has a planar size that is larger than the planar sizes of the second and third light-emitting elements.

[0009] Furthermore, in the present invention, the first light-emitting element may include an AlGaInP-based LED chip.

[0010] Furthermore, in the present invention, the number of the first light-emitting elements in the light source may be less than the number of the second light-emitting elements and the number of the third light-emitting elements.

[0011] Furthermore, in the present invention, when assuming the sides surrounding the light-emitting region where the second light-emitting element and the third light-emitting element are arranged, the number of the first light-emitting elements on each side may be the same as or less than the number of the second light-emitting elements and the number of the third light-emitting elements.

[0012] Furthermore, in the present invention, the light source may be one in which the first light-emitting element, the second light-emitting element, and the third light-emitting element are arranged in a row so that the first light-emitting element does not come to the end.

Advantages of the Invention

[0013] The lighting device of the present invention can be a lighting device with excellent luminous efficiency and little color unevenness in the irradiation region of illumination light by arranging light-emitting elements of a plurality of emission colors having different planar sizes.

Brief Description of the Drawings

[0014] [Figure 1] Perspective view of the lighting device of Embodiment 1 [Figure 2] Side view of the lamp body in the lighting device of Embodiment 1 [Figure 3] Plan view of the light source used in the lighting device of Embodiment 1 [Figure 4] Modified example of the arrangement of the light-emitting elements in the light source of the lighting device of Embodiment 1 [Figure 5] Explanatory diagram of the arrangement of the light-emitting elements and the color unevenness of the irradiation region [Figure 6] Side view of the light-emitting element used in the lighting device of Embodiment 1 [Figure 7] Chromaticity diagram of the light-emitting element and the illumination light in the lighting device of Embodiment 1 [Figure 8] Chromaticity diagram showing the color-tuning region for each foodstuff in the lighting device of Embodiment 1 [Figure 9] Chromaticity diagram of the light-emitting element and the illumination light in the lighting device of Modified Example 1 of the chromaticity of Embodiment 1 [Figure 10] Chromaticity diagram of the light-emitting element and illumination light in a lighting device of a modified example 2 of the chromaticity of Embodiment 1. [Figure 11] Diagram illustrating the linear LED used in the refrigerated display case in Embodiment 2. [Figure 12] Planar schematic diagram of the printed circuit board installed inside the linear LED of Embodiment 2 [Modes for carrying out the invention]

[0015] <Embodiment 1> <Basic configuration> Figure 1 is a diagram showing the configuration of a lighting system including the lighting device 300 according to this embodiment. The lighting device 300 is a spotlight and consists of a lamp body 360, a power supply unit 380, and an arm 375 that connects the lamp body 360 to the power supply unit 380.

[0016] <Light body> Figure 2 is an explanatory diagram showing the interior of the light fixture 360 ​​enclosed by the frame 367. The light fixture 360 ​​comprises a heat sink 364, a light source 320 mounted on it, a lens 368, and a frame 367. As shown in Figure 1, light emitted from the light source 320, which is positioned perpendicular to the optical axis connecting the center of the light source 320 and the center of the lens 368, is emitted by the lens 368 as illumination light 362 at a predetermined radiation angle, illuminating the object 370.

[0017] <Power supply section> As shown in Figure 1, the power supply unit 380 is attached to the wiring duct rail 395 installed on the ceiling 390 by a front mounting part 386 and a rear mounting part 388. The front mounting part 386 has the function of supplying power to the power supply unit 380 from the wiring duct rail 395. Although the inside of the wiring duct rail is not normally visible, Figure 1 shows the inside of the wiring duct rail 395 so that the mounting state of the power supply unit 380 can be seen. The power supply unit 380 is attached to the wiring duct rail 395 by rotating the lever 385, which rotates the mounting part inside the front mounting part 386.

[0018] The power supply unit 380 has a slot for inserting a wireless module 382. The wireless module 382 transmits a wired lighting control signal to the power supply unit 380 based on a wireless lighting control signal 352 sent from an external lighting control device 350.

[0019] The power supply unit 380 has three drive outputs for independently driving each of the three color light-emitting elements. The wireless module 382 transmits control signals to the power supply unit 380, thereby controlling each of the three drive outputs.

