JP2010055825A - Discharge lamp lighting device, headlight device, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device for suppressing electrical stress acting on circuit components or a discharge lamp, a headlight device equipped with the discharge lamp lighting device, and a vehicle equipped with the headlight device. <P>SOLUTION: The discharge lamp lighting device includes a direct current power source part outputting direct current power, and an inverter part supplying rectangular wave alternating current power of reversing polarity of the direct current power output by the direct current power source part in each predetermined reversal time to the discharge lamp. In at least one part of an output rise period of raising output power right after starting, a rise width of the output power right before or right after output reversal of the inverter part is provided smaller than a rise width after completion of the output rise period. The electrical stress acting on the circuit components or the discharge lamp is suppressed in comparison to when the rise width is common with that of a regular period in a whole of the output rise period. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a discharge lamp lighting device, a headlamp device, and a vehicle.

  Conventionally, as a discharge lamp lighting device for lighting a high-intensity discharge lamp such as a metal halide lamp, a discharge lamp lighting device that employs a rectangular wave lighting method to avoid an acoustic resonance phenomenon has been provided. Used for lighting vehicle headlamps.

  This type of discharge lamp lighting device includes a DC power supply unit that outputs DC power, and an inverter that supplies the discharge lamp with rectangular wave AC power obtained by inverting the polarity of the DC power output by the DC power supply unit at predetermined inversion times. A part.

  In the discharge lamp lighting device as described above, when the polarity of the output of the inverter unit is inverted (hereinafter simply referred to as “inversion”), the discharge lamp is accompanied by an instantaneous decrease in the output current from the inverter unit to the discharge lamp. As a result, the discharge of the discharge lamp after the reversal became unstable, which caused flickering and extinction of the discharge lamp and electromagnetic noise. Therefore, in order to suppress flicker, extinction, and electromagnetic noise as described above, a technique of temporarily increasing the output power of the inverter unit (hereinafter simply referred to as “output power”) immediately before or after inversion. Is known (see, for example, Patent Document 1 and Patent Document 2).

  FIG. 36 shows an example of this type of discharge lamp lighting device 1. This discharge lamp lighting device 1 alternates a DC-DC converter unit 2 as a DC power source unit that converts a voltage value of DC power input from a DC power source E, and DC power output from the DC-DC converter unit 2. And an inverter unit 3 for outputting to the discharge lamp La, and a control unit 4 for controlling the DC-DC converter unit 2 and the inverter unit 3 respectively. Further, an igniter unit 5 that generates a high voltage for starting the discharge lamp La is provided between the inverter unit 3 and the discharge lamp La.

  More specifically, the output terminal on the low voltage side of the DC power supply E is connected to the ground, and the DC-DC converter unit 2 has one end of the primary winding P1 connected to the output terminal on the high voltage side of the DC power supply E. And the other end of the primary winding P1 is connected to the ground via the switching element Q1, the output capacitor C1 is connected to the ground at one end, and the anode is connected to the other end of the output capacitor C1. This is a known flyback converter having a diode D1 whose cathode is connected to the ground via the secondary winding S1 of the transformer T1 and having both ends of the output capacitor C1 as output ends. The control unit 4 controls the output power of the DC-DC converter unit 2 by outputting a control signal that is a PWM signal for driving the switching element Q1 of the DC-DC converter unit 2 to be turned on and off.

  The inverter unit 3 includes two series circuits each including two switching elements Q2 to Q5, which are connected in parallel between the output terminals of the DC-DC converter unit 2, and the switching elements Q2 to Q2 of each series circuit. This is a full-bridge type inverter circuit in which the connection point between Q5 is the output end. The inverter unit 3 is configured so that the switching elements Q2 to Q5 connected in series with each other are alternately turned on and off at the same time so that the switching elements Q2 to Q5 are alternately turned on and off, so that the DC-DC converter unit 2 outputs the direct current. Power is converted into rectangular wave AC power and output.

  The igniter unit 5 includes a capacitor Cs connected between the output ends of the inverter unit 3 and a transformer T2 in which one end of each of the primary winding P2 and the secondary winding S2 is connected to one output end of the inverter unit 3. Prepare. The other end of the primary winding P2 of the transformer T2 is connected to the other output end of the inverter unit 3 via the spark gap SG1, and the other end of the secondary winding S2 is connected to the other end of the inverter unit 3 via the discharge lamp La. Connected to the output end of the.

  The control unit 4 and the inversion determination unit 41 that controls the inverter unit 3 and the output power of the DC-DC converter unit 2 (that is, output power from the inverter unit 3 to the discharge lamp La. Hereinafter, simply referred to as “output power”). ) And a detected output voltage (hereinafter, referred to as “voltage detection value”). Current target calculation unit 43 that calculates a current target value that is a target value of the output current of the DC-DC converter unit 2 using the power target value stored in the power target storage unit 42, and usually a current target calculation unit While the current target value input from 43 is output as it is, the current target value is increased during the predetermined periods T1 and T3 (see FIG. 39A) before and after the inverter 3 inverts the polarity of the output. Output with The current target value output from the current target value increasing unit 44 while detecting the output current of the current target increasing unit 44 and the DC-DC converter unit 2 and the detected output current (hereinafter referred to as “current detection value”). And a control signal generation unit 45 that generates a control signal for controlling the DC-DC converter unit 2 so as to be close to each other. Since the control unit 4 as described above can be realized by a known technique, a detailed description thereof is omitted.

  Specifically, the inverter unit 3 includes a drive unit (not shown) that drives each of the switching elements Q2 to Q5 on and off. The inversion determination unit 41 of the control unit 4 inputs a pulsed inversion signal to the drive unit of the inverter unit 3, and the drive unit of the inverter unit 3 receives the inversion signal every time the inversion signal is input. Each of the switching elements Q2 to Q5 is switched on and off so as to invert the output.

