JP2007087816A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting system equipped with a plurality of semiconductor light emitting elements, for example LED, each emitting different colors, wherein prescribed luminescent colors can be maintained regardless of ambient environments, especially temperature changes. <P>SOLUTION: The current value applied to each of light emitting parts 2R, 2G, 2B each emitting light having a plurality of colors in accordance with an ambient temperature when it is actually used is changed so that prescribed luminescent colors can be obtained in accordance with data of set items which an EEPROM 11 memorizes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illuminating device including a plurality of semiconductor light emitting elements such as LEDs, and capable of maintaining a predetermined emission color regardless of the surrounding environment, particularly temperature change, and more specifically, a projector, a scanner, and a copy. A predetermined light emission color different from white light such as a light source such as a machine, a liquid crystal TV, or a headlight for a vehicle, or a white light such as a tunnel light or a fog lamp for a vehicle. The present invention relates to a lighting device.

  An illumination device using a plurality of LEDs as semiconductor light emitting elements has been put into practical use. Such an illuminating device can emit light of any color by combining a plurality of LEDs that emit light of different colors. By the way, the LED has a problem that the light emission characteristic is instantly changed according to the ambient environment, particularly the ambient temperature, in addition to the long-term deterioration of the light emission characteristic due to aging. Hereinafter, the light source of the projector apparatus will be specifically described as an example.

  Conventionally, a high-luminance type light source such as a halogen lamp has been used as a light source of a projector apparatus. However, in recent years, since LEDs as semiconductor light emitting elements have started to be developed with high brightness, projector apparatuses using LEDs as light sources have been developed and put into practical use. Advantages when using an LED as the light source of the projector device include that it does not generate high heat like a halogen lamp, that it can be reduced in size and weight, that it consumes less power, and that it has a long life. In addition, there is no sudden breakage of the ball.

  By the way, a projector apparatus using an LED as a light source is configured so that three types of LEDs emitting red, green, and blue light are set as one set, and white light is obtained by adding light emitted from the set of LEDs. . Such a projector device is shipped after being set (initially set) by the manufacturer in a state in which the relative luminous intensity of each color LED is adjusted in white balance, and supplied to the user. Although the LED of the projector device supplied to the user in this way is inevitably changed in characteristics over the long term due to aging, the characteristics change immediately according to the actual use environment on the user side, The degree of change varies for individual LEDs. Therefore, the characteristics of the LEDs that emit light of each color change to different levels, so that the balance of white light that is initially set at the time of shipment, that is, the white balance changes according to the ambient environment during actual use and collapses. There was a problem that.

  The graph of FIG. 5 shows the change in characteristics depending on the usage environment of the LED. In FIG. 5, it is assumed that the brightness of white light by a pair of LEDs as described above is on the vertical axis, and the LED junction temperature (the LED junction temperature and the ambient temperature during the constant operation of the device are proportional to each other). The temperature of the joint is regarded as the ambient temperature), and the horizontal axis represents the relationship between the two. The graph of FIG. 5 shows the characteristics when the forward current applied to the LED is constant (for example, 20 mA).

  In FIG. 5, “e” indicates an allowable maximum value (variation upper limit), and “f” indicates an allowable minimum value (variation lower limit). “G” is the initial setting value described above. Therefore, when the use environment (ambient temperature) is different from the state in which the initial setting has been performed, the brightness of white light by the pair of LEDs is between the allowable maximum value “e” and the allowable minimum value “f”. It means that it fluctuates. This also means that when the brightness of a set of LEDs changes, the characteristics of the LEDs emitting light of each color do not change to the same degree, but the degree to which each changes, but the brightness of each LED varies. This means that the sum may be between the allowable maximum value “e” and the allowable minimum value “f”.

  Therefore, even if the brightness of a pair of LEDs is within the allowable maximum value “e” and the allowable minimum value “f”, the degree of change in brightness of each LED is different. Indicates that the white balance is shifted, and the larger the difference between the temperature in the initial setting state and the ambient temperature in the use state, the larger the shift in white balance.

