JP5469312B2 - Light distribution variable discharge lamp lighting device, vehicle headlamp - Google Patents

Description

  The present invention relates to a variable light distribution type discharge lamp lighting device and a vehicle headlight lamp equipped with the same.

  HID lamps (High Intensity Discharge Lamps) characterized by long life, large luminous flux, and point light source have become widespread in the market, and for example, their use in headlamp lighting devices is expanding in the in-vehicle field. In addition to simply illuminating the front, an electronic control unit (ECU) that turns the headlamps on and off according to vehicle information such as the steering angle of the steering wheel and vehicle speed, and changes the light distribution in the vertical and horizontal directions Vehicles equipped with are beginning to spread gradually.

  FIG. 22 shows a conventional example of a variable light distribution type headlamp lighting device. In this conventional example, the power conversion device 1 that converts the DC power source E into power necessary for lighting the discharge lamp DL, and the reflector 30 of the discharge lamp DL, for example, are driven by driving the motor 30 according to the light distribution variable signal input. It is comprised from the light distribution variable control apparatus 20 which moves and can vary light distribution.

  The power converter 1 converts the voltage of the DC power source E into a voltage necessary for lighting the discharge lamp DL, and converts the DC voltage that is the output voltage of the DC-DC converter 2 into an AC voltage (rectangular wave). It comprises a full-bridge inverter 3 for conversion, a DC-DC converter 2 and a control circuit (microcomputer) 10 for driving and controlling the full-bridge inverter 3, and a control power source 9, and applies the output of the power converter 1 to the discharge lamp DL. Turn on with. An igniter circuit 4 provided between the full bridge inverter 3 and the discharge lamp DL is a circuit that generates a high voltage for causing the discharge lamp DL to break down at the time of starting.

  On the other hand, the light distribution variable control device 20 receives a light distribution variable signal input, a control signal transceiver 21, a motor control circuit that drives and calculates a motor target position based on a signal from the control signal transceiver 21 and outputs a drive signal. 22, a motor driver 23 that receives a drive signal and outputs a drive current to the motor 30. The motor 30 moves a mechanism (for example, a reflector) for changing the light distribution of the discharge lamp DL by the drive current of the variable light distribution control device 20. Feedback from a position sensor may be added.

  In this conventional example, the power conversion device 1 and the variable light distribution control device 20 do not have communication means with each other, and are therefore driven independently.

  In Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-194086), a power conversion device that adjusts power necessary for stable lighting of a discharge lamp by driving a switching element, communication means with an external device, and a discharge device including these control devices. An electric lighting device is shown. Further, during a period in which a communication signal is transmitted and received between the discharge lamp lighting device and the external device, feedback control for detecting the state of the discharge lamp and adjusting the output power of the power conversion device is stopped, and the switching element is driven. A technique for fixing conditions is disclosed. Thereby, it is possible to prevent malfunction of the control device due to the limit of the processing capability of the control device. In addition, during the period when communication signals are being transmitted and received between the discharge lamp lighting device and the external device, a method of stopping the polarity reversal of the power applied to the discharge lamp to prevent malfunction of the control device and preventing the discharge lamp from extinguishing is also available. It is disclosed.

However, if the driving conditions of the switching element are fixed, the power supply amount to the discharge lamp also fluctuates when power supply environment fluctuations, ambient temperature changes, load characteristic fluctuations, etc. occur, and the discharge becomes unstable. The discharge lamp may go out.
JP 2007-194086 A

  In the configuration of the conventional example of FIG. 22, when performing discharge lamp lighting control or variable light distribution control, for example, at the time of starting up a luminous flux in which the light emission of the discharge lamp itself is unstable, or at the dimming control for adjusting the light output If the light distribution variable control device is moved, a sufficient light output cannot be obtained, so that a desired light distribution characteristic cannot be obtained, or it is released due to vibration of a mechanism unit (for example, a reflector) moved by the light distribution variable control device. There was a possibility that the light would go out.

  The present invention has been made in view of these points, and an object thereof is to enable stable lighting of a discharge lamp when the light distribution is variable while suppressing an increase in cost of a control circuit.

In order to solve the above problems, the invention of claim 1 is a power conversion unit (DC-DC converter 2, DC-DC converter 2, which converts a DC power source E into predetermined power required for lighting the discharge lamp DL, as shown in FIG. A power conversion device 1 having a full-bridge inverter 3) and a control unit (control circuit 10) of the power conversion unit, and a light distribution variable control device that changes the light distribution of the discharge lamp DL according to a predetermined input signal S2. The power conversion device 1 and the variable light distribution control device 20 each have communication means (signal S4 transmission / reception means), and the power conversion device 1 performs control to change the output power to the discharge lamp DL. The period for carrying out and the period for carrying out control for varying the light distribution by the light distribution variable control device 20 are time-divided , and the period for changing the output power to the discharge lamp DL is when the luminous flux of the discharge lamp DL is started up. (T0 to t1 in FIG. 4) and the discharge lamp D It is characterized in that a dimming control period (t3 to t4 in FIG. 4).

The invention of claim 2 is characterized in that, in the invention of claim 1 , when the tube voltage of the discharge lamp DL is higher than a predetermined value, the light distribution variable control device 20 does not perform control to vary the light distribution. (Embodiment 1 ″).

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2 , the polarity of the output of the power converter 1 is not reversed during the period in which the light distribution variable control device 20 varies the light distribution of the discharge lamp DL. (FIGS. 10 and 11).

According to a fourth aspect of the present invention, in the first or second aspect of the invention, during the period in which the light distribution variable control device 20 varies the light distribution of the discharge lamp DL, the power conversion device 1 The period of polarity inversion of the output is changed (FIGS. 12 to 14).