  The inversion determination unit 41 determines, for example, the lighting state of the discharge lamp La based on the elapsed time since the power is turned on, and the inversion signal during the period in which the discharge lamp La is determined to be off. Is maintained at the L level. That is, the first switching elements Q2 and Q5 are turned on and the second switching elements Q3 and Q4 are kept off until the discharge lamp La is turned on after the power is turned on. Then, as the output voltage of the DC-DC converter unit 2 increases, the amplitude of the output voltage from the inverter unit 3 gradually increases, so that the voltage across the spark gap SG1 gradually increases. Eventually, when dielectric breakdown (breakdown) occurs in the spark gap SG1, an induced electromotive force is generated in the secondary winding S2 of the transformer T2 as the current flowing in the primary winding P2 of the transformer T2 increases rapidly. Arc discharge is started in the discharge lamp La (that is, the discharge lamp La is started and lights up) by a high voltage of, for example, several tens of kV in which the voltage due to the induced electromotive force and the output voltage of the inverter unit 3 are superimposed. Then, the output of the inversion signal is started by the inversion determination unit 41 that has determined the lighting of the discharge lamp La, whereby the output of the rectangular wave AC power by the inverter circuit 2 is started.

  The operation of the discharge lamp lighting device 1 will be described with reference to FIG. First, when the power is turned on and the operation is started (S1), various variables used for the operation are initialized in each unit of the control unit 4 (S2), and then the inversion determination unit 41 outputs an inversion signal. By not doing, the inverter unit 3 starts a starting operation (S3). That is, in the inverter unit 3, only the two switching elements Q 2 and Q 5 positioned diagonally are kept on, and the igniter unit 5 starts the discharge lamp La. Thereafter, the reversal determination unit 41 determines whether the discharge lamp La is lit or not lit (S4). If it is determined that the discharge lamp La is not lit, the starting operation in step S3 is continued. On the other hand, if it is determined in step S4 that the discharge lamp La has been turned on, the operation of the inverter unit 3 outputting the rectangular wave AC power to the discharge lamp La is started by moving to the next step S5. In step S <b> 5, the current target calculation unit 43 acquires a voltage detection value by detecting the output voltage of the DC-DC converter unit 2. The current target calculation unit 43 stores the voltage detection values up to three times from the new one and updates as needed, and averages the voltage detection values up to four times together with the newly acquired voltage detection values. A voltage average value is obtained and used for control. Thus, the influence of noise is suppressed by using the voltage average value which is the average value of the voltage detection value for multiple times for control. The current target calculation unit 43 reads the power target value from the power target storage unit 42, obtains a current target value by dividing the read power target value by the voltage average value, and obtains the current target value as the current target value. It outputs to the target raising part 44. Here, the control unit 4 includes a time measuring unit (not shown) that measures an elapsed time (hereinafter simply referred to as “elapsed time”) after the lighting of the discharge lamp La is determined in step S4. The current target calculation unit 43 reads the power target value corresponding to the elapsed time measured by the time measuring unit from the power target storage unit 42. Here, as shown in FIG. 38, in the power target storage unit 42, if the elapsed time is 0 second to 4 seconds, it is 75 W, and the elapsed time is gradually lowered while gradually decreasing from 4 seconds to 50 seconds. For example, a power target value for each elapsed time is stored in the form of a data table, for example, which is reduced to 34 W and maintained at 34 W if the elapsed time is 50 seconds or longer. That is, after the elapsed time reaches 50 seconds, the output power in the period other than the periods T1 and T3 before and after the inversion (hereinafter referred to as “constant power period”) T2 (see FIG. 39A). In a period (hereinafter referred to as “output increase period”) until a steady operation is performed that maintains a constant steady power (34 W) and the steady operation is started, the output power in the constant power period T2 is The output increase operation is performed to increase the steady power of the current. The individual numerical values are not limited to the above, and the steady power is, for example, the rated power of the discharge lamp La that is assumed to be connected to the inverter unit 3, and the power target value at the initial stage of the output increase period is, for example, about twice the steady power. For example, the output increase period may be about several tens of seconds. Then, the current target calculation unit 43 obtains a current target value by dividing the power target value read from the power target storage unit 42 according to the elapsed time by the voltage average value, and obtains the current target value as a current. It outputs to the target raising part 44.

  The inversion determination unit 41 determines the timing at which the inversion signal should be output to the inverter unit 3 and ends the output of the inversion signal from the start of a predetermined pre-inversion period T3 immediately before starting the output of the inversion signal. Then, an output increase signal for temporarily increasing the output power of the DC-DC converter unit 2 is input to the power target increase unit 44 at the end of the predetermined post-inversion period T1 after the completion (that is, the output increase signal is Turn on). When the current target value is input from the current target calculation unit 43, the current target increase unit 44 determines whether or not the output increase signal is on (S6). If the output increase signal is on, the current target calculation unit 43 A new current target value obtained by adding a predetermined amount of increase to the current target value input from (S7) is output to the control signal generation unit 45. On the other hand, if the output increase signal is OFF, the current target calculation unit The current target value input from 43 is output to the control signal generator 45 as it is. The amount of increase is about 0.1 to 1 times the rated current value of the discharge lamp La. For example, if the rated current value is 0.4 A, the increase amount is 0.04 A to 0.4 A, and if the rated current value is 0.8 A, the increase amount is 0.08 A to 0.8 A. Thereby, the synchronous operation which raises the output electric power of the DC-DC converter part 2 and the inverter part 3 temporarily is performed in said period T1 before inversion and period T3 before inversion. The length of the post-inversion period T1 is, for example, 50 μs, and the length of the pre-inversion period T3 is, for example, 200 μs.

  The control signal generation unit 45 acquires the current detection value by detecting the output current of the DC-DC converter unit 2, stores the current detection values for three times from the new ones, and updates them as needed. A current average value is obtained by averaging up to four current detection values together with the newly acquired current detection value, and this is used for control. That is, a control signal for setting the current average value as the current target value is generated and input to the DC-DC converter unit 2 (S8). Specifically, for example, the control signal generation unit 45 includes an error amplifier that generates an output of a voltage value corresponding to the difference between the current average value and the current target value, and an on-duty corresponding to the output voltage value of the error amplifier. A control signal that is a PWM signal is generated. As described above, the influence of noise is suppressed by using the current average value, which is the average value of the current detection values for a plurality of times, for control.

  Steps S9 to S13 are operations of the inversion determination unit 41, respectively. In step S9, the inversion determination unit 41 determines whether or not the timing at which the inverted signal is to be output, that is, the timing for every predetermined inversion time. Is output to the inverter unit 3. The frequency of the output of the inverter unit 3 is several hundred Hz to several kHz. That is, the inversion time is several hundred μs to several ms. Further, in step S11, it is determined whether or not the constant power period T2 during which the inversion signal is not output after the inversion period T1, the pre-inversion period T3, and the output increase signal is turned off during the constant power period T2. (S12) If it is not during the constant power period T2, the output increase signal is turned on (S13).

