JP2007080540A - Illumination system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily reduce change of illuminance and change of a color of mixed color light in a short time even if different secular change in each coloring light occurs in a plurality of light emitting diodes, and to reduce the number of parts. <P>SOLUTION: When a power supply E supplies power to a lighting control device 3, a power supply part 30 supplies power to a light emitting part 1 in order of the red light emitting diodes 10, the green light emitting diodes 11 and the blue light-emitting diodes 12 independently to emit red light, green light and blue glow independently. A photosensor 2 which is a single component detects illuminance for each emitted coloring light independently. Then, a comparing element 32 compares whether a detected value which is the illuminance of the coloring light emitted independently is in agreement with a reference value stored in a storage part 31. If the detected value differs from the reference value as the result of comparison, a detection value is in agreement with a reference value, a correcting unit 33 corrects the power to each light emitting diode 10, 11, 12 respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination system that generates mixed color light from a plurality of colored lights emitted from a plurality of light emitting diodes.

  Conventionally, in this type of illumination system, each of a plurality of light emitting diodes emits one of a plurality of colored lights to generate mixed color light. For example, an illumination device (illumination system) disclosed in Patent Document 1 includes a red light emitting diode, a green light emitting diode, and a blue light emitting diode, and a plurality of lightings corresponding to the red light emitting diode, the green light emitting diode, and the blue light emitting diode, respectively. A circuit and a dimming signal generating circuit for supplying a dimming signal to each lighting circuit. In the lighting device disclosed in Patent Document 1, each of the plurality of lighting circuits receives a dimming signal from the dimming signal generation circuit, and controls the voltage applied to the corresponding light emitting diode, thereby causing each light emission. Red light, green light and blue light are emitted from the diode. The duty ratio of the dimming signal is determined by stored data that associates the mixed color light generated from each color light with the dimming ratio of each light emitting diode.

  However, in the illumination device disclosed in Patent Document 1, the illuminance of each light emitting diode changes as the emission time elapses. As a result, there is a problem that the dimming ratio of each color light is changed and the color change of the mixed color light is increased.

As what solves the said problem, there exists a white light LED illuminating device (illuminating system) currently disclosed by patent document 2, for example. The white light LED lighting device disclosed in Patent Document 2 includes a red LED (red light emitting diode), a white LED (white light emitting diode), and a green LED (green light emitting diode), a red sensor, a blue sensor, and a green sensor. And an LED driver circuit. The operation of the white light LED lighting device disclosed in Patent Document 2 will be described. First, the measurement value of the red sensor is compared with the red setting values of a plurality of white balances, and the closest white balance setting value is determined. Select a combination. Next, the measurement value of the blue sensor is compared and calculated so as to be the blue setting value of the selected white balance, and the LED driver circuit is controlled. Furthermore, since the measured value of the red sensor changes as a result of adjusting the white LED, the measured value of the red sensor is again compared with the red setting value of the white balance, and the closest combination of the white balance setting values is determined. . By repeating the above operation until the measurement values of the red sensor and the blue sensor are not changed, the measurement values of the red sensor and the blue sensor are converged to a specific white balance setting value. Subsequently, the current value to the green LED is adjusted so that the measured value of the green sensor matches the green setting value of a specific white balance.
JP 2004-55361 A (pages 4-7 and FIGS. 1 and 2) JP 2004-253309 (pages 15 to 18 and FIG. 8)

  However, the illumination system disclosed in Patent Document 2 converges to a specific white balance set value by repeatedly comparing and adjusting the measured value of the colored light from the red sensor and the blue sensor and the set value. However, there is a problem that the comparison adjustment time becomes long. In addition, the illumination system disclosed in Patent Document 2 can reduce the color change of mixed color light when a different secular change occurs for each colored light in a plurality of light emitting diodes. There was also a problem that it might become larger. Furthermore, since a plurality of sensors are provided corresponding to each color light, there is a problem that the number of parts increases.

  The present invention has been made in view of the above points, and an object of the present invention is to change the illuminance change of mixed color light even when a plurality of light emitting diodes undergo different secular changes for each colored light. Another object of the present invention is to provide an illumination system capable of reducing color change easily and in a short time and reducing the number of components.

  According to the first aspect of the present invention, a plurality of light emitting diodes each generating one of a plurality of colored lights when power is supplied to generate mixed color light, and the power to each of the plurality of light emitting diodes. Power supply means for supplying the power, and when the power supply means supplies the power for each of the colored light to the plurality of light emitting diodes, the color emitted from the light emitting diode to which the power is supplied A single optical sensor for detecting the illuminance of light; storage means for preliminarily storing an illuminance reference value for each of the colored light; and the illuminance of the colored light emitted from the light emitting diode to which the power is supplied. Comparison means for inputting a detection value from the optical sensor and comparing whether or not the detection value matches the reference value; and from the comparison result, the detection value is different from the reference value. When, characterized in that it comprises a correction means for the detection value to correct the power to match the reference value.