In view of such problems, for example, Patent Document 1 discloses an invention in which characteristics of a plurality of LEDs are measured inside the apparatus, and a user is notified of deterioration of a light source based on the measurement result. In Patent Document 2 and Patent Document 3, when a desired light emission color is obtained using a plurality of LEDs, the light emission of each of the plurality of LEDs is detected by a light receiving element, and on the screen surface based on the detection result. An invention for adjusting white balance is disclosed.
JP 2004-296841 A JP 2004-184852 A JP 2004-253309 A

  By the way, all the prior arts disclosed in the above-mentioned patent documents are for detecting changes in LED characteristics due to aging, and as means for detecting changes in LED characteristics due to aging. A light receiving element is provided inside the apparatus. However, in a lighting device that requires a reduction in size and power consumption, particularly a power source lighting device for a projector device for home use, it is necessary to simplify the configuration inside the lighting device as much as possible. In addition, when the device is downsized and the usage environment is severe, the temperature inside the device is inevitably increased even if an LED is used as the light source. In such a case, the color balance is lost due to the degree of change in the light emission characteristics of the plurality of LEDs each emitting light of a different color depending on the temperature. The problem remains.

  The present invention has been made in view of the circumstances as described above. In an illumination device including a plurality of semiconductor light emitting elements, for example, LEDs, each emitting light of a different color, the present invention is concerned with the surrounding environment, particularly the temperature change. It is an object of the present invention to provide an illumination device that can maintain a predetermined emission color.

  In order to solve the above-described problems, the present invention simply sets the setting item data set so that a predetermined emission color can be obtained by using a plurality of semiconductor light emitting elements each emitting light of different colors as a light source. A configuration is adopted in which the value is stored in advance as a set value and adjusted so that a predetermined emission color is obtained according to the initial set value stored in the storage means. Further, as a specific method of adjustment, values relating to power feeding to each of the plurality of semiconductor light emitting elements according to the comparison result between the temperature detected by the temperature detecting means and the temperature at the time of initial setting stored in advance by the storage means Can be changed, and the ambient temperature can be controlled (cooled) with a fan or the like, for example.

  The illuminating device according to the present invention is a setting item set to obtain the predetermined luminescent color in an illuminating device that obtains a predetermined luminescent color by using a plurality of semiconductor light emitting elements that emit light of different colors as light sources. Storage means for storing the data, and adjustment means for adjusting the setting items so that the predetermined emission color can be obtained according to the data of the setting items stored in the storage means.

  In such a lighting device according to the present invention, the adjustment unit adjusts the setting item so that the predetermined emission color is obtained according to the data of the setting item stored in the storage unit, so that the predetermined emission color is obtained. can get.

  In the lighting device according to the present invention, the setting item is a value related to power feeding to each of the plurality of semiconductor light emitting elements with respect to an ambient temperature.

  In such an illuminating device according to the present invention, in the above illuminating device invention, a value relating to power feeding to each of the plurality of semiconductor light emitting elements with respect to the ambient temperature, for example, a current value is used as a setting item.

  Furthermore, the lighting device according to the present invention is the lighting device invention described above, wherein the storage means sets an initial value of an ambient temperature when the predetermined emission color is obtained and a value related to power feeding to each of the plurality of semiconductor light emitting elements. And the adjustment means changes a value related to power feeding to each of the plurality of semiconductor light emitting elements in accordance with an ambient temperature during actual use.

  In such an illuminating device according to the present invention, in the above-described illuminating device invention, the ambient temperature when the predetermined light emission color stored in the storage means is obtained and the values relating to the power supply to each of the plurality of semiconductor light emitting elements are set. As an initial value, the adjustment unit changes a value related to power feeding to each of the plurality of semiconductor light emitting elements according to the ambient temperature during actual use.