According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the control for varying the light distribution controls the actuator for varying the light distribution.

The invention of claim 6 is characterized in that, in the inventions of claims 1 to 5 , the control for varying the light distribution is to turn on auxiliary light sources 26 and 27 different from the discharge lamp DL (FIGS. 18 and 19). ).

The invention according to claim 7 is the invention according to claim 6 , wherein the auxiliary light source is a halogen lamp 27, and a predetermined period Ts in which a larger current flows from the start of lighting than during stable lighting is defined as a variable light distribution control period. (FIGS. 19 and 20).

According to an eighth aspect of the present invention, in the first to seventh aspects of the present invention, the variable light distribution control device and the power change device are configured by one electronic control unit, and the respective control microcomputers 10 and 22 are synchronously controlled. (FIG. 15).

A ninth aspect of the invention is characterized in that, in the first to eighth aspects of the invention, the control for changing the output power to the discharge lamp and the control for changing the light distribution of the discharge lamp are performed by a single microcomputer 10. (FIG. 16).

A tenth aspect of the present invention is a vehicle headlamp that includes the variable light distribution type discharge lamp lighting device according to any one of the first to ninth aspects (FIG. 21).

  According to the present invention, in the discharge lamp lighting device combined with the variable light distribution control device, the discharge lamp lighting control period and the light distribution variable control period at the time of starting up the luminous flux where the discharge becomes unstable or dimming control, and the light distribution variable control period are set. By dividing, it is possible to control so that the period for performing the control for changing the output power to the discharge lamp and the period for performing the control for varying the light distribution do not overlap in time. Can be ensured, and the control circuit can be simplified.

(Embodiment 1)
FIG. 1 shows the configuration of Embodiment 1 of the present invention. In the present embodiment, the power converter 1 that converts the DC power source E into power necessary for lighting the discharge lamp DL and the DC motor 30 are driven according to the light distribution variable signal input, for example, reflection of the discharge lamp DL. It is an example of the in-vehicle headlamp discharge lamp lighting system that includes a variable light distribution control device 20 that moves the plate and varies the light distribution.

  The power conversion apparatus 1 of Embodiment 1 converts the voltage of the DC power source E into a voltage necessary for lighting the discharge lamp DL, and the DC voltage that is the output voltage of the DC-DC converter 2 is an AC voltage ( (Rectangular wave) is mainly composed of a full bridge inverter 3, a DC-DC converter 2 and a control circuit (microcomputer) 10 for driving and controlling the full bridge inverter 3, and a control power source 9. The output of the power converter 1 is released. It is turned on by applying to the electric lamp DL. An igniter circuit 4 provided between the full bridge inverter 3 and the discharge lamp DL is a circuit that generates a high voltage for causing the discharge lamp DL to break down at the time of starting.

  The DC-DC converter 2 outputs the energy accumulated on the primary side of the transformer T1 to the capacitor C1 via the secondary side diode D1, and adjusts the output power amount by driving the switching element Q1 on and off. An example using the flyback method is shown.

  The power conversion apparatus 1 of this embodiment lights the discharge lamp DL by constant power control, and uses the microcomputer 10 for the control. The values of the lamp voltage and the lamp current of the discharge lamp DL are detected by resistors R1 to R3 and input to the microcomputer 10 via the voltage detection circuit 5 and the current detection circuit 6. The microcomputer 10 averages these detected values by the averaging calculators 15 and 16, and calculates the lamp current command value based on the lamp power command value Ps output from the lamp power command value calculator 12 in the ROM portion and the average voltage value Va. Is is calculated. The lamp power command value Ps is a value (hereinafter referred to as “predetermined power value”) set in advance so that the power required from the start of lighting to the stable lighting maintenance can be obtained at the output of the power conversion device 1. ").

  Furthermore, the lamp current command value Is and the averaged current value Ia are compared and calculated by the comparison calculation unit 14, and the primary side current command value Ic is output so that they are the same value. The primary side control unit 8 drives the DC-DC converter 2 by comparing the primary side current detection value Id detected by the primary side current detection circuit 7 with the primary side current command value Ic. As described above, constant power control is realized. The power source for the microcomputer 10 is generated by the control power source 9, and the power source for the control power source 9 is taken from the DC power source E.

  On the other hand, the variable light distribution control device 20 acquires a motor target position based on a signal from the control signal transceiver 21 that receives the variable light distribution signal input S2 and the control signal transceiver 21, and outputs a drive signal S3. And a motor driver 23 that receives the drive signal S3 and outputs a drive current to the DC motor 30. The motor drive calculation control circuit 22 has at least one MPU.

  Further, the DC motor 30 moves a mechanism (for example, a reflector) for changing the light distribution of the discharge lamp DL by the drive current of the light distribution variable control device 20.

  In the above configuration, when a power change command S1 such as a dimming signal that changes the output power to the discharge lamp DL is input from the outside, the lamp power command value changing unit 11 determines the lamp power command according to the command value level. The value Ps is changed. At this time, when it is confirmed by the movement determining unit 13 that the lamp power command value Ps has been changed from the predetermined power value, the movement prohibition command S4 for prohibiting the output of the motor drive signal is output to the control circuit 22 for motor drive calculation. Is output. In addition, the movement prohibition command S4 is also output during the light beam startup period in which the lamp voltage and lamp current change sharply.

  Therefore, during the period in which the movement prohibition command S4 is output from the movement determination unit 13, the motor drive signal S3 is not output regardless of what signal is input from the light distribution variable signal input S2.

  2 and 3 show a flow of constant power control of the discharge lamp DL and drive control of the DC motor 30. FIG. The flow of FIG. 2 is executed by the control circuit 10 of the power conversion device 1, and the flow of FIG. 3 is executed by the control circuit 22 of the variable light distribution control device 20.

