JPH02136342A - Lighting circuit of high-pressure discharge lamp for vehicle - Google Patents

Abstract

PURPOSE:To shorten the lighting start time and restart time of a discharge lamp by controlling the lamp current or the like at the lighting start or restart of the discharge lamp in response to multiple control modes corresponding to the lights-out time of the high-pressure discharge lamp. CONSTITUTION:A DC booster circuit 3 is connected to a battery 2 serving as a DC power source via a lighting switch 2A. A DC-AC push-pull inverter circuit 4 is connected to the booster circuit 3, and the DC voltage is converted into the sine-wave AC voltage. An LC circuit and an ignitor circuit 5 are connected to the inverter circuit 4, and a metal halide lamp 6 and an ignitor starting circuit 7 are connected to the ignitor circuit 5. The step-up quantity of the booster circuit 3 is adjusted by a control circuit 8 to control the lamp current of the lamp 6. The lamp current at the lighting start or restart of the lamp 6 is controlled in response to multiple control modes corresponding to the lights-out time of the lamp 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The details of the lighting circuit for the high-pressure discharge lamp for vehicles of the present invention will be explained in accordance with the following items.

A. Industrial field of application B3 Overview of the invention C Prior art a. - Numerical background I. Conventional examples 9 Problems to be solved by the invention E1 Means for solving the problems F Examples [Figs. Figure 8 Core a Overall circuit configuration [Figure 1 DC booster circuit [Figure 2] 1° circuit [Figure 2 (A)] 2 Operation [Figure 2 (B)] DC-AC push-pull inverter circuit [Figure 2 (A)] Figure 3] 1. Circuit [Figure 3 (A)] c-2 operation [Figure 3 (B)] LC load and igniter circuit [Figure 4 C1 Circuit [Figure 4]
Figure (A)] d-2 operation [Figure 4 (B) Coigniter starting circuit [Figure 4] e-1 circuit [Figure 4 (A)] 2 operation [Figure 4 (B)] f, control circuit 1. Control mode [Figure 5] f-1-a, Hot restrike mode [Figure 5 (A) f-1-b Medium start mode [Figure 5 (B)] f-1-c Cold start Mode [Fig. 5(C) f-21 circuit configuration [Fig. 6] f-3, timing circuit for light-off time detection [Fig. 7, 8]
] f-3-a circuit [Fig. 7] f-3-b, operation [Fig. 8] f-4 hot restrike mode discrimination circuit [Fig. 7, Fig. 8 f-4-a, circuit [Fig. 7] f-4-b operation [Fig. 8] f-5, overcurrent time control circuit [Fig. 7, 8
f-5-a circuit [Fig. 7 f-5-b, operation [Fig. 8] f-6 medium start mode discrimination circuit [Fig. 7, Fig. 8] f-6-a circuit [Fig. [Fig. 7] f-6-b Operation [Fig. 8] f-7 Mode-specific control circuit [Fig. 7, Fig. 8] f-7-a Circuit f-7-b Operation [Fig. 8] f-8 , PWM control circuit [Figs. 7 and 8 f-8-a. Circuit [Fig. 7] f-8-b Operation g, starting time and restarting time G Effects of the invention (A. Field of industrial application) The present invention relates to a novel lighting circuit for a high-pressure discharge lamp for a vehicle.

Specifically, the lamp current of the discharge lamp at the time of starting lighting is controlled according to the extinguishing time of the high-pressure discharge lamp for vehicles, and thereby the luminous flux reaches the rated luminous flux in a very short time when the discharge lamp is lit or relit. The present invention aims to provide a lighting circuit for a novel high-pressure discharge lamp for vehicles, and in particular, it aims to significantly promote the practical use of metal halide lamps, which are attracting attention as a light source for vehicle headlamps. It is.

(B. Summary of the Invention) A lighting circuit for a high-pressure discharge lamp for a vehicle of the present invention includes a booster circuit that boosts the voltage of an input terminal input from a DC power source via a DC voltage input terminal, and a DC voltage input from the booster circuit. A high-pressure discharge lamp for a vehicle is provided with a converter circuit for converting into a sinusoidal AC voltage, a starting means for lighting the high-pressure discharge lamp via an AC voltage output terminal, and a control means for controlling the output voltage of a no-pressure circuit. In the lighting circuit, the control means includes a mode discrimination means for discriminating between a plurality of control modes corresponding to the extinguishing time of the high-pressure discharge lamp, and a mode discriminating means for discriminating between a plurality of control modes corresponding to the extinguishing time of the high-pressure discharge lamp, and a mode discrimination means for discriminating between a plurality of control modes corresponding to the extinguishing time of the high-pressure discharge lamp. mode-specific control means for displaying a predetermined control mode for controlling the lamp current and sending a control signal to the booster circuit for controlling the output voltage of the booster circuit, The lamp current is controlled at the time of starting, thereby making it possible to significantly shorten the starting time and restarting time when lighting the discharge lamp.

(C, Prior Art) (a - Background of Boat Fishing) In recent years, there has been an increasing demand for safety during night driving, improvement of the aerodynamic characteristics of the car body, and power saving. Even when it comes to lighting, there is no exception to this. Improving visibility is required for safety when driving at night, and slanted headlights and smaller and thinner headlights are required to improve aerodynamic characteristics. It is being

In terms of power saving, metal halide lamps are attracting attention because they have characteristics that far exceed those of conventional halogen lamps in terms of power consumption, light source efficiency, and lifespan.

In other words, metal halide lamps contain a starting gas (
argon, etc.), mercury, and metal iodide, and when a high voltage is applied to the discharge electrode, a mercury arc discharge occurs after the startup gas discharges, and the heat generated by this causes metal iodide to be is vaporized and dissociated in a mercury arc, resulting in the emission of a high luminous flux with the characteristic spectrum of metal atoms.

(b. Conventional Example) A lighting circuit for a high-pressure discharge lamp including such a metal halide lamp is known, for example, as shown in Japanese Patent Application Laid-Open No. 62-259391.

The circuit shown in this publication uses a DC power supply, a step-up upconverter connected to the DC power supply, and a sine wave alternating current to convert the DC voltage from the upconverter to light a high-pressure discharge lamp using a DC power supply. a sine wave converter connected to an upconverter to convert to voltage;
It consists of a starting circuit, etc. By supplying sine wave AC when lighting the discharge lamp, unstable operation of the discharge lamp due to acoustic resonance caused by the supply of square wave AC voltage is eliminated, and the up-converter can be replaced with a controllable DC voltage converter. This makes it possible to adjust the output.