  The operations in steps S5 to S13 as described above are continued until the power is turned off. Furthermore, you may combine suitably well-known techniques, such as abnormality detection and protection operation | movement, and the change of the output power of the DC-DC converter part 2 according to ambient temperature. Further, in the post-inversion period T1 and the pre-inversion period T3, instead of adding the increase amount to the current target value as described above, a predetermined coefficient larger than 1 (hereinafter referred to as “increase rate”) is added to the current target value. The output power may be increased by multiplying.

  According to the discharge lamp lighting device 1 as described above, by increasing the output power in the pre-inversion period T3, the temperature drop during the inversion is suppressed in the discharge lamp La, and by increasing the output power in the post-inversion period T1. By promoting the return of the temperature after the temperature decrease at the electrode of the discharge lamp La, the discharge in the discharge lamp La is stabilized, and flicker, extinction and electromagnetic noise are suppressed. When the lengths of the post-inversion period T1 and the pre-inversion period T3 are the same, the above effects can be obtained if the post-inversion period T1 and the pre-inversion period T3 are about several percent to 20.8% of the inversion time. The inventor believes that it is obtained.

  Further, as shown in FIG. 39B, the power target value is gradually decreased from the start of the post-inversion period T1 to the start of the constant power period T2, and the end of the pre-inversion period T3 from the end of the constant power period T2. It is also conceived to suppress an electrical stress on the circuit components and the discharge lamp La by suppressing a sudden change in output power by gradually increasing the power target value over time. Further, as shown in FIG. 39 (c), increasing the output power only during the pre-inversion period T3 is effective, but as shown in FIGS. 39 (a) and 39 (b), the post-inversion period T1 and the pre-inversion period are effective. It is desirable to increase the output power both in the period T3.

Further, since the temperature of the discharge lamp La rises more quickly than the case where the output raising operation is not performed due to the output raising operation in which the output power is made larger than the steady power for a predetermined time after starting, the light of the discharge lamp La The output can be stabilized in a shorter time.
Special table 10-501919 JP 2002-110392 A

  As described above, a technique for temporarily increasing the output power of the inverter unit 3 (that is, the power supplied to the discharge lamp La) immediately before or after the inversion of the output of the inverter unit 3 is performed at a predetermined time when the discharge lamp La is started. When the technology for supplying the discharge lamp La with a larger power than during steady lighting during the output increase period is simply combined, the direct current is output immediately before and immediately after the output inversion of the inverter unit 3 during the output increase period. There is a possibility that excessive electrical stress is applied to the circuit components and the discharge lamp La constituting the power supply unit 2 and the inverter unit 3.

  The present invention has been made in view of the above reasons, and its purpose is to provide a discharge lamp lighting device capable of suppressing electrical stress applied to circuit components and a discharge lamp, a headlamp device including the discharge lamp device, And providing a vehicle including the headlight device.

  The invention of claim 1 includes a DC power supply unit that outputs DC power, and an inverter unit that supplies a rectangular wave AC power obtained by inverting the polarity of the DC power output from the DC power supply unit every predetermined inversion time to the discharge lamp; A control unit that controls output power of the DC power supply unit, and the control unit synchronizes to temporarily increase the output power of the DC power supply unit at least one of immediately before and after inversion of the output of the inverter unit. Before starting a steady period for controlling the DC power supply unit so that the output power in a period other than during the synchronous operation is maintained at a predetermined steady power when the discharge lamp is started. In the predetermined output increase period, the DC power supply unit is controlled so that the output power in a period other than during the synchronous operation is larger than the steady power, and the control unit is in at least a part of the output increase period. Compared to the steady period The width of increase in the output power of the DC power source unit in the synchronization operation, and wherein the reducing at least one of the duration of the synchronous operation.

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed as compared with the case where the range of increase in the output power of the DC power supply unit in the synchronous operation is made common to the steady period in the entire output increase period. .

  According to a second aspect of the present invention, in the first aspect of the present invention, the control unit detects the output voltage and the output current of the DC power supply unit, respectively, and divides the predetermined power target value by the detected output voltage to obtain a current target. The DC power supply unit is controlled so that the detected output current coincides with the current target value during a period when the synchronous operation is not performed, and the detected output current is compared with the current target value and a predetermined value during the synchronous operation. The direct-current power supply unit is controlled so as to coincide with the sum of the increase amount, and the increase amount is made smaller than during the steady period at least in part of the output increase period.

  According to a third aspect of the present invention, in the first aspect of the present invention, the control unit detects the output voltage and the output current of the DC power supply unit, respectively, and divides a predetermined power target value by the detected output voltage to obtain a current target. The DC power supply is controlled so that the detected output current coincides with the current target value during a period when the synchronous operation is not performed, and the detected output current is equal to or more than the current target value during the synchronous operation. The DC power supply unit is controlled so as to coincide with a product of the predetermined increase rate of the output, and the increase rate is made smaller than during the steady period during at least a part of the output increase period. To do.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the control unit shortens the duration of the synchronous operation during at least a part of the output increase period as compared with during the steady period. And

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  According to a fifth aspect of the present invention, in any of the first to fourth aspects of the present invention, the control unit does not perform a synchronous operation and keeps the output power of the DC power supply unit constant during at least a part of the output increase period. It is a characteristic.

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the control unit gradually decreases the output power of the DC power supply unit during a period other than during the synchronous operation to a steady power during the output increase period. And the increase width of the output power of the DC power supply unit in the synchronous operation is gradually increased.

  According to this invention, compared with the case where the increase width of the output power of the DC power supply unit in the synchronous operation is increased from the beginning of the output increase period to the same level as the steady period, the electrical applied to the circuit components and the discharge lamp by the synchronous operation is increased. Stress can be suppressed.

  The invention of claim 7 is the invention according to any one of claims 1 to 5, wherein the control unit detects the output voltage of the DC power supply unit, and the lower the detected output voltage, the lower the DC power supply unit in the synchronous operation. It is characterized in that the increase range of the output power is reduced.

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  The invention of claim 8 is the invention according to any one of claims 1 to 5, wherein the control unit detects the output current of the DC power supply unit, and the larger the detected output current, It is characterized in that the increase range of the output power is reduced.

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  The invention of claim 9 is the invention according to any one of claims 1 to 5, wherein the control unit gradually increases the increase in the output power of the DC power supply unit in the synchronous operation over a predetermined time when starting the discharge lamp. It is characterized by that.

