JP2003317983A - Discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of determining a kind of a discharge lamp having a substantially equal rated discharge lamp voltage and a different rated discharge lamp electric power and capable of carrying out substantially rated lighting of the determined discharge lamp by a single discharge lamp lighting device. <P>SOLUTION: This discharge lamp lighting device is provided with an electric current detecting circuit 3 for detecting a discharge lamp electric current; a voltage detecting circuit 4 for detecting a restriking voltage Vlap generated at polarity inversion of the discharge lamp voltage; a discharge lamp kind determination circuit DJ for comparing the restriking voltage Vlap and a predetermined voltage and determining a kind of the discharge lamp LA; a target electric power setting circuit WX for setting the discharge lamp electric power so that the determined discharge lamp LA can carry out substantially rated lighting; an electric current calculation circuit IO for calculating a target reference electric current by dividing the electric power of the target electric power setting circuit WX and the discharge lamp voltage of the voltage detecting circuit 4; and a control circuit 5 for comparing the electric current calculated by the electric current calculation circuit IO and the discharge lamp electric current detected by the electric current detecting circuit 3, controlling a voltage converting circuit 1 and carrying out substantially rated lighting of the discharge lamp LA. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a discharge lamp lighting device,
In particular, the present invention relates to a discharge lamp lighting device that uses a plurality of high-pressure discharge lamps having substantially the same rated discharge lamp voltage and different rated discharge lamp powers as compatible discharge lamps.

[0002]

2. Description of the Related Art As a conventional example of this type, there is, for example, the one disclosed in Japanese Patent Laid-Open No. 2001-210490. This product has at least 2 different electrical characteristics at rated lighting.
More than one kind of discharge lamp, in particular, as shown in Table 1 of Japanese Patent Application Laid-Open No. 2001-210490, a plurality of discharge lamps (having a rated discharge lamp voltage of 9
A discharge lamp lighting device capable of rated lighting three kinds of discharge lamps having a rated discharge lamp power of 35 W at 0 V, a voltage of 90 V and a power of 70 W, and a voltage of 90 V and a power of 100 W. It has a sorting means for applying a predetermined output to the discharge lamp during the sorting time in the initial stage of charging, specifies one of a plurality of compatible discharge lamps according to the output of this sorting means, and selects the specified discharge lamp. The discharge lamp is turned on with appropriate characteristics. Then, the predetermined output applied at the time of selecting the discharge lamp has a characteristic adapted to any of the compatible discharge lamps, and the selecting means selects the discharge lamp according to the characteristic of the discharge lamp after a predetermined time when the lamp is turned on with the predetermined output. To identify.

[0003]

However, in the above-mentioned conventional example, no concrete means for specifying the type of the discharge lamp is shown. In particular, for discharge lamps with approximately the same rated discharge lamp voltage and different rated discharge lamp power, the electrical characteristics of each discharge lamp differ from the moment the power is turned on until a prescribed time has elapsed, and the type of discharge lamp is specified by this difference. It only describes what to do.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a discharge lamp lighting device having one discharge lamp lighting device having substantially the same rated discharge lamp voltage and different rated discharge lamp powers. Another object of the present invention is to provide a discharge lamp lighting device that determines the type of the discharge lamp, and lights the determined discharge lamp at a substantially rated value.

[0005]

A discharge lamp lighting device according to claim 1; a DC power supply; a voltage conversion circuit for converting a DC voltage from the DC power supply into a predetermined DC voltage; a predetermined voltage from the voltage conversion circuit. A polarity reversing circuit that converts a DC voltage into a rectangular wave voltage; an igniter circuit that is connected to the polarity reversing circuit and starts a discharge lamp; a current detection circuit that detects a discharge lamp current flowing in the discharge lamp; both ends of the discharge lamp A voltage detection circuit for detecting the discharge lamp voltage and a re-ignition voltage generated when the polarity of the discharge lamp voltage is reversed; a re-ignition voltage detected by the voltage detection circuit and a predetermined voltage stored in a storage unit. And a target power setting circuit that sets the discharge lamp power so that the discharge lamp determined by the discharge lamp type circuit is approximately rated lighting; Setting A current calculation circuit that calculates a target reference current by dividing the electric power set by the circuit and the discharge lamp voltage detected by the voltage detection circuit; the current calculated by the current calculation circuit and the current detected by the current detection circuit And a control circuit for controlling the voltage conversion circuit by comparing the discharge lamp current with the discharge lamp current so as to turn on the discharge lamp at a substantially rated value.

