JP2009110715A - Light-emitting diode luminaire - Google Patents

Abstract

In a light-emitting diode illuminator, a light output and a light color of a light-emitting diode are set to a user-desired light output and light color by detecting an increase and decrease in light output and a peak wavelength change with high accuracy.
A light-emitting diode luminaire includes an LED, an optical sensor that detects an optical output of the LED, and a control unit that controls the optical output of the LED. The photosensor has a plurality of photodetecting elements, and their spectral sensitivity distributions D3 and D6 are different from each other, and some of them overlap. The light receiving sensitivity of each light detecting element is maximum near the light output peak wavelength Fb of the LED, and when the light output increases or decreases, the detection output of each light detecting element increases or decreases uniformly, whereas the light output peak wavelength changes. Sometimes, the detection outputs of the light detection elements have different values. Therefore, increase / decrease and peak wavelength change of the LED light output can be identified and detected with high accuracy, and the light output of the LED and the light color depending on the peak wavelength are set as the user desired light output and light color. be able to.
[Selection] Figure 5

Description

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

  Conventionally, red, green and blue light emitting diodes (hereinafter collectively referred to as LEDs), an optical sensor for detecting the optical output of the LED, and a control unit for controlling the optical output of the LED according to the detection result of the optical sensor, A light-emitting diode illuminating device provided is known (for example, see Patent Document 1). The above-described optical sensor includes three types of photosensors for detecting red light, green light, and blue light, respectively. As shown in FIG. 7, one of the three types of photosensors has a mountain-shaped spectral sensitivity distribution (indicated by a solid line X) in which the light receiving sensitivity is maximized around the peak wavelength in the red light spectrum. Similarly, the other two types of photosensors have a mountain-shaped spectral sensitivity distribution (indicated by a broken line Y and a one-dot chain line Z) in which the photosensitivity is maximum near the peak wavelength of one of green light and the other of blue light. . The spectral sensitivity distributions of the three types of photosensors overlap each other.

  In the above-described light-emitting diode illuminator, for example, when red light is output from an LED and the light emission amount, that is, the light output is smaller than the light output set by the user (hereinafter referred to as a set value), three types of photosensors The detection output of is uniformly reduced as compared with the case where the light output of the LED is equal to the set value. When the light output of red light is larger than the set value, the detection output of the photosensor increases. The control unit detects increase / decrease in the light output of the LED based on this increase / decrease. On the other hand, when the peak wavelength of the red light output from the LED changes due to the temperature characteristics of the LED, the detection outputs of the three types of photosensors are different from those when the light output of the LED is increased or decreased. It varies in the manner. The control unit detects this change and detects a change in the peak wavelength of red light. For this reason, it is possible to detect the increase and decrease of the light output of the LED and the change of the peak wavelength.

However, the spectral sensitivity distribution of each photosensor has a peak shape near the peak wavelength of light of the color corresponding to each photosensor, and the photosensitivity of each photosensor to light of a color other than that color is low. For this reason, when blue light having a peak wavelength deviated from the set peak wavelength is emitted, the detection outputs of all three types of photosensors change with changes in the peak wavelength. Since the photosensor corresponding to green light has low light receiving sensitivity to blue light, detection accuracy of peak wavelength change is low. Therefore, it is difficult to detect the increase and decrease of the light output of the LED and the peak wavelength change with high accuracy, and the light output of the LED and the light color depending on the peak wavelength are set as the user desired light output and light color. Is difficult.
JP 2007-156211 A

  The present invention has been made to solve the above-described conventional problems, and by detecting the increase and decrease of the light output of the light emitting diode and the peak wavelength change with high accuracy, the light output and light color of the light emitting diode can be determined by the user. An object of the present invention is to provide a light-emitting diode illuminating device that can have a desired light output and light color.

