JP2011238380A - Power supply and discrimination circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply which can discriminate the ID resistor over a wider range of resistance and can increase the number of ID resistors to be discriminated.SOLUTION: The power supply 100 connected with an illumination unit 10 comprising a light source 2 and an ID resistor 1 having different resistances for different characteristics of the light source 2 discriminates the characteristics of the light source 2 based on the ID resistor 1 and performs light control of the light source 2 depending on the characteristics thereof. The power supply 100 comprises a reference capacitor 3 connected in series with the ID resistor and provided so that an RC circuit 7 is formed, a reference signal output unit 61 which inputs a reference signal to the RC circuit 7, a time delay measurement unit 62 which measures a time delay based on the output signal from the RC circuit 7 and the reference signal, and a characteristics discrimination unit 63 which discriminates the characteristics of the light source 2 based on the time delay measured by the time delay measurement unit 62.

Description

  The present invention relates to a power supply device that changes a control mode in accordance with the characteristics even when light sources having different characteristics are attached, and a determination circuit thereof.

  Even if there are various specifications such as the type, application, and number of light sources such as LEDs in the lighting mechanism, the characteristics of the LEDs are determined, and dimming control is performed at the rated current according to the characteristics. A power supply device configured to be able to do so is disclosed in Patent Document 1.

  In this illumination mechanism, an ID resistor is provided in parallel with the LED in the illumination mechanism, and when the illumination mechanism and the power supply device are connected by a connector, a voltage is applied to the ID resistor at a voltage equal to or lower than the lighting lower limit voltage of the LED, The voltage distributed to the resistor in the power supply device that changes depending on the type of the ID resistor is detected. More specifically, when the resistance value of the ID resistor is R, the resistance value of the resistor in the power supply device is r, and the applied voltage is E, the voltage V divided by the resistor in the power supply device is V = Er / (R + r) Since the resistance value R of the ID resistor is changed, the voltage V changes accordingly. Therefore, the power supply device is configured to measure the voltage V divided by the resistance in the power supply device, and to determine the characteristics of the LED with reference to a table stored in the memory in the microcomputer based on the result. ing.

  However, in the method of detecting the voltage V applied to the resistance in the power supply device and discriminating the type of the ID resistor in this way, the number of types that can be discriminated is not satisfactory at present. As can be seen from the above-described equation, when the resistance value R of the ID resistor becomes sufficiently larger than the resistance value r of the resistor in the power supply device, the detected voltage regardless of the resistance value R of the ID resistor. V becomes substantially zero. If the difference in the voltage V detected when changing from one ID resistor to another ID resistor becomes smaller than the resolution of the A / D board, it becomes impossible to distinguish two different ID resistors. In the region where the resistance value R is large, it is difficult to distinguish. Conversely, when determining the ID resistance from the voltage divided by each resistor, if the resistance in the power supply device is determined, the resistance value R of the ID resistor that can be determined according to the resistance value r is determined. The value is also roughly determined, and the ID resistor must be selected from a limited type of resistor.

  In addition, since the resistance value of the ID resistor also includes an error due to a manufacturing error or the like, especially in a region where the resistance value R of the ID resistor is large, a difference depending on the type of ID resistor appears or a difference appears due to the error. I don't know what it is. For this reason, in the method for determining the ID resistance by detecting the voltage divided by the resistance in the power supply device as described above, the upper limit side of the range of the resistance value R of the ID resistance must be limited. It is difficult to increase the number of ID resistors that can be discriminated. In order to be able to discriminate even in a region where the resistance value R is large, it is conceivable to increase the resolution of the voltage that can be detected by the A / D board. However, expensive parts are used, resulting in an increase in cost. Will lead to a lack of balance as a product.

JP 2006-351484 A

  The present invention has been made in view of the above-described problems, and does not detect the voltage divided by the ID resistor and discriminate the type of each ID resistor as in the prior art, but is completely new. An object of the present invention is to provide a power supply device and a discrimination circuit that can discriminate an ID resistance by a method, can discriminate in a wider range of resistance values, and can improve the discriminable number.

