JPH10294191A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an overcurrent at slow leak time of a high intensity high pressure discharge lamp form flowing to a lighting device, and enhance safety by detecting an electric current flowing to an inductor of a chopper circuit to output an input DC power source after being converted into voltage, and switching control so as to become continuous just after lighting and become discontinuous until tube electric power becomes maximum. SOLUTION: An electric current flowing to an inductor L2 through a resistance R4 connected in series from a secondary winding of the inductor L2 of a step-down chopper circuit 2 is detected, and is inputted to a control circuit 5. The control circuit 5 prevents extinction or the like of a lamp by continuously switching an electric current flowing to the inductor L2 by a switching element Q2 when discharge voltage is not more than a certain discharge lamp voltage value Va smaller than maximum discharge lamp voltage until the lamp is lighted, and maintains the lamp up to stable lighting. Circuit efficiency at rated time can also be maximized by switching it to discontinuous operation up to reaching fated discharge lamp voltage.

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 suitable for stably lighting a high-intensity high-pressure discharge lamp (HID lamp) such as a metal halide lamp, a high-pressure sodium lamp, and a mercury lamp.

[0002]

2. Description of the Related Art FIG. 19 shows a conventional discharge lamp lighting device for stably lighting a high pressure discharge lamp. This discharge lamp lighting device,
Power is supplied from the DC power supply V1 to the two-piece inverter IV via the power switch SW, and high-frequency power is supplied from the inverter IV to the discharge lamp LA such as a HID lamp to start and turn on the discharge lamp LA. . Inverter IV
Are switching elements Q7 and Q8 connected in series, diodes D7 and D8 respectively connected in antiparallel to switching elements Q7 and Q8, inductor L3 and capacitor C
4, C5.

The discharge lamp LA is connected in parallel with a lamp voltage detection circuit 4 composed of resistors R1 and R2 and a capacitor C6, and outputs a detection voltage V4 corresponding to the lamp voltage Vla. The detection voltage V4 output from the lamp voltage detection circuit 4 is inverted and amplified by an inverting amplifier AP including an operational amplifier OP, resistors R5 to R7, and a reference voltage source Vk, and then has a voltage-frequency conversion type of 50% duty. Oscillator O
Input to SC. The oscillator OSC changes the oscillation frequency to high or low according to the control input voltage, that is, according to the detected value V4 of the lamp voltage of the discharge lamp LA. A diode limiter LM having a limiter voltage Vb is connected to an output terminal of the inverting amplifier AP, that is, a control input terminal of the oscillator OSC, and the output voltage Vf of the inverting amplifier AP is equal to the limiter voltage Vb.
It will never go down.

The above-described lamp voltage detection circuit 4 and inverting amplifier A
P and the diode limiter LM supply the discharge lamp LA with excessive lamp power larger than the rated lamp power during a period until the lamp voltage Vla of the discharge lamp LA reaches a predetermined value equal to or less than the rated value. Of the control circuit 5a for rapidly raising the light flux of the light.

[0005] The output signal of the oscillator OSC is input to the driving circuit DR1 via the inverting circuit N1 and also directly to the driving circuit DR2. As a result, the driving circuit D
R1 controls on / off of the switching element Q7 with a 50% duty, and its frequency changes according to the level of the lamp voltage Vla. Similarly, the drive circuit DR2 performs on / off control of the switching element Q8 with a 50% duty, and the frequency changes according to the level of the lamp voltage Vla. The on / off of the switching elements Q7 and Q8 are just reversed.

In the above configuration, when the lamp voltage Vla of the discharge lamp LA has risen to the rated value, the discharge lamp L
The lamp power Wla1 required for normal lighting of A is supplied, and the switching frequency of the switching elements Q7 and Q8 is changed from immediately after the power is turned on until the lamp voltage Vla reaches a predetermined value (rated value or a value close thereto). The discharge lamp LA is supplied by supplying an excessive lamp power
The light flux is quickly activated.

[0007]

In the discharge lamp lighting device of FIG. 19, the lamp current is large when the lamp voltage of the HID lamp is in a low voltage state, and the lamp voltage such as slow leak of the HID lamp becomes low. In the event of an abnormality,
Since a large current flows, it is necessary to take measures against heat generation of components.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent an overcurrent at the time of a slow leak of an HID lamp from flowing to a lighting device, thereby improving safety. It is to provide an enhanced discharge lamp lighting device.