  Furthermore, the lighting device according to the present invention is the lighting device invention described above, wherein the adjusting means is a temperature detecting means for detecting an ambient temperature of the plurality of semiconductor light emitting elements, a temperature detected by the temperature detecting means, and the storage means. Comparison means for comparing the ambient temperature stored in the memory, and change means for changing a value related to power supply to each of the plurality of semiconductor light emitting elements according to a comparison result by the comparison means.

  In such a lighting device according to the present invention, in the above lighting device invention, the temperature detected by the temperature detecting means is compared with the ambient temperature stored in the storage means, and a plurality of semiconductor light emitting devices are selected according to the comparison result. The value related to the power supply to each element is changed.

  Furthermore, the illumination device according to the present invention is characterized in that, in the invention of the illumination device, the adjusting means further includes a cooling means for lowering an ambient temperature of the plurality of semiconductor light emitting elements.

  In such a lighting device according to the present invention, in the invention of the lighting device described above, the ambient temperature of the plurality of semiconductor light emitting elements is cooled by the cooling means.

  Furthermore, the lighting device according to the present invention is characterized in that, in any one of the above lighting device inventions, each of the plurality of semiconductor light emitting elements is an LED having a different emission wavelength.

  In such an illuminating device according to the present invention, in any one of the above-described illuminating device inventions, each of the plurality of semiconductor light emitting elements is composed of LEDs having different emission wavelengths.

  According to the illuminating device according to the present invention as described above, when adjusting the color temperature (colored light) of the light source of the illuminating device using the semiconductor light emitting element as the light source, in accordance with the change of the surrounding environment (temperature), The color temperature at the time of initial setting can be maintained without the necessity of providing light receiving means for detecting the light emitted from the light emitting element inside the apparatus. Accordingly, since the lighting device can be configured with a simple circuit, it is possible to reduce the size of the lighting device, reduce power consumption, and the like.

  Further, according to the lighting device according to the present invention, in the lighting device invention described above, a value relating to power supply to each of the plurality of semiconductor light emitting elements with respect to the ambient temperature, for example, a current value is used as a setting item, so that control is easy. is there.

  Furthermore, according to the lighting device according to the present invention, in the above lighting device invention, the ambient temperature when the predetermined light emission color stored in the storage means is obtained, and the values related to the power supply to each of the plurality of semiconductor light emitting elements are obtained. As the initial value, the adjustment means changes the value related to the power supply to each of the plurality of semiconductor light emitting elements according to the ambient temperature at the time of actual use, so that means for detecting the light emitted from the light emitting element at the time of actual use becomes unnecessary. Thus, downsizing of the apparatus and reduction of power consumption are realized.

  Furthermore, according to the lighting device according to the present invention, in the lighting device invention described above, the temperature detected by the temperature detecting means and the ambient temperature stored in the storage means are compared, and a plurality of semiconductor light emitting devices are selected according to the comparison result. Since the value related to the power supply to each element is changed, a means for detecting the light emitted from the light emitting element during actual use is not required, and the apparatus can be reduced in size and the power consumption can be reduced.

  Further, according to the lighting device of the present invention, in the invention of the lighting device described above, since the ambient temperature of the plurality of semiconductor light emitting elements is cooled by the cooling means, the temperature change of the semiconductor light emitting element itself is reduced, and the semiconductor light emitting element itself The control of the minimum is necessary.

  Furthermore, according to the lighting device according to the present invention, in any one of the above-described lighting device inventions, each of the plurality of semiconductor light emitting elements is composed of LEDs having different emission wavelengths. It becomes possible to obtain light of any color.

  Hereinafter, an embodiment of a lighting device according to the present invention will be described in detail with reference to the drawings. In the following, as an embodiment of the present invention, an LED is used as a semiconductor light emitting device, a set of red LED, blue LED, and green LED, and a white light emitting color (white light) as a light source. A lighting device that is incorporated in the apparatus and used as a light source will be specifically described.

  FIG. 1 is a block diagram showing a configuration example when the illumination device according to the present invention is incorporated in a projector device 1. However, the state shown in FIG. 1 shows a state at the time of initial setting.