  That is, the power supply device of the present invention is connected to an illumination unit including a light source and an ID resistor having a resistance value that differs for each characteristic of the light source, and determines the characteristics of the light source based on the ID resistance. A power supply device that performs dimming control of the light source in accordance with characteristics, a time delay generating element that is connected in series with the ID resistor to form a time delay generating circuit, and the time delay generation A reference signal output unit that outputs a reference signal input to the circuit, an output signal from the time delay generation circuit, a time delay measurement unit that measures a time delay based on the reference signal, and the time delay measurement unit And a characteristic discriminating unit that discriminates the characteristic of the light source based on the time delay measured by the above.

  The discrimination circuit of the present invention is a discrimination circuit for discriminating an ID resistance, which is connected in series with the ID resistor, and is provided with a time delay generation element provided to form a time delay generation circuit, A reference signal output unit that outputs a reference signal input to the time delay generation circuit; an output signal from the time delay generation circuit; a time delay measurement unit that measures a time delay based on the reference signal; And a resistance determining unit that determines the ID resistance based on the time delay measured by the time delay measuring unit.

  In such a case, since the type of the ID resistor is determined by measuring the time delay generated in the time delay generating circuit, even if the resistance value R becomes large, it is proportional to it. Since a time delay can be generated, a difference can easily appear in each ID resistor, and the difference can be easily discriminated. Further, when the resistance value R of the ID resistor is increased, the time delay can be increased accordingly, so that the influence of the error of the resistor included in the ID resistor can be reduced, and the ID resistor can be easily discriminated. .

  That is, in the case of the configuration in which the divided voltage value is detected as in the conventional case, in the region where the resistance value R of the ID resistor is large, the difference due to the ID resistor hardly appears, whereas the time delay With this configuration, the ID resistance is discriminated, so that even in a region where the resistance value R is large, a difference appears in the measured value, so that the discrimination can be performed. Therefore, since the difference in the resistance value R of the ID resistor can be detected and discriminated in a wider range, more types of ID resistors can be detected.

  Further, in the method of discriminating the ID resistance from the voltage divided by each resistor, since the section having good linearity is limited, the types of resistors that can be used as the ID resistor are limited. For example, since the relationship between the resistance value of the ID resistor and the time delay can be made to have a good linearity, it can be determined even if the interval between the resistance values of the ID resistors to be used is shortened. Various types of resistors can be used as ID resistors. In addition, since the time delay increases as the resistance value increases, more types of ID resistors can be identified by simply extending the measurement time without improving the performance of the measuring instrument, such as shortening the clock of the timer. become able to. Of course, it is possible to increase the types of ID resistors that can be identified by shortening the clock of the timer.

  Furthermore, since the time delay generating element is provided on the power supply device side, it is not necessary to provide the time delay generating element in the illumination unit in order to generate the time delay. Therefore, especially when there are many variations of the illumination unit and the power supply device is limited to several types, only a few types of products need to be calibrated for the time delay element, and the burden in manufacturing and inspection can be reduced. Further, if a time delay generating element is provided in the illumination unit, an error occurs in the time delay element due to heat from the light source, and the types of ID resistors that can be identified may be reduced. On the other hand, in the present invention, since the time delay generating element is provided in the power supply device, it is possible to prevent such a problem from occurring.

  Furthermore, since the number of types of ID resistance that can be detected is improved in this way, the number of illumination units that can be handled by one power supply device is also improved, and a wider product lineup can be supported.

  If the time delay generating element is a reference capacitor, the time constant of the circuit can be RC, and the time delay generated in the time delay generating circuit is a value related to the time constant RC. Therefore, since the measured time delay is proportional to the resistance value R, especially when the resistance value R is large, the difference in time delay among the discrimination resistors is likely to appear, and it is suitable for extending the discriminable range than the conventional one. Yes.

  In order to reduce erroneous detection of the type of ID resistor to be detected, the characteristic determination unit determines the ID resistance based on the time delay measured by the time delay measurement unit, and the resistance The determination unit compares each of the determination results stored in the determination result with the determination result storage unit that stores the respective determination results obtained by determining the ID resistance a plurality of times. A determination unit that determines that the ID resistance is determined; and a light source characteristic that determines the characteristics of the light source based on the first determination result or the second determination result when the determination unit determines that the ID resistance is determined. Any device including a determination unit may be used.