[0009]

According to the discharge lamp lighting apparatus of the present invention, as shown in FIGS. 1 and 2, the apparatus includes at least a switching element Q2 and an inductor L2, converts an input DC power supply 1 into a voltage, and outputs the converted voltage. A lighting circuit for stably lighting and maintaining the discharge lamp LA using a chopper circuit 2 for detecting the current; a detecting means for detecting a current flowing through an inductor L2 of the chopper circuit 2;
Control means for switching the switching element Q2 so that the current flowing through the inductor L2 is discontinuous, and second control means for switching the switching element Q2 so that the current flowing through the inductor L2 is continuous. After the switching element Q2 is controlled by the second control means immediately after the discharge lamp LA is started, the switching to the first control means is performed until the tube power reaches the maximum.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows a circuit configuration of Embodiment 1 of the present invention. In this embodiment, a step-up chopper circuit 1 which is a DC power supply circuit, a step-down chopper circuit 2, a polarity inversion circuit 3,
A control circuit 5 for controlling the driving of the switching element Q2 of the step-down chopper circuit 2 is provided. DC power supply circuit 1
Converts a pulsating voltage obtained by full-wave rectification of a commercial power supply AC with a full-wave rectifier DB into a DC voltage by a so-called step-up chopper circuit including a switching element Q1 such as an inductor L1, a diode D1, a capacitor C1, and a MOSFET. Is to be converted to The step-down chopper circuit 2 includes a switching element Q2 such as a MOSFET that turns on and off at several tens of kHz, a diode D2, and an inductor L.
The current IL2 flowing through the inductor L2 has a triangular wave shape as shown in FIG. 3A, and the resistor R2 is connected in series from the secondary winding of the inductor L2.
4 is detected. Then, the detection output of the current IL2 is sent to the control circuit 5, and is used as a feedback signal for controlling the switching element Q2 of the step-down chopper circuit 2 through the control circuit 5 for zero-cross switching driving. The capacitor C2 removes high frequency components from the output current of the step-down chopper circuit 2. The polarity inversion circuit 3 converts the DC output from the previous step-down chopper circuit 2 into M
A square-wave inverter that converts low-frequency square-wave power alternating at several hundred Hz into a low-frequency square-wave current and supplies the low-frequency square-wave current to the high-pressure discharge lamp LA by a full-bridge circuit including switching elements Q3 to Q6 such as an OSFET. Is configured.

FIG. 2 shows the details of the control circuit 5 for controlling the driving of the switching element Q2. The control circuit 5 determines the duty of a signal for driving the switching element Q2 of the step-down chopper circuit 2 and the zero current detection circuit 14 for detecting the secondary voltage of the inductor L2 of the step-down chopper circuit 2, and 2 switching element Q2
, A PWM circuit 8 for outputting a signal for switching, a OFF-time monitoring circuit 9 for outputting a signal when the switching element Q2 of the step-down chopper circuit 2 is not switched for a certain period of time, a zero current detection circuit 14, and an OFF-time monitoring Switching circuit 10 for switching to one of circuits 9
And a driver circuit 11 for outputting a drive signal.

In this embodiment, a certain discharge lamp voltage value Va smaller than the maximum discharge lamp voltage before the lamp is turned on.
(Refer to FIG. 4.) In the following, the switching circuit 10 operates the off-time monitoring circuit 9 to set the current IL2 flowing through the inductor L2.
Is continuously switched as shown in FIG. 6A to prevent the lamp from going out and the like, and maintain the lamp until stable lighting.

FIG. 5 shows an internal circuit of the off-time monitoring circuit 9. The off-time monitoring circuit 9 includes a variable threshold voltage E1, a capacitor C3, a comparator Cp1, a constant current source E2, a discharging resistor R5 of the capacitor C3, and a switching element Q7 such as a transistor. The threshold voltage E1 has a linearly decreasing voltage at a discharge lamp voltage smaller than Va, and has a constant threshold voltage at a discharge lamp voltage higher than Va. Threshold voltage E1 and discharge lamp voltage Vl
FIG. 7 shows the relationship a. When the charging voltage of the capacitor C3 (FIG. 6B) is equal to or lower than the threshold voltage E1, no drive signal (FIG. 6D) is output to the switching element Q2 of the step-down chopper circuit 2. The off-time monitoring circuit 9 detects the current IL2 flowing through the inductor L2 as shown in FIG.
Continuous switching can be performed as shown in FIG.
When the charging voltage of the capacitor C3 reaches the threshold voltage E1, the comparator Cp1 outputs a “High” level signal to PW
Output to M circuit 8. At this time, a signal "x" for turning on the switching element Q7 is output from the PWM circuit 8 as a feedback signal, the electric charge of the capacitor C3 is extracted, and the drive signal is sent from the driver circuit 11 to the switching element Q2 of the step-down chopper circuit 2 (see FIG. 6 (d) signal of “High” level) is output. The capacitor C3 is kept in a short-circuit state until the output of the PWM circuit 8 goes to the "Low" level.