  In order to achieve the above object, the invention of claim 1 includes a light emitting diode, a light sensor for detecting a light output of the light emitting diode, and a control unit for controlling a light output of the light emitting diode according to a detection result of the light sensor. The light sensor includes a plurality of light detection elements having different spectral sensitivity distributions with respect to incident light and overlapping a part thereof, and each of the plurality of light detection elements. The light receiving sensitivity is maximized in the vicinity of the light output peak wavelength of the light emitting diode.

  According to the first aspect of the invention, when the light output of the light emitting diode increases or decreases, the detection output of each of the plurality of light detecting elements increases or decreases uniformly, whereas when the light output peak wavelength of the light emitting diode changes, Since the spectral sensitivity distribution of each photodetecting element is different, the detection output of each photodetecting element varies in various ways, and the light receiving sensitivity of each photodetecting element is in the vicinity of the light output peak wavelength of the light emitting diode. Therefore, the increase / decrease in the light output of the light emitting diode and the change in the peak wavelength can be identified and detected with high accuracy. Accordingly, the light output of the light emitting diode and the light color depending on the peak wavelength can be set to the user desired light output and light color.

  Hereinafter, a light-emitting diode lighting apparatus (hereinafter referred to as a lighting apparatus) according to an 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 lighting fixture 1 of this embodiment can detect a change in light output of a light emitting diode (hereinafter referred to as LED) 2 and a change in light output peak wavelength caused by a temperature change of the LED 2 or the like.

  The luminaire 1 includes an LED 2, a lighting circuit unit 3 that supplies current to the LED 2 to light the LED 2, first and second optical sensors 4 and 5 that detect the light output of the LED 2, and first and second light. A control unit 6 that controls the light output of the LED 2 using the lighting circuit unit 3 according to the detection results of the sensors 4 and 5, and a power source unit 7 that supplies power to the lighting circuit unit 3 and the control unit 6 are provided. The first and second light detection elements 4 and 5 have a plurality of light detection elements. As shown in FIG. 2, the first optical sensor 4 includes three types of light detection elements 41 to 43 for detecting the amount of light of, for example, three colors emitted from the LED 2. Although not shown, the second photosensor 5 includes three types of photodetecting elements 51 to 53 having the same configuration as the photodetecting elements 41 to 43. The light detection element 41 and the light detection element 51 have different spectral sensitivity distributions with respect to incident light, and a part thereof overlaps. Similar relationships exist between the light detection element 42 and the light detection element 52 and between the light detection element 43 and the light detection element 53. The power supply unit 7 is configured by a battery or a commercial power supply.

  The LED 2 includes a red LED 21, a green LED 22, and a blue LED 23 (hereinafter referred to as a red LED 21 or the like). The red LED 21 and the like are mounted on the substrate 24 to constitute the LED module 25.

  The first optical sensor 4 includes a red light transmission filter 44, a green light transmission filter 45, and a blue light transmission filter 46 (hereinafter referred to as a red light transmission filter 44) between the LED 2 and the light detection elements 41 to 43. .

  The red light transmission filter 44 is provided in the optical path between the LED 2 and the light detection element 41. The light detection element 41 receives the red light emitted from the LED 2 and transmitted through the red light transmission filter 44 and detects the amount of light. The green light transmission filter 45 is disposed in the optical path between the LED 2 and the light detection element 42, and the blue light transmission filter 46 is disposed in the optical path between the LED 2 and the light detection element 43. The light detection element 42 receives the green light emitted from the LED 2 and transmitted through the green light transmission filter 45, and the light detection element 43 receives the green light emitted from the LED 2 and transmitted through the green light transmission filter 46. Each of the light detection elements 42 and 43 detects the amount of received light.