  When the power is turned on, communication settings and initialization of variables and flags to be used are performed in step F01.

  In Step F02, it is determined whether or not a voltage necessary for lighting the discharge lamp DL is supplied from the DC power source E. If not supplied, the process does not shift to the loop of F03 to F15. If it is supplied, the process proceeds to the following loop of F03 to F15.

  In step F03, no-load control is performed before the discharge lamp DL is lit. For example, the polarity inversion of the full bridge inverter 3 is stopped, the output voltage of the DC-DC converter 2 is set to a no-load secondary voltage of several hundred volts, and the igniter circuit 4 is operated to release a high voltage pulse voltage for starting. Apply to the lamp DL.

  In step F04, it is determined whether or not the discharge lamp DL is lit. When the discharge lamp DL is lit, the lamp voltage is drastically reduced as compared to when there is no load. Therefore, it is possible to determine whether the discharge lamp DL is lit by monitoring the output of the voltage detection circuit 5. If not, the process returns to step F03. When it is lit, the process proceeds to a loop for performing the following constant power control.

  For example, in the case of an in-vehicle headlamp with a rated lamp voltage around 85V, it is determined whether the lamp is lit depending on whether the lamp voltage is between 5V and 150V. In the case of an in-vehicle headlamp, the lamp voltage decreases to about 30 V at the start of lighting, and then increases to about 85 V by rating. The judgment value is determined in consideration of variations such as the end of lamp life.

《Constant power control flow》
In the loop of F05 to F15, constant power control of the discharge lamp DL is realized by the microcomputer 10 of FIG.

  In step F05, the lamp voltage is read by A / D conversion. For this purpose, the microcomputer 10 has a first A / D conversion input port, and converts the output of the voltage detection circuit 5 into a digital value and takes it in.

  In step F06, the past value is combined with the read value and averaged. Thereby, the averaged voltage value Va is acquired. As an example of averaging, the detected value is stored in three values from the latest value (updated during reading), and when the next latest value is read, the three values are added together and divided by four.

  In Step F07, the lamp power command value Ps suitable for the lamp voltage Va at that time is read from the table held in the ROM section in the microcomputer 10.

  The flow indicating the operation of the present invention is indicated by Fa1 to Fa4. It is characterized in that the movement prohibition command S4 is output at the time of starting up the luminous flux where the discharge becomes unstable or at the time of dimming control.

  In step Fa1, it is determined whether or not the read lamp power command value Ps has been changed from a predetermined value set in advance. If not changed, the process proceeds to step Fa2. If it has been changed, the process proceeds to step Fa4.

  In Step Fa2, it is determined whether or not the lighting state of the discharge lamp DL is when the luminous flux is raised. If it is not at the time of starting the luminous flux, the process proceeds to Step Fa3. If the luminous flux is set up, the process proceeds to step Fa4.

  In step Fa3, the movable prohibition command S4 is cleared and the process proceeds to step F08. In this case, the output of the drive signal S3 is permitted.

  In step Fa4, a movement prohibition command S4 is output and the process proceeds to step F08. In this case, the output of the drive signal S3 is prohibited.

  In step F8, the lamp current command value Is is calculated by the calculation formula of lamp power command value Ps / average voltage value Va.

  In step F09, the lamp current is read by A / D conversion. For this purpose, the microcomputer 10 has a second A / D conversion input port, and converts the output of the current detection circuit 6 into a digital value and takes it in.

  In Step F10, the average value Ia is obtained by combining the past value with the lamp current read value and performing the averaging as described above.

  In step F11, the lamp current command value Is and the averaged current value Ia are compared.

  In step F12, the primary side current command value Ic is changed according to the calculation result of step F11.

  In step F13, it is determined whether or not the period from the previous polarity inversion of the full bridge inverter 3 to the next polarity inversion has elapsed. If the time has not elapsed, the process proceeds to step F15. If the time has elapsed, the process proceeds to step F14.

  In step F14, a polarity inversion command is output to the full bridge inverter 3.

  In step F15, other controls are performed.

  Thus, constant power control of the discharge lamp DL is realized.

<Motor drive control flow>
In the loop of F16 to F23, the drive control of the DC motor 30 is realized by the motor drive calculation control circuit 22 of FIG.

  In step F16, it is determined whether or not a voltage necessary for driving the DC motor 30 is supplied from the DC power source. If not supplied, the DC motor 30 is not driven. When supplied, control of F17 to F22 is performed.

  In step F17, it is determined whether or not the discharge lamp DL is lit. The determination criteria are the same as in step F04. If not, the process proceeds to step F19. When it is lit, the control of F18 to F22 is performed.

  In Step F18, the target position for driving the DC motor 30 is read, and the process proceeds to Step F20.

  In step F19, the target position for driving the DC motor 30 is set to an initial value, and the DC motor 30 is not driven. In the case of an in-vehicle headlamp, the initial value is the front front.

  In step F20, the current position of the DC motor 30 is read.

  In step F21, the target position of the DC motor 30 is compared with the current position, and the drive calculation of the DC motor 30 is performed.

  In step Fa5, a pulse prohibition command (movement prohibition command S4) is read. In this example, it is assumed that the DC motor 30 is driven by a pulse signal.

  In Step Fa6, it is determined whether or not a pulse prohibition command (movement prohibition command S4) is output. If it is output, the drive pulse signal (drive signal S3) is not output. If not, the process proceeds to step F22.

  In step F22, a drive pulse signal (drive signal S3) is output according to the result calculated in step F21.

  With the above flow, the drive signal S3 is not output by the movement prohibition command S4 during the dimming (power command value change) control period and the luminous flux rising-up control period of the discharge lamp DL. The output of the drive signal S3 is permitted in a period other than the dimming control period and the luminous flux rise control period of the discharge lamp DL.