Next, when the discharge lamp voltage becomes equal to or higher than the predetermined value Va in FIG. 4, the switching circuit 10 operates the zero current detecting circuit 14 to cause the current IL2 flowing through the inductor L2 to perform discontinuous zero-cross switching, thereby obtaining a desired lamp. Turn on the lamp with electric power. The zero current detection circuit 14 detects the secondary voltage (FIG. 3B) of the inductor L2 of the step-down chopper circuit 2, and detects the current IL of the inductor L2 of the step-down chopper circuit 2.
2 (FIG. 3A) becomes zero, the 2
The falling of the next winding voltage is detected, and a trigger pulse (FIG. 3C) is output to the PWM circuit 8. PWM circuit 8
When a trigger pulse is input from the zero current detection circuit 14, the output terminal outputs a "Low" level signal after maintaining the "High" level output state for a certain period of time. The driver circuit 11 outputs this as a drive signal (FIG. 3D) to the switching element Q2 of the step-down chopper circuit 2.

(Embodiment 2) The circuit configuration of the present embodiment is the same as that of Embodiment 1 (FIG. 1), and the configuration of the control circuit 5 corresponding to the switching element Q2 of the step-down chopper circuit 2 is the same. This defines the setting of Va. In the first embodiment, the switching element Q2 is continuously switched by the off-time monitoring circuit 9 immediately after the discharge lamp is turned on, and the zero current detection circuit 14 is turned on at least at a predetermined value Va of the discharge lamp voltage until the discharge lamp power becomes rated. By switching, the switching element Q2 is switched so that the current IL2 flowing through the inductor L2 becomes discontinuous zero-cross switching. However, in this embodiment, one of the failure modes of the lamp, the slow leak (in the arc tube). 30% to 50% of the rated discharge lamp voltage (for example, if the rated discharge lamp voltage is 90 V), which may cause the discharge lamp voltage to decrease due to the gas leakage and an excessive current to continue to flow through the discharge lamp , About 25 V to 45 V), the predetermined value Va for switching from the off time monitoring circuit 9 to the zero current detection circuit 14 is set to One in which a constant.

(Embodiment 3) FIG. 8 shows a circuit configuration of Embodiment 3 of the present invention. In this embodiment, the circuit configuration of FIG.
It is obtained by adding a discharge lamp voltage detection circuit 4. FIG. 9 shows the configuration of the control circuit 5. Discharge lamp voltage detection circuit 4
Detects the discharge lamp voltage of the high-pressure discharge lamp LA by a series circuit of resistors R1 and R2 connected in parallel between the power supply input terminals of the polarity inversion circuit 3 and sends the detected value Vla1 to the control circuit 5, This is used as a feedback signal for driving and controlling the switching element Q2 of the step-down chopper circuit 2 through the circuit 5. By providing the discharge lamp voltage detection circuit 4, when the discharge lamp voltage reaches the predetermined value Va, the off-time monitoring circuit 9 is switched to the zero current detection circuit 14. Then, the value of the discharge lamp voltage is made to correspond to the ON width ton (ON duty) of the switching element Q2 of the step-down chopper circuit 2 (FIG. 10).