(D Problem to be Solved by the Invention) However, although the above-described circuit has made it possible to light a high-pressure discharge lamp using a DC power supply, it is difficult to turn on the discharge lamp until it reaches the specified brightness. The time required for (
There are problems in that it takes too much time (restart time) to reach the specified brightness when the light is turned on again after it has been turned off (starting time).

This is because when a discharge lamp is turned on for the first time, the discharge starts from a cold glass bulb, so it takes time for the metal iodide in the glass bulb to vaporize, and - This is due to the fact that when the bulb is lit again after it has been lit for a while, the pressure inside the glass bulb becomes extremely high after a certain period of time, and therefore the discharge starting voltage becomes high.

(E. Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the lighting circuit for a high-pressure discharge lamp for a vehicle of the present invention has a DC voltage input terminal connected to a DC power source, and the DC voltage input terminal is connected to a DC voltage input terminal. The high-pressure discharge lamp has a booster circuit that boosts the voltage of the input terminal from the terminal, a converter circuit that converts the DC voltage input from the booster circuit into a sinusoidal AC voltage, and an AC voltage output terminal to which the high-pressure discharge lamp is connected. In a lighting circuit for a high-pressure discharge lamp for a vehicle, which includes a starting means for lighting the lamp and a control means for controlling the output voltage of a booster circuit, the control means has a plurality of control means corresponding to the extinguishing time of the high-pressure discharge lamp. mode discriminating means for discriminating the control mode; and a mode discriminating means for displaying a predetermined control mode for controlling the lamp current at the time of lighting start or restart of the discharge lamp according to a signal from the mode discriminating means, and for controlling the y-pressure. and a mode-specific control means for sending a control signal to the booster circuit to control the output voltage of the circuit. The current is controlled.

Therefore, according to the present invention, the control means develops a predetermined control mode regarding the lamp current of the discharge lamp at the time of starting or restarting the high-pressure discharge lamp according to the elapsed time from when the high-pressure discharge lamp is turned off until the next time the high-pressure discharge lamp is turned on. Therefore, the lamp current of the discharge lamp can be controlled by changing the output voltage of the booster circuit, so that the lamp current that matches the physical conditions inside the discharge lamp can always flow, so when the discharge lamp is lit or relit. This luminous flux can reach the rated luminous flux in a short time.

(Embodiment F) [Figures 1 to 8] Details of a lighting circuit for a high-pressure discharge lamp for a vehicle according to the present invention will be described below in accordance with an embodiment shown in the accompanying drawings. The illustrated embodiment is one in which the present invention is applied to a lighting circuit for a metal lamp for an automobile.

(a Overall circuit configuration) [Figure 1] 1 is a lighting circuit for a metal halide lamp for an automobile.

2 is a battery as a DC power source, and the output voltage is D.
It is said to be about C12V.

3 is a DC booster circuit whose input terminal is connected to battery 2.
It is connected to the power supply terminal of the light switch 2A via the lighting switch 2A.

4 is a DC-AC push-pull inverter circuit, the input terminal of which is connected to the output terminal of the DC booster circuit 3, and is provided to convert the DC voltage from the DC booster circuit 3 into a sine wave AC voltage. ing.

5 is an LC load and igniter circuit, the input terminal of which is connected to the output terminal of the DC-AC push-pull inverter circuit 4.

6 is a metal halide lamp connected to the output terminal of the igniter circuit 5, and its lamp characteristics are power consumption 3.
It has a 5W2 luminous flux of 27 oofl (lumens) or more, and a color temperature of about 4000K (Kelvin).

Reference numeral 7 denotes an igniter starting circuit for starting the igniter circuit 5, and includes a circuit for sending a starting signal to the igniter circuit 5 and detecting the lamp current.

Reference numeral 8 denotes a control circuit, which displays a predetermined control mode according to the extinguishing time of the metal halide lamp 6, thereby adjusting the boost amount of the DC booster circuit 3 to control the lamp current of the metal halide lamp 6. This is a circuit installed in

The circuit configuration and operation of each of these parts will be explained below.

(b, DC booster circuit) [Figure 2] The DC booster circuit 3 is a step-up type DC-DCC with one stepper type.
- Equation - It is constructed by connecting two stages of data 9.9' in series.

(b-1 circuit) [Figure 2 (A)] 10 is an input terminal, one of which 10a is connected to the positive terminal of the battery 2 via the lighting switch 2A, and the other 10b is connected to the negative terminal. ing. Therefore, the input terminal (denoted as Vl (V)) is approximately equal to the battery voltage.

Reference numeral 11 denotes a control terminal, into which a control pulse sent from a control circuit 8 to be described later is input, and the amount of boosting is controlled by the duty cycle of the control pulse.

A negative line 12 connects the input terminal tab and the negative terminal +3b of the output terminal 13.

The DC-DC converter 9 includes an inductor 14, an MO3 type FET 15, a rectifying diode 16, and a smoothing capacitor 17.

The inductor 14 has a predetermined inductance so that it can store energy when the FET 15 is on, and release the stored energy when the FET 15 is off, superimposing it on the input voltage and outputting it. ,
One terminal thereof is connected to the input terminal 10a.

The FET 15 has its train connected to the terminal on the side opposite to the input terminal 10a of the inductor 14, and its source connected to the negative line 12. And FET
The gate of 15 is connected to the control terminal 11, and is operated for switching by a control pulse from the control circuit 8.

Diode 16 has its anode connected to the train of FETs 15.

The capacitor 17 is a polar capacitor, and its positive terminal is connected to the cathode of the diode 16, and its negative terminal is connected to the minus line 12.

The DC-DC converter 9' also has the same configuration as the DC, -DC converter 9, and one terminal of its inductor 14' is connected to the positive terminal of the capacitor 17 of the DC-DC converter 9, and the drain of the FET 15' is connected to the positive terminal of the capacitor 17 of the DC-DC converter 9. Its source and source are respectively connected to the other terminal of the inductor 14' and the negative line 12, and its gate is also connected to the control terminal 11. And diode 1
6' has its anode connected to the train of FET 15', its cathode connected to the positive terminal 13a of the output terminal 13, and the capacitor 17' connected to the output terminal 13a.
, 13b.

(b-2 Operation) [FIG. 2(B)] Next, the operation of the DC booster circuit 3 will be explained according to the operational waveform diagram schematically shown in FIG. 2(B).

In addition, FIG. 2 (B) shows an operating waveform diagram in the 9 stages of DC-DC converter, where VGS is the gate-source voltage of FET 15, VDS is the drain-source voltage,
, is the terminal voltage of the inductor 14, IDS is the drain-source current of the FET 15, ID is the current flowing through the diode 16, (2).

is the current flowing through the inductor 14, Vo is the output voltage, and Io
represents the output current. Further, TON represents the duty period of the control pulse, and T represents the off period of the control pulse.