  Even when the DC motor is being driven, if dimming control or luminous flux rise-up control is required, a movement prohibition command S4 is output and output of the drive signal S3 is stopped. Accordingly, priority is given to stable lighting of the discharge lamp over variable light distribution control.

  The sequence of the lighting operation in this embodiment is shown in FIG. The DC power source E is turned on at t = 0, and the stable lighting power (rated power) is passed through the light beam rising period (t = t0 to t1) from the no-load operation (t = 0 to t0) before the discharge lamp DL is turned on. ), The lamp voltage detection value and the lamp current detection value both change rapidly in a short period, and the discharge of the discharge lamp DL is very unstable. Until the discharge lamp DL reaches stable lighting, the movement prohibition command S4 is output, and the motor 30 is not driven (the drive signal S3 is not output) no matter what light distribution variable signal is input.

  Since the lamp power during this period is a predetermined power value (a value held in the ROM portion of the microcomputer 10), the output period of the movement prohibition command S4 may be set according to the lamp power command value Ps.

  When the luminous flux rising period ends at t = t1, the movement prohibition command S4 is canceled, and the DC motor 30 can be driven according to the light distribution variable signal input S2.

  FIG. 6 shows an example of an input power curve and a luminous flux rising curve to the lamp at the time of luminous flux startup in the in-vehicle headlamp lighting system. The solid line indicates the curve at the time of cold start, and the broken line indicates the curve at the time of hot restart. In the case of a lamp for in-vehicle headlamps, during a cold start (solid line part) with a long light extinction period before the start of lighting, in order to start up the light flux in the shortest possible period from the start of lamp lighting, The lamp current is considerably higher than the rated value (for example, about 6 times the rating), and it takes about several seconds to several tens of seconds (for example, 4 to 60 seconds) to reach a stable lighting state.

  On the other hand, during a hot restart (dashed line) where the extinction period before the start of lighting is extremely short (dashed line), the light flux of the lamp rises sharply and does not require a large amount of power, and a stable lighting state is achieved in a short period (several seconds). It reaches.

  Therefore, the output period of the movement prohibition command S4 in the light beam rising period may be changed depending on the start mode (the length of the turn-off period before lighting), for example, as shown in FIG.

  The periods t = t1 to t2 and t2 to t3 in FIG. 4 are stable lighting periods of the discharge lamp DL, and are drive permission periods of the DC motor 30. During these periods, the discharge lamp DL maintains stable lighting by normal constant power control (constant power control is performed).

  In the period from t = t1 to t2, when the light distribution variable signal is received and the drive signal S3 is output from the motor drive calculation result, the DC motor 30 is driven to vary the light distribution.

  In the period from t = t2 to t3, since the drive signal S3 is not output, the DC motor 30 is not driven.

  Next, a period from t = t3 to t4 is a period in which the lighting power of the discharge lamp is changed to a dimming state different from the rated power, and the driving of the DC motor 30 is prohibited. When the lamp power command value Ps is changed to be lower than the rated power by dimming control at t = t3, the movement prohibition command S4 is output, and no matter what light distribution variable signal S2 is input, the DC motor 30 is not driven (drive signal S3 is not output).

  When the lamp power change period ends at t = t4, the movable prohibition command S4 is canceled, and the DC motor 30 can be driven according to the light distribution variable signal input S2.

  When changing the lamp power at the start of dimming or at the end of the dimming period, the power is gradually increased with a slope corresponding to the dimming amount in order to prevent the lamp from turning off due to a sudden change in power. To change.

  Moreover, although the case where lamp electric power is reduced from rated power was shown as an example of dimming control, a movement prohibition command may be output also when lamp electric power is increased above rated power.

  As described above, in the present embodiment, during the period in which the discharge becomes unstable due to the change in lamp power (during dimming, luminous flux rise period), the motor drive by the variable light distribution control device is stopped and the light distribution is variable. By giving priority to the stable lighting control over the control, it is possible to prevent the discharge lamp from being extinguished due to vibration during movement of the light distribution varying mechanism (for example, the reflector). In addition, by moving the variable light distribution control device only during stable lighting of the discharge lamp, it is possible to reliably obtain desired light distribution characteristics.

(Embodiment 1 ')
Here, FIG. 5 shows a sequence of the lighting operation in which only the same period as t = t3 to t4 in FIG. 4 is extracted. In the first embodiment, for example, if the lamp power change amount (dimming power amount) due to dimming is small, a relatively stable discharge can be obtained even if lighting is continued in the dimming state.

  In addition, the discharge is actually unstable during the period from t3 to t3 ′ and t4 to t4 ′ when the power changes. During the period from t3 ′ to t4, the lamp power value is different from the rated power, but the lamp power is It is controlled to be constant (it is not control that changes power). Therefore, the control may be made to output the movement prohibition command S4 only in the periods t5 and t6 including the period in which the lamp power actually changes.

  In FIG. 4, the movement prohibition command S4 is continuously issued during the dimming period. However, in FIG. 5, the movement prohibition instruction S4 is output simultaneously with the start of the dimming control, and the lamp power is surely adjusted. After reaching the next target lamp power after the end, it is released.

  By controlling as shown in FIG. 5, variable light distribution control is possible even in a dimming state, and light distribution design with a higher degree of freedom is possible. In addition, if a threshold is set for the amount of dimming power and the control in FIG. 5 is enabled only when the amount of power change due to dimming is less than or equal to a predetermined value, it is possible to more reliably prevent the lamp from going out due to dimming It becomes.

(Embodiment 1 ")
In the first embodiment, in addition to the control in the first or first embodiment, the variable light distribution control is limited at the end of the lifetime when the lamp discharge becomes unstable.

