JP3696839B2 - Lighting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device including a plurality of light emitting diodes (hereinafter abbreviated as LEDs).
[0002]
[Prior art]
Compared to incandescent and halogen light bulbs, which are conventional lighting sources, LEDs with high reliability and long life are considered to be used as an alternative to these light sources due to recent improvements in luminous efficiency. Yes.
[0003]
Since an LED emits only light having a specific emission wavelength due to its light emission principle, in order to obtain white light, an LED emitting blue light emits yellow-green light by its emission as described in JP-A-2000-208815. It is necessary to use a combination with a phosphor or a combination of a plurality of LEDs such as red, blue, and green as described in JP-A-11-163212.
[0004]
However, the method using a phosphor always causes a decrease in efficiency due to wavelength conversion, and is not a preferable method from the viewpoint of efficiency. Also, with this method, the emission color is uniquely determined by the combination of the LED emission wavelength and the phosphor emission wavelength, so the light color cannot be controlled, and the color tone becomes the initial stage due to phosphor degradation, etc. Even if they are out of alignment, they cannot be corrected. Furthermore, since the phosphor film thickness, LED output, and emission wavelength vary depending on the manufacturing process, it is difficult to unify the light colors.
[0005]
On the other hand, in the method using LEDs that emit a plurality of emission colors, high emission efficiency can be obtained and the emission colors can be adjusted. On the other hand, since each color LED is made of a different composition and material, there is a problem that the temperature dependency and deterioration rate of the light emission output are different, and the color tone changes depending on the use conditions.
[0006]
Japanese Patent Application Laid-Open No. 10-49074 describes a method for solving the same problem as described above in a method using an LED as a light source for backlight of a color display device. That is, using a light sensor for detecting the brightness level of the LED of each emission color, and performing control for adjusting the brightness level of the LED of each emission color according to the detection value of the light sensor, to obtain a constant predetermined color tone Make it possible.
[0007]
[Problems to be solved by the invention]
However, this method can be easily applied to a device that uses a relatively low level of light, such as a color display device, but cannot be applied immediately to a lighting device as a subject of the present invention. The lighting device uses a larger number of LEDs than a color display device, and in order to properly control the drive of these LEDs, it is necessary to have a structure that can provide detection output that reflects the light emitted from the large number of LEDs. It is.
[0008]
If a photosensor is provided for each LED, high detection accuracy can be obtained. However, using such a configuration for a large number of LEDs is not practical because the scale of the apparatus increases and the cost increases. On the other hand, Japanese Patent Application Laid-Open No. 10-49074 describes a method in which one light sensor is shared for each emission color, but a large number of LEDs are dispersed like a light source for illumination. In such a case, a configuration suitable for obtaining a detection output reflecting light emission from all LEDs is not taken into consideration.
[0009]
The present invention detects emission intensity reflecting light emission from a plurality of LEDs with a small number of light detection elements, and controls the driving of each LED based on the detection signal, whereby the emission characteristics of each LED are different. An object of the present invention is to provide an illumination device that can obtain a predetermined light emission state even under conditions.
[0010]
[Means for Solving the Problems]
The lighting device of the present invention includes a plurality of LEDs distributed in at least a two-dimensional direction, a transparent resin layer integrally covering the plurality of LEDs, and the inside, on or near the surface of the transparent resin layer. A light detection unit that detects the light emission intensity of the LED by a light detection element disposed, and a power supply circuit unit that controls driving of the LED based on a detection output from the light detection unit. The number of the light detection elements is smaller than that of the LEDs, and the light detection elements detect the light emission intensity of the LEDs that have propagated through the transparent resin layer.
[0011]
According to this configuration, light emitted from a plurality of LEDs propagates through the transparent resin layer and is detected by the light detection element. Therefore, even when a large number of LEDs are used, light emission from a large number of LEDs is achieved by a small number of light detection elements. The reflected detection is possible. Accordingly, it is possible to keep the light emission output constant continuously over a long period of time.
[0012]
In the above configuration, the LED may be mounted on a substrate in a bare chip, and the transparent resin layer may be provided so as to cover the LED and the substrate.
[0013]
Preferably, when the upper surface of the substrate and the surface of the transparent resin layer are substantially parallel, the maximum value of the distance between the LEDs is d, and the refractive index of the transparent resin layer is n, the transparent resin layer The thickness h is configured to satisfy the condition of the following formula.