The voltage detection circuit detects the re-ignition voltage generated when the polarity of the discharge lamp voltage is inverted, and the discharge lamp type circuit stores the re-ignition voltage detected by the voltage detection circuit in the storage unit. The type of the discharge lamp is determined by comparing it with a predetermined voltage. Then, the target power setting circuit sets the rated power of the discharge lamp whose type is determined.

The current calculation circuit calculates a target reference current from the rated power of the discharge lamp set by the target power setting circuit and the discharge lamp voltage detected by the voltage detection circuit, and the target reference current and the current detection circuit detect the target reference current. The discharge lamp currents are compared with each other, and the discharge lamp is turned on at a substantially rated value.

A discharge lamp lighting device according to a second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein a plurality of discharge lamps having substantially the same rated discharge lamp voltage and different rated discharge lamp powers are qualified discharge lamps. It is a feature.

A discharge lamp lighting device according to a third aspect of the present invention is the discharge lamp lighting device according to the second aspect, wherein the re-ignition voltage is detected during the period from the start of the discharge lamp to the steady lighting state. It is a feature.

A discharge lamp lighting device according to a fourth aspect is the discharge lamp lighting device according to the first aspect, further comprising a measuring circuit for measuring a time during which the discharge lamp current generated when the polarity of the discharge lamp current is not flowing is flowing. The discharge lamp type circuit is provided with a first storage unit, and the type of the discharge lamp is determined by comparing the measured time with a predetermined time stored in the first storage unit. Is turned on at a substantially rated value.

A discharge lamp lighting device according to a fifth aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein an illuminance detection circuit for detecting the illuminance from the discharge lamp is provided and a second storage section is provided in the discharge lamp type circuit. The discharge lamp is provided, and the detected illuminance is compared with a predetermined illuminance stored in the second storage unit to determine the type of the discharge lamp, and the discharge lamp is lit substantially at a rated value. .

A discharge lamp lighting device according to a sixth aspect of the present invention is the discharge lamp lighting device according to any one of the third to fifth aspects, wherein the discharge lamp is a high pressure discharge lamp. .

A discharge lamp lighting device according to a seventh aspect of the present invention is the discharge lamp lighting device according to the sixth aspect, wherein the high pressure discharge lamp is characterized in that the bulb is not filled with mercury.

The discharge lamp lighting device according to claim 8 is the discharge lamp lighting device according to claim 7, wherein the discharge lamp lighting device is mounted on a vehicle body and is used as a vehicle headlight. It is a thing.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The first embodiment of the present invention will be described below.
An embodiment will be described with reference to FIGS. 1 to 5.

The present discharge lamp lighting device is mounted, for example, in a vehicle body and used as a vehicle headlight.

The structure of each part will be described below.

The DC power supply DC is a voltage conversion circuit 1 described later.
12V in the case of a vehicle
It is a battery.

The voltage conversion circuit 1 converts a DC voltage from the DC power supply DC into a predetermined DC voltage Vdc,
In the present embodiment, the switching element Q such as FET
A flyback DC-DC converter having a transformer 1, a transformer T1, a diode D1, a capacitor C1 and a control circuit 5 is adopted. This flyback type DC-D
The C converter stores energy in the transformer T1 when the switching element Q1 is on and discharges energy to the polarity reversing circuit 2 side described later when it is off. The frequency of this on / off control is, for example,
It is a high frequency of about kHz. The capacitor C1 smoothes the voltage output from the diode D1 and has a capacitance of, for example, about several μF. Further, the control circuit 5 controls the frequency of the switching element Q1 and can convert the DC voltage from the DC power supply DC into a predetermined DC voltage Vdc by this control operation. Of course, the control circuit 5 may be a PWM type control circuit. In addition,
Input side of control circuit 5 and discharge lamp current error circuit ER described later
Is connected to the output side of.