  In general, the discharge lamp gradually increases its lamp voltage during stable lighting by repeating lighting maintenance and lighting starting operation for a long period of time. At the end of the lamp life, depending on the lamp type, the lamp voltage rises to about 100 V in the case of the in-vehicle headlamp discharge lamp. In the case of lighting at a constant lamp power, when the lamp voltage increases, the lamp current at the time of lighting decreases. For this reason, when the lamp voltage rises to a value above a certain level, the amount of luminous flux decreases and the discharge becomes unstable as compared with the initial state of the lamp life, and the frequency of occurrence of extinction increases.

  Therefore, in FIG. 1 of the first embodiment, when the averaged ramp voltage value Va is read by the movable determination unit 13 and the averaged ramp voltage value Va exceeds a predetermined value, the movable prohibition command S4 is output thereafter. Retain it until the next discharge lamp replacement. If the discharge lamp is replaced, the averaged lamp voltage value Va becomes equal to or less than a predetermined value, so that the movable prohibition command S4 is cleared.

  As described above, in addition to the effects of the first or first embodiment, it is possible to prevent the discharge lamp from going out even at the end of the lamp life.

(Embodiment 2)
FIG. 7 shows the configuration of the second embodiment of the present invention. In the second embodiment, lighting control and variable light distribution control of the discharge lamp DL are performed as described below.

1) The motor drive (variable light distribution) is not performed by the variable light distribution control device during the luminous flux startup period of the discharge lamp DL and the lamp power change by the dimming control.

2) During motor driving (variable light distribution) by the variable light distribution control device, the lamp power is not changed by dimming control until the motor driving period ends. When a power change command for performing dimming control is input from the outside during motor driving (variable light distribution), dimming control is performed after the motor driving period ends.

3) During the lamp power change by the light control, the motor drive (variable light distribution) is not performed by the variable light distribution control device until the lamp power change period ends. When a power change command for performing dimming control is input from the outside during dimming control, motor driving (variable light distribution) is performed after the end of the power change period.

  In the first embodiment, in order to ensure stable lighting of the discharge lamp DL, the variable light distribution control is prohibited (or stopped) even during motor driving (variable light distribution) during the ramp light flux startup period and dimming control. However, in the second embodiment, the priority order of the lighting control during the lamp luminous flux rising period remains the same (the highest priority), and the priority order of the dimming control and the variable light distribution control is the same.

  FIG. 7 is a circuit block diagram, and only functions different from those of the first embodiment will be described.

  At the time of lamp luminous flux startup and dimming control, the fact that the lamp power command value Ps has been changed is input to the movable determination unit 13, and the output of the drive signal S3 is output by the movable prohibition command S4 output from the movable determination unit 13. Ban. When the light beam start-up period and the dimming control period are completed, the output of the drive signal S3 is permitted by canceling the movable prohibition command S4 (prohibition command clear).

  When the DC motor is driven (light distribution variable), the fact that the drive signal S3 is output is input to the movable determination unit 13 by the drive status output S5 output from the motor drive calculation control circuit 22. The movable determination unit 13 prohibits the lamp power command value Ps from being changed by the power change command S1 during the output period of the drive signal S3. When the output period of the drive signal S3 ends, the change determination unit 13 permits the change of the lamp power command value Ps based on the power change command S1 (cleared prohibition command).

  Next, the flow of constant power control of the discharge lamp DL and the drive control of the DC motor 30 are shown in FIGS. The flow of FIG. 8 is executed by the control circuit 10 of the power conversion device 1, and the flow of FIG. 9 is executed by the control circuit 22 of the variable light distribution control device 20.

  Steps F01 to F07 and F08 to F15 are the same as those in the first embodiment. Hereinafter, only functions different from those of the first embodiment will be described.

<Ramp constant power control flow>
In step Fb1, the dimming signal is read out.

  In step Fb2, it is determined whether the light control is currently being performed, regardless of the signal read in step Fb1. If dimming control is not in progress, the process proceeds to step Fb3. If dimming control is in progress, the process proceeds to step Fb7.

  For example, it is assumed that the instruction is to dimm a lamp with a rated 35 W to 32 W when the dimming signal is read. In this case, since the lamp may be extinguished when the lamp power is suddenly reduced, it is preferable to reduce the lamp power over several seconds from 35 W. During this reduction, a flag is set to indicate that the dimming control is in progress. This flag is used to determine whether or not the dimming control is being performed in step Fb2.

  In step Fb3, the motor drive signal is read out.

  In step Fb4, it is determined whether or not the motor 30 is currently being driven. If not, the process proceeds to step Fb5. If driving, the process proceeds to step Fb6.

  In step Fb5, it is determined whether the light flux is currently being set up or whether the result read in step Fb1 requires dimming control. If the luminous flux is starting up or if dimming control is not required, the process proceeds to step Fb6. If the luminous flux is starting up or if dimming control is necessary, the process proceeds to step Fb7.

  In Step Fb6, the prohibition of driving signal S3 output by the movable prohibition command S4 is cleared (permitted driving), and the process proceeds to Step F08.

  In step Fb7, the lamp power command value Ps is changed in accordance with the dimming signal (this flow is not executed when the luminous flux is starting up).

  In Step Fb8, the output of the drive signal S3 is prohibited by the movement prohibition command S4, and the process proceeds to Step F08.

<Motor drive control flow>
In step Fb9, it is determined whether the DC motor 30 is currently being driven regardless of the signal read in step F21. If not, the process proceeds to Step Fb10. If driving, the process proceeds to step Fb14.

  In Step Fb10, a pulse prohibition command (movement prohibition command S4) is read. In this example, it is assumed that the DC motor 30 is driven by a pulse signal.