[0014]
h> d / (2 × tan (arcsin (1 / n))
Accordingly, it is possible to prevent light emitted from one LED from entering and being absorbed into another LED, to increase the light extraction efficiency, and to increase the amount of light incident on the light detection element.
[0015]
The substrate further includes a depression provided on the surface portion of the substrate and a metal film provided on the surface of the substrate, the wall surface of the depression forms an inclined surface, and a reflective surface is formed by the metal film, A plurality of the LEDs are mounted on the bottom of the depression, and the transparent resin layer may be provided so as to cover the substrate including the depression.
[0016]
Further, in the above configuration, a plurality of the LEDs are provided for each of the plurality of light emission colors, and the light detection unit detects the light emission intensity of the LED for each light emission color by the light detection element, and the control circuit Is configured to control the driving of the LED based on the detection output for each emission color from the light detection unit so that the balance of the emission intensity of the LED for each emission color is in a predetermined state. be able to.
[0017]
In this configuration, the light detection unit may include a photodetector whose light receiving sensitivity matches the emission peak wavelength of each corresponding emission color for each emission color of the LED. Accordingly, it becomes easy to detect the emission intensity of the LEDs having different emission colors for each emission color.
[0018]
The LEDs are sequentially turned on with a pulse voltage for each emission color, and the light detection unit performs light detection in synchronization with the lighting timing by the number of the light detection elements equal to or less than the number of emission colors. Accordingly, it is possible to adopt a configuration in which the light detection element is also used for a plurality of emission colors to perform light detection. According to this configuration, for example, by emitting LEDs having respective emission colors in the order of red, green, and blue, and monitoring the output voltage from the photodetector at the same timing, the output ratio of each light color is Understand. By controlling the driving of the LED so that this ratio becomes a predetermined value set, it is possible to obtain a desired color tone or to obtain a constant light emission intensity.
[0019]
In this configuration, it is preferable that the LEDs that are simultaneously turned on for each emission color are arranged such that the distance between them is larger than the distance between the adjacent LEDs in the LED array. Since LEDs generate heat while emitting light, if the spacing between the LEDs that generate heat at the same time is increased, the influence of mutual heat can be avoided, and the heat generated during high-density mounting of elements can be reduced. Can be achieved.
[0020]
It is preferable to apply an antireflection coating on the surface of the transparent resin layer. By forming an antireflection film such as MgF _{2 on} the surface of the transparent resin layer, light propagating inside the resin can be efficiently extracted to the outside.
[0021]
Further preferably, a front Symbol LED integrally sealed in the transparent resin layer, and the light detecting element, and said power supply circuit, a configuration in which each mounted luminaire. By mounting the light source part and the circuit part for controlling the light source part on the same substrate, it is possible to realize integration, miniaturization, and thinning of the lighting device.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 shows a basic system of a lighting device according to an embodiment of the present invention, in which a plurality of LEDs and light detection elements are combined. The LED light source unit 1 includes a light emitting surface 2 on which a plurality of LEDs are arranged and a light detection unit 3. The power supply circuit unit 4 includes a control circuit 5 and a drive circuit 6. These elements can be manufactured on the same substrate, or can be separated from each other and connected by wiring. The light detection unit 3 can be configured using, for example, a photodiode as a light detection element. The light detection unit 3 detects the light output of the light emitting surface 2, and the detection output is input to the control circuit 5. The control circuit 5 reduces the output power of the drive circuit 6 when the light output of the light emitting surface 2 is larger than a predetermined set value, and as a result, the light output of the light emitting surface 2 is reduced. When the light output of the light emitting surface 2 is smaller than a predetermined set value, the reverse operation is performed.
[0024]
As described above, when the light output from the LED is detected by using the light detection unit 3 using a photodiode or the like, and the operation of the drive circuit 6 is feedback-controlled, the deterioration of the LED or the difference in thermal characteristics occurs. In this case, it is possible to maintain the light emission intensity, maintain the light emission intensity ratio when a plurality of light-color LEDs are used, and generate a predetermined light color.
[0025]
Further, by performing the control as described above, a predetermined light color can be realized even if there is a difference in light emission color or light emission intensity of the LED, so that it is not necessary to select the LED.
[0026]
Hereinafter, embodiments of the present invention will be described more specifically.