In this embodiment, a flyback type DC is used.
Although the -DC converter is adopted, of course, a forward type DC-DC converter may be used.

When the discharge lamp lighting device is used in a vehicle other than a vehicle and an AC power source is used for the DC power source DC, an AC-DC converter may be used as the voltage conversion circuit 1. .

The polarity reversing circuit 2 has a predetermined DC voltage Vdc.
Is converted into a rectangular wave voltage, and in the present embodiment, a so-called full-bridge type inverter circuit having switching elements Q2 to Q5 such as FETs is adopted. Here, the predetermined DC voltage Vdc is about 400 to 500 V when the discharge lamp LA described later is started. Further, although a control unit for performing on / off control of the switching elements Q2 to Q5 is not shown, this control unit may be a self-excited type or a separately excited type. The frequency of this on / off control is a low frequency of, for example, several hundred Hz. Further, when the switching elements Q2 to Q5 are transistors, a feedback diode is connected in parallel to each of the switching elements Q2 to Q5.

The igniter circuit IG is a discharge lamp L which will be described later.
A high voltage pulse having a high voltage of several tens of kV is applied to A to start the discharge lamp LA. In this embodiment,
The trigger circuit and the transformer (not shown) shown in FIG. 1 of JP 2001-313193 A are adopted.

The discharge lamp LA is a high-pressure discharge lamp such as a high-pressure sodium lamp, a metal halide lamp, or a mercury lamp. Here, in the present embodiment, the discharge lamp LA1 having a rated discharge lamp voltage of 90 V and a rated discharge lamp power of 35 W, the voltage being 90
Consider three types of discharge lamps: LA2 with V and 70 W, and LA3 with 90 V and 100 W. These discharge lamps include sodium in the bulb,
It may be one containing a halide such as scandium and containing substantially no mercury. When such a discharge lamp is adopted, environmental pollution can be prevented.

The current detection circuit 3 detects the discharge lamp current flowing through the discharge lamp LA. The current detection circuit 3 is a detection resistor (not shown) for detecting the discharge lamp current.
Etc. may be provided in series between the voltage conversion circuit 1 and the polarity inversion circuit 2 to directly detect the discharge lamp current. Alternatively, an additional circuit may be separately provided to indirectly detect the discharge lamp current.

The voltage detection circuit 4 detects the re-ignition voltage Vlap generated when the polarity of the discharge lamp voltage Vla as shown in FIG. 2 is reversed. This restrike voltage is
The high-pressure discharge lamp is liable to occur before the transition from the starting state to the stable lighting state, and the re-ignition voltage Vlap becomes particularly large immediately after the starting. Here, a detection resistor (not shown) or the like for detecting the re-ignition voltage Vlap may be provided in parallel with the polarity reversing circuit 2 to directly detect the re-ignition voltage Vlap. Alternatively, an additional circuit may be separately provided to indirectly detect the re-ignition voltage Vlap. The voltage detection circuit 4 also detects the re-ignition voltage Vlap and, at the same time, the discharge lamp voltage of the discharge lamp LA.

The discharge lamp type circuit DJ receives the re-ignition voltage Vlap from the voltage detection circuit 4, determines the type of the discharge lamp LA, and sends a target power value to a target power setting circuit WX described later. Here, the discharge lamp type circuit DJ has the configuration shown in FIG.

