JPH11283782A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device for controlling lighting of a HID lamp based on the abnormality state of an electric power source. SOLUTION: Voltage V is generated by an electric power source or a rectifier circuit 2, the output of a level shift circuit 3c is sent to a microcomputer 3e through an A/D converter 3d, the upper limit value and the lower limit value are detected by comparators CP1, CP2, a signal is sent out of the comparator CP1 or the comparator CP2 in a case where a voltage V1 is lower than the standard voltage of the comparator CP2 or the voltage V2 is higher than the standard voltage of the comparator CP1 to turn on either one of switching elements 3a, 3b and to extinguish an HID lamp. In this case, when the electric power source voltage is gotten into abnormal state, the voltage is automatically restored by the microcomputer 3e in a case where the abnormality is temporal and the electric power source 1 is completely stopped by the microcomputer 3e in a case where the abnormality is continuous.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device provided with an HID lamp used for a vehicle headlight or the like.

[0002]

2. Description of the Related Art FIG. 3 is a schematic block diagram showing a part of a conventional discharge lamp lighting device. In the conventional discharge lamp lighting device, the analog control circuit 9 outputs a control signal to the lamp drive circuit 4 based on a current value from a power supply (not shown). Then, the lamp driving circuit 4 controls the four FETs F1 to F based on the control signal from the analog control circuit 9.
The HID lamp 6 is turned on with a predetermined power by controlling the FETs F1 to F4 of the inverter circuit 5 which constitutes a full bridge circuit with the HID lamp 6.

In this discharge lamp lighting device, when the power supply becomes abnormal and the analog control circuit 9 detects an overcurrent, the analog control circuit 9 instructs the lamp drive circuit 4 to stop the lighting of the HID lamp 6. Output a control signal,
The ID lamp 6 was protected.

[0004]

However, in the discharge lamp lighting device having the above configuration, when the power supply becomes abnormal, the analog control circuit 9 controls the lamp drive circuit 4 and the power supply (not shown). The HID lamp 6 is stopped, and then restarted. It is not possible to select a stop time according to the level of the abnormality or to restart the HID lamp 6. It was difficult to judge instantly whether it was or not.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a discharge lamp lighting device for controlling lighting of an HID lamp based on an abnormal state of a power supply. is there.

[0006]

According to the first aspect of the present invention,
In a discharge lamp lighting device including an HID lamp, a driving circuit for lighting the HID lamp, a control circuit for controlling the driving circuit by a control unit, and a power supply for supplying a voltage, the control circuit includes: ON / OFF of voltage supply from power supply
A switching element for turning off is added, and the control unit controls the switching element according to a variation pattern when a voltage value of a supply voltage from the power supply is out of a predetermined range. It is characterized by the following.

According to a second aspect of the present invention, in the discharge lamp lighting device of the first aspect, first and second comparators are added to the control circuit, and the control section includes an inverting input of the first comparator. Applying a reference voltage to a terminal and a non-inverting input terminal of the second comparator; applying a supply voltage from the power supply to a non-inverting input terminal of the first comparator and an inverting input terminal of the second comparator; The switching element is configured to output a voltage supplied from the power supply based on output signals from the first and second comparators.
By performing N / OFF, the range of the voltage value of the supply voltage from the power supply is set, and the supply voltage from the power supply is
When the voltage is out of the predetermined range of the voltage value, the switching element turns off the voltage supply from the power supply, and the control unit controls the switching element to turn on the voltage supply from the power supply again. In addition, the lighting control of the HID lamp is performed based on a repeated ON / OFF state of the switching element.

According to a third aspect of the present invention, in the discharge lamp lighting device according to the first or second aspect, at least one of an LED lighting circuit and an alarm circuit is added, and the power supply voltage is controlled by the LED lighting circuit or the alarm circuit. The abnormal state is detected.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing a part of a discharge lamp lighting device according to one embodiment of the present invention. The discharge lamp lighting device according to the present embodiment includes a power supply 1, a rectifier circuit 2, a control circuit 3, a lamp drive circuit 4, an inverter circuit 5, and an HID lamp 6.

The power supply 1 supplies power to each circuit constituting the discharge lamp lighting device. The rectifier circuit 2 is configured by a diode bridge circuit, and rectifies an AC voltage output from the power supply 1.

The control circuit 3 includes switching elements 3a, 3
b, level shift circuit 3c, A / D converter 3d, and resistor R
1 to R3, a microcomputer (hereinafter referred to as a microcomputer) 3e as a control unit, comparators CP1 and CP2, and switching elements 3a and 3b, a level shift circuit 3c, and an A / D converter. The microcomputer 3e is connected in parallel to the rectifier circuit 2 with a series circuit including the switch 3d and the resistors R1 to R3. The switching elements 3a and 3b are configured by FETs, and turn on / off a DC power supplied from the power supply 1 via the rectifier circuit 2. The rectifier circuit 2 includes sources of the switching elements 3a and 3b. The drains are connected respectively. The level shift circuit 3c adjusts the DC power supplied through the rectifier circuit 2 to a predetermined voltage level. The A / D converter 3d converts the input analog signal into a digital signal suitable for the microcomputer 3e. The microcomputer 3e controls lighting of the HID lamp 6. Comparators CP1 and CP2 are
The microcomputer 3 is connected to the non-inverting input of the comparator CP1 and the inverting input of the comparator CP2, and a predetermined reference voltage is applied thereto. The inverting input of the comparator CP1 has a resistor (R1 + R
2) and the voltage V1 (= R3 · V /
(R1 + R2 + R3)) is applied and the comparator CP
1 is connected to the gate of the switching element 3a. Further, the non-inverting input of the comparator CP2 has a voltage V2 (= (R1 + R2) .V) obtained by dividing the voltage V applied to both ends of the series circuit including the resistors R1 to R3 by the resistor R1 and the resistor (R2 + R3). / (R1 + R2 + R3))
Is applied, and the output of the comparator CP2 is connected to the gate of the switching element 3b. Lamp drive circuit 4
Outputs an FET drive signal for driving the FETs F1 to F4 of the inverter circuit 5 based on the output signal from the microcomputer 3e.