  According to the present invention, the electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  A tenth aspect of the invention includes a temperature estimation unit that generates an output corresponding to the estimated temperature by estimating the temperature of the discharge lamp according to any one of the first to ninth aspects, and the control unit increases the output. The higher the temperature estimated by the temperature estimation unit at the start of the period, the shorter the output increase period.

  According to the present invention, when the temperature of the discharge lamp is already high at the start of the output increase period and the output increase period may be short, the output increase period is shortened. Such electrical stress can be suppressed.

  An eleventh aspect of the invention includes the discharge lamp lighting device according to any one of the first to tenth aspects and a discharge lamp that is turned on by the discharge lamp lighting device.

  A twelfth aspect of the present invention includes the headlamp device according to the eleventh aspect.

  According to the first aspect of the present invention, in at least a part of the output increase period, at least one of the range of increase in the output power of the DC power supply unit in the synchronous operation and the duration of the synchronous operation is compared with that in the steady period. Therefore, the electrical stress applied to the circuit components and the discharge lamp can be suppressed as compared with the case where the width of the increase in the output power of the DC power supply unit in the synchronous operation is made common to the steady period in the entire output increase period.

  According to the invention of claim 4, the control unit shortens the duration of the synchronous operation for at least part of the output increase period as compared to during the steady period, and according to the invention of claim 5, the control unit The output power of the DC power supply unit is kept constant during at least a part of the output increase period without performing the synchronous operation. According to the invention of claim 6, the control unit is not in the synchronous operation during the output increase period. According to the invention of claim 7, the output power of the DC power supply unit in the period is gradually reduced to steady power, and the increase width of the output power of the DC power supply unit in the synchronous operation is gradually increased. Detects the output voltage of the DC power supply unit, and the lower the detected output voltage, the smaller the increase in the output power of the DC power supply unit in the synchronous operation. According to the invention of claim 8, the control unit Detecting the output current of the DC power supply In addition, the larger the detected output current, the smaller the increase in the output power of the DC power supply unit in the synchronous operation. According to the invention of claim 9, the control unit has a predetermined time at the start of the discharge lamp, Since the increase in the output power of the DC power supply unit in the synchronous operation is gradually increased, electrical stress applied to the circuit components and the discharge lamp can be suppressed by the synchronous operation.

  According to the invention of claim 10, the output rise period is shortened when the temperature of the discharge lamp is already high at the start of the output rise period and the output rise period may be short. Electrical stress applied to the discharge lamp can be suppressed.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
Since the basic configuration of this embodiment is the same as that of the conventional example described with reference to FIGS. 36 to 39, the illustration and description of common portions are omitted.

  In the above conventional example, the amount of increase (that is, the increase width of the output power in the synchronous operation) is always a constant value, whereas in this embodiment, the amount of increase is variable.

  As a change in the amount of increase, for example, as shown in FIG. 2 and FIG. 3, the amount of increase is maintained at a minimum value (0.2 A in FIG. 2 and 0 A in FIG. 3) from elapsed time 0 second to 4 seconds. The amount of increase may be gradually increased linearly from the minimum value to the maximum value (for example, 0.4 A) from time 4 seconds to 50 seconds. That is, the amount of increase during the power increase period is greater than during the steady period. For example, in the example of FIG. 2, when the elapsed time is 4 seconds, the increase amount is 0.2A as shown in FIG. 1A, and when the elapsed time is 50 seconds or more, as shown in FIG. The amount of increase is 0.4A. By changing the amount of increase in this way, it is possible to suppress the electrical stress applied to the discharge lamp La and circuit components during the power increase period, while ensuring the effect of suppressing flicker, extinction and electromagnetic noise in the steady period. .

  Alternatively, the current target increase unit 44 detects the output power of the DC-DC converter unit 2 and, as shown in FIGS. 4 and 5, the output power is a power target value (maximum power at the start of the power increase period). ) Is set to a minimum value (0.2 A in FIG. 4 and 0 A in FIG. 5), and when the output power is a power target value (rated) in a steady period, the increase amount is set to a maximum value (for example, 0. 0). As 4A), when the output power is in a predetermined range between the rated value and the maximum power, the amount of increase may be reduced as the output power increases.

  Alternatively, as shown in FIGS. 6 and 7, when the voltage detection value is an expected value (for example, 20 V) of the voltage detection value at the start (starting time) of the power increase period, the increase amount is set to the minimum value (0 in FIG. 6). .2A, 0A in FIG. 7), and when the voltage detection value is an expected value of the voltage detection value in the steady period (that is, the rated voltage of the discharge lamp La, for example, 85V), the increase amount is set to the maximum value (for example, 0.4A) ). In the example of FIG. 6, when the voltage detection value is within a predetermined range, the amount of increase is gradually increased linearly with respect to the voltage detection value. In the example of FIG. 7, if the voltage detection value is less than 30V, the increase amount is the minimum value, and if the voltage detection value is 30V or more, the increase amount is the maximum value. That is, it is estimated that the output power is higher as the voltage detection value is lower due to the negative characteristics of the discharge lamp La. Therefore, when the voltage detection value is lower, the output power is not set too high in the post-inversion period T1 and the pre-inversion period T3. However, the amount of increase is reduced.

  Alternatively, as shown in FIGS. 8 and 9, when the detected current value is an expected value (eg, 2.6 A) of the detected current value at the start (starting time) of the power increase period, the increase amount is set to the minimum value (FIG. 8). Is 0.2 A, and is 0 A in FIG. 9, and when the current detection value is the expected value of the current detection value in the steady period (that is, the rated current of the discharge lamp La, for example, 0.4 A), the increase amount is the maximum value ( For example, it may be 0.4A). Further, in the example of FIG. 8 and the example of FIG. 9, when the current detection value is within a predetermined range (2.2 A to 2.6 A in the example of FIG. 9), the amount of increase is gradually and linearly increased. It is reduced to.

  Further, in the example of FIG. 3, the elapsed time is from 0 to 4 seconds, in the example of FIG. 5 the output power is 60 W or more, in the example of FIG. 7 the voltage detection value is less than 30 V, In the example, the increase amount is set to 0 in each of the periods where the current detection value is 2.6 A or more, that is, the post-inversion period T1 and the pre-inversion period T3 are not substantially provided in each of the above periods. The output current of the converter unit 2 is kept constant. According to these configurations, the electrical stress applied to the discharge lamp La is reduced as compared with the case where the amount of increase is not zero.