That is, the discharge lamp classification circuit DJ has an input section T to which an ON signal from a timer circuit T1 described later is inputted.
1 (I), an input portion F (I) to which a rectangular wave signal for driving the switching elements Q2 to Q5 is input, and a timer circuit T
A switch SW1 which is turned on by an ON signal from 1, an inverting circuit NOT which inverts an input rectangular wave signal, a transistor Tr1 which is turned on / off by a signal of the inverting circuit NOT, and predetermined DC power supplies Vc1 and Vc2. A resistor R1 that limits the current from the DC power supply Vc1, a resistor R2 and a capacitor C2 that form a timer, one end of the resistor R1 is connected to the non-inverting input side, and one end of the resistor R2 is connected to the inverting input side. A logical product circuit AND1 that receives the output of the switch SW1 and the output of the comparator CP1, a switch SW2 that is turned on by the high voltage from the logical product circuit AND1, and the voltage detection circuit 4 detects when the switch SW2 is turned on. Re-ignition voltage Vlap
Is input, the input re-ignition voltage Vlap is compared with a predetermined voltage stored in the storage unit M1, and the target power value is output to the target power setting circuit WX. There is.

The determination mode in which the discharge lamp type circuit DJ determines the type of discharge lamp is as follows.

That is, as shown in FIG. 4, at t = t1, from the timer circuit T1 to the input portion T1 of the discharge lamp classification circuit DJ.
When the ON signal is input to (I), the rectangular wave signal for driving the switching elements Q2 to Q5 is input to the input section of the inverting circuit NOT connected to the input section F (I). Then, when the rectangular wave signal of the input portion F (I) is turned on at t = t1, an inverted signal of the rectangular wave signal is output to the output side of the inverting circuit NOT, and the transistor Tr1 is turned off at t = t1. . Then, as shown in FIG. 4, the current from the DC power supply Vc2 starts charging the capacitor C2 at t = t1.
When both ends of the capacitor C2 reach a predetermined voltage, the comparator CP1 outputs a high voltage, and the AND circuit A
ND1 also outputs a high voltage. Then switch SW2
Is turned on, and the re-ignition voltage Vlap detected by the voltage detection circuit 4 is input to the comparison circuit 1. This re-ignition voltage Vlap
And the predetermined voltage stored in the storage unit M1 by the comparison circuit 1 are compared to determine the type of the discharge lamp and output it to the target power setting circuit WX described later.

The target power setting circuit WX determines the power supplied to the discharge lamp LA, and the discharge lamp type circuit DJ
The target electric power value is set so that the discharge lamp discriminated by is turned on at the rated power. Then, this target power value is output to the current calculation circuit IO described later.

The current calculation circuit IO is a target power setting circuit W.
The target power value from X is divided by the discharge lamp voltage of the discharge lamp LA detected by the voltage detection circuit 4 to calculate the target current value, and the calculation result is the discharge lamp current error circuit E described later.
Output to the R inversion input terminal. Here, the current calculation circuit I
The input side of O is connected to the output side of the target power setting circuit WX and the voltage detection circuit 4.

The discharge lamp current error circuit ER calculates / amplifies the difference between the target current value from the current calculation circuit IO and the discharge lamp current detected by the current detection circuit 3, and this amplified signal is the discharge lamp current. It is sent from the error circuit ER to the control circuit 5.

The timer circuit T1 measures the elapsed time after the power is turned on and outputs an ON signal when a predetermined time has elapsed. The timer circuit T1 is composed of, for example, an RC circuit (not shown) such as a resistor and a capacitor.

Here, the discharge lamp type circuit DJ, the target power setting circuit WX, the current operation circuit IO and the timer circuit T1 are
It may be a microcomputer that operates according to a predetermined program.

Next, the operation of the present discharge lamp lighting device will be described.

When the DC power source DC is turned on, the control circuit 5
Is driven to chop the switching element Q1 of the voltage conversion circuit 1. Then, the output side of the voltage conversion circuit 1,
That is, the unloaded output voltage (4
00-500V) is generated. This output voltage energizes the discharge lamp LA and causes the igniter circuit IG to generate a high voltage pulse which is a high voltage. High-voltage pulse is discharge lamp LA
And the discharge lamp LA is started. After starting, the discharge lamp LA is continuously powered by being supplied with power from the capacitor C1 of the voltage conversion circuit 1. When the discharge lamp LA is turned on, the igniter circuit IG stops the generation of the high voltage pulse.