[0020] <Lighting control device> The lighting control device 350 consists of a tablet, smartphone, or PC, and runs lighting control software 351. The user uses the lighting control software 351 to set the chromaticity of the lighting light suitable for the food. The lighting control software 351 adjusts the light emission intensity of three colored light-emitting elements to achieve that chromaticity. The light emission intensity of the three colored light-emitting elements is transmitted as a wireless lighting control signal 352.

[0021] <Light source> Figure 3 is a plan view of the light source 320 used in this embodiment. The light source 320 consists of 10 first light-emitting elements 323R (indicated as "R" in the figure) that emit red light, which is the first light-emitting color; 12 second light-emitting elements 323L (indicated as "L" in the figure) that emit yellow-green light, which is the second light-emitting color; and 12 third light-emitting elements 323B (indicated as "B" in the figure) that emit blue light, which is the third light-emitting color, mounted on a light-emitting region 322 on the surface of a substrate 321 having a wiring pattern. These elements are connected in series by wiring inside the substrate 321. The planar size of the substrate 321 is 30 mm x 30 mm (planar area is 900 mm²). 2 ) The light source 320 emits light with a total luminous flux of approximately 3000 lm using these 34 light-emitting elements.

[0022] Referring to Figure 3, the light-emitting elements of the same color in the light source 320 are arranged almost diagonally, as shown by the dotted line in the illustration.

[0023] Furthermore, the number of first light-emitting elements 323R is less than the number of second light-emitting elements 323L and third light-emitting elements 323B on each side of the outer perimeter (side 322N where LBRLB is located, side 322NE where BL is located, etc.) when the light-emitting region 322 is considered as an octagon, thus providing a measure to prevent color unevenness, which will be described later. Because the total number of first light-emitting elements 323R is less than the number of light-emitting elements of other colors, it is easier to realize a configuration in which relatively few first light-emitting elements 323R are arranged on each side of the outer perimeter of the light-emitting region 322. Note that the number of first light-emitting elements 323R may be the same as or less than the number of second light-emitting elements 323L, or the number of first light-emitting elements 323R may be the same as or less than the number of third light-emitting elements 323B.

[0024] The edges of the outer perimeter surrounding the light-emitting region 322 in Figure 3 are added for illustrative purposes only, and there is no specific boundary line on the outer perimeter.

[0025] The shape of the light-emitting region 322 can vary, but if there are four or more light-emitting elements, four or more sides can be considered to enclose the entire region. Even if there are a sufficiently large number of light-emitting elements, an octagon can be assumed and eight sides can be considered. Note that a "side" is composed of two or more light-emitting elements. One light-emitting element may belong to both of two adjacent sides.

[0026] The light source 320 is equipped with wiring terminals 326R (indicated as "R-" in the figure), 326L (indicated as "L-" in the figure), 326B (indicated as "B-" in the figure), and a common wiring terminal 326C (indicated as "C+" in the figure), and each terminal is connected to a power supply unit 380 which has three outputs. Each light-emitting element is connected in series by wiring inside the circuit board 321. The color of the illumination light emitted by the light source 320 is controlled by controlling the current value applied to each light-emitting element. The light source 320 is equipped with two mounting holes 325 and is fastened to the heat sink 364 by passing screws through the mounting holes 325.

[0027] Figure 4 shows a modified arrangement of the light-emitting elements 323 in the light-emitting region 322 of the light source 320. The number of first light-emitting elements 323R is set to 10, and the number of second light-emitting elements 323L and third light-emitting elements 323B are both set to 8. In this modified arrangement, the light source 320 emits light with a total luminous flux of approximately 2400 lm using these 26 light-emitting elements.

[0028] <Measures to prevent uneven coloring in the irradiated area> Figure 5 is a simplified schematic diagram illustrating this embodiment to explain measures to prevent color unevenness in the irradiated area. In the light source 20, light emitted from light-emitting elements 23A, 23B, and 23C of different colors is irradiated onto the irradiated area 70, with the irradiation angle adjusted by the lens 68. At that time, in areas A and C, which are the periphery of the irradiated area 70, only light emitted from light-emitting elements 23A or 23C located near the light source reaches the area, resulting in color unevenness in the irradiated area 70. Furthermore, since humans perceive red as a stimulating color, they are more likely to notice the reddish tint in the periphery of the irradiated area 70.