  The red light transmission filter 44 and the like are configured by an optical member whose wavelength characteristic of transmittance is adjusted in advance. The red light transmission filter 44 has the maximum transmittance in the vicinity of the peak wavelength of monochromatic red light output as synthesized light from the red LED 21 or the like when the ambient temperature is room temperature. The red light transmission filter 44 is configured such that the light receiving sensitivity of the light detecting element 41 is maximized in the vicinity of the above peak wavelength, and the spectral sensitivity distribution of the light detecting element 41 has a mountain shape. Specifically, the light receiving wavelength at which the light receiving sensitivity is maximized is a value slightly shorter than the peak wavelength of the red light. The normal temperature is approximately 25 degrees, for example. The vicinity of the light output peak wavelength is a wavelength range of, for example, approximately 50 [nm] from the light output peak wavelength, and excludes the light output peak wavelength.

  Similarly, the green light transmission filter 45 and the blue light transmission filter 46 have a maximum transmittance in the vicinity of the peak wavelength of single-color green light or blue light output as synthesized light from the red LED 21 or the like when the ambient temperature is room temperature. It is. The green light transmission filter 45 and the blue light transmission filter 46 are configured such that the light receiving sensitivity of the light detecting elements 42 and 43 is maximized in the vicinity of the above peak wavelength, and the spectral sensitivity distribution of the light detecting elements 42 and 43 has a mountain shape. Has been. Specifically, the light receiving wavelength at which the light receiving sensitivity is maximized is a value slightly shorter than the peak wavelength of the green light or blue light.

  As shown in FIG. 3A, the spectral sensitivity distribution of the first photosensor 4 is formed by combining the spectral sensitivity distributions D1 to D3 of the light detection elements 41 to 43, respectively. The spectral sensitivity distribution of the first optical sensor 4 is a combination of the three peak-shaped spectral sensitivity distributions, and is more than the peak wavelengths Fr, Fg, and Fb of the red light, green light, and blue light output from the LED 2. It has a peak of light receiving sensitivity at a slightly shorter light receiving wavelength.

  The second optical sensor 5 includes a red light transmission filter 54, a green light transmission filter 55, and a blue light transmission filter 56 (hereinafter referred to as a red light transmission filter 54, etc.) between the LED 2 and the light detection elements 51 to 53. . The red light transmission filter 54 and the like have substantially the same configuration as the red light transmission filter 44 and the like, but there is a difference between the red light transmission filter 54 and the red light transmission filter 44 and the like. The red light transmission filter 54 and the like have the light receiving sensitivities of the light detecting elements 51 to 53 at a peak at a ternary light receiving wavelength slightly longer than the peak wavelengths of the red light, green light, and blue light output from the LED 2. It is a point that is configured.

  As shown in FIG. 3B, the spectral sensitivity distribution of the second photosensor 5 is composed of the spectral sensitivity distributions D4 to D6 of the light detection elements 51 to 53. The spectral sensitivity distribution of the second optical sensor 5 is a combination of three mountain-shaped spectral sensitivity distributions, and is more than the peak wavelengths Fr, Fg, and Fb of the red light, green light, and blue light output from the LED 2. It has a peak of light receiving sensitivity at a slightly longer light receiving wavelength.

  When the spectral sensitivity distribution of each of the first and second photosensors 4 and 5 is shown together on the same wavelength axis, as shown in FIG. The distribution is shifted from the light output peak wavelength of the LED 2 in different directions on the wavelength axis, specifically, one is shifted to the left in the figure and the other is shifted to the right in the figure. The spectral sensitivity distribution D1 of the light detecting element 41 constituting the first photosensor 4 has the maximum light receiving sensitivity at a light receiving wavelength slightly shorter than the peak wavelength Fr of the red light output from the LED 2, and the light constituting the second photosensor. The spectral sensitivity distribution D4 of the detection element 51 has a maximum light receiving sensitivity at a light receiving wavelength slightly longer than the peak wavelength Fr of the red light. Thus, the spectral sensitivity distributions D1 and D4 of the photodetecting elements 41 and 51 are different from each other, and some of them overlap.