First, when a square wave pulse with a certain duty cycle is sent from the control terminal 11 to the gate of the FET 15, the FET
Fifteen switching operations are performed.

That is, when the FET 15 is in the on state, VDS decreases, and the terminal voltage L of the inductor 14 becomes approximately VI, and the current I
L flows through the inductor 14, and its inductance is L.
When this happens, electromagnetic energy of L X I L”/2 is stored.

Then, when the FET 15 is turned off, the above-mentioned energy is returned and taken out in a superimposed form at the input terminal (1).

At this time, the input/output relationship in the 9th stage of the DC-DC converter is as follows.Therefore, in the 2nd stage of the DC-DV converter 9.9', the duty cycle of the control pulse (denoted as D%) is ( 1) Substituting into Eq.

In this way, the output voltage can be changed by controlling the duty cycle D% of the control pulse.

For example, when the input voltage V+ = 12V and the duty cycle is varied between D%; 10 and 60%, the output voltage is ■. =148 to 75V.

(c, DC-AC push-pull inverter circuit) [3rd
] The DC-AC push-pull inverter circuit 4 is
A self-excited current source inverter using LC resonance is used to convert the DC voltage from the C booster circuit 3 into a sinusoidal AC voltage proportional to the DC voltage.

(C-1 circuit) [Figure 3 (A)] 18 is an input terminal, and its positive terminal 18a and negative terminal 18b are the output terminals +3a, 1 of the DC booster circuit 3.
3b, respectively.

19 is a plus line, and 19' is a minus line.

20 is a choke coil, one terminal of which is connected to the positive line 19, and the other terminal connected to the center tap on the primary side of the transformer 21.

Both 22 and 23 are FETs, one of which is FET2.
The train of FETs 22 and 23 is connected to one terminal of the primary winding of the transformer 21, and the train of the other FET 23 is connected to the other terminal of the primary winding of the transformer 21; The source of is connected to the negative line 19'. The gates of FET22.23 are connected to feedback winding 24, and FET22.23 has its gate connected to feedback winding 24.
A constant current diode 25, 25' is inserted between each gate of FET 23 and the positive line 19, and FET 22
．． A resistor 2 is connected between each gate of 23 and the negative line 19'.
6.26' are inserted respectively.

Zener diodes 27 and 27 are inserted between the gate of FET 22 and the negative line 19' with their respective cathodes facing each other in series connection, and similarly Zener diodes 27' and 27' are FET2
These Zener diodes 27, 27, 27', 2
7' is provided to protect the FETs 22 and 23 from surge voltage applied via the transformer 21 when starting the lamp.

28 is a capacitor connected between the primary winding terminals of the lance 21.

29 is a capacitor connected between the secondary winding terminals of the transformer 21.

30 and 30' are output terminals connected to both ends of the secondary winding of the transformer 21.

(c-2 Operation) [FIG. 3(B)] Next, the operation of the DC-AC push-pull inverter circuit 4 will be explained. In addition, in FIG. 3(B), V as (i
=22.23) is the FET gate-source voltage, T'
o (i = 22.23) is the train current, VlDS (i =
22.23) indicates the train-source voltage, and the subscript
1=22.23 each represents FET22.23. Also, c26 indicates the terminal voltage of the capacitor 28.

When the DC voltage from the DC booster circuit 3 is applied to the input terminal 18, the FET
A gate voltage is applied to 22 and 23, but at this time, the FET with the lower threshold voltage, for example, FET 22
turns on and oscillation begins.

The current flowing into the input terminal 18 becomes a substantially constant DC current due to the constant current action of the choke coil 20.
Drain current 1 is approximately constant while FET 22 is in the on state.
It flows at 22o. At this time, a half-sine AC voltage due to resonance between the capacitor 28 and the primary winding of the transformer 21 is applied between the train and source of the other FET 23 which is in the off state.

Then, when a sinusoidal gate voltage centered around the terminal voltage of the resistor 26' is applied to the gate of the FET 23 via the feedback winding 24, the FET 23 is turned on and the FE
T22 is turned off, thus two FETs 22
．． 23 are reciprocally switched, the respective drain currents 122o and 123D have a rectangular waveform with opposite phases to each other, and the voltage applied to the capacitor 28
c28 becomes a sine wave.

Therefore, the above-mentioned V C2a is outputted to the output terminals 30 and 30' via the transformer 21. For example, when the input voltage is 15 to 50 V, a sine wave AC output with an output voltage of about 220 to 700 V and a lagging power factor of about 08 is obtained. In addition, the oscillation frequency f at this time is the transformer 21
It is determined by the inductance of the primary winding (denoted as LP (H)) and the capacitance Hc of the capacitor with the smaller capacitance among the capacitors 28 and 29, (d, LC load and igniter circuit) [Fig. ] Next, the LC load and igniter circuit 5 will be explained.

(d-1 circuit) [FIG. 4(A) 31 and 31' are input terminals, which are individually connected to output terminals 30 and 30' of the DC-AC push-pull inverter circuit 4.

32 is a lance, and one winding 32a is a saturable inductance that saturates when the current flowing through it exceeds a predetermined value.One end is connected to the input terminal 31, and the other end is output via a capacitor 33. It is connected to one of the terminals 34. Thus, the LC load consists of the winding 32a of the transformer 32 and the capacitor 33. One end of the other winding 32b of the transformer 32 is connected to a common terminal of a relay contact of an igniter starting circuit 7, which will be described later, via a connection line 35, and the other end of the winding 32b is connected to a predetermined breakdown voltage. V81. A bidirectional two-terminal thyristor SSS (Silicon Symmetr
ical 5w1tch) 36. Further, a resistor 37 and a capacitor 38 constituting a CR circuit are inserted between the other terminal of the 5SS 36 and the connection line 35.

39 is the input terminal 31 and one winding 32a of the transformer 32
This is the power line that connects the

39' is a power line, which connects the input terminal 31' and the output terminal 34' via one winding 40a of the lamp current detection transformer 40; A resistor 41 and a diode 42 are connected in series and inserted between the terminal on the connection line 35 side.

In addition, the metal halide lamp 6 is connected to the above output terminal 34.34.
’ is connected between.

(d-2, operation) [Figure 4 (B)] Therefore, the operation of the igniter circuit 5 is as follows.

In the waveform diagram shown in FIG. 4(B), VIN is the input voltage, V
C8, represents the terminal voltage of the capacitor 38, and vou'r represents the output voltage when the lamp is started.

First, a sine wave alternating current (approximately 220 to 700 V) from the DC-AC push-pull inverter circuit 4 is input via the input terminals 31, 31'.