When the DC power supply DC is turned on, the current calculation circuit IO, the target power setting circuit WX and the timer circuit T1
Is powered and driven. The target power setting circuit WX sets the target power value to be supplied to the discharge lamp LA by the above-described operation and sends it to the current calculation circuit IO.

Here, in the target power setting circuit WX,
Set the target power value at the initial start to the maximum rated discharge lamp power of the compatible discharge lamps. That is, in the case of the present embodiment, the target power value at the time of initial starting is 10 for the discharge lamp LA3.
Set to 0W. With this setting,
The discharge lamp LA1 with the smallest rated discharge lamp power as shown in
Rises fastest, that is, in the starting state (t = 0
The discharge lamp LA1 has the largest re-ignition voltage during the period from the transition from t1) to the steady lighting state (t> t1). Then, the re-ignition voltage of the discharge lamp LA3 having the latest rise becomes the smallest. Of course, the type of the discharge lamp LA may be determined based on the difference in the re-ignition voltage after shifting to the steady lighting state.

Then, the target power setting circuit WX sends the target power value to the current calculation circuit IO. Current calculation circuit IO
Calculates the target current value by dividing the target power value set by the target power setting circuit WX by the discharge lamp voltage detected by the voltage detection circuit 4, and sends it to the inverting input terminal of the discharge lamp current error circuit ER. . The discharge lamp current detected by the discharge lamp current detection circuit 3 is input to the non-inverting input terminal of the discharge lamp current error circuit ER. The discharge lamp current error circuit ER compares the target current value with the discharge lamp current, calculates a difference, amplifies the difference, and sends it to the control circuit 5. The control circuit 5 changes the chopping frequency or the on-duty of the switching element Q1 so that the difference sent from the discharge lamp current error circuit ER becomes zero or approximates to zero.
Then, the DC voltage Vdc of the voltage conversion circuit 1 is changed,
The electric power of the discharge lamp LA becomes the target electric power value. Alternatively, it is close to the target power value.

By the above operation, for example, it is possible to determine the types of a plurality of discharge lamps having substantially the same rated discharge lamp voltage and different rated discharge lamp powers, and to make the lamps substantially rated lighting. For this reason, it is possible to prevent the problem that the life is shortened by supplying excessive power to a discharge lamp having a low rated discharge lamp power.

Further, by applying this embodiment, it is possible to discriminate a plurality of types of discharge lamps having different rated discharge lamp powers. (Second Embodiment) A second embodiment of the present invention will be described below with reference to FIGS. 6 and 7. Since the basic structure is the same as that of the first embodiment, the same structures are designated by the same reference numerals and the description thereof is omitted.

In the present embodiment, the measurement circuit T2, which will be described later, measures the idle section TS in which the discharge lamp current Ila generated when the polarity of the discharge lamp current Ila as shown in FIG. The type of discharge lamp is determined according to time. Next, a determination mode for determining the type of discharge lamp will be described.

In the present embodiment, the target power value at the initial start is set to 100 W of the discharge lamp LA3. The discharge lamp L with the smallest rated discharge lamp power is set in this way.
When A1 is mounted, the rising of the discharge lamp LA1 is the fastest, that is, the pause section TS is the shortest, compared to when the discharge lamp LA2 or LA3 is mounted. Also,
When the discharge lamp LA3 having the highest rated discharge lamp power is mounted, the discharge lamp LA3 has the latest rising time, that is, the pause section TS is the longest. The measurement circuit T2 measures the difference in length of the pause section TS to determine the type of discharge lamp.

The difference between the present embodiment and the first embodiment is the configuration of the discharge lamp type circuit DJ, and the discharge lamp type circuit DJ has the configuration shown in FIG.

That is, the discharge lamp type circuit DJ has a resistor R
A comparator CP connected to the inverting input side of the detection current from the current detection circuit 3 via 3 and connected to a non-inverting input side of the predetermined DC power supply Vc3 via a resistor R4.
2 and a measuring circuit T that receives the high voltage from the comparator CP2 and measures the time during which the high voltage is output.
2 by comparing the measured time with a predetermined time stored in the storage unit M2 to determine the type of the discharge lamp,
The comparison circuit 2 for outputting the target power value to the target power setting circuit WX.