  In Step Fb11, it is determined whether or not the output of the drive signal S3 is prohibited by the pulse prohibition command (movement prohibition command S4). If not prohibited, the process proceeds to Step Fb12. If it is prohibited, the process proceeds to Step Fb13.

  In step Fb12, it is determined whether or not the result read in step F21 requires motor drive control. If the drive control of the DC motor 30 is not necessary, the process proceeds to Step Fb13. If drive control of the DC motor 30 is necessary, the process proceeds to Step Fb15.

  In step Fb13, the motor driving signal S5 is stopped (the motor driving signal S5 is not output).

  In Step Fb14, it is determined whether or not the output of the drive signal S3 is prohibited by the pulse prohibition command (movement prohibition command S4). If not prohibited, the process proceeds to step Fb15. If it is prohibited, the process proceeds to Step F17.

  In step Fb15, a drive pulse signal (drive signal S3) is output.

  In step Fb16, a motor driving signal S5 is output.

  In the motor control flow, when the dimming control signal is input while the drive signal S3 is being output, the DC motor 30 is set to the initial state (light distribution is performed) after the output period of the drive signal S3 is completed in order to ensure the visibility in the traveling direction. It is good also as control which transfers to dimming control after returning to the front front.

  As described above, by adopting the configuration of the second embodiment, the DC motor 30 for variable light distribution control is stopped even if the power change command S1 by dimming is output during the variable light distribution control in addition to the effects of the first embodiment. Therefore, it is possible to reduce the illusion and discomfort to the vehicle driver.

  The present invention can obtain the same effect not only in vehicle lighting but also in general lighting having a movable mechanism. Therefore, the DC power source E is not limited to the on-vehicle battery, and as illustrated in FIG. 7, a commercial AC power source may be converted to a DC voltage by an AC-DC converter (step-up chopper). In this case, the DC-DC converter 2 is preferably configured as a step-down chopper.

  Further, as a communication means of the light distribution variable signal input means, the power conversion device 1 and the light distribution variable control device 20, it is conceivable to use an analog method, a digital method, an in-vehicle LIN communication, a communication such as CAN or FLEXMY.

(Embodiment 3)
FIG. 10 shows a circuit block diagram of the third embodiment. The difference is that the polarity inversion by the polarity inversion frequency control unit 18 is stopped by the polarity inversion stop command unit 19 in response to the output of the movable determination unit 13. In the third embodiment, an example in which the stepping motor 31 is used as the load of the light distribution variable control device 20 will be described. The stepping motor 31 in FIG. 10 is a two-phase excitation type, but may be a 1-2 phase excitation type.

  As described in the first embodiment, the discharge lamp DL is lit by applying an AC voltage (rectangular wave) obtained by inverting the polarity of the output voltage of the DC-DC converter 2 by the full bridge inverter 3. Further, the polarity inversion frequency of the full bridge inverter 3 is a value set in advance in the polarity inversion frequency control unit 18 from the start of lighting of the discharge lamp DL to the stable lighting.

  In the present embodiment, as shown in FIG. 11, in the period t7 to t8 during which the drive signal S3 of the stepping motor 31 is output, the polarity inversion stop command S6 is output from the movable determination unit 13 and the polarity of the full bridge inverter 3 is output. The reversing operation is stopped, and the discharge lamp DL is lit with a DC voltage. In this case, the polarity of the DC voltage may be either.

  When the output period of the drive signal S3 ends, the polarity inversion stop command S6 is cleared, and the full bridge inverter 3 continues the polarity inversion operation with the value set in the polarity inversion frequency control unit 18.

  As described above, by adopting the configuration of the third embodiment, in addition to the effects of the first or second embodiment, polarity inversion in which discharge becomes unstable is not performed during the period in which the stepping motor 31 is driven (the lamp current is not zero-crossed). Thus, particularly when the lamp current is lower than the rated current, it is possible to more reliably prevent the discharge lamp from extinguishing.

  In addition, in order to prevent as much as possible the decrease of the electrode due to the continued lighting with the DC voltage, the polarity of the DC voltage is alternately set to the opposite polarity every time the driving signal S3 of the stepping motor 31 is output, thereby extending the life. It is possible to realize a discharge lamp lighting device that achieves the above.

(Embodiment 4)
FIG. 12 shows a circuit block diagram of the fourth embodiment. Since the fourth embodiment has the same configuration as FIG. 10 of the third embodiment except for the inside of the microcomputer 10, only the microcomputer 10 is shown. In the present embodiment, as shown in FIG. 12, during the period in which the drive signal S3 of the stepping motor 31 is output, the polarity inversion frequency change command S7 is output from the movable determination unit 13 to the polarity inversion frequency change unit 18a. Thus, the frequency setting value in the polarity inversion frequency control unit 18 for setting the polarity inversion frequency of the full bridge inverter 3 is changed.

  In order to prevent the lamp from extinguishing, as shown in FIG. 13, when the lamp current value is relatively large, the number of times the lamp current is zero-crossed is reduced, while when the lamp current value is relatively small, the electrode temperature is set. The polarity inversion frequency is changed in accordance with the lamp current value so that the polarity is inverted at a high frequency in order to maintain a high temperature.

  For example, in an in-vehicle headlamp lamp, the lamp life is taken into consideration, and is changed within a range of about 200 Hz to 1000 Hz. Regarding the setting of the polarity reversal frequency when the lamp current is small, the above effect and the frequency setting range are disclosed in Japanese Patent Application No. 2003-332646.

  As described above, with the configuration of the fourth embodiment, in addition to the effects of the first or second embodiment, the polarity inversion frequency is changed according to the lamp current value during the period in which the stepping motor is driven. Regardless of this, since the discharge of the lamp is stabilized, it is possible to more reliably prevent the discharge lamp from extinguishing.