  In this configuration, even when different aging occurs for each colored light in a plurality of light emitting diodes, the illuminance of each colored light can be individually controlled. Reduction can be performed easily and in a short time. In addition, since the single optical sensor can individually detect the illuminance of each colored light, the number of parts can be reduced.

  The invention according to claim 2 is the invention according to claim 1, wherein the storage means stores in advance illuminance characteristics with respect to the emission time from the initial stage to the end of life for each of the colored light, and the correction means includes: When the detected value is different from the reference value based on the comparison result, the correction value of the power is set for each predetermined emission time until the end of the lifetime based on the detected value and the illuminance characteristic, The power is corrected using the correction value every time a predetermined emission time elapses. With this configuration, even if the frequency of detecting the illuminance of each color light by the optical sensor is low, the illuminance change and color change of the mixed color light can be easily reduced to the end of the life of each color light.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the power supply means supplies the power to each of the plurality of light emitting diodes by pulse width modulation. In this configuration, when correcting the power supplied to each light emitting diode, it is possible to supply the light by changing the pulse width while keeping the magnitude of the power constant. Can be prevented.

  According to a fourth aspect of the present invention, in the invention according to the third aspect, the power supply means shifts the power supply timing for each of the colored lights, and each of the plurality of colored lights is emitted alone. The optical sensor detects the illuminance of the colored light emitted separately for each period in which each of the plurality of colored lights is emitted independently, and the comparing means emits the light alone. The illuminance of the colored light is inputted as the detection value from the optical sensor, and the comparison is performed. In this configuration, the illuminance of each colored light can be detected without changing the pulse width of the power supplied to each light emitting diode.

  According to the present invention, in a plurality of light emitting diodes, even when different secular changes occur for each colored light, it is possible to easily and quickly reduce illuminance change and color change of mixed color light, The number of parts can be reduced.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of the illumination system according to the first embodiment. FIG. 2 is a diagram showing the illuminance ratio with respect to the emission time of each light emitting diode in the illumination system of the first embodiment. FIG. 3 is a time chart of the lighting system according to the first embodiment.

  First, the basic configuration of the first embodiment will be described. The illumination system of Embodiment 1 generates white light, and as shown in FIG. 1, includes a light emitting unit 1, a light sensor 2, and a lighting control device 3, and a power source E via a switch 4. Connected. The power source E is, for example, a commercial power source, and supplies power to the lighting control device 3 when the switch 4 is turned on (closed), and supplies power to the lighting control device 3 when the switch 4 is turned off (open). To stop.

  The light emitting unit 1 includes a red light emitting diode 10, a green light emitting diode 11, and a blue light emitting diode 12. The red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 are individually connected to a power supply unit 30 to be described later, and emit red light, green light, and blue light when power is supplied. Accordingly, the light emitting unit 1 generates white light by combining red light, green light, and blue light from the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12. By the way, as shown in FIG. 2, the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 rapidly decrease in illuminance after a certain emission time even if the supplied power is constant from the beginning. To do. In particular, the illuminance of the red light emitting diode 10 decreases more rapidly than the green light emitting diode 11 and the blue light emitting diode 12 (t1 and t2 in FIG. 2).

  As shown in FIG. 1, the optical sensor 2 is a single component and is connected to a comparison unit 32 described later. The power from the power source E is supplied to the lighting control device 3, and the power supply unit 30 described later has a red light emitting diode 10, a green light emitting diode 11, and a blue light emitting diode with respect to the light emitting unit 1 as shown in FIG. When power is supplied independently in the order of 12, the optical sensor 2 detects the illuminance of the colored light emitted from the light emitting diodes 10, 11, and 12 to which power is supplied. More specifically, when the power supply unit 30 supplies power to the red light emitting diode 10, the optical sensor 2 detects the illuminance of red light. Similarly, the illuminance of green light is detected when power is supplied to the green light emitting diode 11, and the illuminance of blue light is detected when power is supplied to the blue light emitting diode 12.

  As illustrated in FIG. 1, the lighting control device 3 includes a power supply unit 30, a storage unit 31, a comparison unit 32, and a correction unit 33, and operates by receiving power from the power source E.