[0027]
(Embodiment 1)
FIG. 2A is a plan view of the LED light source unit according to Embodiment 1 of the present invention. FIG. 2B shows a cross-sectional view taken along the line AA ′ of FIG. In this LED light source unit, a plurality of single color LEDs 8 and a single light detection element 9 are mounted on a substrate 7 and are integrated by being covered with a transparent resin layer 10. Since the light detection element 9 detects light propagating through the transparent resin layer 10, if one light detection element 9 is arranged for the plurality of LEDs 8, the light emission intensity can be detected appropriately.
[0028]
The substrate 7 is preferably a metal substrate in order to efficiently diffuse and dissipate the heat generated by the LED 8, but may be an epoxy resin or a composite substrate containing alumina. A recess 7a is formed on the substrate 7, and each LED 8 is mounted on the bottom surface of the recess 7a in a bare chip. By applying the metal plating 11 to the inclined portion and the bottom portion of the recess 7a, the light emission of the LED 8 can be efficiently emitted toward the front surface. Furthermore, by applying the metal plating 11 to the entire upper surface of the substrate 7, the light reflected inside by the transparent resin layer 10 can be reflected to the outside again, and the efficiency of taking out the emitted light of the LED 8 to the outside is improved. Can do.
[0029]
As the transparent resin layer 10, it is desirable to use an acrylic resin or an epoxy resin having a small thermal expansion coefficient, and it is desirable to use a silicone resin particularly when the LED 8 generates a large amount of heat and deterioration of the resin becomes a problem. These transparent resin layers can have a lens function or the like by molding. In addition to the bare chip mounting, the LED 8 may be used in a form such as a general shell type or a surface mounting type, and may be covered with the transparent resin layer 10.
[0030]
As described above, by enclosing a plurality of LEDs 8 with the same continuous transparent resin layer 10, light emitted from all the LEDs 8 propagates through the resin and enters the light detection element 9. Therefore, it is possible to obtain a detection output reflecting the light emission of all the LEDs 8 by using a smaller number of light detection elements 9 than the number of LEDs 8.
[0031]
In order to sufficiently exhibit such a function, it is desirable to set the thickness of the transparent resin layer 10 appropriately. For example, when the upper surface of the substrate 7 and the surface of the transparent resin layer 10 are substantially parallel, the thickness h (see FIG. 2B) of the transparent resin layer 10 is set so as to satisfy the condition of the following formula (1). That's fine. In this equation, d is the maximum value of the distance between the LEDs 8 (see FIG. 2A), and n is the refractive index of the transparent resin layer 10.
[0032]
h> d / (2 × tan (arcsin (1 / n)) (1)
Thereby, it is possible to prevent light emitted from one LED 8 from being incident on and absorbed by the other LED 8, to increase the light extraction efficiency, and to increase the amount of incident light to the light detection element 9. .
[0033]
In addition, a Si substrate is used as the substrate 7 and the bare chip LED 8 is mounted, and a photodiode as the photodetecting element 9 can be formed on the Si substrate, for example, like a laser diode unit. Thereby, it is possible to reduce the cost by downsizing the module, simplifying the structure, or reducing the assembly process and the number of parts.
[0034]
In the present embodiment, the plurality of LEDs 8 are mounted on the substrate 7 to be distributed on a plane, that is, in a two-dimensional direction. Although this embodiment can be thin and is most preferable as a lighting device, the present invention can be applied to other embodiments. In other words, even if a plurality of LEDs are arranged somewhat including a three-dimensional direction, it is possible to obtain an effect by detecting light propagated in the transparent resin layer 10.
[0035]
The structure described above is an example in which a single light emitting color module is configured using a single color LED 8. That is, such a module can be created for a plurality of colors and combined to form a white light illumination device. In that case, control is performed by inputting the output from the light detection element 9 of each module to the control circuit 5 shown in FIG.
[0036]
In addition, a plurality of light emitting LEDs 8 can be used in the above structure. In that case, the control may be performed as in the third embodiment described later.
[0037]
(Embodiment 2)
FIG. 3A shows a plan view of an LED light source unit in Embodiment 2 of the present invention. FIG. 3B shows a cross-sectional view taken along the line BB ′ of FIG. In this LED light source unit, LEDs 12 to 14 having red, green, and blue emission colors are mounted on a substrate 7 and a transparent resin layer 10 covers them. Photodetecting elements 15 to 17 for each color are arranged at the end of the transparent resin layer 10.