The discriminating mode in which the discharge lamp type circuit DJ discriminates the type of the discharge lamp is as follows.

That is, as described above, the discharge lamp current Il
No signal is input to the inverting input side of the comparator CP2 in the pause section TS in which a is paused. That is, the comparator CP2 outputs a high voltage. Discharge lamp current Ila
In the section where is flowing, a signal is input to the inverting input side of the comparator CP2, and the voltage on the inverting input side becomes higher than the voltage on the non-inverting input side. That is, the comparator C
P2 outputs a low voltage. The above-mentioned comparator CP2
Compares the time when the high voltage is output with the predetermined time stored in the storage unit M2, the comparison circuit 2 determines the type of the discharge lamp, and sets the target power value to the target power setting circuit WX. Output.

By the above operation, for example, it is possible to discriminate a plurality of types of discharge lamps having substantially the same rated discharge lamp voltage and different rated discharge lamp powers, and to make the lamps substantially rated. Of course, if this embodiment is applied, it is possible to determine the types of a plurality of discharge lamps having different rated discharge lamp powers.

The functions, effects, and the like not specifically mentioned in the above description are the same as those in the first embodiment. (Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to FIG.

Here, since the basic structure is the same as that of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

Also in this embodiment, the target power value at the initial start is set to 100 W of the discharge lamp LA3. When the discharge lamp LA1 having the smallest rated discharge lamp power is mounted in this way, the discharge lamp LA2 or LA3 is installed.
The discharge lamp LA1 rises fastest, that is, the illuminance becomes the largest, as compared with the case where is mounted. Further, when the discharge lamp LA3 having the highest rated discharge lamp power is mounted, the discharge lamp LA3 has the slowest rise, that is,
The illuminance is the smallest. This difference in illuminance is measured by an illuminance detection circuit PC, which will be described later, to determine the type of discharge lamp.

The difference between the present embodiment and the first embodiment is that an illuminance detection circuit PC is provided near the discharge lamp LA in the present embodiment. An optical sensor containing cadmium sulfide CdS as a main component is used for the illuminance detection circuit PC, and the illuminance detected by the illuminance detection circuit PC and a storage unit M3 at a predetermined time after the power is turned on.
By comparing with the predetermined illuminance stored in, the comparison circuit 3 determines the type of the discharge lamp and outputs the target power value to the target power setting circuit WX as in the first embodiment.

By the above operation, for example, as in the first and second embodiments, for example, the types of a plurality of discharge lamps having substantially the same rated discharge lamp voltage and different rated discharge lamp powers are discriminated and substantially rated lighting is performed. be able to. Of course, if this embodiment is applied, it is possible to determine the types of a plurality of discharge lamps having different rated discharge lamp powers.

Here, in the present embodiment, the type of the discharge lamp is discriminated by the illuminance difference at a predetermined time after the power is turned on. However, the discharge lamp's illuminance is summed up at the predetermined time after the power is turned on. The type may be determined.

The functions, effects and the like not specifically mentioned in the above description are the same as those in the first embodiment.

[0057]

According to the discharge lamp lighting device of the present invention, the maximum ignition voltage generated when the polarity of the discharge lamp voltage is reversed by the discharge lamp type circuit, and the polarity of the discharge lamp current is reversed. The time when the generated discharge lamp current is not flowing or the illuminance from the discharge lamp is detected and compared with each predetermined value stored in the storage unit to determine the type of discharge lamp and the target power setting circuit and current calculation circuit Since the specified discharge lamp can be turned on substantially at the rated voltage by the control circuit, for example, the types of a plurality of discharge lamps having substantially the same rated discharge lamp voltage but different rated discharge lamp powers can be discriminated and turned on at the substantially rated lighting. You can Environmental pollution can be prevented by using a discharge lamp that does not contain mercury.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment.