Then, when the relay contact of the igniter starting circuit 7 is closed, the power line 39 and the connection line 35 are electrically connected, and the connection line 39 - connection line 35 -> capacitor 38 -> resistor 41 -> diode 42 - power line 39' is connected. Charging of capacitor 38 begins to form a loop.

While the input voltage is negative, the diode 42 blocks the discharge path of the capacitor 38, so the potential increases. Note that the time constant at this time is determined by the capacitance of the capacitor 38 and the resistance value of the resistor 41.

Then, when the potential of the capacitor 38 reaches the breakover voltage VBD of the 5SS36, the 5SS36 turns on, and the instantaneous voltage at this time is applied to the winding 32b of the transformer 32, and the turns ratio n of the transformer 32 is applied to both ends of the winding 32a.
A high-voltage pulse (hereinafter referred to as "igniter pulse") determined by the igniter pulse is transmitted. In other words, the igniter pulse voltage is VIIIll if the efficiency of the transformer 32 is η.
It is approximately ×n×η (■・volt). The generated igniter pulse is then superimposed on the sine wave alternating current and applied to the metal halide lamp 6 via the output terminals 34, 34'.

Therefore, since several such igniter pulses are applied, the metal halide lamp 6 is lit, and at the same time,
Since the relay contact of the igniter starting circuit 7 is opened, the electrical connection between the power supply line 39 and the connection line 35 is cut off.

Note that the pulse interval of the igniter pulse is defined by the capacitance of the capacitor 38, the resistor 41, and the breakdown voltage VBD of the 5SS36.

(e. Igniter starting circuit) [Fig. 4] The igniter starting circuit 7 sends a lighting start signal to the igniter circuit 5 to light the metal halide lamp 6, and then stops the generation of igniter pulses.

(e-1 circuit) [Figure 4 (A)] 43 is an SSS, one end of which is connected to the skin ground side terminal of the secondary winding 40b of the transformer 40 of the igniter circuit 5, and the other terminal is grounded. ing.

44 is a resistor, 45 is a capacitor, forming an RC low-pass filter, and one terminal of the resistor 44 is 5SS.
43, and a capacitor 45 is interposed between the other terminal of the resistor 44 and the ground line.

46 is a rectifying diode, the anode of which is connected to the skin ground side terminal of the capacitor 45, and an electrolytic capacitor 47 is inserted between the cathode of the diode 46 and the ground line. A rectifier circuit is constructed by:

48 is an NPN transistor with a common emitter, the gate of which is connected to the cathode of the diode 46 via a resistor 49, and the collector connected to the positive terminal of the battery or the power supply terminal of a constant voltage power supply circuit connected to the positive terminal of the battery via a resistor 50. It is connected to the.

Reference numeral 51 denotes an NPN transistor whose emitter is grounded and whose collector is connected to the collector of the transistor 48. The base thereof is connected to a CR circuit consisting of a resistor 52 and an electrolytic capacitor 53, and then connected to a power supply terminal via a resistor 54.

Reference numeral 55 denotes an NPN transistor, whose emitter is also grounded, and its base is connected to the collectors of the transistors 48 and 51 described above via a resistor 56.

57 is a relay having two contacts 57a and 57b; one end of a coil 57c is connected to the collector of the transistor 55, and the other terminal is connected to a power supply terminal. As mentioned above, one contact 5 of the relay 57
The common terminal of 7a is connected to the opposite terminal of the resistor 41 side of the capacitor 38 of the igniter circuit 5 via the connection line 35, and the No (normal oven) terminal is connected to the power supply line 39 of the igniter circuit 5, and the NC ( Normally closed) 1 child is open. Also, the other contact 5
The common terminal of 7b is connected to a control circuit 8, which will be described later, and the N
The O terminal is connected to a power supply terminal, and the NC terminal is grounded.

(e-2. Operation) [Fig. 4(B)] The operation of the igniter starting circuit 7 is as follows. In addition, in FIG. 4(B), FLY57 indicates the operation of the relay 57.

First, immediately after the lamp is started, the lamp current is not flowing yet and no voltage is applied to the transformer 40, so the transistor 48 is off. Therefore, the transistor 55 is turned on and the relay 57 is operated, and its contacts 57a and 57b are turned on.
is switched from the NC contact to the NC contact, thereby causing the above-described operation of the igniter circuit 5.

Note that while the igniter pulse is being generated, a high voltage pulse is applied to the igniter starting circuit 7 via the transformer 40, which is connected to the SSS 43, the resistor 44, and the capacitor 45.
The off state of the transistor 48 is maintained because it is cut by the filter consisting of the following.

When the metal halide lamp 6 is lit, the lamp current at this time causes a voltage of 5S through the transformer 40.
In addition to S43, this is the RC low-pass filter 44.4
5, is rectified by a diode 46 and a capacitor 47, the base potential rises, and the transistor 48 is turned on. Therefore, the transistor 55, which has been on until now, is turned off, so the relay 57 is turned off, and the contacts 57a and 57b are switched to the NC side, so that generation of the igniter pulse is stopped.

Furthermore, even though the metal halide lamp 6 does not light up, the relay 57 is turned on, and the igniter circuit 5 continues.
In order to avoid a situation where the igniter pulse continues to be applied, the transistor 51 is turned on and the transistor 55 is turned off after the time specified by the time constant and base potential of the CR circuit consisting of the resistor 52 and the capacitor 53 has elapsed. It looks like this.

Next, the control circuit 8 will be explained, but before explaining its circuit configuration, the control mode of the control circuit 8 will be explained.

(f-1 control mode) [Fig. 5] As shown in Fig. 5, there are three modes depending on the control mode or the time the metal halide lamp 6 is turned off. control mode (hereinafter referred to as "hot restrike mode"),
A control mode (hereinafter referred to as "medium start mode"
) and a control mode for lighting the lamp for the first time (hereinafter referred to as "cold start mode"). Incidentally, FIG. 5 schematically shows temporal changes in the lamp current of the metal halide lamp 6, with the vertical axis representing the lamp current and the horizontal axis representing time.

(f control circuit) (f-1-hot restrike mode) [Figure 5 (A)
When the lamp is relit within about 0 to 18 seconds after being extinguished, the glass bulb of the metal halide lamp 6 has become sufficiently hot, so that the luminous flux after the lamp is relit rises instantaneously and reaches the rated luminous flux. Therefore, the lamp current after the lamp is turned off is controlled to be a steady current (referred to as IC(A)) as shown in FIG. 5(A).

(f-1-b, medium start mode) [5th
Figure (B)] When the lamp is turned on again within about 18 to 45 seconds after it has been turned off, it is necessary to apply a high starting voltage because the gas pressure within the metal halide lamp 6 is extremely high. Steady current ■ at the initial stage of lighting in this condition. Immediately after the initial current (rho (A)) is large compared to the current, steady current is applied.