The configuration of the control circuit 5 includes an inverting circuit 6 for inverting the detected value of the discharge lamp voltage, and a discriminating circuit 7 for comparing the detected value of the discharge lamp voltage with the inverted value to obtain a lower value. Is added. The inversion circuit 6 is a circuit for inverting the value according to the detected discharge lamp voltage. In FIG. 11, a solid line indicates a detection value Vla1 obtained by dividing the discharge lamp voltage, and a dotted line indicates a detection value Vla1. Shown is an inverted value Vla2 of the detected value Vla1 of the discharge lamp voltage. The slope of this dotted line can be changed. In the determination circuit 7,
By comparing the values of Vla1 and Vla2, a lower value is selected and output to the PWM circuit 8. The discharge lamp voltage value obtained by this comparison becomes the threshold voltage of the PWM circuit 8,
ON width t of switching element Q2 of step-down chopper circuit 2
On (on duty) is determined as shown in FIG. As described above, by providing the discharge lamp voltage detection circuit 4, when the discharge lamp voltage reaches the predetermined value Va, it is possible to switch from the off-time monitoring circuit 9 to the zero current detection circuit 14, and after switching, The ON width of the switching element Q2 of the step-down chopper circuit 2 can be controlled according to the value of the discharge lamp voltage.

(Embodiment 4) FIG. 12 shows a circuit configuration of Embodiment 4 of the present invention. In this embodiment, by adding the discharge lamp current detection circuit 12, when the discharge lamp current value reaches a predetermined value, the off-time monitoring circuit 9 sends the zero current detection circuit 1
Switch to 4. FIG. 13 shows the configuration of the control circuit 5. The discharge lamp current detection circuit 12 detects the discharge lamp current of the high pressure discharge lamp LA by the resistor R3 connected in series between the power supply input terminals of the polarity inversion circuit 3, and sends the detected value Ila1 to the control circuit 5. The control circuit 5 has a switching circuit 10 for obtaining the detected value of the discharge lamp current and switching from the off-time monitoring circuit 9 to the zero current detection circuit 14. The other configuration is the same as that of the third embodiment, and the description is omitted here.

(Embodiment 5) FIG. 14 shows the configuration of a control circuit according to Embodiment 5 of the present invention. The configuration of the main circuit of this embodiment is the same as that of FIG. 12, but the configuration of the control circuit 5 is different.
A timer circuit 13 is added. When the discharge lamp current detection circuit 4 detects the discharge lamp current, the timer circuit 13 starts accumulating time. Since the time from the start to the rated discharge lamp voltage is roughly determined, the time constant of the timer circuit 13 is set to the time when the discharge lamp voltage reaches the predetermined value Va. When the time reaches the predetermined value Va, the switching circuit 10 switches from the off-time monitoring circuit 9 to the zero current detection circuit 14.

(Embodiment 6) FIG. 4 is an explanatory view of Embodiment 6 of the present invention. In the present embodiment, as shown in FIG. 4, by setting the duty width of the ON signal output from the driver circuit 11 to be narrow in the low lamp voltage region where damage due to multiple currents such as ramp slow leak can occur in the first embodiment. In addition, a circuit characteristic with a small lamp current in a low lamp voltage range is obtained.

(Embodiment 7) Similarly, in Embodiment 2,
Zero current detection circuit 14 switched at a predetermined value Va of the lamp voltage when the lamp is abnormal, including a lamp slow leak
By setting the ON width of the drive signal output from the driver circuit 11 to be smaller than usual by the control according to the above, the danger due to multiple currents at the time of ramp slow leak can be reliably eliminated as shown in FIG.

FIG. 15 shows, as a comparative example, a circuit characteristic by only the ON width control shown in FIG. 10 when the OFF time monitoring circuit 9 is not operated. In the present embodiment, the zero current detection circuit 14 and the off time monitoring circuit 9 are switched at a predetermined value Va in a low voltage region where a slow leak can occur, and the ON width of the drive signal is set to be small in the low voltage region. It is.

In the above embodiment, only a part of the discharge lamp lighting device has been mentioned, and the detailed circuit diagram has not been mentioned. However, when this is applied to an actual discharge lamp lighting device, for example, become.

Embodiment 8 FIGS. 16 to 18 show an example of a lighting device in which the present invention is embodied as a product. FIG.
Is a power input unit, FIG. 17 is a power factor improving unit, and FIG. 18 is a lighting circuit unit, and are connected at points J1 to J8.

In the power supply input section shown in FIG.
1, the fuse F from the AC power supply AC connected to TM2.
S, a thermal protector TP, a low resistance R0, and a filter circuit are connected to an AC input terminal of the rectifier circuit DB, and a DC output terminal of the rectifier circuit DB is connected to a capacitor C9. This capacitor C9 has a small capacity, and the actual smoothing operation is performed by a boosting chopper circuit of the power factor improving section at the subsequent stage. The filter circuit includes a surge voltage absorbing ZNR (a non-linear resistance of zinc oxide) and a coil L
5, L6 and capacitors Cx, Cy, C8, C81,
C82, the middle point of the series circuit of the capacitors C81 and C82 is connected to the terminal TM5 via the capacitor C83, and the terminal TM5 is connected to the ground (earth).

