JP2009129687A - Light emitting diode lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting diode lighting apparatus in which failure of a power supply circuit can be prevented by reducing a load to a power supply circuit by eliminating necessity of switching on and off of power supply to an LED of each color for detecting optical output of LEDs of each color and lighting these in the order. <P>SOLUTION: The LED lighting apparatus includes a plurality of colors of LEDs, a power supply circuit for lighting the LEDs, and a photosensor. The photosensor is constructed so that its photosensitivity distributions F1-F3 may correspond to spectral distributions S1-S3 of LED of each color, and may not mutually overlap. Thereby, the photosensor can detect simultaneously optical output of each color of LED and that it is not necessary to switch on and off power supply to each color of LEDs for detecting optical output of each color of LED and light these in order like the conventional one, and the optical output detection of each color can be made with all colors of LEDs lighted. Thereby, a load required for the power supply circuit can be reduced and failure of power supply circuit can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light-emitting diode luminaire using a light-emitting diode as a light source.

  2. Description of the Related Art Conventionally, there has been a light-emitting device including a plurality of light-emitting diodes having different emission colors, an optical sensor that measures the light output, and a control unit that controls the light emission intensity of the light-emitting diode based on the measurement result of the optical sensor It is known (see, for example, Patent Document 1). In this device, basically, all the light emitting diodes emit light and white light is output as illumination light. However, one or two or more light emitting diodes are turned on sequentially in a predetermined period, and the light is emitted. The output is detected by a light sensor, and the light output of each color light emitting diode is obtained. And based on the result, each light emitting diode is controlled by the control means, and the illumination light is stabilized at a desired white point.

  Further, the light-emitting diode illuminating device is composed of the same members as the light-emitting device described above, and basically controls the supply current to the light-emitting diode for each emission color by the control means, and outputs white light as illumination light. Is known (see, for example, Patent Document 2). In this instrument, a current is sent to the light emitting diodes in a pulsed manner. In a predetermined period, a current pulse to one color light emitting diode is turned on, and a current pulse to the other light emitting diodes is turned off. The light emitting diodes are turned on one by one in order, and each light output is detected by a light sensor. The control means controls the light output of each light emitting diode based on the detection result, and sets the chromaticity of the illumination light as desired and chromaticity.

By the way, in the techniques described in Patent Document 1 and Patent Document 2, it is possible to control the chromaticity of illumination light with high accuracy. However, since the light emitting diodes are sequentially turned on when the light output of each color light emitting diode is detected, measurement is performed. Since it is necessary to turn on the power supply for the target light emitting diode and turn off the power supply for the light emitting diode that is not the measurement target, the power supply circuit is loaded by repeated on / off of the power supply, and the power supply circuit There is a risk of failure.
JP 2005-157316 A JP 2002-533870 A

  The present invention has been made to solve the above-described conventional problems, and it is necessary to turn on / off the power supply to the light emitting diodes of the respective colors in order to detect the light output of the light emitting diodes of the respective colors, and turn them on in order. An object of the present invention is to provide a light-emitting diode luminaire that can prevent a failure of a power supply circuit by eliminating the load and reducing the load on the power supply circuit.

  In order to achieve the above object, the invention of claim 1 includes a plurality of light emitting diodes having different spectral distributions, a power supply circuit for lighting the light emitting diodes, an optical sensor for detecting a light output of the light emitting diodes, A light emitting diode illumination comprising: a control unit that controls a light output of each of the light emitting diodes by controlling a current supplied from the power supply circuit to each of the light emitting diodes based on a detection result of the light sensor; In the instrument, the photosensor is configured such that the light receiving sensitivity distribution corresponds to the spectral distribution of each light emitting diode and does not overlap each other.

  According to a second aspect of the present invention, in the light-emitting diode illuminator according to the first aspect, in addition to the light-receiving sensitivity distribution, the optical sensor further has a light-sensitive sensitivity distribution in a wavelength band that deviates from the spectral distribution of the light-emitting diode. Is.

  According to the first aspect of the present invention, the light receiving sensitivity distribution of the photosensor corresponds to the spectral distribution of each of the light emitting diodes having different emission colors and does not overlap with each other. It can be detected at the same time. As a result, there is no need to turn on / off the power supply to the light emitting diodes of each color in order to detect the light output of the light emitting diodes of each color as in the past, and the light emitting diodes of all colors are lit. Thus, the light output of each color can be detected, and the load on the power supply circuit can be reduced. For this reason, failure of the power supply circuit can be prevented.

  According to the invention of claim 2, since the light outside the wavelength band of the output light of the light emitting diode can be detected by the optical sensor, the light intensity of the external light is generally substantially constant regardless of the wavelength. From the detection result, it is possible to estimate the light intensity of substantially the same wavelength as the output light of each light emitting diode in the external light. Therefore, based on the estimation result, the light output of each light emitting diode by the optical sensor can be estimated. By correcting the detection result, a detection error due to external light can be eliminated. For this reason, the light output of the light emitting diode can be controlled with high accuracy based on the detection of the light output with high accuracy, and the chromaticity of the illumination light can be set to the desired chromaticity with high accuracy.