  In order to improve the detection accuracy by taking into account the error of the reference capacitor so that there is not much difference from the arithmetic value, using the error correction value determined based on the error of the reference capacitor, the time delay What is necessary is just to further provide the error correction part which correct | amends the time delay measured by the measurement part.

  In order to prevent an error from occurring in the time delay measured due to the charge remaining in the reference capacitor and to make it possible to more accurately determine the ID resistance, the charge accumulated in the reference capacitor is discharged. What is necessary is just to further provide the forced discharge circuit to be made.

  As described above, according to the power supply device and the determination circuit of the present invention, the reference signal is input to the time delay generation circuit including the ID resistor and the time delay generation element, and the time delay is measured from the output signal with respect to the reference signal. Since the ID resistance is discriminated based on the time delay, even if the resistance value R of the ID resistance increases, the time delay increases in proportion to the ID resistance, and the difference between the ID resistances is likely to appear. In addition, since the influence of the error of the resistance value included in each ID resistor on the measurement result can be reduced, the types of ID resistors that can be identified can be increased.

The schematic diagram which shows the light irradiation apparatus which concerns on one Embodiment of this invention. The functional block diagram in the embodiment. The typical graph shown about the measurement of the time delay in the embodiment. The flowchart which shows the measurement procedure of the electrostatic capacitance of the reference | standard capacitor | condenser at the time of the assembly in the same embodiment. 6 is a flowchart showing a procedure for determining an ID resistance in the embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in the schematic diagram of FIG. 1, the light irradiation device 200 of the present embodiment includes an illumination unit 10 that uses an LED 2 as a light source, and a power supply device 100 that is connected to the illumination unit 10 and performs dimming of the illumination unit 10. It is composed of

  The illumination unit 10 includes a connector C connected to the power supply device 100, the LED 2, and an ID resistor 1 corresponding to the characteristics of the LED 2. The LED 2 and the ID resistor 1 are A circuit in which a time delay occurs when connected to the power supply apparatus 100 is configured.

  The illumination unit 10 has various numbers of LEDs 2 and their rated currents or rated voltages depending on applications, and various types are prepared. The ID resistor 1 has a different resistance value R for each type of the illumination unit 10.

  The power supply device 100 is connected to the variable voltage power supply 5 connected to the LED 2 and the ID resistor 1, performs the determination of the ID resistor 1, and varies the control according to the determined characteristic of the illumination unit 10. And a control mechanism S for the voltage power source 5.

  The variable voltage power source 5 applies a commanded voltage or current from the control unit 6 to be described later to the LED 2.

  The control mechanism S includes a reference capacitor 3 connected in series with the ID resistor 1 as shown in the functional block diagram of FIG. 2 so as to constitute an RC circuit 7 as a time delay generation circuit, and the reference capacitor 3. The Schmitt trigger 4 provided in series with the capacitor 3 and the control unit 6 that determines the ID resistor 1 and controls the variable voltage power source 5 to apply a voltage according to the type of the specified illumination unit 10. It is composed of. Further, the reference capacitor 3 is provided with a forced discharge circuit 8 for discharging the accumulated electric charge.

  As will be described later, the actual capacitance of the reference capacitor 3 is obtained by measurement, and an error with respect to the displayed capacitance is known. Even if an error is included in the capacitance of the reference capacitor 3, it can be used in consideration of the error by an error correction value to be described later.

  The Schmitt trigger 4 is for, for example, outputting a rectangular wave to the control unit 6 on the condition that the voltage of the reference capacitor 3 is equal to or higher than a predetermined voltage so that the control unit 6 can easily detect the square wave. is there.

  The forced discharge circuit 8 is constituted by an FET (field effect transistor) provided in parallel with the reference capacitor 3, and its gate is connected to a terminal of the control unit 6 to control forced discharge circuit described later. The part 65 controls the on / off of the current flowing from the drain to the source.

  The function of the control unit 6 is realized by a control microcomputer having a memory such as an I / O port, a timer, a counter, a CPU, a RAM, and a ROM, and at least a reference signal output unit 61, It functions as a time delay measurement unit 62, a characteristic determination unit 63, a power supply control unit 64, and a forced discharge circuit control unit 65. Here, the reference capacitor 3, the reference signal output unit 61, the time delay measurement unit 62, and the characteristic determination unit 63 correspond to a determination circuit in the claims.