  The power supply unit 30 is individually connected to each of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12, and further connected to the correction unit 33. When the electric power is supplied from the power source E to the lighting control device 3, the power supply unit 30 is individually in the order of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12, as shown in FIG. Supply power. Thereafter, in a normal state, the power supply unit 30 supplies power to each of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 by pulse width modulation (PWM), and outputs red light, green light, and blue light. Simultaneously emits white light. At this time, the power supply unit 30 can change each pulse width within a predetermined maximum range (see FIG. 3). In order to increase the illuminance of each colored light, the pulse width is increased and each colored color is increased. In order to reduce the illuminance of light, the pulse width is narrowed.

  As shown in FIG. 1, the storage unit 31 is connected to the comparison unit 32 and the correction unit 33 and stores a reference value of illuminance in advance for each of red light, green light, and blue light. The reference value of the illuminance is an average value of illuminance in the initial state of the light emitting diodes of the same lot as the light emitting diodes 10, 11, and 12. Thereby, the value which reduced the dispersion | variation of each light emitting diode can be used as a reference value. Instead of the average value of the illuminance by the light emitting diodes of the same lot, the initial value of the illuminance of each of the light emitting diodes 10, 11 and 12 may be detected at the time of manufacture, and the initial value may be used as the reference value.

  The comparison unit 32 is connected to the optical sensor 2 and further connected to the storage unit 31 and the correction unit 33. When the power supply unit 30 supplies power in the order of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12, the comparison unit 32 includes the light emitting diodes 10, 11, The illuminance of the colored light emitted from 12 is input from the optical sensor 2 as a detection value. Thereafter, the comparison unit 32 compares the detected value with the reference value stored in the storage unit 31 and outputs a comparison signal based on the comparison result to the correction unit 33. In the above comparison, the detection value matches the reference value includes not only the case where the detection value is equal to the reference value but also the case where the detection value is within 10% above and below the reference value. Thereby, it is possible to remove the influence of the variation in the detected value.

  The correction unit 33 is connected to the power supply unit 30, the storage unit 31, and the comparison unit 32. The correction unit 33 receives a comparison signal for each color light from the comparison unit 32. If the detection value is different from the reference value, the correction unit 33 emits the corresponding color light so that the detection value matches the reference value. The power to the diodes 10, 11, and 12 is corrected. Specifically, when the detection value is smaller than the reference value, the correction unit 33 outputs a correction signal to the power supply unit 30 so that the pulse width of power to the light emitting diodes 10, 11, and 12 is widened.

  Next, a method for correcting the illuminance of each colored light in the illumination system of Embodiment 1 will be described. Note that the storage unit 31 has already stored a reference value of illuminance for each colored light emitted from each of the light emitting diodes 10, 11, and 12. First, the switch 4 shown in FIG. 1 is turned on to supply power from the power source E to the lighting control device 3. Next, the case of red light will be described. As shown in FIG. 3, when the power supply unit 30 supplies power to the red light emitting diode 10 alone, the optical sensor 2 detects the illuminance of the red light. Thereafter, the comparison unit 32 shown in FIG. 1 inputs the illuminance of red light from the optical sensor 2 as a detection value, and compares whether or not the detection value matches the reference value. When the detected value is different from the reference value based on the comparison result, the correction unit 33 outputs a correction signal to the power supply unit 30 to correct the power to the red light emitting diode 10 so that the detected value matches the reference value. . The correction of the illuminance of red light is thus completed. After the correction of the illuminance of the red light is completed, the power supply unit 30 supplies power to the green light emitting diode 11 alone, and the optical sensor 2 detects the illuminance of the green light (see FIG. 3). The illuminance of the green light is corrected in the same manner as described above. After the correction of the illuminance of the green light is completed, the power supply unit 30 supplies power to the blue light emitting diode 12 alone, and the optical sensor 2 detects the illuminance of the blue light (see FIG. 3). The illuminance of blue light is corrected as in the case of light. The correction of the illuminance of each color light is not limited to the order of red light, green light, and blue light as described above, and may be performed in any order.

  From the above, each time when the switch 4 is turned on until the end of the life of each light emitting diode 10, 11, 12, the light emitting diode 10, 11, 12 has a different secular change for each colored light. Even if it exists, the illuminance of each colored light can be controlled individually.

  As described above, according to the first embodiment, the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 have red light, Since the illuminance of green light and blue light can be individually controlled, the illuminance change and color change of white light (mixed color light) can be easily and quickly reduced. Moreover, since the single optical sensor 2 can individually detect the illuminance of red light, green light and blue light, the number of parts can be reduced. Furthermore, the power supply unit 30 of the lighting control device 3 supplies power to the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 by pulse width modulation, and the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode. When the power supplied to 12 is corrected, the pulse width can be changed while keeping the magnitude of the power constant, so that the red light emitting diode 10, the green light emitting diode 11 and the blue light emitting diode 12 are supplied. An increase in power load can be prevented.