  In FIG. 1, 2R represents a red light emitting part, 2G represents a green light emitting part, and 2B represents a blue light emitting part. 3R is a red light emitting unit current control circuit for controlling a current (IfpR) applied to the red light emitting unit 2R, and 3G is a green light emitting unit current control circuit for controlling a current (IfpG) applied to the green light emitting unit 2G. 3B shows a blue light emitting unit current control circuit for controlling the current (IfpB) applied to the blue light emitting unit 2B. In FIG. 1, each of the light emitting units 2R, 2G, and 2B is illustrated as being configured by one LED, but the number of LEDs that configure each of the light emitting units 2R, 2G, and 2B is 1 The number may be one by one, the same number of two or more, or a different number.

  In addition, since the light emission intensity of the LED changes almost directly in proportion to the applied current value, each light emitting unit current control circuit 3R, 3G, 3B controls the current value applied to each light emitting unit 2R, 2G, 2B. Thus, it is possible to control the light emission intensity of each of the light emitting units 2R, 2G, and 2B in direct proportion to the applied current value.

  Reference numeral 9 indicates a fan device as a forced cooling means. The fan device 9 rotates a fan (not shown) with a motor (not shown) to cool the light emitting units 2R, 2G, 2B. However, the cooling means is not limited to the so-called air cooling method using the fan device 9, and a water cooling method for circulating the cooling water can also be adopted. Reference numeral 8 denotes a fan voltage control circuit that controls the voltage of the motor that rotates the fan of the fan device 9.

  Further, reference numeral 13 indicates a temperature sensor, and in this embodiment, each of the LEDs of the light emitting units 2R, 2G, and 2B or any one junction temperature is regarded as the ambient temperature and measured. Reference numeral 11 denotes an EEPROM, which is a rewritable nonvolatile storage means. For example, a flash memory or a small hard disk drive can be used instead of the EEPROM.

  Reference numeral 12 denotes a ROM, which is a nonvolatile storage means that cannot be rewritten. The ROM 12 stores in advance a program file in which a computer program for executing control by the control unit 10 is recorded, various data necessary for executing the computer program, and the like. Further, the ROM 12 stores in advance data on the characteristics of the LEDs (the relationship between the applied current value for each ambient temperature and the light emission luminance). This data may be general data, but by storing the actual measured data for each LED manufacturer (manufacturer), the ambient temperature can be adjusted according to the manufacturer of the LED mounted on the lighting device. Correction for changes can be performed more accurately.

  Each of the light emitting section current control circuits 3R, 3G, 3B, the fan voltage control circuit 8, the EEPROM 11, the ROM 12, and the temperature sensor 13 are connected to a CPU (microcomputer) 10. The CPU 10 executes processing to be described later using a computer program, various data, and the like stored in advance in the ROM 12.

  Reference numeral 14 denotes a lens group for irradiating (projecting) white light, which is obtained by adding three colors of light emitted from the light emitting units 2R, 2G, and 2B, to the external screen 16 in focus. The brightness of the light or the wavelength and intensity of the light irradiated on the screen 16 is measured by a photometer or a photometer 15. However, the photometer or light measurement device 15 is necessary only at the time of initial setting by the manufacturer, and the screen 16 is necessary in a state where the projector apparatus 1 is actually used, but the photometer or light measurement device 15 is not necessary. Absent.

  Next, an initial setting of the lighting device according to the present invention having the configuration shown in FIG. 1 will be described below. This initial setting is a process for obtaining a white emission color while adjusting the white balance by using the light emitting units 2R, 2B, and 2G that emit three colors of light. It is performed, not the process performed by the user.

  FIG. 2 is a flowchart showing a processing procedure for such initial setting, which is executed by the CPU 10 in accordance with a computer program stored in the ROM 12 in advance. However, since this initial setting is a process performed by the manufacturer before shipment, a computer program for initial setting is stored in the external storage means, and the CPU 10 is connected to the external storage means only at the time of initial setting. You may make it perform.