[0038]
Spectral filters 18 to 20 that transmit only the emission wavelength regions of the respective LEDs 12 to 14 are attached to the respective light detection elements 15 to 17, and a photodetector corresponding to each emission color is configured. Accordingly, each of the light detection elements 15 to 17 measures the wavelength intensity distribution of the light propagating through the transparent resin layer 10 in each color region. The characteristics of the spectral filters 18 to 20 are desirably configured such that the light receiving sensitivity matches the emission peak wavelength of each emission color.
[0039]
The operation of each of the drive circuits for the LEDs 12 to 14 is feedback-controlled by the control circuit so that the emission intensity of each color obtained from each of the light detection elements 15 to 17 and the emission intensity ratio are maintained at predetermined set values.
[0040]
The photodetecting elements 15 to 17 may be embedded in a transparent resin layer as in the photodetecting element 9 of FIG.
[0041]
(Embodiment 3)
FIG. 4A shows a plan view of the LED light source unit of the illumination device according to Embodiment 3 of the present invention. FIG. 4B is a cross-sectional view taken along the line CC ′ of FIG. The LED illumination device according to the present embodiment is configured so that each light color LED is sequentially turned on by a pulse voltage, and the light emission intensity of the LEDs of a plurality of colors can be detected by a light detection element smaller than the number of light emission colors. .
[0042]
As shown in FIGS. 4A and 4B, the LED light source unit includes LEDs 22 to 24 each having red, green, and blue emission colors mounted on a substrate 21. The LEDs 22 to 24 are covered with the transparent resin layer 10. The transparent resin layer 10 has a light guide portion 10 a that extends from the side portion of the substrate 21 to the back surface portion. In the vicinity of the back surface of the substrate 21, the light detection element 25 is disposed so as to face the end portion of the light guide portion 10 a on the substrate 21 side. Light emitted from the LEDs 22 to 24 propagates through the transparent resin layer 10 and is guided to the light detection element 25 through the light guide portion 10a.
[0043]
The LEDs 22 to 24 are made to emit light at different timings for each emission color. Therefore, the light detection element 25 can detect the light emission intensity sequentially for each light emission color, and it is sufficient to provide one light detection element 25 in common for the three light emission color LEDs.
[0044]
An antireflection coating 26 is applied to the surface of the transparent resin layer 10. The anti-reflective coating 26 is preferably MgF ₂ , TiO ₂ , SiO ₂ , CeO ₂ , CeF ₃ , ZnS, ZrO _2, etc., which are easy to deposit and mechanically strong and stable. By coating these on the surface of the transparent resin layer 10, it is possible to reduce the rate at which the light emitted from the LEDs 22 to 24 propagating inside is reflected again toward the inside at the interface with the atmosphere.
[0045]
FIG. 4C shows a timing chart of driving pulse voltages applied to the LEDs 22 to 24. The pulse voltages 27 to 29 are output so that the red (R), green (G), and blue (B) LEDs 22 to 24 are sequentially turned on in synchronization with the clock signal 30. The light detection element 25 resets the detection value by the clock signal 30. Therefore, the ratio of the voltage values obtained in time series by the light detection element 25 represents the light emission output ratio of the LEDs 22 to 24. In order to maintain the ratio at a predetermined set value, the operation of the circuits for driving the LEDs 22 to 24 is feedback controlled by the control circuit, and the LEDs 22 to 24 of the respective colors are caused to emit light.
[0046]
As described above, when using LEDs with different emission colors, the LEDs are sequentially turned on for each emission color, and the emission intensity is detected and feedback controlled at the same timing, thereby controlling the driving of LEDs of multiple colors with a single photodiode. It becomes possible.
[0047]
Note that the emission period of each emission color is preferably as short as possible, and it is desirable to use a pulse voltage having a period of 10 ms or less.
[0048]
(Embodiment 4)
FIG. 5A shows a plan view of an LED light source unit according to Embodiment 4 of the present invention. In this LED light source unit, the LED is driven in the same manner as in the third embodiment. However, the arrangement of each LED and the light emission timing of each LED are set so that a plurality of LEDs that are far from each other are lit simultaneously in the LED array.