(Embodiment 2)
A second embodiment of the present invention will be described.

  As shown in FIG. 1, the illumination system of the second embodiment includes the light emitting unit 1 and the optical sensor 2 in the same manner as the illumination system of the first embodiment, but the following is not in the illumination system of the first embodiment. There is a characteristic part described in.

  The illumination system of Embodiment 2 includes a timer (not shown) inside the lighting control device 3, for example. The timer is connected to the correction unit 33 and measures the time from the detection of each color light.

  In addition, the storage unit 31 of the lighting control device 3 according to the second embodiment has an illuminance characteristic with respect to the emission time from the initial stage to the end of life as shown in FIG. 2 for each of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12. Are stored in advance together with the same illuminance reference value as in the first embodiment. In addition, the memory | storage part 31 of Embodiment 2 is the same as that of the memory | storage part of Embodiment 1 in points other than the above.

  Further, the correction unit 33 of the lighting control device 3 according to the second embodiment not only corrects the power as in the first embodiment but also detects when the detection value is different from the reference value based on the comparison result of the comparison unit 32. Based on the value and the illuminance characteristic, a power correction value is set for each predetermined emission time until the end of the lifetime. The correction unit 33 corrects the power using the correction value every time the emission time predetermined by the measurement of the timer (not shown) elapses. In addition, the correction | amendment part 33 of Embodiment 2 is the same as that of the correction | amendment part of Embodiment 1 in points other than the above.

  Next, a method for correcting the illuminance of each colored light in the illumination system of Embodiment 2 will be described. In addition, the memory | storage part 31 has already memorize | stored the reference value and illuminance characteristic of illuminance for every colored light radiate | emitted from each light emitting diode 10,11,12. First, as in the first embodiment, red light, green light, and blue light are individually turned on, and the comparison unit 32 compares whether or not the detection value of the optical sensor 2 matches the reference value. When the detected value is different from the reference value based on the comparison result, the correction unit 33 outputs a correction signal to the power supply unit 30 so that the detected value matches the reference value, and outputs the correction signal to each of the light emitting diodes 10, 11, and 12. Correct the power. At the same time, the correction unit 33 sets the power correction value at the emission time determined in advance based on the detection value and the illuminance characteristic until the end of the lifetime. After the setting, the correction unit 33 corrects the power to each of the light emitting diodes 10, 11, 12 using the correction value every time the predetermined emission time elapses.

  From the above, it is possible to set a correction value from the detection of the illuminance of each color light to the end of life, and to correct the power supplied to each of the light emitting diodes 10, 11 and 12 based on the correction value.

  As described above, according to the second embodiment, the same effect as that of the first embodiment can be obtained, and even when the illuminance detection frequency of the red light, the green light, and the blue light by the optical sensor 2 is low, the white light The illuminance change and color change of (mixed color light) can be easily reduced to the end of the lifetime of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12.

  As a modification of the first or second embodiment, the timing for individually detecting the illuminance of each colored light and correcting the power is not limited to immediately after the switch 4 is turned on, and each colored light is emitted. It may be performed at a suitable time according to the application such as during the operation. Even if it does in this way, there can exist an effect similar to Embodiment 1 or 2. FIG.

  As another modification of the first or second embodiment, in a normal state, the power supply unit may supply direct-current power to each of the light-emitting diodes 10, 11, and 12 instead of pulse width modulation. . In this case, in order to increase the illuminance of each colored light, the magnitude of the DC power is increased, and in order to decrease the illuminance of each colored light, the magnitude of the DC power may be decreased. Even if it does in this way, there can exist an effect similar to Embodiment 1 or 2. FIG.

(Embodiment 3)
Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a time chart of the illumination system according to the third embodiment. FIG. 4 is an extension of the time chart of FIG.

  As shown in FIG. 1, the illumination system of the third embodiment includes the light emitting unit 1 in the same manner as the illumination system of the first embodiment, but has the following characteristic portions that are not included in the illumination system of the first embodiment. is there.

  As illustrated in FIG. 4, the power supply unit 30 of the lighting control device 3 according to the third embodiment shifts the power supply timing to the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 to change red light and green light. A period in which each of light and blue light is emitted independently is provided. That is, the power supply unit 30 shifts the power supply timing for each color light without changing the pulse width from the previous one. The power supply unit 30 of the third embodiment is the same as the power supply unit of the first embodiment except for the points described above.

