JP2004319189A - Vehicular discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular discharge lamp lighting device capable of executing output control of a discharge lamp in its startup and normal time according to ambient brightness. <P>SOLUTION: This vehicular discharge lamp lighting device is equipped with: the discharge lamp 1; a high-voltage pulse generation circuit 2 for applying high-voltage pulses to the discharge lamp 1 to start the discharge lamp 1; a voltage increasing-decreasing converter 4 for controlling voltage/current to be supplied to the discharge lamp 1 by increasing and decreasing the voltage of a D.C. power source E1; an inverter 3 for converting the output of the converter 4 into low-frequency power to supply it to the discharge lamp 1; a lamp current detection part 5 for detecting the current I1a2 of the discharge lamp 1; a lamp voltage detection part 6 for detecting the voltage 1a2 of the discharge lamp 1; a control circuit 7 for inputting outputs of the respective detection parts 5 and 6 to control the converter 4 and the inverter 3; and a light detection device 20 for detecting the ambient brightness. The control circuit 7 is provided with a control means direction part 8 for outputting a control command according to the ambient brightness based on a signal detected by the detection device 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle headlamp lighting device for lighting a discharge lamp as a headlamp of an automobile.
[0002]
[Prior art]
[Patent Document 1]
JP-A-7-9911
FIG. 12 is a schematic configuration diagram of a conventional vehicle lighting device (for example, Japanese Patent Application Laid-Open No. H11-32440). The vehicular lamp A includes an information acquisition unit C including a light detection device B for detecting ambient brightness outside, and an irradiation control unit E for changing a light distribution, a light amount, or a light color of the lamp D. In the above configuration, the light quantity can be changed by the information acquisition means C including the light detection device B according to the surrounding brightness.
[0004]
[Problems to be solved by the invention]
In the prior art, a method is employed in which the amount of light is changed by a signal detected by the light detection device B. However, in a vehicle headlamp system using a discharge lamp, a start-up time that affects the life of the discharge lamp is reduced. Cannot be controlled. In recent years, as headlights are continually lit in the daytime (daylight) mainly in Europe and North America, it is conceivable that the life of the discharge lamps may be shortened due to a longer lighting time.
[0005]
The present invention has been made in view of such a point, and provides a vehicular discharge lamp lighting device capable of performing output control at the time of starting and steady state of a discharge lamp according to ambient brightness. That is the task.
[0006]
[Means for Solving the Problems]
According to the present invention, a control means command unit for commanding predetermined control based on a signal detected by a light detection device provided outside the lighting device is provided in the discharge lamp lighting device, and the surrounding brightness is In this case, output control is performed at the time of starting and at the time of steady operation of the discharge lamp.
The discharge lamp lighting device for a vehicle according to the first aspect of the present invention includes a discharge lamp, a high-voltage pulse generating circuit for applying a high-voltage pulse to the discharge lamp to start the discharge lamp, and raising and lowering the voltage of the DC power supply to release the voltage. A buck-boost converter 4 for controlling the voltage / current supplied to the electric lamp 1, an inverter 3 for converting the output of the buck-boost converter 4 into low-frequency power and supplying it to the discharge lamp 1, and detecting a current Ila 2 of the discharge lamp 1. A lamp current detecting section 5, a lamp voltage detecting section 6 for detecting a voltage Vla2 of the discharge lamp 1, a control circuit 7 for inputting the output of each of the detecting sections 5 and 6, and controlling the buck-boost converter 4 and the inverter 3. And a light detecting device 20 for detecting ambient brightness, wherein the control circuit 7 outputs a control command according to the ambient brightness based on a signal detected by the light detecting device 20. It is specially equipped with the command unit 8. It is an.
[0007]
According to a second aspect of the present invention, in the first aspect, there is provided a day / night discriminating unit for discriminating day / night from the detection result of the light detection device, and the steady-state output power to the discharge lamp is controlled according to day / night. It is characterized by doing.
According to a third aspect of the present invention, in the first aspect, there is provided an information storage means for storing a detection result of the light detection device, and performs light start-up control according to day and night from the start of the discharge lamp to a steady time. It is characterized by the following.
According to a fourth aspect of the present invention, in the third aspect, the setting of the maximum value of the target output power is variable as the light start-up control means.
According to a fifth aspect of the present invention, in the third aspect, the setting of the maximum power supply time is variable as the light start-up control means.