[0029] To address color unevenness, that is, to improve color mixing in the illuminated area, the actual lighting device incorporates a light diffusion effect in the lens 68, and also uses multiple light-emitting elements 23A, 23B, and 23C in the light source 20, which are arranged in a mixed pattern.

[0030] Furthermore, as shown in Figure 3, by making the number of red light-emitting elements in the "edges" that make up the periphery of the light-emitting region the same as or less than the number of light-emitting elements of other colors, the red color unevenness in the illuminated area can be reduced.

[0031] <Structure of pentagon> The first light-emitting element 323R comprises an AlGaInP-based LED chip that emits red light, a resin (encapsulating resin) that covers the top and sides of the LED chip, and terminals for supplying current to the light-emitting element.

[0032] The second light-emitting element 323L includes an InGaN-based LED chip that emits blue light, a phosphor-containing resin that covers the upper surface and the side surfaces of the LED chip, and has terminals for flowing current through the light-emitting element. The phosphor is one or several of a green phosphor that absorbs the light of the blue LED and emits green light, a yellow phosphor that emits yellow light, and a red phosphor that emits red light.

[0033] The third light-emitting element 323B includes an InGaN-based LED chip that emits blue light, a resin (sealing resin) that covers the upper surface and the side surfaces of the LED chip, and has terminals for flowing current through the light-emitting element. The sealing resin may contain a phosphor for adjusting chromaticity, or may not contain a phosphor.

[0034] In each of the above light-emitting elements, the yellow-based phosphor is, for example, (Y 1-x Gd x )3Al5O 12 :Ce 2+ (0 ≦ x ≦ 1), the green-based phosphor is, for example, Lu3Al5O 12 :Ce 2+ , and the red-based phosphor is, for example, Sr x Ca 1-x AlSiN3:Eu 3+ (0 ≦ x ≦ 1) phosphors, Sr[LiAl3N4]:Eu 2+ or K₂SiF₆:Mn 4+ phosphors can be preferably used. Quantum dot type phosphors can also be preferably used in the same manner as these phosphors.

[0035] <Size of the light-emitting element> Figure 6 is a side view of the second light-emitting element 323L and the third light-emitting element 323B. "L, B" in Figure 6 indicates the side surfaces of the second light-emitting element 323L and the third light-emitting element 323B, and "R" in Figure 6 indicates the side surface of the first light-emitting element 323R. The height of the second light-emitting element 323L and the third light-emitting element 323B is 0.78 mm, and the height of the first light-emitting element 323R is 1.35 mm. The first light-emitting element 323R is higher. Also, the first light-emitting element 323R includes a lens for controlling light distribution at the upper part.

[0036] The planar size 323RA of the first light-emitting element 323R is 2.0 mm × 2.0 mm (planar area is 4.0 mm²). 2 ) The planar dimensions of the second light-emitting element 323L and the third light-emitting element 323B are 323LA and 323BA, respectively, and are 1.4 mm × 1.4 mm (planar area is 1.96 mm²). 2 )

[0037] The reason for using a larger-sized first light-emitting element 323R than other colored light-emitting elements is to improve the luminous efficiency [lm / W] of the light-emitting element. When an AlGaInP-based LED chip is used as the first light-emitting element 323R, it is more susceptible to efficiency degradation due to heat generation compared to when an InGaN-based LED chip is used. Therefore, the efficiency degradation is suppressed by increasing the area and lowering the current density per unit area.

[0038] Since the planar size of the first light-emitting element 323R is larger than the planar sizes of the second and third light-emitting elements, the light intensity of the first light-emitting element 323R can be increased by increasing the drive current value.

[0039] <Visual sensitivity efficiency of light-emitting elements> The luminous efficiency of the first light-emitting element 323R, the second light-emitting element 323L, and the third light-emitting element 323B are 44 [lm / W], 145 [lm / W], and 26 [lm / W], respectively. The value of 44 [lm / W] for the first light-emitting element 323R is lower than that of the second light-emitting element 323L, but this has been improved by increasing the planar size 323RA. Note that the letter l (L) can be confused with 1, so units including lm are written in brackets [].