  The reference signal output unit 61 outputs a rectangular wave as a reference signal to the RC circuit 7 when the illumination unit 10 is connected to the power supply device 100. Further, before the reference signal output unit 61 outputs the reference signal, the forced discharge circuit control unit 65 turns on the forced discharge circuit 8 to discharge the electric charge accumulated in the reference capacitor 3. Thus, the charge in the reference capacitor 3 does not adversely affect the time delay measurement.

  The time delay measuring unit 62 measures the time delay based on the output signal from the RC circuit 7 and the reference signal. Specifically, the measurement start flag is turned on when a rectangular wave is output from the reference signal output unit 61 as shown in FIG. The counter starts counting when the measurement start flag is turned on, and the output signal is output from the Schmitt trigger 4 when the voltage of the output signal from the RC circuit 7 which is the output signal becomes a predetermined voltage. Thus, the measurement end flag is turned on and the count is ended. In this way, the time delay measurement unit 62 measures the time from when the rectangular wave is output from the reference signal output unit 61 until the signal returns to the time delay measurement unit 62. Here, the time delay is an amount represented by a time constant RC that is ideally the product of the resistance value R of the ID resistor 1 and the capacitance C of the reference capacitor 3. The time delay can be described by a value based on RC such as a constant multiple of RC. Then, the time delay measuring unit 62 refers to the error correction value from the error correction value storage unit 621 described later, and corrects the error correction value to the count value that is the measured time delay to obtain the count correction value as a RAM. The count correction value storage unit 622 configured above is temporarily stored.

  The characteristic discriminating unit 63 discriminates the characteristic of the LED 2 based on the time delay measured by the time delay measuring unit 62. More specifically, the characteristic discriminating unit 63 is configured to identify the type of the LED 2 based on at least two time delay measurement results. That is, the characteristic determination unit 63 includes at least a resistance determination unit 631, an ID data storage unit 636, an error correction value storage unit 621, an ID temporary determination result storage unit 632, a candidate determination result storage unit 633, a determination unit 634, and a light source characteristic determination. Part 635.

  The resistance discriminating unit 631 discriminates the ID resistor 1 based on the time delay measured by the time delay measuring unit 62. More specifically, the resistance determination unit 631 includes an ID data storage unit 636 in which a time delay-ID resistance correspondence table regarding the time delay and the type of the ID resistor 1 corresponding thereto is stored in advance in the ROM. The type of the ID resistor 1 is discriminated from the measured time delay. Here, the resistance determination unit 631 is configured to determine the ID resistance 1 using the corrected time delay stored in the count correction value storage unit 622 for the time delay.

  The error correction value storage unit 621 measures a time delay error caused by the error of the reference capacitor 3 using a reference resistor at the time of initial assembly of the power supply device 100 as will be described later, and measures the measured time delay. Is stored in the ROM, and the correction coefficient is stored such that the error between the calculation time delay and the calculation time delay is small. More specifically, the error correction value storage unit 621 stores a correction coefficient to be applied to the count value of the counter.

  The temporary discrimination result storage unit 632 updates and stores the discrimination result every time the resistance discrimination unit 631 discriminates the ID resistor 1, and is formed on the RAM.

  The candidate determination result storage unit 633 newly stores the determination result stored in the temporary determination result storage unit 632 when it is determined in the determination unit 634 described later that the ID resistance 1 is not determined. It is formed on the RAM.

  The temporary discrimination result storage unit 632 and the candidate discrimination result storage unit 633 correspond to a discrimination result storage unit in which the resistance discrimination unit in the claims stores each discrimination result obtained by discriminating the ID resistance a plurality of times.

  The determination unit 634 is configured to determine that the ID resistor 1 has been determined when a plurality of determination results are compared and matched. More specifically, referring to the temporary determination result storage unit 632 and the candidate determination result storage unit 633, the first determination result and the second determination result are compared, and only when they match. It is determined that the ID resistor 1 has been determined.

  The light source characteristic determination unit 635 determines the characteristic of the light source based on the second determination result when the determination unit 634 determines that the ID resistor 1 has been determined. More specifically, the light source characteristic determination unit 635 is connected with reference to a specification storage unit 637 that stores a correspondence table of specifications of the illumination unit 10 determined by the types and characteristics of the ID resistor 1 and the LED 2. The specification of the illuminating unit 10 is determined, and information such as a voltage necessary for flowing a rated current and an upper limit current and an upper limit voltage at which the LED 2 is not broken is acquired.