  First, the CPU 11 gradually controls the applied current value IfpG (or IfpR, IfpB) by controlling the current control circuit 3G (or 3R, 3B) of the light emitting unit 2G (or 2R, 2B) that emits light having the lowest luminance. In other words, a substantially maximum value that can be used in any environment without any practical problem is set as a reference value for initial setting of the applied current value of the light emitting unit 2G (or 2R, 2B) (step S11). At this time, the CPU 10 supplies the current value control circuits 2R and 2B (or 2G) to the light emitting units 2R and 2B (or 2G and 2B, 2R and 2G) other than the light emitting unit 2G (or 2R and 2B) having the lowest light emission luminance. And 2B, 2R and 2G) by controlling current IfpR and IfpB (or IfpG and IfpB, IfpR and IfpG), that is, light emission other than the light emitting part 2G (or 2R, 2B) having the lowest light emission luminance. The portions 2R and 2B (or 2G and 2B, 2R and 2G) are prevented from emitting light. Note that the substantially maximum value is not a maximum value that is actually full, but a value having a slight margin slightly lower than that.

  By the way, the light emitting part having the lowest luminance described above is not a comparison of standard values of single LEDs constituting each light emitting part 2R, 2G, 2B, but a set of light emitting parts 2R provided in the lighting device according to the present invention. , 2B, and 2G, the light emitting portion of the light having the lowest luminance. Specifically, even if each LED alone emits green light and has the lowest luminance according to the standard, for example, the green light emitting unit 2G is configured by two LEDs that emit green light. If the red light emitting part 2R is composed of one LED that emits light, and the blue light emitting part 2B is composed of one LED that emits blue light, the green light composed of two LEDs The light emitting unit 2G is not necessarily the light emitting unit having the lowest luminance. In this case, it is possible that one of the light emitting units 2R (or 2B), which is composed of one LED of another color (red or blue), is the light emitting unit having the lowest luminance.

  Next, the CPU 10 controls the current control circuit for the light emitting unit to gradually increase the current of the light emitting unit having the lower light emission luminance among the remaining light emitting units (step S12). Is added to the emitted light of the light emitting part having the lowest luminance. The light obtained by adding the two colors of light is applied to the screen 16 by the lens group 14, and the brightness on the screen 16 is measured by a photometer (color thermometer) or a light measuring device 15. The result of this measurement is fed back to the CPU 10. Accordingly, the CPU 10 keeps the light emission intensity of the light emitting part that is emitting light first among the two color light emitting parts that are emitting light at that time, as set in step S11, and the light emitting part that is subsequently emitted emits light. The applied current value is gradually increased by controlling the current control circuit for the light emitting section that has been emitted later until the light obtained by adding the light to be obtained has a predetermined color temperature (NO in step S13).

  For example, if the light emitting part having the lowest luminance is the green light emitting part 2G, and the light emitted from the blue light emitting part 2B is added to the light emitted from the green light emitting part 2G, the color of the added light is cyan. Accordingly, the CPU 10 sets the value obtained by measuring the luminance or the intensity of the green wavelength and the intensity of the blue wavelength with the photometer or the photometer 15 to be a predetermined value (YES in step S13). The green light emitting unit current control circuit 3G is controlled to adjust the current value applied to the green light emitting unit 2G. The predetermined value in this case may be referred to a value calculated from the characteristics of the LED constituting the light emitting unit, and the red color from white light adjusted in advance to be the same color as standard white light. It is good also as a value of the photometer (color thermometer) at the time of interrupting | blocking the electric current of the light emission part 2R, or the optical measuring device 15. FIG.