[0049]
The LEDs 32 to 34 mounted on the substrate 31 are wired in groups of a series, b series, and c series, respectively, according to the emission color. Thereby, the LEDs 32 to 34 are lit for each series. The LEDs 32 to 34 are arranged so that the LEDs that are turned on at the same time have a large distance between them. Although the condition may not always be satisfied depending on the number of LEDs used, for example, the LEDs that emit light simultaneously are set to be only LEDs that are not adjacent to each other. In other words, it is desirable that the LEDs that are simultaneously turned on for each emission color have a distance between them that is greater than the distance between adjacent LEDs in the LED array.
[0050]
As shown in FIG. 5B, a pulse voltage 35 is applied to the LEDs 32 to 34, a pulse voltage 36 is applied to the b series, and a pulse voltage 37 is applied to the c series in synchronization with the clock signal 38. , Each lights up sequentially. Therefore, the only LEDs that are lit simultaneously are the same series of LEDs that are far from each other. As a result, the distribution of heat generated from the LED can be diffused, and when the LED is integrated and mounted, the decrease in the LED element life and the light emission efficiency due to the temperature rise can be mitigated.
[0051]
(Embodiment 5)
FIG. 6A shows a plan view of a lighting apparatus according to Embodiment 5 of the present invention. A DD ′ cross-sectional view of FIG. 6B is shown in FIG. 6B. This lighting device has a configuration in which a plurality of lighting devices in which a plurality of LEDs are mounted in a transparent resin layer are combined.
[0052]
As shown in FIG. 6A, four LED light source units 39 are fixed to the lighting fixture 40. Inside the luminaire 40, a light detection element 41 and a power supply circuit 42 for controlling and driving the LEDs are arranged. Each LED light source unit 39 is configured by integrating the LED 43 with a substrate 45 by a transparent resin layer 44. The LED light source 39 can be fitted and attached to the lighting fixture 40, and can be detached and detachable, and thus can be exchanged. The light detection element 41 is disposed so as to face the end portion of the transparent resin layer 44 in the LED light source unit 39 fitted therein, and propagates from each LED 43 in the transparent resin layer 44 as in the above embodiment. Light can be detected suitably.
[0053]
Each LED light source unit 39 may have a configuration in which LEDs 43 having different emission colors are used in combination as in the second to fourth embodiments, or a single emission color LED 43 in the first embodiment. The illumination device of this embodiment can also be configured by combining LED light source units 39 of different emission colors. However, it is necessary to appropriately select the configurations of the light detection element 41 and the power supply circuit 42 accordingly.
[0054]
As in this embodiment, it is possible to illuminate a wide area by mounting a plurality of LEDs on a substrate, unitizing a LED sealed with a transparent resin layer, and lighting the plurality of units on the same plane. Become. In addition, by unitizing, even when some LEDs are not lit due to an element defect or the like, only that part can be easily replaced. In addition, even if a highly efficient LED is developed in the future, the above control method can be used to light the LED using the same drive circuit and control circuit regardless of the size, shape, and drive voltage of the LED.
[0055]
In addition, even when the structure in which one LED 8 shown in FIGS. 2A and 2B is mounted is replaced with a structure in which a plurality of LEDs 53 are mounted as shown in FIGS. Can do. FIG. 7A shows a plan view of a part of the LED light source section. FIG. 7B shows a cross-sectional view taken along line EE ′ of FIG. These drawings show a portion corresponding to one of the recesses 7a in FIG. 2A.
[0056]
In this LED light source unit, a plurality (9 in the figure) of LEDs 53 are bare-chip mounted on the bottom of a recess 52 provided in the substrate 51 and are integrated by being covered with a transparent resin layer 54. The wall surface of the recess 52 forms a gently inclined portion, and a metal plate 55 is applied to the surface of the substrate 51, whereby a large reflector is formed on the wall surface of the recess 52. Although not shown, the light detection element is disposed inside, on the surface, or in the vicinity of the transparent resin layer 54.
[0057]
As described above, by adopting a structure in which a plurality of LEDs 53 are mounted in one recess 52, the LED light source having directivity can be significantly thinned. Further, in such a structure, a method of detecting luminescence propagating in the transparent resin layer 54 by the light detection element is particularly advantageous for improving detection accuracy.
[0058]
This structure may be applied to the R, G, and B LEDs 12, 13, and 14 shown in FIGS. 3A and 3B, respectively. That is, for each color, a structure in which a plurality of LEDs are mounted in one recess 52 is adopted.