  The power supply control unit 64 is, for example, current control or voltage control suitable for each specification of the illumination unit 10 based on information such as a rated current, a rated voltage, an upper limit current, and an upper limit voltage acquired by the light source characteristic determination unit 635. Is performed on the variable voltage power source 5.

  The operation relating to the initial setting of the power supply device 100 and the determination of the ID resistor 1 will be described particularly with respect to the lighting device configured as described above.

  First, the procedure for measuring the actual capacitance of the reference capacitor 3 performed when the lighting device is assembled and setting the error correction value used for measuring the time delay will be described with reference to the flowchart of FIG. At the time of initial assembly, an input is made from the outside so as to shift to the initial setting operation mode for the microcomputer (step S1). Next, a reference resistor whose resistance value is known in advance is attached to the illumination unit 10 or the power supply device 100, a rectangular wave is output from the reference signal output unit 61, and the time delay is measured by the time delay measurement unit 62 ( Step S2). Since the time delay is ideally represented by a value based on the time constant RC in the RC circuit 7, it is compared with the measured time delay and the error of the capacitance C of the reference capacitor 3 is calculated (step) S3). Finally, the error correction value storage unit 621 configured on the ROM stores error correction value information for correcting the measured count value based on the error of the capacitance C. (Step S4).

  Next, the operation for determining the ID resistor 1 will be described with reference to the flowchart of FIG.

  First, the lighting unit 10 is connected to the power supply device 100 via the connector C, and a check is made as to whether the ID resistor 1 is connected (step S5). Thereafter, the information stored in the count correction value storage unit 622, the temporary determination result storage unit 632, and the candidate determination result storage unit 633 is reset (step S6).

  Next, after the electric charge accumulated in the reference capacitor 3 is discharged by the forced discharge circuit 8 (step S7), the RC formed by the reference capacitor 3 and the ID resistor 1 by the reference signal output unit 61 Output of a rectangular wave to the circuit 7 is started (step S8). From the time when the rectangular wave is output from the reference signal output unit 61 until the voltage of the output signal from the RC circuit 7 reaches a threshold value that is a specified predetermined voltage, that is, until the output signal is output from the Schmitt trigger 4 Is counted by the time delay measuring unit 62. The measured count value indicating the time delay is corrected based on the error correction value stored in the error correction value storage unit 621 (step S9). A value obtained by multiplying the count value by the error correction value is stored in the count correction value storage unit 622 on the RAM as the count correction value (step S10).

  Based on the count correction value indicating the time delay stored in the count correction value storage unit 622, the resistance determination unit 631 refers to the ID data storage unit 636 to determine the ID resistor 1 from the correspondence table ( Step S11). If there is no data of ID resistor 1 corresponding to the time delay, the measurement is performed again (step S12). If there is data, the determination result determined by the resistance determination unit 631 is stored in the temporary determination result storage unit 632 (step S13).

  When a new determination result is stored in the temporary determination result storage unit 632, the determination unit 634 determines the determination result stored in the temporary determination result storage unit 632 and the candidate determination result storage unit 633. Is compared with the determination result stored in (step S14). In the first time delay measurement result, the candidate determination result storage unit 633 is stored in the temporary determination result storage unit 632 and the candidate determination result storage unit 633 since the information is not updated after the reset. Since the discriminating result does not match, the measurement is repeated once more. At this time, the information on the first determination result stored in the temporary determination result storage unit 632 is stored in the candidate determination result storage unit 633 (step S15). When the resistance determination unit 631 determines the ID resistance 1 based on the time delay obtained by the second measurement, the temporary determination result storage unit 632 stores the first determination result obtained in the previous measurement. The newly determined second determination result is updated and stored from the existing state (step S13).