When a lamp current is applied that causes a transition to , the lamp luminous flux shows a sharp rising peak or takes time to reach the rated luminous flux.

Therefore, as shown in FIG. 5(B), the lamp current I immediately after lighting. The lamp current is controlled so that the lamp current reaches the steady current IC after exponentially attenuating from the current IC.

(f-1-c cold start mode) [Figure 5 (
C)] When the lamp is turned on for the first time, or when the lamp is turned on after 45 seconds or more have elapsed after the lamp has been turned off, the glass bulb of the metal halide lamp 6 starts to turn on from a cold state, so the initial current decreases immediately after the lamp is turned on. ■. for a certain period of time (seconds) (
Hereinafter, it will be referred to as ``28 Hours''. ) After flowing, the steady current I decays exponentially. controlled to move to .

(f-2, Circuit Configuration) [FIG. 6] Next, the circuit configuration of the control circuit 8 will be explained using a block diagram, and then the details of each block will be explained.

Reference numeral 58 denotes a timing circuit for detecting extinguishing time, which detects the time point when the lamp is turned on in order to determine each control mode after detecting the turning on of the metal halide lamp 6;
A timing signal is generated at this time.

59 is a hot restrike mode, and detects the time when the above-mentioned extinguishing time detection timing circuit 58 sends a timing signal from the time when the previous lighting ends, and determines whether to shift to the pot restrike mode. It is established to make this determination. This discrimination signal is then sent to a mode-specific control circuit, which will be described later.

60 is an overcurrent time control circuit, and call 1
The overcurrent time t of the lamp current in the start mode is controlled, and in the medium start mode, the initial current I0 is controlled so as not to flow immediately after the lamp is lit by a signal from a medium start mode discrimination circuit, which will be described later. The overcurrent time control circuit 60 is configured to send signals corresponding to the call to start mode and the medium start mode to a mode-specific control circuit to be described later. Further, a control signal is sent to the hot restrike mode discrimination circuit 59, whereby the hot restrike mode discrimination circuit 59 enters a standby state in which it is possible to detect the next light-off time.

Reference numeral 61 denotes a medium start mode discrimination circuit, which uses a signal synchronized with the signal used for mode discrimination in the restrike mode circuit 59 to discriminate whether or not it is medium start mode. For example, a signal is sent to the above-mentioned overcurrent time control circuit 60 to set the overcurrent time t immediately after lamp lighting to 0.

Reference numeral 62 denotes a mode-specific control circuit, including a hot restrike mode discrimination circuit 59 and an overcurrent time control circuit 6.
This is for receiving a signal from 0+1 and producing a control output corresponding to each control mode.

63 is PWM (Pulse Width Mo
duration) control circuit, which generates a control pulse with a duty cycle proportional to the voltage level of the control signal sent from the mode-specific control circuit 62, and
It is provided for sending out to the control terminal 11 of the booster circuit 3.

(f-3. Timing circuit for light-off time detection) [Fig. 7,
[FIG. 8] The extinguishing time detection timing circuit 58 is provided to provide the timing to start detection when detecting the extinguishing time of the metal halide lamp 6, and the lamp starting operation of the igniter circuit 5 by the igniter starting circuit 7 is stopped. It captures the moment. The reason why such a timing signal is required is to increase the output of the DC-AC push-pull inverter circuit 4 when starting the lamp.
This is because the duty cycle D% of the control pulse applied to the C booster circuit 3 must be controlled, and the operations in each of the control modes described above must be performed after the metal halide lamp 6 is once lit.

(f-3-a. Circuit) [Figure 7] Reference numeral 64 is a resistor, one end of which is connected to the positive terminal of the electrolytic capacitor 65, and the other end connected to the power supply terminal. The resistor 64 and the electrolytic capacitor 65 form a CR circuit having a predetermined time constant.

A Zener diode 66 has a cathode connected to the positive terminal of the electrolytic capacitor 65 and an anode grounded to prevent malfunction when the power is turned on.

67 is a PNP transistor whose emitter is connected to the cathode of the Zener diode 66, and whose heath is connected via a capacitor 68 to the common terminal of the contact 57b of the relay 57 in the igniter starting circuit 7.

Also, a resistor 6 is connected between the emitter and the transistor 67.
9 is inserted, and a capacitor 68 and a resistor 69 form a differential circuit.

70 is an NPt1 transistor whose emitter is grounded, and its base is connected to the collector of the above-mentioned transistor 67 via a resistor 71.

72 is a relay having one contact 72a, one end of whose coil 72b is connected to the collector of the transistor 70, and the other end is connected to the power supply terminal.

(f-3-b, Operation) [Fig. 8] However, the operation of the light-off time detection timing circuit 58 is as follows. In the operating waveform diagram schematically shown in FIG. 8, ■8 is the power supply voltage, V67 is the emitter potential of the transistor 67, Ry57 is the operation of the relay 57, v c6a
is the potential of capacitor 68, V 67C is the potential of transistor 6
The collector potential of transistor 70, V7oc, indicates the collector potential of transistor 70.

First, when the lighting switch 2A is turned on, V67° gradually changes to the Zener diode 66 with a time constant determined by the resistance value of the resistor 64 and the capacitance of the electrolytic capacitor 65.
The Zener potential of will continue to rise.

Then, when the lighting switch 2A is turned on and the relay 57 of the igniter starting circuit 7 is turned on, the waveform of c68 becomes V
The differential waveform rises instantaneously to B and then falls exponentially. Incidentally, in this state, the base potential of the L transistor 7 is higher than V67, so it remains off, and the transistor 70 is also off, so the relay 72
doesn't work either.

Then, when the lamp is lit and the relay 57 of the igniter starting circuit 7 is turned off, the capacitor 68 is discharged via the contact 57b of the relay 57, so that v caa
The waveform becomes a differential waveform opposite to the previous one, and transistor 67 is turned on, so that transistor 70 and relay 72 are turned on.
is turned on, and the contact 72a is switched.

(F-4 hot restrike mode discrimination circuit) [Figures 7 and 8 The pot restrike mode discrimination circuit 59 receives the timing signal from the above-mentioned timing circuit 58 for detecting lights-off time, and determines whether the lights are turned off at this point. The mode-specific control circuit 6 dumps the time and sends a judgment signal as to whether or not this time is 18 seconds or less, that is, whether to move to the pot restrike mode.
At the same time, a sampled and bolded signal indicating the light-off time is sent to a medium start mode discrimination circuit 61, which will be described later.