(Embodiment 2)
Since the basic configuration of this embodiment is the same as that of the conventional example described with reference to FIGS. 36 to 39, the illustration and description of common portions are omitted.

  In the above conventional example, the current target increase unit 44 increases the current target value by adding the increase amount to the current target value input from the current target calculation unit 43 in the post-inversion period T1 and the pre-inversion period T3. On the other hand, in this embodiment, the current target increase unit 44 increases the current target value by multiplying the current target value input from the current target calculation unit 43 in the post-inversion period T1 and the pre-inversion period T3 by one or more increase rates. This is different from the conventional example.

  Here, for example, when the rate of increase is always 2, if the current target value in the constant power period T2 is 2.6 A as shown in FIG. 10A, the period in the post-inversion period T1 and the pre-inversion period T3 The current target value is 5.2A, and as shown in FIG. 10B, if the current target value in the constant power period T2 is 0.4A, the current target value in the post-inversion period T1 and the pre-inversion period T3 is 0.8A. If the rate of increase is made constant in this way, excessive electric current is generated in the circuit components and the discharge lamp La constituting the DC power supply unit 2 and the inverter unit 3 in the post-inversion period T1 and the post-inversion period T3 during the output increase period. There is a possibility of stress.

  Therefore, in the present embodiment, the rate of increase is made variable in the same manner as the amount of increase made variable in the first embodiment.

  As an increase rate change, for example, as shown in FIG. 11 and FIG. 13, the increase rate is maintained at a minimum value (1.1 in FIG. 11, 1 in FIG. 13) from elapsed time 0 second to 4 seconds, and elapsed time. The rate of increase may be gradually increased linearly from the minimum value to the maximum value (for example, 2) over a period of 4 seconds to 50 seconds. That is, during the power increase period, the increase rate is made larger than during the steady period. For example, in the example of FIG. 11, when the elapsed time is 4 seconds, the rate of increase is 1, 1 as shown in FIG. 12A, and when the elapsed time is 50 seconds or more, as shown in FIG. The rate of increase is 2. By changing the rate of increase in this way, it is possible to suppress the electrical stress applied to the discharge lamp La and circuit components during the power increase period, while ensuring the effect of suppressing flicker, extinction and electromagnetic noise in the steady period. .

  Alternatively, the current target increasing unit 44 detects the output power of the DC-DC converter unit 2, and as shown in FIGS. 14 and 15, the output power is a power target value (maximum power at the start of the power increasing period). ) Is the minimum value (1.1 in FIG. 14 and 1 in FIG. 15), and when the output power is the power target value (rated) in the steady period, the increase rate is the maximum value (for example, 2). It is good. In the example of FIG. 14, when the output power is within a predetermined range, the rate of increase is gradually decreased linearly with respect to the output power. In the example of FIG. 15, the increase rate is the maximum value when the output power is less than 60 W, and the increase rate is the minimum value when the output power is 60 W or more.

  Alternatively, as shown in FIGS. 16 and 17, when the voltage detection value is an expected value (for example, 20 V) of the voltage detection value at the start (starting time) of the power increase period, the increase rate is set to the minimum value (1 in FIG. 16). .1, 1 in FIG. 17, and when the voltage detection value is an expected value of the voltage detection value in the steady period (that is, the rated voltage of the discharge lamp La, for example, 85 V), the rate of increase is set to the maximum value (for example, 2). Also good. In the example of FIG. 16, when the voltage detection value is within a predetermined range, the increase rate is gradually increased linearly with respect to the voltage detection value. In the example of FIG. 17, if the voltage detection value is less than 30V, the increase rate is the minimum value, and if the voltage detection value is 30V or more, the increase rate is the maximum value. That is, it is estimated that the output power is higher as the voltage detection value is lower due to the negative characteristics of the discharge lamp La. Therefore, when the voltage detection value is lower, the output power is not set too high in the post-inversion period T1 and the pre-inversion period T3. However, the rate of increase is reduced.

  Alternatively, as shown in FIG. 18 and FIG. 19, when the current detection value is an expected value (for example, 2.6 A) of the current detection value at the start (starting time) of the power increase period, the increase rate is set to the minimum value (FIG. 18). 1.1 and 1 in FIG. 19, and when the current detection value is the expected value of the current detection value in the steady period (that is, the rated current of the discharge lamp La, for example, 0.4 A), the increase rate is the maximum value ( For example, it may be 2). In the example of FIG. 18, when the current detection value is within a predetermined range, the rate of increase is gradually decreased linearly with respect to the current detection value. In the example of FIG. 19, if the current detection value is equal to or greater than a predetermined value, the increase rate is set to the minimum value, and if the current detection value is less than the predetermined value, the increase rate is set to the maximum value.

  Further, in the example of FIG. 13, the elapsed time is from 0 to 4 seconds, in the example of FIG. 15, the output power is 60 W or more, in the example of FIG. 17, the voltage detection value is less than 30 V, In the example, the rate of increase is set to 1 in each period in which the current detection value is equal to or greater than the predetermined value, that is, the post-inversion period T1 and the pre-inversion period T3 are not substantially provided in each of the above periods. The output current of the converter unit 2 is kept constant. According to these configurations, the electrical stress applied to the discharge lamp La is reduced as compared with the case where the rate of increase is not 1.

(Embodiment 3)
Since the basic configuration of this embodiment is the same as that of the conventional example shown in FIGS. 36 to 39, illustration and description of common portions are omitted.

  In the conventional example, the length of the pre-inversion period T3 is constant, whereas in the present embodiment, the length of the pre-inversion period T3 (that is, the duration of the synchronization operation; hereinafter referred to as “rise time”). Is different from the conventional example described above.

  As the change of the rising time, for example, as shown in FIGS. 20 and 22, the rising time is maintained at the minimum value (50 μs in FIG. 20 and 0 μs in FIG. 22) from the elapsed time 0 second to 4 seconds, and the elapsed time 4 The rising time may be gradually increased linearly from the minimum value to the maximum value (for example, 200 μs) from second to 50 seconds. That is, the rising time is made longer during the power increase period than during the steady period. For example, in the example of FIG. 20, when the elapsed time is 4 seconds, the rising time is 50 μs as shown in FIG. 21 (a), and when the elapsed time is 50 seconds or more, the rising time is as shown in FIG. 21 (b). The time is 200 μs. By changing the rising time in this way, it is possible to suppress the electrical stress applied to the discharge lamp La and the circuit components during the power rising period, while ensuring the effect of suppressing flicker, extinction and electromagnetic noise in the steady period. .