  Then, the determination unit 634 compares the first determination result stored in the candidate determination result storage unit 633 with the second determination result stored in the temporary determination result storage unit 632, so that they match. It is judged again whether it is (step S14). Only when they match, it is determined that the ID resistor 1 has been successfully determined (step S16). If they do not match, the candidate determination result storage unit 633 newly stores the second determination result stored in the temporary determination result storage unit 632 (step S15), and measures a new time delay. The determination of the ID resistor 1 is performed again, and the temporary determination result storage unit 632 stores a new third determination result. That is, the temporary determination result storage unit 632 and the candidate determination result storage unit 633 are updated one by one with the latest information each time the ID resistance 1 is determined. If the ID resistance 1 is not successfully discriminated even after being repeated a predetermined number of times (step S17), that fact may be displayed and the discrimination operation may be terminated (step S18).

  When the determination unit 634 determines that the ID resistance 1 has been successfully determined, the light source characteristic determination unit 635 refers to the specification storage unit 637 and stores the determination result stored in the candidate determination result storage unit 633. From the above, the specification of the illumination unit 10 is determined, and information related to the specification is acquired.

  Based on the specifications of the illumination unit 10 determined by the light source characteristic determination unit 635, the power supply control unit 64 starts control so that the variable voltage power supply 5 causes a current to flow through the LED 2 at a rated current or a rated voltage, for example. To do.

  The light irradiation device 200, the power supply device 100, and the determination circuit configured in this way input a rectangular wave to the RC circuit 7 including the ID resistor 1 and the reference capacitor 3, and appear in the output. The time delay is measured, and the ID resistor 1 is determined based on the time delay. Therefore, according to the lighting device of the present embodiment, the ID resistor 1 is discriminated by measuring the voltage divided into the resistance value R of the ID resistor 1 and the resistance value r in the power supply device 100 as in the prior art. In the case where the resistance value R is increased, the resistance value R becomes substantially the same value, so that the identification of the ID resistor 1 is difficult. On the other hand, the time delay is the product RC of the resistance value R and the capacitance C. Since the value is determined based on the represented value, the time delay increases substantially proportionally when the resistance value R increases, and even if the resistance value R is large, a difference among the ID resistors 1 is likely to appear.

  Further, in the conventional method of measuring the partial pressure, when the ID resistor 1 having a large resistance value R is discriminated, the difference between the ID resistors 1 having different resistance values R becomes smaller. The influence of the resistance value error appears, and it is difficult to distinguish many types of ID resistors 1. On the other hand, in the method of measuring the time delay as in the present embodiment, the time delay increases as the resistance value increases, and the difference between the ID resistors 1 having different resistance values R hardly changes, and the resistance value R It is hard to be influenced by the error included in. Therefore, according to the illumination device of the present embodiment, the ID resistor 1 can be determined even in a region where the resistance value R is large.

  Further, since the reference capacitor 3 is provided only in the power supply apparatus 100, only the ID resistor 1 needs to be provided in the illumination unit 10. Therefore, even if there are many variations of the illumination unit 10, the labor involved in calibration of the reference capacitor 3 is not affected at all. That is, since it is only necessary to calibrate only the power supply device 100 that is used in common for each illumination unit 10, labor during manufacturing can be greatly reduced. Further, since the reference capacitor 3 is not provided in the illuminating unit 10, there is no fear of causing an error in capacitance due to the heat generated by the light source, and there is no influence on the measurement accuracy. Variations can be prevented from occurring.

  In addition, since the time delay and the resistance value of the ID resistor 1 are in a substantially proportional relationship, it is possible to discriminate more types of ID resistors 1 simply by increasing the measurement time of the time delay measuring unit 62. it can. That is, the number of determinations can be easily increased without changing the time delay measurement unit 62 and shortening the clock. Of course, since there is a proportional relationship, even if the clock is shortened, the types of ID resistors 1 that can be discriminated by shortening the interval between the resistance values of the ID resistors that can be used can be easily increased.

  As described above, according to the lighting device of the present embodiment, it is possible to make a determination even in a region where the resistance value R of the ID resistor 1 is large, and it is possible to use the ID resistor 1 having a relatively large resistance value R. Many types of ID resistors 1 can be identified. Therefore, more illumination units 10 can be controlled by one power supply device 100.

  Further, the error included in the reference capacitor 3 is measured at the time of assembly, the time delay measured based on the result is corrected, and the discrimination of the ID resistor 1 succeeds only when the two discrimination results coincide. Therefore, the number of false detections can be greatly reduced.