(f-4-a circuit) [Fig. 7] Reference numeral 73 is a resistor, one end of which is connected to the common terminal of the relay contact 72a of the timing circuit 58 for light-off time detection, and the other end is grounded.

74 is an electrolytic capacitor, the positive terminal of which is connected to the common terminal of the relay contact 72a, and the diode 7
5, and the electrolytic capacitor 74 is connected to the collector of the PNPI-Rangistav 6 through the resistor 73.
forming a circuit.

The transistor 76 is provided to control the charging timing of the electrolytic capacitor 74, and its base is connected to an overcurrent time control circuit 60, which will be described later, and is switched in response to a signal from the circuit 6o. . The emitter of the transistor 76 is connected to a power supply terminal.

77 is a comparator whose inverting input terminal is connected to the No terminal of the relay contact 72a, and a sample-hold capacitor 78 is interposed between it and the ground line via a resistor.

Reference voltages r and lf are applied to the non-inverting input terminal by a voltage dividing resistor connected to the power supply terminal, and this V raf is set such that the potential of the capacitor 78 is higher than this in the hot restrike mode. is selected as a value. Note that when the power is turned off, the capacitor 78 is discharged via a diode connected between the voltage dividing resistor and the power supply terminal.

79 is an NPN transistor whose emitter is grounded, and its base is connected to the output terminal of the comparator 77 via a resistor.

A light emitting diode 80 has its cathode connected to the collector of the transistor 79 and its anode connected to a power supply terminal via a limiting resistor 81. Note that this light emitting diode 80 forms a photocoupler together with a phototransistor provided in the mode-specific control circuit 62.

(f-4-b Operation) [FIG. 8] Next, the operation of the hot restrike mode discrimination circuit 59 will be explained. In the operating waveform diagram shown in FIG. 8, V771+ is the voltage applied to the inverting input terminal of the comparator 77, V77
□- represents the voltage applied to the non-inverting input terminal, VC14 represents the potential of the capacitor 74, and V77 represents the output voltage of the comparator 77, which corresponds to the operation of the light emitting diode 80.

First, the capacitor 74 is fully charged just before the lamp goes out, and it gradually discharges immediately after the power supply stops and the lamp goes out, and its potential is determined by the resistance value of the resistor 73 and the capacitance of the capacitor 74. Time constant (approx. 70
seconds) and decreases very slowly.

When the power is turned on again, the relay 72 is turned on, its contact 72a is switched, and the potential of the capacitor 74 is sampled and held by the capacitor 78 and input to the comparator 77.

Then, the comparator 77 compares this potential with the reference voltage Vra.
f which comparison is made and the result of this comparison is sent to the transistor 79.
The light emitting diode 80 is turned on or off accordingly.

In other words, in hot restrike mode, 0 after lights out.
Since the power is turned on within ~18 seconds, relay contact 72
When a is switched, previously V771-<Vraf, and the output of the comparator 77 is at H (high) level, but at the time the relay contact 72a is switched, the amount of discharge of the capacitor 74 is small, and V77 , -≧V raf, so the output of the comparator 77 becomes L (low) level, and this is sent to the transistor 79, so the light emitting diode 80 is not lit. Also, when the control mode is other than pot restrike mode, V771-
< V rat, and since the H signal from the comparator 77 is sent to the transistor 79, the light emitting diode 8
0 becomes lit.

Note that after this control mode is determined, the transistor 76 is activated by a signal from the overcurrent time control circuit 60.
Since the capacitor 74 is turned on, charging of the capacitor 74 is started.

(f-5, overcurrent time control circuit) [Fig. 7,
[Fig. 8] The overcurrent time control circuit 60 controls the overcurrent time t in the cold start mode, or controls the lamp current I to the metal halide lamp 6 immediately after lamp lighting based on a signal from the medium start mode discrimination circuit 61, which will be described later. . A signal is sent to the mode-specific control circuit 62 to prevent the current from flowing continuously. Further, a signal related to the charging timing of the electrolytic capacitor 74 of the hot restrike mode discriminating circuit 59 described above is generated.

(f-5-a, circuit) [Figure 7] 82 is a comparator, the inverting input terminal of which is connected to the power supply terminal via a parallel-connected resistor 83 and diode 84, and the non-inverting input terminal It is connected to the movable side terminal of a variable resistor 85 inserted between the power supply terminal and the ground line.

86 is an electrolytic capacitor, the positive terminal of which is connected to the inverting input terminal of the comparator 82, and the negative terminal of which is grounded.

87 is an NPN transistor with a common emitter, the base of which is connected to the output terminal of the comparator 82 via a resistor 88 and to a medium start mode discrimination circuit 61 (described later) via a connection line 89; It is forcibly turned off by a control signal from.

90 is a light emitting diode, the cathode of which is connected to the collector of the transistor 87, and the anode of which is connected to the power supply terminal via a limiting resistor 91. and,
The light emitting diode 90 is connected to a mode-specific control circuit 62 which will be described later.
Together with the phototransistor, it forms a photocoupler.

Reference numeral 92 denotes an N P N l-transistor with a common emitter, the pace of which is connected to the anode of the light emitting diode 90 through a resistor 93, and the collector connected to the above-mentioned hot restrike mode through a resistor 94. It is connected to the pace of the transistor 76 of the discrimination circuit 59.

(f-5-b, operation) [Fig. 8] However, the operation of the overcurrent time control circuit 60 is as follows. In addition, in the operation waveform diagram shown in FIG.
621 is the non-inverting input voltage of comparator 82, V82
□- is the inverted input voltage, V 820uT is the output voltage, V
arc y V 92C each transistor 87.92
represents the collector potential of .

First, in the cold start mode, when the lamp is turned off, the electrolytic capacitor 86 is discharged through the diode 84, and its potential is set to 0. When the power is turned on, the resistance value of the resistor 83 and the capacitance of the capacitor 86 change. The capacitor 86 is charged with a time constant determined by . Incidentally, during this time V82. ≧V82, -, the output of the comparator 82 is at H level, the transistor is in the on state, and the light emitting diode 90 is lit.

Thereafter, the potential of the capacitor 86 increases, and the reference voltage V
When ref is exceeded, ■8□1-≧V82++ occurs, so the comparator 82 sends an L signal to the pace of the transistor 87, so the transistor 87 is turned off and the light emitting diode 90 is turned off. The time in between corresponds to the overcurrent time. Further, while the light emitting diode 90 is lit, the transistor 92
is off, so the transistor 76 of the hot restrike mode discrimination circuit 59 described above is off, and when the light emitting diode 90 is off, the transistors 92 and 76 are on and the capacitor 74 is off. charging starts. In addition, the transistor 920
The on operation is performed after a certain delay time from the time when the transistor 87 is turned off, thereby providing a margin for the sampling period by the capacitor 78.