  The light receiving sensitivities of the light detecting elements 41 and 51 are substantially equal to each other at a light receiving wavelength substantially equal to the peak wavelength Fr of red light. That is, the distribution curves of the distribution sensitivity distributions D1 and D4 of the light detection elements 41 and 51 intersect, and the light receiving wavelength of the portion forming the valley bottom in the figure is substantially equal to the peak wavelength Fr of red light. The spectral sensitivity distributions D2 and D5 of the photodetecting elements 42 and 52 and the spectral sensitivity distributions D3 and D6 of the photodetecting elements 43 and 53 also have the same relationship as the spectral sensitivity distributions D1 and D4 of the photodetecting elements 41 and 51.

  The control unit 6 can be configured by a microprocessor including a CPU. The control unit 6 detects a change in the light output of the LED 2 and a change in the light output peak wavelength based on a change in the detection output of the light detection elements 41 to 43 and 51 to 53, for example, a change in the output voltage or current. Moreover, the control part 9 controls each light output of red LED21 grade | etc., Based on the signal from the operation part not shown operated by the user for the light output and light color setting of LED2.

FIG. 4 shows the relationship between the ambient temperature and the light output peak wavelength of the LED 2. The light output peak wavelength of the LED 2 becomes longer due to the temperature increase of the LED 2 and becomes shorter due to the temperature decrease of each LED 2. For example, when the optical output peak wavelength when the ambient temperature is normal temperature T ₀ is F ₀ , when the ambient temperature increases from T ₀ to T ₁ (T ₁ > T ₀ ), the temperature of the LED 2 also increases. The optical output peak wavelength increases from F ₀ to F ₁ (F ₁ > F ₀ ).

  Next, the detection output change of the first and second photosensors 4 and 5 when the light output peak wavelength of the LED 2 changes due to the ambient temperature change will be described. Here, taking a peak wavelength of blue light output as synthesized light from the red LED 21 or the like as an example, a change in detection output of the light detection elements 43 and 53 accompanying a change in the light output peak wavelength will be described.

5 and 6 show the relationship between the peak wavelength of blue light before and after the change in the ambient temperature and the spectral sensitivity distributions D3 and D6 of the light detection sensors 43 and 53, and the ambient temperature and the light detection elements 43 and 53. The relationship with the detection output is shown. Here, when the ambient temperature is normal temperature T ₀ , the peak wavelength of the blue light is Fb, the light receiving sensitivity of the light detecting elements 43 and 53 with respect to the light of the light receiving wavelength Fb is S _0, and the light detecting element 43 at that time, The detection output of 53 is set to V ₀ . This detection output is represented by an output voltage, for example.

When the ambient temperature increases from T ₀ to T ₁ (T ₁ > T ₀ ), the temperature of the red LED 21 and the like also increases, and the peak wavelength of blue light becomes longer from Fb to Fb ′ (Fb ′> Fb). The spectral sensitivity distributions of the light detecting elements 43 and 53 are different, the light receiving sensitivity of the light detecting element 43 with respect to the light receiving wavelength Fb ′ is S ₁ smaller than S ₀ , and the light receiving sensitivity of the light detecting element 53 is S ₁ is greater than S ₀ . Accordingly, the detection output of the light detection element 43 decreases from V ₀ to V ₁ , and the detection output of the light detection element 53 increases from V ₀ to V ₂ . Thus, if the peak wavelength of blue light becomes longer than that at room temperature as the ambient temperature increases, the detection output of the light detection element 43 decreases and the detection output of the light detection element 53 increases. Similarly, when the peak wavelength of blue light becomes shorter than that at room temperature as the ambient temperature decreases, the output of the light detection element 43 increases and the output of the light detection element 53 decreases. Therefore, when the peak wavelength of blue light changes, one of the detection outputs of the light detection elements 43 and 53 increases and the other decreases, and they change in various ways.

  By the way, when the light output of blue light, that is, the light quantity decreases or increases, the detection outputs of both the light detection elements 43 and 53 decrease or increase at the same rate. That is, the detection outputs of the light detection elements 43 and 53 increase and decrease uniformly as the light output of the LED 2 increases and decreases.