  Alternatively, the inversion determination unit 41 detects the output power of the DC-DC converter unit 2 and, as shown in FIGS. 23 and 24, the output power is a power target value (maximum power) at the start of the power increase period. Is set to the minimum value (50 μs in FIG. 23, 0 μs in FIG. 24), and the increase time may be set to the maximum value (for example, 200 μs) when the output power is the power target value (rated) in the steady period. . In the example of FIG. 23, when the output power is within a predetermined range, the rise time is gradually shortened linearly with respect to the output power. In the example of FIG. 24, the rising time is the maximum value when the output power is less than 60 W, and the rising time is the minimum value when the output power is 60 W or more.

  Alternatively, as shown in FIGS. 25 and 26, when the voltage detection value is an expected value (for example, 20 V) of the voltage detection value at the start (starting time) of the power increase period, the increase time is set to the minimum value (50 μs in FIG. 25). In FIG. 26, it is 0 μs), and when the voltage detection value is an expected value of the voltage detection value in the steady period (that is, the rated voltage of the discharge lamp La, for example, 85 V), the rising time may be the maximum value (for example, 200 μs). . In the example of FIG. 25 and the example of FIG. 26, when the voltage detection value is within a predetermined range, the rise time is gradually increased linearly with respect to the voltage detection value. That is, because the negative voltage characteristic of the discharge lamp La presumes that the lower the voltage detection value, the higher the output power, so when the voltage detection value is low, the rise time is shortened so as to suppress the electrical stress in the pre-inversion period T3. -ing

  Alternatively, as shown in FIG. 27 and FIG. 28, when the current detection value is an expected value (eg, 2.6 A) of the current detection value at the start (starting time) of the power increase period, the increase time is set to the minimum value (FIG. 27). 50 μs and 0 μs in FIG. 28), and when the current detection value is the expected value of the current detection value in the steady period (that is, the rated current of the discharge lamp La, for example, 0.4 A), the rising time is the maximum value (for example, 200 μs). ). In the example of FIG. 27, when the current detection value is within a predetermined range, the rise time is gradually shortened linearly with respect to the current detection value. In the example of FIG. 28, when the current detection value is 2.2 A or more, the rising time is the minimum value, and when the current detection value is less than the predetermined value, the rising time is the maximum value.

  Furthermore, in the example of FIG. 22, the elapsed time is from 0 to 4 seconds, in the example of FIG. 24, the output power is 60 W or more, and in the example of FIG. 26, the voltage detection value is less than the predetermined value. In the example of 28, the rising time is set to 0 μs in each period in which the current detection value is 2.2 A or more, that is, the period T3 before inversion is not substantially provided in each of the above periods, and the DC-DC converter unit 2 The output current is kept constant except during the post-inversion period T1. According to these configurations, the electrical stress applied to the discharge lamp La is reduced as compared with the case where the rising time is not 0 μs.

  In the above example, the length of the pre-inversion period T3 is variable, but the effect is the same if the length of the post-inversion period T1 is variable.

  Further, the change in the rise time described in the present embodiment may be combined with the change in the increase amount described in the first embodiment and the change in the increase rate described in the second embodiment.

Here, when the temperature of the discharge lamp La is high to some extent when the power is turned on, for example, when the time from when the discharge lamp La is turned off to when it is turned on again is short, the power is higher than when the temperature of the discharge lamp La is low. The rising period may be short, and it is desirable to shorten the power rising period in order to reduce useless electrical stress on the circuit components and the discharge lamp La. Therefore, in Embodiments 1 to 3, the temperature estimation unit 6 that estimates the temperature of the discharge lamp La is provided as shown in FIG. 29, and the temperature estimation is not necessarily started from 0 seconds when the elapsed time is started. As the temperature estimated by the unit 6 is higher, the elapsed time may be started on the assumption that the longer elapsed time has already passed. Temperature estimation unit of FIG. 29. 6, a parallel circuit of a resistor R _D and a capacitor C _T, one end of which is connected to ground, a constant voltage source at the other end is connected to one end via a switch SW to the parallel circuit 5V And a resistor _RC connected to. The switch SW is ON / OFF controlled by, for example, the inversion determination unit 41 of the control unit 4 so that the switch SW is turned on while the discharge lamp La is turned on and turned off while the discharge lamp La is turned off. In other words, the capacitor C _T of the temperature estimating section 6 during the lighting of the discharge lamp La is charged via the resistor R _C, during extinction of the discharge lamp La is of being discharged through the resistor R _D, release immediately after that switch SW lighting of lamp La the charging voltage of the capacitor C _T is immediately after being turned on is input to the control unit 4 as the output voltage of the temperature estimation section 6. When the discharge lamp La is turned on again after being turned off, the output voltage of the temperature estimation unit 6 becomes higher as the period during which the lamp is turned off is shorter and as the time during which the lamp is turned on is longer, that is, It can be estimated that the temperature of the discharge lamp La is higher as the output voltage of the temperature estimation unit 6 is higher. The control unit 4 stores, for example, the relationship between the output voltage of the temperature estimation unit 6 and the initial value of the elapsed time as shown in FIG. 30, and the output voltage of the temperature estimation unit 6 is high when the discharge lamp La is turned on (that is, The initial value of the elapsed time is increased as the estimated temperature of the discharge lamp La is higher). For example, in the case of FIG. 30, if the output voltage of the temperature estimation unit 6 is 1 V when the discharge lamp La is turned on, the elapsed time is started from 30 seconds. As a result, the power increase period is shortened by 30 seconds. The temperature estimation unit 6 may be a well-known temperature sensor disposed close to the discharge lamp La. In this case, the discharge lamp is based on the temperature detected by the temperature sensor (the temperature in the vicinity of the discharge lamp La). The actual temperature of La will be estimated.