[0040] <Maximum drive current value for light-emitting elements> The absolute maximum rated current value of the first light-emitting element 323R is 1050mA, and the absolute maximum rated current values ​​of the second light-emitting element 323L and the third light-emitting element 323B are 3000mA. A maximum drive current value smaller than the absolute maximum rated current value is set for each light-emitting element. For example, the maximum drive current value of the first light-emitting element 323R is 950mA, the maximum drive current value of the second light-emitting element 323L is 700mA, and the maximum drive current value of the third light-emitting element 323B is 500mA. The reason for setting the maximum drive current values ​​in this way is that the second light-emitting element 323L has high efficiency, so sufficient luminous flux can be obtained even with a smaller drive current value than the red first light-emitting element, and the chromaticity of the third light-emitting element 323B is far from the food-specific color tuning range described later, so it is not necessary to increase the light intensity.

[0041] When the user sets the chromaticity and light intensity in the lighting control device, a drive current is supplied to each light-emitting element. The drive current value for each color is set to, for example, 40% of the maximum drive current value. The drive current has a waveform of PWM (Pulse Width Modulation) dimming, for example, by switching the maximum drive current value ON and OFF.

[0042] <Chromaticity of light-emitting elements> Figure 7 is a chromaticity diagram (CIE1931 chromaticity coordinate diagram) illustrating the chromaticity range of these light-emitting elements and the resulting illumination light, with the line connecting the chromaticities of the blackbody radiation locus shown as the BBL (Black Body Locus).

[0043] The chromaticity coordinate R of the first emission color of the first light-emitting element 323R is (0.700, 0.300), and the first emission color appears red.

[0044] The chromaticity coordinate L of the second emission color of the second light-emitting element 323L is (0.419, 0.560), and the second emission color appears yellowish-green.

[0045] The chromaticity coordinate B of the third emission color of the third light-emitting element 323B is (0.091, 0.133), and the third emission color appears blue.

[0046] Figure 8 is a chromaticity diagram showing the color tuning ranges for different food items in the lighting device 300. The range enclosed by the chromaticity of the second light-emitting element 323L, the third light-emitting element 323B, and the first light-emitting element 323R, which are light-emitting elements used in this embodiment, includes chromaticity ranges such as "M" (lighting for meat), "DT1, DT2" (lighting for prepared foods and bread), "F" (lighting for fresh fish), "VG" (lighting for vegetables), and "NR" (general food items that do not emphasize color too much). However, "for meat, bread, and fresh fish" are merely examples of suitable objects, and "M" is also suitable for lighting objects other than those listed, such as red fruits and "DT2" is suitable for fried foods.

[0047] <Modification example 1: Changing the chromaticity of the light-emitting element> Modification 1 of chromaticity involves replacing the second light-emitting element 323L with a white (yellowish-white) second light-emitting element 323Yw. Figure 9 shows the chromaticity coordinates of the emitted color of the light-emitting elements and the color tuning range of the illumination light in this case. The chromaticity of the first light-emitting element 323R and the third light-emitting element 323B remains unchanged. The arrangement of the light-emitting elements within the light source 320 is the same except that the second light-emitting element 323L is replaced with the second light-emitting element 323Yw.

[0048] The chromaticity coordinate Yw of the second emission color of the second light-emitting element 323Yw is (0.390, 0.490), and the second emission color appears as a yellowish-white.

[0049] <Modified example 2: Changing the chromaticity of the light-emitting element> Modification 2 of chromaticity involves replacing the second light-emitting element 323L with a white (yellowish-white) second light-emitting element 323Yw2 (whose chromaticity is slightly different from that of the second light-emitting element 323Yw), replacing the third light-emitting element 323B with the third light-emitting element 323Bw (bluish-white), and replacing the first light-emitting element 323R with the first light-emitting element 323R2. Figure 10 shows the chromaticity coordinates of the emitted color of each light-emitting element and the color tuning range of the illumination light in Modification 2 of chromaticity. The arrangement of the light-emitting elements within the light source 320 is the same as in Figure 3, except that the second light-emitting element 323L is replaced with the second light-emitting element 323Yw2, the third light-emitting element 323B with the third light-emitting element 323Bw, and the first light-emitting element 323R with the first light-emitting element 323R2.

[0050] The chromaticity coordinate Yw2 of the second emission color of the second light-emitting element 323Yw2 is (0.44, 0.47), and the second emission color appears as a yellowish-white.

[0051] The chromaticity coordinate Bw of the third emission color of the third light-emitting element 323Bw is (0.23, 0.26), and the third emission color appears as a bluish-white.