  Therefore, the detection outputs of the light detection elements 43 and 53 change in different manners when the light output of the LED 2 increases or decreases and when the peak wavelength changes. The same applies to the light detection elements 41 and 51 and the light detection elements 42 and 52. When the detection outputs of both of the light detection elements 41 and 51 increase or decrease, the control unit 6 identifies that the amount of blue light has increased or decreased, and one of the detection outputs decreases or increases from that at normal temperature, and the other detection output When the output increases or decreases, it is identified that the peak wavelength of the blue light has changed. Similarly, the control unit 6 also detects increase / decrease in light output and change in peak wavelength of green light and red light based on detection output changes of the light detection elements 42 and 52 and the light detection elements 43 and 53. When the light output increases or decreases, the control unit 6 controls the current supplied to each of the red LEDs 21 and the like so as to correct the increase and decrease in order to set the light output to the user desired light output. Further, when the peak wavelength is changed from the set value in any of red light, green light, and blue light, which is the combined light of the red LED 21 or the like, the light color depending on the light output peak wavelength is set as desired by the user. In order to obtain a light color, the control unit 6 controls the current supplied to each of the red LEDs 21 and the like so as to correct the change.

  In the lighting fixture 1 comprised as mentioned above, based on the detection output change of the photon detection elements 41-43, 51-53, the increase / decrease in LED light output and the peak wavelength change can be identified and detected. it can.

  Further, in order to detect the light output and peak wavelength of each of red light, green light, and blue light, one set of light detection elements is provided for those lights, and each of the light detection elements of each set is Since it is the maximum in the vicinity of the peak wavelength of the light of the corresponding color, as in the conventional case, three types of photosensors are provided corresponding to the three color light, and the light output and peak wavelength of one color light are changed to the light of other colors. Compared with the case of detecting by a photosensor corresponding to the above, it is possible to detect the light output increase / decrease and peak wavelength change of each color with high accuracy. For this reason, in the red light, the green light, or the blue light output by the LED 2, or the combined light thereof, the light output and the light color can be set to the user desired light output and light color.

  In addition, this invention is not limited to the structure of said embodiment, A various deformation | transformation is possible according to a use purpose.

The block diagram of the light-emitting-diode lighting fixture which concerns on the 1st Embodiment of this invention. The block diagram of the 1st optical sensor of the said instrument. (A) is a spectral sensitivity distribution diagram of the first photosensor, (b) is a spectral sensitivity distribution diagram of the second photosensor, and (c) is a graph of the first and second photosensors represented on the same wavelength axis. Spectral sensitivity distribution diagram. The temperature-light output peak wavelength characteristic figure of the light emitting diode of the said instrument. (A) is a figure which shows the relationship between the optical output peak wavelength of the said light emitting diode before a temperature change, and a part of spectral sensitivity distribution of the said 1st and 2nd photosensor, (b) shows the same relationship after a temperature change. FIG. The figure which shows the relationship between ambient temperature and the detection output of the said 1st and 2nd optical sensor. The spectral sensitivity distribution figure of three types of photosensors in the conventional light emitting diode lighting fixture.

Explanation of symbols

1 LED luminaire 2 LED
21 Red LED
22 Green LED
23 Blue LED
4 1st sensor 5 2nd sensors 41-43, 51-53 Photodetection element 44, 54 Red light transmission filter 45, 55 Green light transmission filter 46, 56 Blue light transmission filter

Claims (1)

In a light emitting diode lighting apparatus comprising: a light emitting diode; a light sensor that detects a light output of the light emitting diode; and a control unit that controls a light output of the light emitting diode according to a detection result of the light sensor.
The optical sensor has a plurality of photodetecting elements whose spectral sensitivity distributions with respect to incident light are different from each other and partially overlapped with each other,
The light-emitting diode illuminator characterized in that the light-receiving sensitivity of each of the plurality of light-detecting elements is maximized in the vicinity of the light output peak wavelength of the light-emitting diode.

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