The power factor improving section shown in FIG.
1 and a boost chopper circuit including a switching element Q1 and a diode D1, and receives a full-wave rectified output of the rectifier circuit DB from a point J1, and boosts the smoothed voltage to an electrolytic capacitor C1 (FIG. 18) connected to a point J2. A DC voltage is obtained. The switching element Q1 of the boost chopper circuit is connected to a resistor R7 from the drive output of the boost chopper control circuit 15.
1 and R72, and the current is detected by a resistor R73. The current flowing through the inductor L1 is detected via a resistor R74 connected to the secondary winding. Further, the output voltage generated at the point J2 is equal to the resistances R8 and R9.
, And the input voltage at the point J1 is changed by the resistors R91 and R91.
92. The operating power supply Vcc1 of the boost chopper control circuit 15 is connected to the resistors R93 and R9 when the power is turned on.
4 from the point J1, but when the switching operation of the switching element Q1 starts, the inductor L1
Is rectified by the diodes D71 and D72,
The DC voltage obtained at the capacitor C71 via the resistor R70 is supplied via the diode D73. The DC voltage obtained by the capacitor C71 is converted into a constant voltage by a three-terminal type voltage regulator IC1, and becomes an operating power supply Vcc of the lighting circuit control circuit 16. The lighting circuit unit control circuit 16 performs zero current detection, overcurrent detection, and lamp voltage detection via points J3 to J5 from the lighting circuit unit shown in FIG. 18, and performs rectangular wave drive and step-down via points J6 to J8. Outputs chopper drive signal.

The lighting circuit section shown in FIG. 18 includes a step-down chopper circuit section 2 and a point J2 obtained on the electrolytic capacitor C1.
Is reduced to an arbitrary DC voltage by the action of the switching element Q2, the diode D2, and the inductor L2, and a lamp voltage is obtained in the capacitor C2. The lamp voltage obtained at the capacitor C2 is detected via the resistors R1 and R2 and the point J5. Also, the inductor L2
Is detected via the resistor R4 and the point J3, and the current flowing through the step-down chopper circuit 2 is
3. Detected via point J4. The switching element Q2 of the step-down chopper circuit unit 2 uses the drive signal supplied to the point J8 to switch the transformer T5 and the resistors R51 and R52.
Is driven through.

Next, the polarity inversion circuit section is a full bridge circuit composed of four switching elements Q3 to Q6. Each of the switching elements Q3 to Q6 is connected to resistors R11 and R12 by general-purpose driver circuits IC2 and IC3. R2
1, R22; R31, R32; and R41, R42. The signal for the square wave drive is point J6.
It is supplied via J7. In addition, each driver circuit I
As the operating power supply for C2 and IC3, the above-described constant voltage Vcc is used.
Is supplied. Further, capacitors C11 and C1 for driving the switching elements Q3 and Q4 on the high potential side are provided.
2; C31 and C32 are a resistor R13 and a diode D1
1, and charged from the constant voltage Vcc via D31. The discharge lamp LA is connected to the output of the full bridge circuit via the pulse transformer PT of the igniter circuit 17. The discharge lamp LA is, for example, M98 (70W) of ANSI standard.
Or M130 (35 W), and the arc tube is a ceramic arc tube. TM3 and TM4 are terminals for connecting the discharge lamp LA.

[0029]

According to the present invention, the peak value of the starting current can be reduced by operating the switching element so as to continuously switch the current flowing through the chopper inductor of the lighting circuit immediately after the starting of the discharge lamp. It can be suppressed and the starting current can be flowed reliably, so that it is difficult to turn off. Further, by switching to the discontinuous zero-cross switching operation until the rated discharge lamp voltage is reached, the circuit efficiency at the rated time can be maximized. In particular, if the predetermined value of the discharge lamp voltage for switching from the continuous switching operation to the discontinuous zero-crossing switching operation is set to the voltage in the case of the occurrence of the slow leak, the overcurrent at the time of the slow leak does not flow to the lighting device. It is safe.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a configuration of a main circuit according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of a control circuit according to the first embodiment of the present invention.