  Other embodiments will be described.

  In the above-described embodiment, the reference signal output unit outputs a rectangular wave to the RC circuit. However, any reference signal may be used as long as the signal can measure time delay.

  In the above-described embodiment, the illumination unit is not determined unless the results of the ID resistances determined twice in succession match. However, for example, the type of ID resistor is reduced, and the time delay interval is increased. Alternatively, if the detection error is allowed to some extent, the illumination unit may be determined based on only one ID resistance determination result.

  In the embodiment, the ID resistance determination circuit and the circuit for applying a voltage to the LED are configured independently. However, the LED and the ID resistance are provided in parallel, and one circuit is provided. You may put them together. In this case, it is possible to determine the ID resistance by turning off the LED control FET and the like so that a current flows only through the ID resistance and performing measurement.

  In the embodiment, the microcomputer is used to measure the time delay due to the RC circuit and the illumination unit is discriminated. However, in the present invention, it is necessary to perform A / D conversion as in the conventional illumination device. Therefore, a PLD (programmable logic device) or the like may be used.

  The time delay generating element is not limited to a capacitor. For example, a reference coil may be used instead of the reference capacitor.

  In the embodiment, the determination unit is configured to determine that the ID resistance is determined only when the two determination results match. However, the ID resistance is determined only when a plurality of determination results match. You may comprise so that it may judge. For example, it may be determined that the ID resistance is determined only when three determination results match.

  As the ID resistor, a commercially available resistance value may be used that is determined by a certain standard, but in the power supply device of the present invention, even if a resistance value is freely selected and a set of ID resistors is made. It can be determined sufficiently.

  In addition, various modifications and combinations of embodiments may be performed without departing from the spirit of the present invention.

1 ... ID resistor 2 ... LED (light source)
DESCRIPTION OF SYMBOLS 3 ... Reference capacitor 10 ... Illumination part 100 ... Power supply device 61 ... Reference signal output part 62 ... Time delay measurement part 63 ... Characteristic discrimination part 7 ... RC circuit (time delay Generator circuit)
8 ... Forced discharge circuit 631 ... Resistance determination unit 632 ... Temporary determination result storage unit 633 ... Candidate determination result storage unit 634 ... Determination unit 635 ... Light source characteristic determination unit

Claims (6)

Connected to an illuminating unit comprising a light source and an ID resistor having a different resistance value for each characteristic of the light source, distinguishing the characteristic of the light source based on the ID resistance, and adjusting the light source according to the characteristic A power supply device for controlling,
A time delay generating element connected in series with the ID resistor and provided to form a time delay generating circuit;
A reference signal output unit for outputting a reference signal input to the time delay generation circuit;
A time delay measuring unit for measuring a time delay based on an output signal from the time delay generating circuit;
A power supply apparatus comprising: a characteristic determination unit configured to determine a characteristic of the light source based on the time delay measured by the time delay measurement unit.   The power supply apparatus according to claim 1, wherein the time delay generating element is a reference capacitor. The characteristic determination unit;
A resistance determination unit for determining the ID resistance based on the time delay measured by the time delay measurement unit;
A discrimination result storage unit for storing each discrimination result obtained by discriminating the ID resistor a plurality of times;
A plurality of determination results stored in the determination result are compared with each other, and a determination unit that determines that the ID resistance is determined only when they match,
2. A light source characteristic determination unit that determines a characteristic of the light source based on the first determination result or the second determination result when the determination unit determines that the ID resistance is determined. Or the power supply device of 2.   4. The power supply apparatus according to claim 2, further comprising an error correction unit that corrects the time delay measured by the time delay measurement unit using an error correction value determined based on an error of the reference capacitor.   5. The power supply apparatus according to claim 2, further comprising a forced discharge circuit that discharges the electric charge accumulated in the reference capacitor. A discrimination circuit for discriminating ID resistance,
A time delay generating element connected in series with the ID resistor and provided to form a time delay generating circuit;
A reference signal output unit for outputting a reference signal input to the time delay generation circuit;
A time delay measuring unit for measuring a time delay based on an output signal from the time delay generating circuit;
A discrimination circuit comprising: a resistance discrimination unit that discriminates the ID resistance based on the time delay measured by the time delay measurement unit.