The operation of this embodiment will be described below. A voltage V is generated by the power supply 1 and the rectifier circuit 2, and the voltage is reduced to a predetermined voltage level by the level shift circuit 3c. The output from the level shift circuit 3c is input to the microcomputer 3e via the A / D converter 3d,
A lower limit value and an upper limit value are detected by P1 and CP2, and a signal is output from the comparator CP1 or CP2 when the voltage V1 falls below the reference voltage of the comparator CP2 or when the voltage V2 rises above the reference voltage of the comparator CP1. Thus, one of the switching elements 3a and 3b is turned on, and the HID lamp 6 can be turned off.

Therefore, in the present embodiment, when the power supply voltage becomes abnormal, the switching elements 3a, 3
b is in the ON state, so that the HI
The D lamp 6 can be turned off, and in the case of a temporary abnormality, it can be automatically recovered. Further, when the abnormality is continuous, the power supply 1 can be completely stopped by the microcomputer 3e.

As shown in FIG. 2, if the LED lighting circuit 7 and the alarm circuit 8 are further added to the block diagram shown in FIG. The user can easily know by the warning.

[0015]

According to the first or second aspect of the present invention,
In a discharge lamp lighting device including an HID lamp, a driving circuit for lighting the HID lamp, a control circuit for controlling the driving circuit by a control unit, and a power supply for supplying a voltage, a voltage from a power supply is supplied to the control circuit. A switching element for turning ON / OFF the supply is added, and the control unit controls the switching element according to a fluctuation pattern when the voltage value of the supply voltage from the power supply is out of a predetermined range. Therefore, for example, when the abnormal state of the power supply continues continuously, the HID lamp is turned off to protect the HID lamp, and when the abnormal state of the power supply is momentary, the HI
It was possible to set the automatic recovery of the lighting of the D lamp, and to provide a discharge lamp lighting device that controls the lighting of the HID lamp based on the abnormal state of the power supply.

According to a third aspect of the present invention, at least one of an LED lighting circuit and an alarm circuit is added to the discharge lamp lighting device according to the first or second aspect of the present invention.
An abnormal state of the power supply voltage can be detected by the D lighting circuit or the alarm circuit.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a part of a discharge lamp lighting device according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a part of a discharge lamp lighting device according to another embodiment of the present invention.

FIG. 3 is a schematic block diagram showing a part of a discharge lamp lighting device according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 power supply 2 rectifier circuit 3 control circuit 3a, 3b switching element 3c level shift circuit 3d A / D converter 3e microcomputer 4 lamp drive circuit 5 inverter circuit 6 HID lamp 7 LED lighting circuit 8 alarm circuit 9 analog control circuit CP1, CP2 comparator F1 to F4 FET R1 to R3 Resistance

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[Procedure amendment]

[Submission date] April 2, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Signs] 1 power supply 2 rectifier circuit 3 control circuit 3a, 3b switching element 3c level shift circuit 3d A / D converter 3e microcomputer 4 lamp drive circuit 5 inverter circuit 6 HID lamp 7 RED lighting circuit 8 alarm circuit 9 analog control Circuit CP1, CP2 Comparator F1 to F4 FET R1 to R3 Resistance V, V1, V2 Voltage

Claims (3)

[Claims] 1. A discharge lamp lighting device comprising an HID lamp, a driving circuit for lighting the HID lamp, a control circuit for controlling the driving circuit by a control unit, and a power supply for supplying a voltage. A switching element for turning on / off the voltage supply from the power supply is added to the control circuit, and the control unit responds to a fluctuation pattern when the voltage value of the supply voltage from the power supply is out of a predetermined range. hand,
A discharge lamp lighting device, wherein the switching element is controlled. 2. The control circuit further comprises a first comparator and a second comparator, wherein the control unit applies a reference voltage to an inverting input terminal of the first comparator and a non-inverting input terminal of the second comparator. Applying a supply voltage from the power supply to a non-inverting input terminal of the first comparator and an inverting input terminal of the second comparator, wherein the switching element outputs an output signal from the first and second comparators; ON / OF of voltage supply from the power supply based on
By performing F, the range of the voltage value of the supply voltage from the power supply is set, and when the supply voltage from the power supply is out of the predetermined range of the voltage value, the switching element supplies the voltage from the power supply. When the voltage supply is turned off, the control unit controls the switching element to turn on the voltage supply from the power supply again, and turns on the HID lamp based on a repeated ON / OFF state of the switching element. The discharge lamp lighting device according to claim 1, wherein the control is performed. 3. An abnormal state of the power supply voltage is detected by adding at least one of an LED display circuit and an alarm circuit by using the LED lighting circuit or the alarm circuit. The discharge lamp lighting device as described in the above.