  Next, the CPU 10 gradually increases the current applied to the remaining one color light emitting section (red light emitting section 2R) by controlling the red light emitting section current control circuit 3R (step S14). In this case, the CPU 10 does not change the applied current value for the green light emitting unit 2G and the blue light emitting unit 2B that have already emitted light. Accordingly, the lens group 14 irradiates the screen 16 with light obtained by adding the red light emitted from the red light emitting unit 2R to the two colors of light emitted from the green light emitting unit 2G and the blue light emitting unit 2B. The light irradiated on the screen 16 is measured by a photometer (color thermometer) or a light measuring device 15 and the measurement result is fed back to the CPU 10. Therefore, the CPU 10 controls the red light emission unit current control circuit 3R until the measurement result by the photometer or the light measurement device 15 reaches the color temperature of white light (NO in step S15) as in the case described above. If white light cannot be obtained by the process of step S14, the processes of steps S12 and S14 described above may be repeated.

  When the adjustment of the white light, that is, the white balance is completed as described above (YES in step S15), the CPU 10 applies the ambient temperature, which is the measured value of the temperature sensor 13 at that time, and the light emitting units 2R, 2G, 2B of the respective colors. The read current value is read (step S16), and these data are written and stored as initial setting data (initial setting temperature, initial setting current value) in the EEPROM 11 (step S17). This completes the initial setting. Thereafter, the projector apparatus 1 is disconnected from the photometer or the light measuring instrument 15, and when the computer program for initial setting is read from the external storage means, the connection with the storage means is also disconnected and shipped. .

  It should be noted that the manufacturer name of the LED mounted on the lighting device according to the present invention is written in the EEPROM 11 as data, thereby maintaining the predetermined predetermined colored light (white in the present embodiment) which will be described later. This can be used to improve accuracy during processing.

  Next, when the user actually uses the projector device 1, when the use environment (ambient temperature) is different from the environment (temperature) at the time of initial setting, the emission color (white in the present embodiment) is set at the initial setting. FIG. 3 is a flowchart showing the processing procedure, and the timing showing the relationship between the temperature detected by the temperature sensor 13 shown in FIG. 4 and the voltage supplied to the fan device 9 by the fan voltage control circuit 8. This will be described with reference to the chart. 4A shows the temperature detected by the temperature sensor 13, and FIG. 4B shows the voltage (fan voltage) supplied by the fan voltage control circuit 8 to the motor of the fan device 9 over time. Yes.

  When the user turns on the power of the projector device 1 and starts up the projector device 1, all the LEDs constituting the light emitting units 2R, 2G, and 2B that are the light sources of the illumination device emit light and emit white light (step S21). YES) This timing is the timing of “LED ON” in FIG.

  By the way, if it is not as much as the halogen lamp, the LED junction temperature (which is regarded as the ambient temperature in the present embodiment) gradually increases with time if the LED continues to emit light. This state is shown as a temperature increase from the point of “LED ON” in FIG. In the lighting device according to the present invention, such a temperature rise is detected by the temperature sensor 13 (step S22), and data of the detection result (hereinafter referred to as detected temperature) is output to the CPU 10. The CPU 10 periodically reads the detected temperature output from the temperature sensor 13 and compares the result with the initial set temperature, that is, the ambient temperature stored in the EEPROM 11 at the initial setting shown in the flowchart of FIG. 2 (step S23).

  As a result of the comparison in step S23, when the temperature difference between the detected temperature detected by the temperature sensor 13 and the initial set temperature is equal to or greater than the predetermined temperature difference (YES in step S24), the CPU 10 Control to change the emission intensity is performed. Specifically, the CPU 10 indicates the relationship between the applied current value for each junction temperature of the LED that emits light of each color constituting the light emitting units 2R, 2G, and 2B of each color stored in advance in the ROM 12 and the brightness. With reference to the data, a correction (current) value necessary to make the brightness of the light emitting section 2G (or 2R, 2B) having the lowest luminance the same as the brightness at the initial setting at the detected temperature at that time (step) S25). That is, the correction value is the difference between the reference value set at the initial setting and the current value required at the detected temperature at that time.