  In the fourth embodiment, since the polarity of the full bridge inverter is always inverted even during the driving period of the stepping motor, it is possible to reduce the power supply capacity of the high side driver that drives the switching element of the full bridge inverter compared to the third embodiment. Furthermore, since it is easy to set the lighting time for each polarity (lighting time on the positive polarity side and lighting time on the negative polarity side) to be equal, it is easy to prevent the life of the discharge lamp from being reduced due to the decrease in electrode pieces. is there.

  Further, as shown in FIG. 14, a time difference t9 is provided from when the output of the drive pulse signal S3 is permitted by the movement permission command (clearance of the movement prohibition command S4) to when the drive pulse signal S3 is actually output, The change of the frequency setting value in the polarity reversal frequency control unit 18 is performed at the same time as the output of the drive pulse signal S3 is permitted by the movement permission command, so that the discharge lamp DL can be stably lit by changing the polarity reversal frequency. It is possible to carry out variable light distribution control after being held in place.

(Embodiment 5)
15 and 16 show the configuration of the fifth embodiment. Embodiment 5 shows the structural example of the power converter device and light distribution variable control apparatus in this invention. In FIG. 15, the light distribution variable control device and the power conversion device are configured by one ECU (electronic control unit), and the light distribution variable control device and the power conversion device are driven and controlled by separate microcomputers 10 and 22, respectively. is there. The igniter circuit 4 may or may not be included in the ECU.

  On the other hand, in FIG. 16, in addition to the configuration of FIG. 15, lamp lighting control and motor drive control are performed by one microcomputer 10. By adopting these configurations, effects such as downsizing of the lighting device and cost reduction can be expected by sharing the case and reducing the number of parts by integrating the microcomputer (MPU).

  Generally, when MPUs are aggregated, the aggregated MPUs are required to have high processing capacity, which may cause an increase in cost in some cases. However, in the present invention, control for changing the output power to the discharge lamp is possible. Since the light distribution variable control is completely time-shared, it does not have to be an MPU having a high processing capacity. Therefore, when MPUs are aggregated, cost reduction can be expected.

  Furthermore, if, for example, control that completely fixes the primary current command value is used instead of constant power control during the light distribution variable control period, feedback control (from lamp current detection and lamp voltage detection to 1 is performed during the light distribution variable control period. This is effective when complicated variable light distribution control is required.

  In the first to fourth embodiments, the power conversion device 1 and the light distribution variable control device 20 are separate ECUs (electronic control units) each including a microcomputer (MPU), and the lighting state of the discharge lamp DL and the motor Although this is a system having means (communication means for signals S4 and S5) for communicating the driving state with each other, in FIG. 16 of the fifth embodiment, the light distribution variable control period and the output power change control period with one microcomputer (MPU). Therefore, it is possible to reduce the communication means and to realize a cheaper discharge lamp lighting device.

  In addition, as is common to the above-described embodiments, as a load of the variable light distribution control device, variable light distribution control using an actuator such as a solenoid or a liquid crystal shutter is applied in addition to the examples given in the previous embodiments. Even in the present invention, the same effect can be obtained.

(Embodiment 6)
17 to 19 show a configuration of the sixth embodiment. In the sixth embodiment, a configuration example in which the configuration of the load of the variable light distribution control device is different from the first to fifth embodiments. Other circuit block diagrams are the same as those in FIG.

  FIG. 17 is an example in which the load of the variable light distribution control device is configured by a plurality of motors 31a and 31b. By using a plurality of motors, the operable range of a mechanism (for example, a reflector) that varies the light distribution of the discharge lamp increases, so that more complex light distribution variable control is possible. For example, in an in-vehicle headlamp lighting device, when there is one motor, the light distribution can be varied only in the vertical direction or the horizontal direction, but if there are two motors, the light distribution can be distributed in the vertical and horizontal directions. The light can be varied. However, when the load of the variable light distribution control device increases, the control circuit for controlling the drive becomes complicated, and an MPU having a higher processing capacity or a plurality of MPUs is required. There is a risk of increasing costs.

  In the present invention, constant power control and variable light distribution control of the discharge lamp are performed in a time-sharing manner. Therefore, even when the load of the variable light distribution control device increases, the size of the above device and the increase in cost are suppressed as much as possible. Thus, it is possible to obtain stable lighting of the discharge lamp.

  FIGS. 18 and 19 are examples in which the load of the variable light distribution control device is configured by the auxiliary light source lighting device 25 and the auxiliary light sources 26 and 27. In this embodiment, the drive signal output period for variable light distribution control in the embodiments shown so far is replaced with the auxiliary light source lighting period. As the auxiliary light source, the LED 26 shown in FIG. 18, the halogen lamp 27 shown in FIG. 19, and the like can be considered, but there is no limitation on the type of light source, the number of uses, and the like, which may be used depending on the required light distribution. Or a combination of different light sources is also conceivable.

  In the configurations of FIGS. 18 and 19, since the light distribution is varied by turning on / off the auxiliary light source, the vibration of the mechanism unit (for example, a reflector) that is movable by the light distribution variable control device described in the first to fifth embodiments is used. The resulting extinguishing of the discharge lamp DL does not occur. However, when lighting control equivalent to the power conversion device shown in the present invention is also required for an auxiliary light source such as an LED, as in the configuration of FIG. Since there is a fear, the effect by application of this invention can be anticipated.