  Hereinafter, a light-emitting diode lighting apparatus (hereinafter referred to as a lighting apparatus) according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a configuration of a lighting fixture according to the present embodiment. The luminaire 1 includes a plurality of light emitting diodes (hereinafter referred to as LEDs) 2 having different spectral distributions, a lighting circuit 3 for lighting the LED 2, a light sensor 4 for detecting the light output of the LED 2, and a lighting circuit 3. And a control unit for controlling the light output of each of the LEDs 2 by controlling the current supplied from the power circuit 5 to each of the LEDs 2 based on the detection result of the light sensor 4. 6. The photosensor 4 is configured such that the light receiving sensitivity distribution corresponds to the spectral distribution of each LED 2 and does not overlap each other.

  The LED 2 includes a red LED 21, a green LED 22, and a blue LED 23 (hereinafter collectively referred to as a red LED 21 and the like), which are mounted on a substrate 24 and constitute an LED module 25. The peak wavelength of each light output of the red LED 21 and the like is, for example, approximately 620 [nm], 540 [nm], and 460 [nm]. The numerical value of the peak wavelength is not limited to the above. Each light output is controlled from the red LED 21 or the like, and white light is output as their combined light.

  FIG. 2 shows the configuration of the optical sensor 4. The optical sensor 4 includes a red light transmissive filter 41, a green light transmissive filter 42, a blue light transmissive filter 43 (hereinafter collectively referred to as a red light transmissive filter 41 and the like), and detects transmitted light corresponding to each of these. The light detection elements 44, 45, and 46 are configured.

  The red light transmission filter 41 is an optical band-pass filter made of a red glass substrate. This band pass filter is set so that its bandwidth falls within a wavelength band of ± approximately 40 [nm] with respect to the peak wavelength (approximately 620 [nm]) of the light output of the red LED 21. 44 is maximized at a light receiving wavelength substantially equal to the peak wavelength fr of the light output of the red LED 21. The green light transmission filter 42 and the blue light transmission filter 43 are also configured to have the same relationship between the green LED 22 and the blue LED 23 and between the light detection elements 45 and 46. In addition, each of the red light transmission filters 41 and the like has a bandwidth set so that the light reception sensitivity distributions of the light detection elements 44 to 46 do not overlap each other. The bandwidth can be set by adjusting the chromaticity of the glass substrate or the concentration of the pigment component. The light detection elements 44 to 46 can be configured by phototransistors or photodiodes. The bandwidth is not limited to the above.

  FIG. 3 shows the spectral distribution of the red LED 21 and the like and the light receiving sensitivity distribution of the optical sensor 4. Since the light reception sensitivity distribution F1 by the light detection element 44 depends on the filter characteristics of the red light transmission filter 41 described above, it corresponds to the spectral distribution S1 of the red LED 21, and the light reception wavelength band in which the light reception sensitivity is effective is, for example, It is about 580-660 [nm]. Similarly, the light reception sensitivity distribution F2 by the light detection element 45 corresponds to the spectral distribution S2 of the green LED 22, and the light reception wavelength band in which the light reception sensitivity is effective is approximately 500 to 580 [nm], for example. Further, the spectral distribution S3 by the light detection element 46 corresponds to the spectral distribution S3 of the blue LED 23, and the light receiving wavelength band in which the light receiving sensitivity is effective is approximately 420 to 500 [nm], for example.

  In the present embodiment, the light reception sensitivity distribution of the optical sensor 4 is adjusted by the red light transmission filter 41 and the like, and corresponds to each spectral distribution of the red LED 21 and the like, and does not overlap with each other. The light output can be detected simultaneously. As a result, it is not necessary to turn on / off the power supply to the LEDs of each color in order to detect the light output of the LEDs of each color as in the prior art, and to turn on each color with all the LEDs turned on. Can be detected. Therefore, the load applied to the power supply circuit 5 can be reduced, and failure of the power supply circuit 5 can be prevented.

  Next, the lighting fixture which concerns on the 2nd Embodiment of this invention is demonstrated with reference to FIG.4 and FIG.5. Since the configuration of the lighting fixture of the present embodiment is the same as that of the first embodiment except for the optical sensor, the overall configuration is not shown. FIG. 4 shows a configuration of an optical sensor of the lighting fixture according to the present embodiment. Compared with the configuration of the first embodiment, the light sensor 4 of the lighting fixture 1 includes an infrared transmission filter 47 and an ultraviolet transmission filter 48, and two light detection elements 49 that detect transmitted light corresponding to each of them. , 50. The infrared transmission filter 47 and the ultraviolet transmission filter 48 transmit light in a wavelength band deviated from the spectral distribution of the red LED 21 or the like, that is, infrared and ultraviolet.