  Next, CPU11 calculates | requires the electric current value required for other light emission parts 2R and 2B (or 2G and 2B, 2R, and 2G) (step S26). Specifically, based on the ratio between the reference value and the correction value obtained as described above, the current values of the LEDs of the other light emitting units 2R and 2B (or 2G and 2B, 2R and 2G) at the time of initial setting Correct. The CPU 10 is configured so that the corrected current values of the LEDs of the light emitting units 2R, 2G, and 2B are applied from the light emitting unit current control circuits 3R, 3G, and 3B to the LEDs of the light emitting units 2R, 2G, and 2B. (Step S27), substantially the same white light can be obtained if not completely as in the initial setting.

  As described above, it is necessary to increase the applied current value to the light emitting section 2G (or 2R, 2B) having the lowest luminance, in other words, it is necessary to increase the reference value at the time of initial setting. At the time of initial setting shown in the above, the current value (reference value) of the light emitting part 2G (or 2R, 2B) having the lowest luminance is not set to the maximum value, and a value with a slight margin of eyes slightly lower than that is set. Must be set to

  Furthermore, the LED characteristics (relationship between the applied current value for each ambient temperature and the light emission brightness) stored in advance in the ROM 12 are not general data, but are actually measured by LED manufacturers (manufacturers). By storing the data, the above-described correction for the change in ambient temperature during actual use can be performed more accurately.

  By the way, the correction of the light emission luminance of the light emitting units 2R, 2G, 2B of each color according to the ambient temperature (temperature detected by the temperature sensor 13) is performed as described above. It is not necessary to perform such correction, or even if correction is unavoidable, significant correction is not necessary. Therefore, in the present embodiment, the light emission luminances of the light emitting portions 2R, 2G, and 2B of the respective colors described above are corrected and cooled. This will be specifically described below.

  When the determination result in step S24 described above is NO or after the processing in step S27 is completed, the CPU 10 compares the detected temperature detected by the temperature sensor 13 with a predetermined temperature range (step S28). Here, the predetermined temperature range is specifically the temperature range between the upper limit value and the lower limit value shown in FIG. Note that the upper limit value and lower limit value of these predetermined temperature ranges are stored in the ROM 12 or the EEPROM 11 in advance.

  Next, the CPU 10 determines whether or not the fan of the fan device 9 is rotating, in other words, whether or not it is cooling (step S29). When the cooling is not in progress (NO in step S29), the CPU 10 determines whether or not the detected temperature is equal to or higher than a predetermined temperature range (step S30). If the detected temperature is not equal to or greater than the predetermined temperature range (NO in step S30), the CPU 10 returns the process to step S22. Therefore, if the detected temperature is not equal to or greater than the predetermined temperature range when the cooling is not being performed, the CPU 10 reads the detection value of the temperature sensor 13 at predetermined time intervals without performing cooling, that is, periodically, and repeats the same processing as described above. . If the detected temperature is equal to or greater than the predetermined temperature range (YES in step S30), the CPU 10 controls the fan voltage control circuit 8 so that the fan of the fan device 9 rotates at the number of rotations corresponding to the detected temperature (step S31). Accordingly, cooling is started when the detected temperature is equal to or higher than the predetermined temperature range in a state where the cooling is not being performed. This timing is shown as “fan rotation start” in FIG. Thereafter, the CPU 10 returns the process to step S22.

  On the other hand, if the fan of the fan device 9 is already rotating, in other words, if it is cooling (YES in step S29), the detected temperature is not less than the predetermined temperature range (NO in step S32). The process proceeds to S31 and the fan voltage control circuit 8 is controlled so that the fan of the fan device 9 rotates at a rotation speed corresponding to the detected temperature. Therefore, cooling is continued when the detected temperature is not lower than the predetermined temperature range in the cooling state.

  After that, the CPU 10 returns the process to step S22. If the detected temperature further increases when the detected temperature is read from the temperature sensor 13 next time, the CPU 10 increases the speed corresponding to the increased detected temperature. Then, the fan voltage control circuit 8 is controlled so that the fan of the fan device 9 rotates. Therefore, according to the detected temperature, that is, the higher the detected temperature, the fan of the fan device 9 rotates at a higher speed and the cooling effect becomes greater. In this state, as the detected temperature shown in FIG. 4A increases, the fan voltage shown in FIG. 4B increases, and the detected temperature shown in FIG. This is shown by the fact that the fan voltage shown in FIG.