FIG. 2 is a waveform diagram showing a waveform of a re-ignition voltage.

FIG. 3 is a circuit diagram showing a discharge lamp type circuit in the first embodiment.

FIG. 4 is a time chart showing the operation of the discharge lamp type circuit.

FIG. 5 is a diagram showing changes with time of re-ignition voltage of various discharge lamps.

FIG. 6 is a waveform diagram showing a waveform of a discharge lamp current.

FIG. 7 is a circuit diagram showing a discharge lamp type circuit according to a second embodiment.

FIG. 8 is a circuit diagram showing a discharge lamp type circuit according to a third embodiment.

[Explanation of symbols]

DC DC power supply 1 Voltage conversion circuit 2 polarity inversion circuit LA discharge lamp IG igniter circuit 3 Current detection circuit 4 Voltage detection circuit M1 memory DJ discharge lamp type circuit WX target power setting circuit IO current operation circuit 5 control circuit T2 measuring circuit M2 First storage unit PC illuminance detection circuit M3 second memory

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masatoshi Ueno             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company F term (reference) 3K072 AA13 AA14 AB09 AC01 AC11                       AC15 BA05 BB01 DD06 DE01                       DE02 DE04 DE05 DE06 DE07                       GA02 GB03 GB18 GC04 HA10

Claims (8)

[Claims] 1. A DC power supply; a voltage conversion circuit for converting a DC voltage from the DC power supply into a predetermined DC voltage; a polarity reversing circuit for converting a predetermined DC voltage from the voltage conversion circuit into a rectangular wave voltage; An igniter circuit that is connected to the reversing circuit and starts the discharge lamp; a current detection circuit that detects the discharge lamp current that flows in the discharge lamp; a discharge lamp voltage across the discharge lamp and a discharge lamp voltage that occurs when the polarity is reversed A voltage detection circuit for detecting the re-ignition voltage, and a discharge lamp for determining the type of the discharge lamp by comparing the re-ignition voltage detected by the voltage detection circuit with a predetermined voltage stored in the storage unit. A type circuit; a target power setting circuit that sets the discharge lamp power so that the discharge lamp discriminated by the discharge lamp type circuit is approximately rated lighting; and a power and voltage detection circuit set by the target power setting circuit A current calculation circuit for calculating a target reference current by dividing the discharged discharge lamp voltage; voltage conversion by comparing the current calculated by the current calculation circuit with the discharge lamp current detected by the current detection circuit A discharge lamp lighting device, comprising: a control circuit for controlling a circuit to turn on a discharge lamp at a substantially rated value. 2. The discharge lamp lighting device according to claim 1, wherein a plurality of discharge lamps having substantially equal rated discharge lamp voltages and different rated discharge lamp powers are used as compatible discharge lamps. 3. The discharge lamp lighting device according to claim 2, wherein a re-ignition voltage is detected during a period in which the discharge lamp is changed from a starting state to a steady lighting state. 4. A measuring circuit for measuring a time during which the discharge lamp current is generated, which is generated when the polarity of the discharge lamp current is reversed, is provided, and a discharge memory type circuit is provided with a first storage section.
2. The type of discharge lamp is determined by comparing the measured time with a predetermined time stored in the first storage unit, and the discharge lamp is lit at a substantially rated temperature. Discharge lamp lighting device. 5. An illuminance detection circuit for detecting the illuminance from the discharge lamp is provided, and a second storage unit is provided in the discharge lamp type circuit, and the detected illuminance and the predetermined illuminance stored in the second storage unit. The discharge lamp lighting device according to claim 1, wherein the type of the discharge lamp is discriminated by comparing with, and the discharge lamp is lit substantially at a rated level. 6. The discharge lamp lighting device according to claim 3, wherein the discharge lamp is a high pressure discharge lamp. 7. The discharge lamp lighting device according to claim 6, wherein the high pressure discharge lamp has no bulb filled with mercury. 8. The discharge lamp lighting device is mounted on a vehicle body,
The discharge lamp lighting device according to claim 7, which is used as a headlight of a vehicle.