[0052] The chromaticity coordinate R2 of the first emission color of the first light-emitting element 323R2 is (0.60.0.38), and the first emission color appears red.

[0053] Modification 2 of the chromaticity is highly efficient because it has the chromaticity of three light-emitting elements within a chromaticity range that offers high luminous efficiency, making it suitable for general lighting. On the other hand, its chromaticity variable range is slightly narrower compared to Embodiment 1 and its Modification 1 of chromaticity. Therefore, this light source can be used to illuminate objects that do not require flashy color effects, and is also suitable for general lighting that does not involve illuminating specific objects.

[0054] The chromaticity of each light-emitting element can also be expressed using the chromaticity coordinates (u',v') of CIE1976 instead of the chromaticity coordinates (x,y) of CIE1931, and the two can be converted to each other using the conversion formulas u'=4x / (-2x+12y+3) and v'=9y / (-2x+12y+3). The chromaticity of each light-emitting element may also be expressed using other chromaticity coordinate systems.

[0055] <Embodiment 2> <Basic configuration> Embodiment 2 is a linear LED type lighting device for a refrigerated display case.

[0056] <Refrigerated display case> Figure 11 is an explanatory diagram showing the front of a refrigerated display case 410 cut off to illustrate the use of linear LEDs in a refrigerated display case. The refrigerated display case 410 has an opening 411, a top plate 414, a shelf 415, and a bottom plate 416. Linear LEDs 460 are installed under the top plate 414 and the shelf 415 to illuminate the food placed on the shelf 415 and the bottom plate 416.

[0057] <Linear LED tube> The straight-tube LED 460 is equipped with a cylindrical or semi-cylindrical translucent cover member and has a printed circuit board 421 inside. Figure 12 is a schematic plan view of the printed circuit board 421. On the surface of the printed circuit board 421, the first light-emitting element 323R, the second light-emitting element 323L, and the third light-emitting element 323B (denoted as R, L, and B respectively) are mounted in rows of 10, 12, and 12 elements, respectively, per unit length. Note that Figure 12 shows half of the unit length of the printed circuit board 421. The arrangement of the light-emitting elements is based on the principle of repeating LRB so that the leftmost end is not R, and since there are few R elements, repeating BLB or LBL is inserted in some places. In addition, the rightmost end (not shown) is also arranged so that there is no R element, in order to prevent red from being conspicuous at the ends. The number of rows of light-emitting elements arranged on the surface of the printed circuit board 421 is not limited to one row; there may be two or three rows, for example. However, if there are three or more rows, one red light-emitting element may be placed at the leftmost and rightmost ends.

[0058] The lighting of the 460 straight-tube LEDs is controlled to emit light in a color suitable for the food placed on the shelves. The lighting can be controlled by wired control rather than wireless control by installing control wiring inside the refrigerated display case 410.

[0059] <Provisos and Variations> In this specification, "light-emitting element" refers to a so-called LED package, which includes a compound semiconductor LED chip and terminals for applying current to it. The term "LED" is generally avoided because it can be confusing whether it refers to an LED chip, an LED package, or an LED lighting fixture. However, since there are conventional expressions such as calling an LED package an LED, or calling a fluorescent lamp replacement LED lighting device a straight-tube LED, we follow these conventional expressions as appropriate.

[0060] The light-emitting element may be a CSP (Chip Size Package) type LED, an SMD (Surface Mount Device) type LED, or a COB (Chip On Board) type LED.

[0061] The light-emitting element is not limited to LEDs; any light-emitting device is acceptable, including organic EL (organic LED), devices with separate phosphors and excitation sources, devices using electrical discharge, and devices excited by electron beams.

[0062] The light source is not limited to examples using three-color light-emitting elements, but may also use four or more colors of light-emitting elements. For example, the light source may include daylight LEDs, cool white LEDs, and incandescent LEDs.

[0063] The first light-emitting elements 323R and 323R2 can be any red light-emitting element in a broad sense, and may be amber in color or a color with a dominant wavelength between 600 nm and 700 nm.

[0064] The third light-emitting element 323B can be any blue light-emitting element in a broad sense, and its dominant wavelength may be between 420 nm and 480 nm.