  Further, when the halogen lamp 27 is used as the auxiliary light source, as shown in FIG. 20, the power supply voltage decreases due to the inrush current immediately after the start of lighting, and the output power to the discharge lamp DL fluctuates, so that the discharge becomes unstable. This is a factor (same when using an auxiliary light source that requires a relatively large electric power as well as a halogen lamp). However, since the lighting power of both the LED 26 and the halogen lamp 27 is stable after stable lighting, the luminous flux rise of the discharge lamp DL and dimming control can be performed as long as the lighting of the auxiliary light source is stable. is there. Therefore, as in the light control example shown in FIG. 5 of the first embodiment, a period for stopping variable light distribution control (drive signal output stop period) such as when the lamp light flux is started up or during light control is supplemented. The period from the start of lighting of the light source to stable lighting (about several tens of milliseconds (Ts) in the halogen lamp of FIG. 20) may be limited.

(Embodiment 7)
FIG. 21 shows the configuration of the seventh embodiment. In this embodiment, a variable light distribution type discharge lamp lighting device is applied to a headlamp 110 of a vehicle 100. The headlamp control device 120 controls the headlamp DL and the light distribution variable control motor 30 in a time-sharing manner. When applied to a vehicle headlamp, the vehicle itself vibrates according to the road surface condition when the vehicle travels, as well as the vibration of the movable part for variable light distribution. is there. Therefore, in order to maintain the stable lighting of the discharge lamp used as the vehicle headlamp, the application of the present invention has an effect of ensuring the stable lighting of the discharge lamp and simplifying the control circuit.

It is a block circuit diagram which shows the structure of Embodiment 1 of this invention. It is a flowchart which shows the lighting control of Embodiment 1 of this invention. It is a flowchart which shows the light distribution variable control of Embodiment 1 of this invention. It is operation | movement explanatory drawing which shows the basic operation | movement of Embodiment 1 of this invention. It is operation | movement explanatory drawing which shows the other operation | movement of Embodiment 1 of this invention. It is operation | movement explanatory drawing which shows the light beam starting operation | movement of Embodiment 1 of this invention. It is a block circuit diagram which shows the structure of Embodiment 2 of this invention. It is a flowchart which shows the lighting control of Embodiment 2 of this invention. It is a flowchart which shows the light distribution variable control of Embodiment 2 of this invention. It is a block circuit diagram which shows the structure of Embodiment 3 of this invention. It is operation | movement explanatory drawing which shows the basic operation | movement of Embodiment 3 of this invention. It is a block circuit diagram which shows the principal part structure of Embodiment 4 of this invention. It is operation | movement explanatory drawing which shows the basic operation | movement of Embodiment 4 of this invention. It is operation | movement explanatory drawing which shows the other operation | movement of Embodiment 4 of this invention. It is a block circuit diagram which shows the basic composition of Embodiment 5 of this invention. It is a block circuit diagram which shows one modification of Embodiment 5 of this invention. It is a block circuit diagram which shows an example of the light distribution variable means of Embodiment 6 of this invention. It is a block circuit diagram which shows another example of the light distribution variable means of Embodiment 6 of this invention. It is a block circuit diagram which shows another example of the light distribution variable means of Embodiment 6 of this invention. It is a characteristic view which shows the characteristic of the auxiliary light source of Embodiment 6 of this invention. It is explanatory drawing which shows the use condition of the vehicle headlamp lamp of Embodiment 7 of this invention. It is a circuit diagram of a conventional example.

Explanation of symbols

DL discharge lamp 1 power conversion device 10 control circuit 20 light distribution variable control device 22 control circuit 30 DC motor S1 power change command S2 light distribution variable signal input S3 drive signal S4 movable prohibition command

Claims (10)

A power conversion device that converts a DC power source into predetermined power required for lighting a discharge lamp, and a power conversion device having a control unit of the power conversion unit;
A variable light distribution control device that changes the light distribution of the discharge lamp according to a predetermined input signal;
The power conversion device and the light distribution variable control device each have communication means,
A time period for carrying out the control for changing the output power to the discharge lamp by the power conversion device and a time period for carrying out the control for changing the light distribution by the variable light distribution control device ,
The variable light distribution type discharge lamp lighting device characterized in that the period during which the output power to the discharge lamp is changed is the time when the luminous flux of the discharge lamp is raised and the dimming control period of the discharge lamp. 2. The variable light distribution type discharge lamp lighting device according to claim 1 , wherein when the tube voltage of the discharge lamp is higher than a predetermined value, the variable light distribution control device does not perform control to vary the light distribution. 3. The variable light distribution type discharge lamp lighting device according to claim 1 , wherein the polarity of the output of the power conversion device is not inverted during a period in which the light distribution of the discharge lamp is varied by the variable light distribution control device. The period for changing the light distribution of the discharge lamp by the light distribution variable control device, to claim 1 or 2, characterized in that the period for polarity inverting the output of the power converter in accordance with the output of the power converter varies The light distribution variable discharge lamp lighting device described. The variable light distribution type discharge lamp lighting device according to any one of claims 1 to 4, wherein the control of varying the light distribution controls an actuator for varying the light distribution . A control for varying the light distribution, the discharge lamp light distribution variable type discharge lamp lighting device according to any one of claims 1 to 5, characterized in that turning on the different auxiliary light sources and. 7. The variable light distribution discharge lamp lighting device according to claim 6 , wherein the auxiliary light source is a halogen lamp, and a predetermined period during which a larger current flows from the start of lighting than when stable lighting is set as a variable light distribution control period . 8. The variable light distribution type according to claim 1, wherein the variable light distribution control device and the power change device are constituted by one electronic control unit, and each control microcomputer performs synchronous control. Discharge lamp lighting device. 9. The variable light distribution type discharge lamp according to claim 1 , wherein control for changing output power to the discharge lamp and control for varying the light distribution of the discharge lamp are performed by a single microcomputer. Lighting device. A vehicular headlamp lamp equipped with the variable light distribution type discharge lamp lighting device according to any one of claims 1 to 9.

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