According to a sixth aspect of the present invention, in the first aspect, the control is performed such that the no-load output voltage value at the time of starting is reduced under a bright ambient condition.
According to a seventh aspect of the present invention, in the sixth aspect, the control is performed such that the no-load voltage value is set to be low at the beginning of lighting, and the no-load voltage value is gradually increased as the lighting time elapses.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
FIG. 1 shows the configuration of the first embodiment. In this embodiment, a discharge lamp 1, a high-voltage pulse generating circuit 2 for applying a high-voltage pulse to the discharge lamp 1 to start the discharge lamp 1, an inverter 3 for supplying low-frequency power to the discharge lamp 1, and a DC power supply A step-up / step-down converter 4 that steps up / down the voltage of E1 and controls the voltage / current supplied to the discharge lamp 1, a lamp current detector 5 that detects the current of the discharge lamp 1, and a lamp voltage that detects the voltage of the discharge lamp 1. A discharge lamp lighting device 100 including a detection unit 6, a step-up / step-down converter 4, and a control circuit 7 for controlling the inverter 3, in which a light detection device 20 for detecting ambient brightness is added outside the control circuit 7. It is. Inside the control circuit 7, a control means command section 8 for commanding predetermined control, a lamp voltage discriminating circuit 9 for discriminating the lamp voltage of the discharge lamp 1, and a command for a predetermined output power W based on the discriminated result. A target output power setting unit 10, a target output current setting unit 11 for setting a target value of the lamp current, an error amplifier P2 for comparing the detected value of the lamp current with the target value, and a step-up / down converter according to the output of the error amplifier P2. And a PWM control unit P1 for controlling the ON time width of the switching element of the converter 4. The target output current setting unit 11 divides the target output power W output from the target output power setting unit 10 by the voltage Vla detected by the lamp voltage detection unit 6 to determine a command value of the supplied lamp current. The error amplifier P2 compares the lamp current command value set by the target output current setting unit 11 with the lamp current Ila2 actually flowing detected by the lamp current detection unit 5, detects an error, and detects the PWM of the buck-boost converter. A feedback signal is sent to the control unit P1. L1 is an inverter driving unit that controls the period of inversion of the output polarity of the inverter 3 composed of a full bridge circuit or the like (see Patent Document 1).
[0009]
A level signal as shown in FIG. 2A is input from the light detection device 20 to the discharge lamp lighting device, and the control means command section 8 receives this signal and receives "1" or "1" shown in FIG. A signal "0" is output, and in response to this signal, the target output power setting unit 10 sets the target output power as shown in FIG. That is, if the signal according to the ambient brightness output from the light detection device 20 is equal to or smaller than the predetermined threshold α, the output of the control unit command unit 8 becomes “1”, and it is determined that it is nighttime. When the signal output from the light detection device 20 according to the ambient brightness is larger than a predetermined threshold value α, the output of the control unit command unit 8 becomes “0”, and it is determined that it is daytime. The output power command value in the steady state is switched between nighttime and daytime as shown in FIG.
[0010]
In the above configuration, when the lighting device is energized from the DC power supply E1 including a vehicle-mounted battery or the like, the buck-boost converter 4 and the inverter 3 start operating, the high-voltage pulse generation circuit 2 generates a high-voltage pulse, and the discharge lamp 1 The insulation between the electrodes is broken, and the discharge lamp 1 starts lighting. At this time, the lamp voltage Vla2 is detected by the lamp voltage detector 6 provided on the output side of the step-up / step-down converter 4. Further, a signal detected by the light detection device 20 is input to the control unit command unit 8, and the control unit command unit 8 has a predetermined threshold value α. The target output power setting unit 10 sets the target output power setting unit 10 to perform the output control. If the output power is larger than the threshold α, the target output power setting unit 10 sets the target output power setting unit 10 to perform the output control with the output lowered than usual, and performs the output control. .
[0011]
According to the present embodiment, the output control of the discharge lamp in the steady state can be switched between daytime and nighttime. Can be reduced. In addition, power consumption can be reduced during daytime lighting when light quantity is not required, and energy is saved.
[0012]
(Embodiment 2)
FIG. 3 shows the configuration of the second embodiment. The basic configuration is the same as that of the first embodiment, and includes an information storage unit IM that can store a signal detected by the photodetector 20. The ambient brightness is detected from the start of lighting or the start of traveling. A detection signal of the ambient brightness is input from the information storage unit IM to the control unit command unit 8, the target output power is set by the target output power setting unit 10, and the output is controlled.