  In addition, the optical sensor 2 according to the third embodiment detects the illuminance of the red light, the green light, and the blue light that are independently emitted for each period in which each of the red light, the green light, and the blue light is independently emitted. The optical sensor 2 according to the third embodiment is the same as the optical sensor according to the first embodiment except for the points described above.

  Furthermore, the comparison unit 32 of the lighting control device 3 according to the third embodiment inputs the illuminances of the red light, the green light, and the blue light emitted independently from the optical sensor 2 as detection values, and the red light, the green light, and the blue light. Each time, the detected value is compared with the reference value stored in the storage unit 31. Note that the comparison unit 32 of the third embodiment is the same as the comparison unit of the first embodiment except for the points described above.

  Next, a method for correcting the illuminance of each colored light in the illumination system of Embodiment 3 will be described. Note that the storage unit 31 has already stored a reference value of illuminance for each colored light emitted from each of the light emitting diodes 10, 11, and 12. First, the power supply unit 30 shifts the power supply timing to each of the light emitting diodes 10, 11, and 12 to provide a period in which each colored light is emitted independently. Subsequently, the optical sensor 2 detects the illuminance of the colored light emitted independently for each period in which each colored light is emitted independently. Thereafter, as in the first embodiment, the comparison unit 32 inputs the detection value from the optical sensor 2 and compares whether or not the detection value matches the reference value. From the comparison result, when the detected value is different from the reference value, the correction unit 33 corrects the power to each of the light emitting diodes 10, 11, and 12 so that the detected value matches the reference value.

  From the above, the illuminance of each colored light is changed even when a different secular change occurs for each colored light in each of the light emitting diodes 10, 11, 12 until the end of the life of each light emitting diode 10, 11, 12. It can be controlled individually.

  As described above, according to the third embodiment, the same effects as those of the first embodiment can be obtained, and the pulse width of the power supplied to each of the red light emitting diode 10, the green light emitting diode 11, and the blue light emitting diode 12 is changed. Without this, the illuminance of red light, green light and blue light can be detected.

  As a modification of the third embodiment, the timing for correcting the power by detecting the illuminance of each colored light by shifting the power supply timing may be performed immediately after the switch 4 is turned on. Even if it does in this way, there can exist an effect similar to Embodiment 3. FIG.

  Further, as a modification of any one of the first to third embodiments, a plurality of light emitting diodes that emit each colored light may be provided. If it does in this way, while having the same effect as either of Embodiments 1-3, the illuminance of each coloring light can be enlarged.

It is the schematic of the illumination system of Embodiment 1-3 by this invention. It is a figure which shows the illumination intensity ratio of each light emitting diode in an illumination system same as the above. It is a time chart of the illumination system of Embodiment 1, 2 by this invention. It is a time chart of the illumination system of Embodiment 3 by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission part 10 Red light emitting diode 11 Green light emitting diode 12 Blue light emitting diode 2 Photosensor 3 Lighting control apparatus 30 Power supply part 31 Memory | storage part 32 Comparison part 33 Correction | amendment part E Power supply

Claims (4)

A plurality of light emitting diodes each generating mixed color light by emitting any one of a plurality of colored lights when power is supplied;
Power supply means for supplying the power to each of the plurality of light emitting diodes;
A single unit for detecting the illuminance of the colored light emitted from the light emitting diode to which the power is supplied when the power supply means supplies the power to the plurality of light emitting diodes for each of the colored light. With a light sensor
Storage means for storing in advance a reference value of illuminance for each colored light;
Comparison means for inputting the illuminance of the colored light emitted from the light emitting diode to which the power is supplied as a detection value from the optical sensor, and comparing whether or not the detection value matches the reference value. ,
And a correction unit configured to correct the power so that the detected value matches the reference value when the detected value is different from the reference value based on the comparison result. The storage means stores in advance the illuminance characteristics with respect to the emission time from the initial stage to the end of life for each colored light,
When the detected value is different from the reference value based on the comparison result, the correcting means sets the correction value of the power for each predetermined emission time until the end of the lifetime based on the detected value and the illuminance characteristic. The illumination system according to claim 1, wherein the illumination system is set and the power is corrected using the correction value every time the predetermined emission time elapses.   3. The illumination system according to claim 1, wherein the power supply means supplies the power to each of the plurality of light emitting diodes by pulse width modulation. The power supply means shifts the power supply timing for each color light and provides a period in which each of the plurality of color lights is emitted alone,
The optical sensor detects the illuminance of the colored light emitted independently for each period in which each of the plurality of colored light is emitted alone,
The illumination system according to claim 3, wherein the comparison unit inputs the illuminance of the colored light emitted alone as the detection value from the optical sensor and performs the comparison.

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