Furthermore, in the medium start mode, the transistor 87 is forcibly turned off by a signal from the medium start mode discrimination circuit 61, so that the light emitting diode 90 is turned off.

Note that in the hot restrike mode, the operation is similar to that in the cold start mode, but since the light emitting diode 80 of the hot restrike mode discrimination circuit 59 is turned off in the mode-specific control circuit 62, which will be described later, it is ignored. It looks like this.

(F-6 Medium Start Mode Discrimination Circuit) [Figures 7 and 8] The medium start mode discrimination circuit 61 detects the potential of the capacitor 78 of the hot restrike mode discrimination circuit 59, and compares it with the reference voltage. It is determined whether the mode is a start mode or not, and when it is determined that the mode is a medium start mode, the transistor 87 of the overcurrent time control circuit 6o is forcibly turned off.

(f-6-a, circuit) [Figure 7] 95 is a comparator whose inverting input terminal is connected to the inverting input terminal of the comparator 77 of the hot restrike mode discrimination circuit 59, and the non-inverting input terminal A reference voltage V'ref is applied in a divided form by a resistor 96.97. And these resistors 96.
The reference voltage V'raf determined by the resistance value of the comparator 97 is selected so that the inverted input voltage of the comparator 95 exceeds this reference voltage V'raf when the metal halide lamp is turned on again within about 45 seconds after being turned off.

98 is a PNPI-runsistor whose base is connected to the output terminal of the comparator 95 via a resistor 99, its emitter is connected to the power supply terminal, and its collector is grounded via series-connected resistors 100 and 101. ing.

102 is an NPN transistor with a common emitter, the base of which is connected between resistors 100 and 101;
The collector is also connected via a connection line 89 to the base of a transistor 87 (provided in the overcurrent time control circuit 60).

(f-6-1), Operation) [FIG. 8] Next, the operation of the medium start mode discrimination circuit 61 will be explained. In addition, V in the operation waveform diagram shown in FIG.
95+. is the potential of the non-inverting input terminal of the comparator 95,
v95, - represents the potential of the inverting input terminal, and ■95olIT represents the output potential.

First, the comparator 95 detects the potential of the capacitor 78 of the hot restrike mode discrimination circuit 59, compares this with the reference voltage V'ref applied to the resistor 97, and then sends the output to the transistor 98. Therefore, this results in a switching operation of the transistor 102.

In other words, in the medium start mode, the initial
5, and > V951-, so the output of the comparator 95 is at H level) - The Runsistor 102 is in the off state,
The I-transistor 87 of the overcurrent time control circuit 60 described above is in a state in which it can receive a signal from the comparator 82 at its base. and,
Since the potential of the capacitor 78 sampled in accordance with the timing signal from the light-off time detection timing circuit 58 is higher than the reference voltage, V951->
V95 becomes low, and the output of the comparator 95 goes to L level, which is sent to the transistor 98, which turns on the transistor 102. Therefore, the transistor 87 of the overcurrent time control circuit 60 is forcibly turned off.

Also, in cold start mode, V921 and >
Since V921-, the output of the comparator 95 remains at H level, and the overcurrent 1-time control circuit 60
The forced off signal described above is not sent.

(F-7 Mode-Specific Control Circuit) [Figures 7 and 8] The mode-specific control circuit 62 receives signals from the light-emitting diode 80 of the hot restrike mode discrimination circuit 59 and the light-emitting diode 90 of the overcurrent time control circuit 60. It plays the role of receiving the signals, creating control outputs for each mode, and sending them to a PWM control circuit 63, which will be described later.

(f-7-a, circuit) 103 is an operational amplifier, and together with a resistor 104 and a capacitor 105, an integrating circuit is formed. That is, the inverting input terminal of the operational amplifier 103 is connected to the power supply terminal via the resistor 104, and the capacitor 1 is connected between the output terminal and the inverting input terminal.
05 is connected, and a resistor 106 and a phototransistor 107 are connected in parallel with the capacitor 105.

Also, the non-inverting input terminal of the operational amplifier 103 is connected to the variable resistor 10.
It is connected to the movable terminal 8.

Note that the phototransistor 107 is adapted to receive light from the light emitting diode 90 of the overcurrent time control circuit 60 described above. Further, the variable resistor 108 is provided for adjusting the overcurrent current value during the cold start mode.

109 is a phototransistor and the operational amplifier 103
, and is provided to receive light from the light emitting diode 80 of the hot restrike mode discrimination circuit 59.

110 is a diode whose anode is connected to the phototransistor 109, and whose cathode is connected to the positive terminal of an electrolytic capacitor 111 whose negative Fi1 terminal is grounded and the variable resistor 1.
12 movable terminals, and is also connected to an input terminal of a PWM control IC of a PWM control circuit 63, which will be described later.

Note that one end of the variable resistor 112 is connected to a power supply terminal via a voltage dividing resistor 113, and the other end is grounded, so that the value of the steady current IC of the metal halide lamp 6 is determined by adjusting the variable resistor 112. It has become.

(f-7-b Operation) [FIG. 8] The operation of the mode-specific control circuit 62 is as follows. Incidentally, V6200 in the operating waveform shown in FIG. 8 represents the output voltage.

First, in the hot restrike mode, the light emitting diode 80 of the hot restrike mode discrimination circuit 59 turns off instantly after the lamp is turned on, so the phototransistor 109 is turned off, and the variable resistor 112 and the resistor are turned off, completely independent of the output from the operational amplifier 103. A signal with a voltage level determined by 113 is output.

Further, in the medium start mode, since the light emitting diode 80 is lit, the phototransistor 109 is on, and immediately after the lamp is lit, the light emitting diode 90 of the overcurrent time control circuit 60 is turned off, so that the phototransistor 107 is turned on. is in the off state, the output of the operational amplifier 103 decreases exponentially with a time constant determined by the resistance value of the resistor 104 and the capacitance value of the capacitor 105, and reaches the voltage level determined by the variable resistor 112 and the resistor 113. When it approaches, the diode 110 turns off and the output becomes constant.

Furthermore, in the cold start mode, the phototransistor 109 is in an on state, and the light emitting diode 90 of the overcurrent time control circuit 60 is lit until the overcurrent time t has elapsed after the lamp is lit. The output of the amplifier 103 becomes a substantially constant voltage defined by the resistor 104, the resistor 106, and the reference voltage. After that, when the light emitting diode 90 goes out, the phototransistor 107 turns off, so the operation is the same as in the medium start mode. becomes.

The operating states of the phototransistors 107 and 109 described above after the lamp is turned on are as follows.