  In each of the first to third embodiments, the control unit 4 may be configured as shown in FIG. The control unit 4 in FIG. 31 includes a primary side current detection unit 46 that detects a current (hereinafter referred to as “primary side current”) that flows through the primary winding P1 of the transformer T1 of the power conversion unit 2, and the power conversion unit 2. A secondary side current detector 47 for detecting a current (hereinafter referred to as “secondary side current”) flowing in the secondary winding S1 of the transformer T1, and a control signal (PWM signal) output from the control signal generator 45. D / A conversion circuit for generating a voltage value corresponding to the on-duty of the control signal (that is, a higher voltage value as the output current instructed to the power converter 2 is higher) 48, a first comparator CP1 having a non-inverting input terminal connected to ground and a secondary-side current detection unit 47 connected to the inverting input terminal, and a primary-side current detection unit 46 connected to a non-inverting input terminal. In addition, the D / A conversion circuit is connected to the inverting input terminal. 48 is connected to the second comparator CP2, the set terminal is connected to the output terminal of the first comparator CP1, the reset terminal is connected to the output terminal of the second comparator CP2, and the Q terminal is connected to the switching element Q1 of the power converter 2. And a drive circuit 49 including a flip-flop circuit. That is, when the current value of the secondary current detected by the secondary current detector 47 becomes 0, the switching element Q1 is turned on, and the current value of the primary current detected by the primary current detector 46 Is greater than the current value instructed by the control signal generator 45, the switching element Q1 is turned off. In other words, since the switching element Q1 is turned on when the secondary current becomes 0, the utilization factor of the transformer T1 is improved, and the DC control is performed by feedback control based on the primary current. -The output power of the DC converter unit 2 is controlled. The drive circuit 49 measures the time during which the switching element Q1 is turned off (hereinafter referred to as “off time”), and when the off time reaches a predetermined maximum off time, the set terminal is at the H level. Even if not (that is, even if the secondary current is not 0), the switching element Q1 is turned on. Further, the drive circuit 49 has a peak that accompanies a decrease in the switching frequency of the switching element Q1 when the output voltage of the inverter unit 2 is low and the slope of the secondary current waveform is small, such as when the temperature of the discharge lamp La is low. In order to prevent an increase in current, it has a function of adjusting the maximum off-time according to the state. Further, the control signal generator 35 outputs the PWM signal for the upper 8 bits and the PWM signal for the lower 8 bits of the control signal from different terminals, and the D / A conversion circuit 48 includes the above two. The D / A conversion circuit 48 outputs an analog signal having a resolution of 16 bits by adding each of the PWM signals after A / D conversion.

  Furthermore, in each of the first to third embodiments, the DC-DC converter unit 2 may be changed to a known buck converter (step-down chopper circuit) as shown in FIG. In the example of FIG. 32, an AC-DC converter that converts AC power supplied from the AC power source AC into DC power is used as the DC power source E that supplies power to the DC-DC converter unit 2. Since this AC-DC converter is a known circuit in which a filter circuit, a rectifying / smoothing circuit, and a boost converter are combined, detailed description thereof is omitted.

  Or it is good also as a circuit structure which combines the switching element of the inverter part 3 with the switching element of the DC-DC converter part 2. FIG. Since such a circuit configuration can be realized by a well-known technique, illustration and detailed description are omitted.

  In the first to third embodiments, the output power in the post-inversion period T1 and the pre-inversion period T3 is increased by increasing the current target value. However, the power target value may be increased. When the configuration is such that the voltage detection value is brought close to the voltage target value obtained by dividing the target value by the current detection value, the voltage target value may be increased.

  In addition, as in the example of FIG. 2, when the output power of the DC-DC converter unit 2 varies not only with the on-duty of the input control signal (PWM signal) but also with the frequency, the control unit 4 performs DC-DC You may make it control the DC-DC converter part 2 with the frequency of the control signal input into the converter part 2. FIG. Further, the frequency of the control signal in the constant power period T2 is made constant regardless of the elapsed time, while the output power as shown in FIG. 4 is controlled by changing the on-duty of the control signal, as in the second embodiment. The control based on the on-duty of the control signal and the control based on the frequency may be properly used such that the change in the rate of increase is performed by changing the frequency of the control signal. For example, while the frequency of the control signal in the constant power period T2 is 280 kHz regardless of the elapsed time, it is inverted by changing the frequency of the control signal between 300 kHz and 500 kHz according to the elapsed time as shown in FIG. The output power in the post-period T1 and the pre-inversion period T3 is changed. That is, as shown in FIG. 34A, when the elapsed time is 4 seconds, the frequency f2 of the control signal from the start time of the pre-inversion period T3 to the end time of the post-inversion period T1 is 300 kHz. ), When the elapsed time is 50 seconds, the frequency f2 of the control signal in the above period is 500 kHz, and the frequency f1 of the control signal in the constant power period T2 is 280 kHz regardless of the elapsed time.

  The various discharge lamp lighting devices 1 described above constitute a headlamp device together with a discharge lamp La used as a vehicle-mounted headlamp, and can be mounted and used in an automobile CR as shown in FIG. In this case, a battery mounted on the automobile CR is used as the DC power source E.