[0013]
For example, when it is determined to be daytime, the target output power of Table 1 in FIG. 4 is set, and when it is determined to be nighttime, the target output power of Table 2 in FIG. 4 is set and output control is performed. In the figure, Ts is a period for supplying the maximum power after the start of lighting.
[0014]
According to the present embodiment, it is possible to perform output control at the time of starting and steady state of the discharge lamp in accordance with the surrounding brightness, and it is possible to suppress a decrease in the life of the discharge lamp. In addition, power consumption can be reduced during daytime lighting when light quantity is not required, and energy is saved.
[0015]
(Embodiment 3)
FIG. 5 shows the configuration of the third embodiment. The basic configuration is the same as that of the second embodiment, and further includes a unit RS for resetting the information storage unit IM and a timer TJ for counting time. For example, when the detection signal of the surrounding brightness detected by the light detection device 20 changes abruptly, for example, during a tunnel driving in the daytime, the light detection signal within a certain time counted by the timer TJ is used. When the change becomes larger than the prescribed value, the storage of the information storage means IM is reset by the reset means RS, and the surrounding brightness information is obtained again by the control means command unit 8 and stored in the information storage means IM. Optimum control of the starting output or steady-state output.
According to the present embodiment, in addition to the effects of the second embodiment, it is possible to cope with even during tunnel driving in the daytime, perform optimal output control, and perform safe driving.
[0016]
(Embodiment 4)
FIG. 6 shows a main part configuration of the fourth embodiment. The basic configuration is the same as that of the second embodiment shown in FIG. 3, and the internal configuration of the control unit command unit 8 is the configuration shown in FIG. As a light beam rising unit, a signal detected by the light detection device 20 is input to the calculation unit 81, and the maximum power according to the detection signal of the surrounding brightness is calculated. The result of the calculation is input to the target output power setting unit 10, and the light flux rising output control at the time of starting is performed. As a specific calculation method, a means for changing linearly as shown in FIG. 7 is conceivable, but it may be changed non-linearly. Further, the maximum power may be increased in accordance with an increase in the surrounding brightness, or may be decreased in contrast.
According to the present embodiment, it is possible to perform luminous flux start-up output control at the time of starting the discharge lamp according to the surrounding brightness, and it is possible to suppress a reduction in the life of the discharge lamp.
[0017]
(Embodiment 5)
FIG. 8 shows a main part configuration of the fifth embodiment. The basic configuration is the same as that of the second embodiment shown in FIG. 3, and the internal configuration of the control unit command unit 8 is the configuration shown in FIG. As a light beam rising unit, a signal detected by the light detection device 20 is input to the calculation unit 82, and a maximum power supply time according to a detection signal of ambient brightness is calculated. The result of the calculation is input to the target output power setting unit 10, and the light flux rising output control at the time of starting is performed. As a specific calculation method, a means for changing linearly as shown in FIG. 9 is conceivable, but it may be changed non-linearly. In addition, the maximum power supply time may be increased in accordance with an increase in ambient brightness, or may be decreased in contrast.
According to the present embodiment, it is possible to perform luminous flux start-up output control at the time of starting the discharge lamp according to the surrounding brightness, and it is possible to suppress a reduction in the life of the discharge lamp.
[0018]
(Embodiment 6)
FIG. 10 shows the operation of the sixth embodiment. Although the basic configuration is the same as that of the second embodiment shown in FIG. 3, this embodiment further includes a no-load voltage setting unit, and the control unit command unit 8 outputs a signal for which daytime and nighttime judgment is made. It is input to the no-load voltage setting unit, and the no-load voltage value shown in FIG. 10 is commanded. The drive unit P1 of the buck-boost converter 4 is controlled by the set no-load voltage value to output a predetermined no-load voltage. The no-load voltage affects the starting characteristics of the discharge lamp 1, and the higher the voltage value, the better the starting characteristics. However, on the other hand, when the voltage is increased, a voltage stress is applied to the discharge lamp lighting device, which affects the life of the discharge lamp lighting device. In this embodiment, the minimum no-load voltage value that satisfies the starting performance is set in the daytime, and the normal setting is used in the nighttime. Thereby, output control at the time of starting can be performed according to the brightness of the surroundings, and a reduction in the life of the lighting device and the discharge lamp can be suppressed.