[0065] The bluish-white light emitted by the third light-emitting element 323Bw may also be a chromaticity within the range enclosed by (0.336, 0.24), (0.352, 0.44), (0.15, 0.2), and (0.2, 0.1) in the CIE1931 chromaticity coordinate system.

[0066] The yellowish-white light emitted by the second light-emitting elements 323Yw and 323Yw2 may be any chromaticity within the range enclosed by the CIE1931 chromaticity coordinates (0.5, 0.5), (0.423, 0.355), (0.342, 0.312), (0.352, 0.44), (0.37, 0.63), and the chromaticity boundary lines. Among these, the region where y is greater than the BBL chromaticity line is preferred.

[0067] The emission color of the second light-emitting element 323L is preferably in the yellowish-white chromaticity region, within which the x-value is not more than 0.04 away from the chromaticity boundary line.

[0068] The chromaticity of each light-emitting element in the embodiment is just an example, and other chromaticities may be used. Furthermore, differences in chromaticity coordinates are acceptable, within a range of chromaticity that is distinguishable by humans. The "McAdam color discrimination ellipse (McAdam ellipse)" has been proposed as the chromaticity range that humans perceive as the same color. Even looking at the specifications of commercially available LEDs, some allow for a 3-step difference in the McAdam ellipse.

[0069] Lighting devices may include not only spotlights and linear LED tubes, but also downlights, universal (directional) downlights, or planar or linear light sources called base lights.

[0070] While the example of controlling the light emission color of the lighting device shows wireless control, wired control may also be used.

[0071] In this application, the chromaticity of the emitted light of the light-emitting element is the chromaticity that can be observed externally as a component of the illumination light. Since the light from the light-emitting element passes through an optical system such as a lens and is emitted externally as illumination light, the chromaticity includes the effect of spectral changes due to transmission through the lens, etc.

[0072] Furthermore, the embodiments disclosed herein are illustrative in all respects and do not constitute a limiting interpretation. Therefore, the technical scope of the present invention is not construed solely by the embodiments described herein, but is defined based on the claims. This also includes all modifications within the meaning and scope of the equivalents of the claims. [Explanation of Symbols]

[0073] 70 Irradiation area 300 Lighting devices 321 circuit board 320, 20 light sources 322 Emitting Region 322N, 322NE sides 323, 23A, 23B, 23C light-emitting element 323R, 323R2 First light-emitting element 323L, 323Yw, 323Yw2 Second light-emitting element 323B, 323Bw Third light-emitting element 323BA, 323LA, 323RA Planar Size 325 mounting holes 326B, 326L, 326R Wiring Terminals 326C Common Wiring Terminal 350 Lighting control device 351 Lighting control software 352 Lighting control signal 360 light body 362 Illumination Light 364 Heatsink 367 slots 368, 68 lenses 370 Objects 375 Arm 380 Power supply section 382 Wireless Module 385 Lever 386 Front mounting section 388 Rear mounting section 390 Ceiling 395 Wiring duct rail 410 Refrigerated display case 411 Aperture 414 Top plate 415 shelf board 416 Bottom plate 421 Printed circuit board 460 straight-tube LED

Claims

1. An illumination device having a light source comprising a first light-emitting element that emits light in a first emission color, a second light-emitting element that emits light in a second emission color different from the first emission color, and a third light-emitting element that emits light in a third emission color different from the first and second emission colors, wherein the light-emitting device emits illumination light of a specific chromaticity by controlling the light intensity ratio of the emission from the first light-emitting element, the second light-emitting element, and the third light-emitting element, The planar size of the first light-emitting element is larger than the planar size of the second light-emitting element and the planar size of the third light-emitting element. Lighting device.

2. The first light-emitting element includes an AlGaInP-based LED chip. The lighting device according to claim 1.

3. The number of the first light-emitting elements in the light source is less than the number of the second light-emitting elements and the number of the third light-emitting elements. The lighting device according to claim 1.

4. When considering the edges surrounding the light-emitting region where the first light-emitting element, the second light-emitting element, and the third light-emitting element are arranged, the number of first light-emitting elements on each edge is equal to or less than the number of second light-emitting elements and the number of third light-emitting elements. The lighting device according to claim 1.

5. The light source is configured such that the first light-emitting element, the second light-emitting element, and the third light-emitting element are arranged in a row such that the first light-emitting element is not at the end. The lighting device according to claim 1.

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