  When the cooling proceeds in this manner, the detected temperature becomes lower than the predetermined temperature range in step S32 (YES in step S32), so the CPU 10 causes the fan voltage control circuit 8 to stop the rotation of the fan of the fan device 9. Is controlled (step S33). This timing is shown as “fan stop” in FIG.

  As described above, since the fan of the fan device 9 repeats rotation and stop according to the rise and fall of the ambient temperature, the ambient temperature is maintained within a certain range once the cooling is started. By controlling the light emission luminance of each of the light emitting units 2R, 2G, and 2B, the light emission color of the lighting device according to the present invention can be maintained substantially the same white as that at the initial setting.

  In the above-described embodiment, the case where the lighting device according to the present invention is incorporated as the lighting device of the projector device 1 to obtain white light has been described, but it is needless to say that the lighting device of the present invention can be applied to other than white light. Is possible. For example, since a sodium lamp emits a single light of 589 nm, it has good permeability to fog and smoke, so it is used for lighting in tunnels, automobile fog lamps, and the like. Therefore, the illumination according to the present invention is determined by setting an initial setting value with the light emission portion emitting red light and the light emitting portion emitting green light as the strongest spectrum of 589 nm as much as possible. It is possible to use the device in place of a sodium lamp. In this case as well, the initially set wavelength can be maintained regardless of the change in ambient temperature. Of course, the illumination device according to the present invention can be similarly used for other various emission colors.

It is a block diagram which shows the structural example at the time of incorporating the illuminating device which concerns on this invention in a projector apparatus. It is a flowchart which shows the process sequence for the initial setting of the illuminating device which concerns on this invention. It is a flowchart which shows the process sequence for maintaining the luminescent color in the state at the time of initial setting at the time of actual use of the illuminating device which concerns on this invention. It is a timing chart which shows the relationship between the detection temperature of the temperature sensor of the illuminating device which concerns on this invention, and the electric power feeding voltage to the fan apparatus by a fan voltage control circuit. It is a graph which shows the general change of the characteristic by the use environment of LED.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Illumination device 2R, 2G, 2B Red, green, blue light emission part 3R, 3G, 3B Light emission part current control circuit 8 Fan voltage control 9 Fan 13 Temperature sensor 14 Lens group 10 CPU
11 EEPROM
12 ROM
16 screen 15 photometer

Claims (6)

In an illumination device that obtains a predetermined emission color using a plurality of semiconductor light emitting elements each emitting light of a different color as a light source,
Storage means for storing data of setting items set to obtain the predetermined emission color;
An illuminating apparatus comprising: an adjustment unit that adjusts the setting item so that the predetermined emission color can be obtained according to the data of the setting item stored in the storage unit.   The lighting device according to claim 1, wherein the setting item is a value related to power feeding to each of the plurality of semiconductor light emitting elements with respect to an ambient temperature. The storage means stores, as an initial value, an ambient temperature when the predetermined light emission color is obtained and a value related to power feeding to each of the plurality of semiconductor light emitting elements,
The lighting device according to claim 2, wherein the adjustment unit changes a value related to power feeding to each of the plurality of semiconductor light emitting elements according to an ambient temperature during actual use. The adjusting means includes
Temperature detecting means for detecting an ambient temperature of the plurality of semiconductor light emitting elements;
Comparison means for comparing the temperature detected by the temperature detection means with the ambient temperature stored in the storage means;
The lighting device according to claim 3, further comprising: a changing unit that changes a value related to power feeding to each of the plurality of semiconductor light emitting elements according to a comparison result by the comparing unit.   The lighting device according to claim 4, wherein the adjusting unit further includes a cooling unit that reduces an ambient temperature of the plurality of semiconductor light emitting elements.   The lighting device according to claim 1, wherein each of the plurality of semiconductor light emitting elements is an LED having a different emission wavelength.

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