Note that the "-" in the table indicates that the output voltage of the mode-specific control circuit 62 is obtained regardless of the operation of the phototransistor 107.

(f-8, PWM control circuit) [Figures 7 and 8] The PWM control circuit 63 receives the control output from the mode-specific control circuit 62 described above, and generates a control pulse having a duty cycle corresponding to the control output. DC booster circuit 3
It is sent to the control terminal of.

(f-8-a circuit) [Figure 7] Reference numeral 114 is a PWM control IC whose input terminal is connected to the cathode of the diode 110 of the mode-specific control circuit 62 described above, and from which each When an output voltage is applied according to the control mode, a square wave pulse having a duty cycle proportional to this is generated,
It is designed to be output to the control terminal 11 of the DC booster circuit 3.

(f-8-b, operation) When the output signal from the mode-specific control circuit 62 is input to the PWM control IC 114, a control pulse with a duty cycle proportional to the level of this output voltage is applied to the DC boost voltage. It will not be sent to circuit 3.

That is, since a voltage at a substantially constant level is input to the IC 114 in the 1-restrike mode, a control pulse with a constant duty cycle, for example D%=10%, is output accordingly.

In addition, in the medium start mode, an input terminal that exponentially decreases immediately after the lamp is lit is applied to the IC 114, so a control pulse that changes over the duty cycle D% = 60% to 10% is output accordingly. be done.

In the cold start mode, a constant input voltage is applied to the IC 114 from immediately after the lamp turns on until the overcurrent time is seconds, so a control pulse with a constant duty cycle, for example, D% = 60%, is output. After that, a control pulse with a varying duty cycle D% is output in the same way as in the medium start mode.

(g, starting time and restart time) According to lighting circuit 1, metal halide lamp 6
The time it takes to reach 30% of the rated luminous flux is 6 seconds or less, and the time it takes to reach 30% of the rated luminous flux after restarting is 1 second or less. The luminous flux will reach .

(G. Effects of the Invention) As is clear from the above description, the lighting circuit for the high-pressure discharge lamp for vehicles of the present invention has a DC voltage input terminal to which a DC power source is connected, and input from the DC voltage input terminal is provided. It has a booster circuit that boosts the voltage at the terminal, a converter circuit that converts the DC voltage input from the booster circuit into a sine wave AC voltage, and an AC voltage output terminal that is connected to the high-pressure discharge lamp, and controls the lighting of the high-pressure discharge lamp. In the lighting circuit for a high-pressure discharge lamp for a vehicle, the lighting circuit includes a starting means for controlling the output voltage of the booster circuit, and a control means for controlling the output voltage of the booster circuit. 511, and a mode discriminating means for controlling the lamp current at the time of starting or restarting the discharge lamp according to the signal from the mode discriminating means, and for controlling the output voltage of the booster circuit. and mode-specific control means for sending a control signal to the booster circuit to control the voltage, thereby controlling the lamp current when starting or restarting the discharge lamp according to the extinguishing time of the high-pressure discharge lamp. It is characterized in that it is made to look like this.

Therefore, according to the present invention, the control means develops a predetermined control mode regarding the lamp current of the discharge lamp at the time of starting or restarting the high-pressure discharge lamp according to the elapsed time from when the high-pressure discharge lamp is turned off until the next time the high-pressure discharge lamp is turned on. Therefore, the lamp current of the discharge lamp can be controlled by changing the output voltage of the booster circuit, and as a result, the lamp current can always be adjusted to match the physical conditions inside the discharge lamp, making it possible to turn on or relight the discharge lamp. Sometimes, this luminous flux can reach the rated luminous flux in a short time.

In the above embodiment, a two-stage DC-DC converter is used in the DC booster circuit, but it is difficult to obtain a predetermined output voltage even if the duty cycle range of the control pulse is increased due to the influence of the resistance of the inductor. This circuit configuration was only adopted because of the limited number of circuits, and the present invention is not limited to the specific circuit configuration described above. Similarly, the control circuit has at least mode discrimination means for discriminating the control mode according to the extinguishing time of the lamp, and mode-specific control means for controlling the lamp current for each control mode accordingly. Any configuration may be used.

[Brief explanation of the drawing]

Figures 1 to 8 show an example of the implementation of a lighting circuit for a high-pressure discharge lamp for vehicles according to the present invention. Figure 1 is an overall circuit block diagram, and Figure 2 shows the configuration and operation of a DC booster circuit. 3 is a diagram for explaining the circuit diagram, (B) is a schematic operation waveform diagram, and FIG. 3 is a diagram for explaining the configuration and operation of the DC-AC push-pull inverter circuit, (
A) is a circuit diagram, (B) is a schematic operating waveform diagram, FIG. 4 is a diagram for explaining the LC load and igniter circuit, and the igniter starting circuit; (A) is a circuit diagram; (B
) is a schematic operation waveform diagram, Figures 5 to 8 are diagrams for explaining the circuit and operation of the control circuit, and Figure 5 is a diagram for explaining the control mode, showing the lamp current after lamp lighting. FIG. 6 is a graph showing temporal changes in , where (A) is a graph in a hot restrike mode, (B) is a graph in a medium start mode, (C) is a graph in a cold start mode; The figure is a circuit block diagram, No. 7
The figure is a circuit diagram, and FIG. 8 is a schematic operational waveform diagram. 59.61...Mode discrimination means, 62...Mode-specific control means Koito Seisakusho Co., Ltd. Code explanation 1...Lighting circuit for high pressure discharge lamp for vehicle, 2...DC power supply, 3...Boost pressure circuit, 4... converter circuit, 5.7... starting means, 6... high pressure discharge lamp, 8... control means, 10...
・DC voltage input terminal, 30.30'...AC voltage output terminal, H9iiP
another

Claims (1)

[Claims] a booster circuit having a DC voltage input terminal connected to a DC power supply and boosting an input voltage from the DC voltage input terminal;
A converter circuit that converts a DC voltage input from a booster circuit into a sinusoidal AC voltage, a starting means for lighting the high-pressure discharge lamp having an AC voltage output terminal to which a high-pressure discharge lamp is connected, and a booster circuit. A lighting circuit for a high-pressure discharge lamp for a vehicle, comprising: a control means for controlling an output voltage of the high-pressure discharge lamp; In response to the signal from the mode determining means, a predetermined control mode for controlling the lamp current when starting or restarting the discharge lamp is displayed, and a control signal for controlling the output voltage of the booster circuit is sent to the booster circuit. A device for a vehicle, characterized in that the lamp current is controlled according to the extinguishing time of the high-pressure discharge lamp at the time of lighting start or restart of the discharge lamp. High pressure discharge lamp lighting circuit