[0019]
(Embodiment 7)
FIG. 11 shows the operation of the seventh embodiment. Although the basic configuration is the same as that of the second embodiment shown in FIG. 3, this embodiment further includes a no-load voltage setting unit, and the control unit command unit 8 outputs a signal for which daytime and nighttime judgment is made. It is input to the no-load voltage setting unit, and the no-load voltage value shown in FIG. 11 is commanded. The drive unit P1 of the buck-boost converter 4 is controlled based on the set no-load voltage value, and outputs a predetermined no-load voltage. In this embodiment, control is performed in the daytime to gradually increase the voltage value from the minimum no-load voltage value that satisfies the starting performance. In addition, normal settings are made at night. Thereby, output control at the time of starting can be performed according to the brightness of the surroundings, and a reduction in the life of the lighting device and the discharge lamp can be suppressed. In addition, by gradually increasing the no-load voltage value, the engine can be reliably started.
[0020]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the output control at the time of starting of a discharge lamp and a steady state can be performed according to the surrounding brightness | luminance, and there exists an effect that the life reduction of a discharge lamp can be suppressed. For example, in the above-mentioned daytime headlights that are always lit, other vehicles and pedestrians are mainly lit in order to encourage the pedestrian to recognize the vehicle, so the light start-up characteristics and light quantity required at night are It is considered unnecessary, and it is desirable to suppress a decrease in the life of the discharge lamp due to a long lighting time, and the application of the present invention is particularly effective.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram showing a configuration of a first embodiment of the present invention.
FIG. 2 is an operation explanatory diagram of the first embodiment of the present invention.
FIG. 3 is a block circuit diagram showing a configuration according to a second embodiment of the present invention.
FIG. 4 is an explanatory diagram of an operation according to the second embodiment of the present invention.
FIG. 5 is a block circuit diagram showing a configuration according to a third embodiment of the present invention.
FIG. 6 is a block circuit diagram showing a main part configuration of a fourth embodiment of the present invention.
FIG. 7 is an operation explanatory view of Embodiment 4 of the present invention.
FIG. 8 is a block circuit diagram showing a main part configuration of a fifth embodiment of the present invention.
FIG. 9 is an operation explanatory view of Embodiment 5 of the present invention.
FIG. 10 is an operation explanatory view of Embodiment 6 of the present invention.
FIG. 11 is an operation explanatory view of Embodiment 7 of the present invention.
FIG. 12 is a block circuit diagram showing a configuration of a conventional example.
[Explanation of symbols]
E1 DC power supply 1 Discharge lamp 2 High voltage pulse generation circuit 3 Inverter 4 Buck-boost converter 5 Lamp current detection unit 6 Lamp voltage detection unit 7 Control circuit 8 Control unit command unit 20 Light detection device

Claims (7)

A discharge lamp,
A high-voltage pulse generating circuit that applies a high-voltage pulse to the discharge lamp to start the discharge lamp, a buck-boost converter that controls the voltage / current supplied to the discharge lamp by raising and lowering the voltage of the DC power supply,
An inverter that converts the output of the buck-boost converter into low-frequency power and supplies it to the discharge lamp;
A lamp current detector for detecting a current of the discharge lamp,
A lamp voltage detector for detecting a voltage of the discharge lamp,
A control circuit that controls the buck-boost converter and the inverter by inputting the output of each of the detection units,
A light detection device that detects ambient brightness,
The discharge lamp lighting device for a vehicle, wherein the control circuit includes a control unit command unit that outputs a control command according to ambient brightness based on a signal detected by a light detection device. 2. A vehicle discharger according to claim 1, further comprising day / night discriminating means for discriminating day / night from the detection result of said light detection device, and controlling steady-state output power to the discharge lamp in accordance with day / night. Lighting device. 2. A discharge lamp for a vehicle according to claim 1, further comprising information storage means for storing a detection result of the light detection device, wherein light start control according to day and night is performed from the start of the discharge lamp to a steady time. Lighting device. 4. The discharge lamp lighting device for a vehicle according to claim 3, wherein the setting of the maximum value of the target output power is variable as the light start-up control means. 4. The discharge lamp lighting device for a vehicle according to claim 3, wherein the setting of the maximum power supply time is variable as the light start-up control means. 2. The discharge lamp lighting device for a vehicle according to claim 1, wherein under no-light conditions, the no-load output voltage value at the time of starting is controlled to be low. 7. The vehicular discharge lamp lighting device according to claim 6, wherein a no-load voltage value is set to be low at the beginning of lighting, and control is performed to gradually increase the no-load voltage value as the lighting time elapses.

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