  The infrared transmission filter 47 is composed of an optical band-pass filter composed of a glass substrate having a dielectric film deposited on the surface thereof. The band-pass filter has a band width of a predetermined wavelength of ultraviolet rays, for example, approximately 900 [ nm] is set so as to be within a wavelength band of ± about 40 [nm] with respect to the wavelength of [nm], and the light receiving sensitivity by the light detection element 49 is maximized at a light receiving wavelength of about 900 [nm].

  The ultraviolet transmission filter 48 is also composed of a band-pass filter configured in the same manner as described above, and this band-pass filter has a band width of about ± 40 [with respect to a predetermined wavelength of infrared, for example, a wavelength of about 300 [nm]. nm] is set so as to be within the wavelength band, and the light receiving sensitivity of the light detection element 50 is maximized at a light receiving wavelength of about 300 [nm]. The photodetecting elements 49 and 50 can be configured by phototransistors or photodiodes.

  FIG. 5 shows the spectral distribution of the red LED 21 and the like and the light receiving sensitivity distribution by the photodetecting elements 44 to 46, 49, 50. Since the spectral distribution of the red LED 21 and the like and the light receiving sensitivity distribution of the light detection elements 44 to 46 have been described with reference to FIG. 3 described above, description thereof will be omitted. In the light receiving sensitivity distribution F4 by the light detecting element 49, the effective light receiving wavelength band of the light receiving sensitivity is set to a wavelength range of about 860 to 940 [nm], for example, and the light receiving sensitivity distribution F5 by the light detecting element 50 is The effective light reception wavelength band of light reception sensitivity is set to a wavelength range of about 260 to 340 [nm], for example. As described above, the optical sensor 4 further includes the light receiving sensitivity distributions F4 and F5 in the wavelength band deviated from the spectral distributions S1 to S3 of the red LED 21 and the like in addition to the light receiving sensitivity distributions F1 to F3 described above.

  In the present embodiment, the light detection elements 49 and 50 can detect light outside the wavelength band of output light such as the red LED 21, specifically infrared light and ultraviolet light. By the way, in general, the intensity of external light is substantially constant regardless of the wavelength. Therefore, based on the above detection result, it is possible to estimate the light intensity of substantially the same wavelength as the output light of the red LED 21 or the like in the external light. Based on the estimation result, the red LED 21 or the like by the light detection elements 44 to 46 can be estimated. By correcting the detection result of each light output, it is possible to eliminate detection errors due to external light. For this reason, it is possible to control the light output of the red LED 21 and the like with high accuracy based on the detection of the light output with high accuracy, and to set the chromaticity or color temperature of the illumination light to a desired chromaticity or color temperature with high accuracy. it can. As a result, it is possible to control the chromaticity or color temperature of illumination light with high accuracy even outdoors where there is a lot of outside light.

  In addition, this invention is not limited to the structure of the said 1st and 2nd embodiment, A various deformation | transformation is possible according to the intended purpose. For example, the red light transmission filter 41, the green light transmission filter 42, the blue light transmission filter 43, the infrared transmission filter 47, and the ultraviolet transmission filter 48 may be a dielectric film, a metal film, a combination thereof, or any one of them on the surface. You may be comprised by the glass substrate etc. with which the light absorption member which has wavelength selectivity other than the vapor-deposited glass substrate or colored glass was disperse | distributed. In this case, in order to control the light receiving sensitivity distribution by the photodetecting elements 44 to 46, 49, 50, the film thickness of the dielectric film or the metal film or the material of the light absorbing member is adjusted.

The block diagram of the light-emitting-diode lighting fixture which concerns on the 1st Embodiment of this invention. The block diagram of the optical sensor of the said instrument. The figure which shows the relationship between the spectral distribution of the light emitting diode of the said instrument, and the light reception sensitivity distribution of an optical sensor. The block diagram of the optical sensor of the light emitting diode lighting fixture which concerns on the 2nd Embodiment of this invention. The figure which shows the relationship between the spectral distribution of the light emitting diode of the said instrument, and the light reception sensitivity distribution of an optical sensor.

Explanation of symbols

1 LED luminaire 2 LED
21 Red LED
22 Green LED
23 Blue LED
4 Photosensor 41 Red light transmission filter 42 Green light transmission filter 43 Blue light transmission filters 44 to 46, 49, 50 Photodetecting element 47 Infrared transmission filter 48 Ultraviolet transmission filter 5 Power supply circuit 6 Control unit

Claims (2)

A plurality of light emitting diodes having different spectral distributions from each other, a power supply circuit for lighting the light emitting diode, a light sensor for detecting a light output of the light emitting diode, and a detection result of the light sensor, from the power supply circuit In a light-emitting diode luminaire comprising: a control unit that controls a light output of each light-emitting diode by controlling a current supplied to each light-emitting diode;
The light sensor has a light receiving sensitivity distribution corresponding to a spectral distribution of each light emitting diode and does not overlap each other.   The light-emitting diode illuminating apparatus according to claim 1, wherein the photosensor further has a light-receiving sensitivity distribution in a wavelength band deviating from a spectral distribution of the light-emitting diode in addition to the light-receiving sensitivity distribution.

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