(A) (b) is explanatory drawing which respectively shows the waveform of the lamp current of Embodiment 1 of this invention, (a) shows the state whose elapsed time is 4 second, (b) shows the elapsed time of 50 seconds. The state which is. It is explanatory drawing which shows an example of the relationship between elapsed time and a raise amount in the same as the above. It is explanatory drawing which shows another example of the relationship between elapsed time and a raise in the same as the above. It is explanatory drawing which shows an example of the relationship between output electric power and a raise amount in the same as the above. It is explanatory drawing which shows another example of the relationship between output electric power and a raise in the same as the above. It is explanatory drawing which shows an example of the relationship between the voltage detection value and increase amount in the same as the above. It is explanatory drawing which shows another example of the relationship between the voltage detection value and increase amount in the same as the above. It is explanatory drawing which shows an example of the relationship between the electric current detection value in the same as the above, and a raise amount. It is explanatory drawing which shows another example of the relationship between the electric current detection value and increase amount in the same as the above. (A) (b) is explanatory drawing which respectively shows the waveform of the lamp current of the comparative example of Embodiment 2 of this invention, (a) shows the state whose elapsed time is 4 second, (b) is elapsed time. Indicates a state of 50 seconds. It is explanatory drawing which shows an example of the relationship between elapsed time and the rate of increase in Embodiment 2 of this invention. (A) (b) is explanatory drawing which shows the waveform of the lamp current in the example of FIG. 11, respectively (a) shows the state whose elapsed time is 4 seconds, (b) is the elapsed time is 50 seconds. Indicates the state. It is explanatory drawing which shows another example of the relationship between elapsed time and an increase rate in the same as the above. It is explanatory drawing which shows an example of the relationship between output electric power and an increase rate in the same as the above. It is explanatory drawing which shows another example of the relationship between output electric power and an increase rate in the same as the above. It is explanatory drawing which shows an example of the relationship between the voltage detection value in the same as the above, and an increase rate. It is explanatory drawing which shows another example of the relationship between the voltage detection value and increase rate in the same as the above. It is explanatory drawing which shows an example of the relationship between the electric current detection value and an increase rate in the same as the above. It is explanatory drawing which shows another example of the relationship between the electric current detection value and an increase rate in the same as the above. It is explanatory drawing which shows an example of the relationship between the elapsed time and rising time in Embodiment 3 of this invention. (A) (b) is explanatory drawing which shows the waveform of a lamp electric current same as the above respectively, (a) shows the state whose elapsed time is 4 seconds, (b) shows the state where elapsed time is 50 seconds. . It is explanatory drawing which shows another example of the relationship between elapsed time and rising time in the same as the above. It is explanatory drawing which shows an example of the relationship between output electric power and rising time in the same as the above. It is explanatory drawing which shows another example of the relationship between output electric power and rising time in the same as the above. It is explanatory drawing which shows an example of the relationship between the voltage detection value and rise time in the same as the above. It is explanatory drawing which shows another example of the relationship between the voltage detection value and rising time in the same as the above. It is explanatory drawing which shows an example of the relationship between the electric current detection value and rising time in the same as the above. It is explanatory drawing which shows another example of the relationship between the electric current detection value and rise time in the same as the above. It is a circuit block diagram which shows the principal part of the example of a change same as the above. It is explanatory drawing which shows an example of operation | movement of the example of a change of FIG. It is a circuit block diagram which shows another example of a change same as the above. It is a circuit block diagram which shows another example of a change same as the above. It is explanatory drawing which shows an example of the relationship between the frequency and elapsed time of the control signal in the period after inversion and the period before inversion in another modification example same as the above. (A) and (b) are explanatory diagrams showing the waveform of the lamp current in the modified example of FIG. 33, (a) shows a state where the elapsed time is 4 seconds, and (b) shows the elapsed time of 50 seconds. The state which is. It is explanatory drawing which shows an example of the usage pattern same as the above. It is a circuit block diagram which shows an example of a discharge lamp lighting device. It is a flowchart which shows operation | movement same as the above. It is explanatory drawing which shows an example of the relationship between elapsed time and electric power target value in the same as the above. (A)-(c) is an example of the waveform of the output voltage of an inverter part same as the above, and is explanatory drawing which shows a respectively different example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge lamp lighting device 2 DC-DC converter part (DC power supply part in a claim)
3 Inverter part 4 Control part 6 Temperature estimation part La Discharge lamp

Claims (12)

A DC power supply that outputs DC power;
An inverter unit that supplies a rectangular wave AC power obtained by inverting the polarity of the DC power output by the DC power source unit every predetermined inversion time to the discharge lamp;
A control unit for controlling the output power of the DC power supply unit,
The control unit performs a synchronous operation to temporarily increase the output power of the DC power supply unit at least one immediately before and after the inversion of the output of the inverter unit,
When the discharge lamp is started, the control unit performs a predetermined output increase period before starting a steady period for controlling the DC power supply unit so that the output power in a period other than during the synchronous operation is maintained at a predetermined steady power. The DC power supply is controlled so that the output power in the period other than during the synchronous operation is larger than the steady power,
The control unit reduces at least one of an increase in the output power of the DC power supply unit in the synchronous operation and a duration of the synchronous operation in at least a part of the output increase period as compared with the steady period. A discharge lamp lighting device. The control unit detects the output voltage and the output current of the DC power supply unit, respectively, obtains a current target value by dividing a predetermined power target value by the detected output voltage, and is detected during a period when the synchronous operation is not performed. The DC power supply unit is controlled so that the output current matches the current target value, and during the synchronous operation, the DC power supply unit is set so that the detected output current matches the sum of the current target value and the predetermined increase amount. To control,
2. The discharge lamp lighting device according to claim 1, wherein the amount of increase is set to be smaller during at least part of the output increase period than during the steady period. The control unit detects the output voltage and the output current of the DC power supply unit, respectively, obtains a current target value by dividing a predetermined power target value by the detected output voltage, and is detected during a period when the synchronous operation is not performed. The DC power supply is controlled so that the output current matches the current target value, and the DC output is adjusted so that the detected output current matches the product of the current target value and a predetermined rate of increase of 1 or more during synchronous operation. Which controls the power supply,
2. The discharge lamp lighting device according to claim 1, wherein the rate of increase is set to be smaller during at least part of the output increase period than during the steady period.   The discharge lamp lighting device according to any one of claims 1 to 3, wherein the control unit shortens the duration of the synchronous operation during at least a part of the output increase period than during the steady period. .   5. The control unit according to claim 1, wherein the control unit makes the output power of the DC power supply unit constant without performing a synchronous operation during at least a part of the output increase period. The discharge lamp lighting device described.   The control unit gradually reduces the output power of the DC power supply unit during a period other than the synchronous operation during the output increase period to a steady power, and gradually increases the output power of the DC power supply unit in the synchronous operation. The discharge lamp lighting device according to any one of claims 1 to 5, wherein the discharge lamp lighting device is raised.   The control unit detects the output voltage of the DC power supply unit, and decreases the output power increase of the DC power supply unit in the synchronous operation as the detected output voltage is lower. The discharge lamp lighting device according to any one of 5.   The control unit detects the output current of the DC power supply unit, and reduces the increase amount of the output power of the DC power supply unit in the synchronous operation as the detected output current is larger. The discharge lamp lighting device according to any one of 5.   6. The control unit according to claim 1, wherein the control unit gradually increases the increase in the output power of the DC power supply unit in the synchronous operation over a predetermined time at the start of the discharge lamp. Discharge lamp lighting device. A temperature estimating unit that estimates the temperature of the discharge lamp and generates an output corresponding to the estimated temperature;
The discharge lamp lighting device according to any one of claims 1 to 9, wherein the control unit shortens the output increase period as the temperature estimated by the temperature estimation unit at the start of the output increase period is higher. .   A headlamp device comprising: the discharge lamp lighting device according to any one of claims 1 to 10; and a discharge lamp that is turned on by the discharge lamp lighting device.   A vehicle comprising the headlamp device according to claim 11.

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