[0059]
【The invention's effect】
According to the present invention, light emitted from a plurality of LEDs propagates through the transparent resin layer and is detected by the light detection element. Therefore, even when a large number of LEDs are used, light emission from a large number of LEDs is achieved by a small number of light detection elements. The reflected detection is possible, and a predetermined light emission state can be obtained even under a condition where the light emission characteristics of each LED are different.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic structure of a lighting device of the present invention. FIG. 2A is a plan view showing an LED light source unit of the lighting device in Embodiment 1. FIG. 2B is a cross-sectional view of the LED light source unit. FIG. 3B is a cross-sectional view of the LED light source unit of the illumination device in the embodiment 2. FIG. 4A is a plan view of the LED light source unit of the illumination device in the embodiment 3. FIG. FIG. 4C is a waveform diagram showing a power source waveform for driving the LED light source unit. FIG. 5A is a plan view showing the LED light source unit of the illumination device in Embodiment 4. FIG. 5B is a power source for driving the LED light source unit. FIG. 6A is a plan view of the illumination device in Embodiment 5. FIG. 6B is a cross-sectional view of the device. FIG. 7A is a plan view showing a part of the LED light source section using the changed LED arrangement. 7B] Cross-sectional view of the LED light source section [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 LED light source part 2 Light emission surface 3 Light detection part 4 Power supply circuit part 5 Control circuit 6 Drive circuit 7, 21, 31, 51 Substrate 7a, 52 Indentation 8, 12-14, 22-24, 32-34, 43, 53 led
9, 15-17, 25, 41 Photodetection element 10, 44, 54 Transparent resin layer 10a Light guide part 11, 55 Metal plating 18-20 Spectral filter 26 Antireflection coating 27-29, 35-37 Pulse voltage 30, 8 Clock signal 39 LED light source 40 Lighting fixture 42 Power supply circuit

Claims (10)

A plurality of LEDs distributed in at least a two-dimensional direction; a transparent resin layer integrally covering the plurality of LEDs; and a photodetecting element disposed inside, on or near the transparent resin layer A light detection unit that detects the light emission intensity of the LED, and a power supply circuit unit that controls driving of the LED based on a detection output by the light detection unit,
The number of the light detection elements is smaller than that of the LEDs, and the light detection elements detect the light emission intensity of the LEDs that have propagated through the transparent resin layer.   The lighting device according to claim 1, wherein the LED is bare-chip mounted on a substrate, and the transparent resin layer is provided so as to cover the LED and the substrate. When the top surface of the substrate and the surface of the transparent resin layer are substantially parallel, the maximum value of the distance between the LEDs is d, and the refractive index of the transparent resin layer is n, the thickness h of the transparent resin layer Satisfies the condition of the following formula.
h> d / (2 × tan (arcsin (1 / n))   The substrate further comprises a depression provided on the surface of the substrate and a metal film provided on the surface of the substrate, the wall surface of the depression forms an inclined surface, and a reflective surface is formed by the metal film, The lighting device according to claim 2, wherein a plurality of the LEDs are mounted on a bottom portion, and the transparent resin layer is provided so as to cover the substrate including the depression.   The LED is provided for each of a plurality of light emission colors, the light detection unit detects the light emission intensity of the LED for each light emission color by the light detection element, and the control circuit includes the light detection unit. The driving of the LED is controlled so that the balance of the light emission intensity of the LED for each light emission color becomes a predetermined state based on the detection output for each light emission color from The lighting device described.   The illumination device according to claim 5, wherein the light detection unit includes a light detector whose light receiving sensitivity matches a light emission peak wavelength of each corresponding light emission color for each light emission color of the LED.   The LEDs are sequentially turned on with a pulse voltage for each emission color, and the light detection unit performs light detection in synchronization with the lighting timing by the number of light detection elements equal to or less than the number of emission colors. The illumination device according to claim 5, wherein the light detection is performed for a plurality of emission colors by using the light detection element also.   6. The lighting device according to claim 5, wherein the LEDs that are turned on simultaneously for each emission color are arranged such that a distance between them is larger than a distance between adjacent LEDs in the LED array. .   The lighting device according to claim 1, wherein an antireflection film coating is applied to a surface of the transparent resin layer. Wherein before Symbol LED integrally sealed in the transparent resin layer, and the light detecting element, the illumination apparatus according to said power supply circuit, in claim 1 which is respectively mounted on the luminaire.

Images