FIG. 3 is a waveform chart showing an operation of the zero current detection circuit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing circuit characteristics of a sixth or seventh embodiment of the present invention.

FIG. 5 is a circuit diagram illustrating a configuration of an off-time monitoring circuit according to the first embodiment of the present invention.

FIG. 6 is a waveform chart showing an operation of the off-time monitoring circuit according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a relationship between a threshold voltage and a discharge lamp voltage according to the first embodiment of the present invention.

FIG. 8 is a circuit diagram according to a third embodiment of the present invention.

FIG. 9 is a circuit diagram of a control circuit according to a third embodiment of the present invention.

FIG. 10 is an explanatory diagram illustrating control characteristics of an ON width according to a third embodiment of the present invention.

FIG. 11 is an explanatory diagram for explaining an operation of the inverting circuit according to the third embodiment of the present invention.

FIG. 12 is a circuit diagram of a fourth embodiment of the present invention.

FIG. 13 is a circuit diagram of a control circuit according to a fourth embodiment of the present invention.

FIG. 14 is a circuit diagram of a control circuit according to a fifth embodiment of the present invention.

FIG. 15 is an explanatory diagram showing circuit characteristics when the off-time monitoring circuit of the present invention is not operated.

FIG. 16 is a circuit diagram of a power input unit of a lighting device that embodies the present invention as a product.

FIG. 17 is a circuit diagram of a power factor improving unit of a lighting device that embodies the present invention as a product.

FIG. 18 is a circuit diagram of a lighting circuit unit of a lighting device that embodies the present invention as a product.

FIG. 19 is a circuit diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Step-up chopper circuit 2 Step-down chopper circuit 3 Polarity inversion circuit 5 Control circuit LA discharge lamp

Claims (14)

[Claims] 1. A lighting circuit including at least a switching element and an inductor, using a chopper circuit for converting an input DC power supply into a voltage and outputting the converted voltage, and for stably lighting and maintaining a discharge lamp, and detecting a current flowing through an inductor of the chopper circuit. Detecting means, a first control means for receiving the output of the detecting means and causing the switching element to perform a switching operation so that a current flowing through the inductor becomes discontinuous, and a current flowing through the inductor becoming continuous. Second control means for performing a switching operation of the switching element, wherein the switching element is controlled by the second control means immediately after the start of the discharge lamp, and then switched to the first control means until the tube power reaches a maximum. Discharge lamp lighting device characterized by the above-mentioned. 2. The discharge lamp lighting device according to claim 1, wherein the lighting circuit comprises a step-down chopper circuit, and performs direct current lighting of the discharge lamp. 3. The discharge lamp lighting device according to claim 1, wherein the lighting circuit includes a step-down chopper circuit and a polarity inverting circuit having a four-bridge full bridge configuration, and performs rectangular wave AC lighting of the discharge lamp. 4. The discharge lamp lighting device according to claim 1, wherein the lighting circuit comprises a four-stone full bridge circuit, and the discharge lamp is lit by rectangular wave AC. 5. The discharge lamp lighting device according to claim 1, wherein the lighting circuit comprises a two-bridge half-bridge circuit, and the discharge lamp is lit by a rectangular wave AC. 6. The apparatus according to claim 1, further comprising a tube voltage detecting means for detecting a voltage of the discharge lamp, and a means for detecting the tube voltage and switching from the second control means to the first control means. The discharge lamp lighting device according to any one of claims 1 to 5. 7. The apparatus according to claim 1, further comprising a tube current detecting means for detecting a current of the discharge lamp, and a means for detecting the tube current and switching from the second control means to the first control means. The discharge lamp lighting device according to any one of claims 1 to 5. 8. A means for switching the second control means to the first control means in a time period when the elapsed time reaches 30% to 50% of the rated tube voltage by measuring an elapsed time by a timer circuit after the discharge lamp is turned on. 2. The device according to claim 1, wherein
The discharge lamp lighting device according to any one of claims 1 to 5. 9. The discharge lamp lighting device according to claim 1, wherein a current flowing through the discharge lamp is maintained until the tube voltage of the discharge lamp reaches a predetermined value equal to or less than a rated value. A discharge lamp lighting device characterized in that at least the tube current at the time of steady lighting is reduced. 10. The discharge lamp lighting device according to claim 1, wherein when switching from the second control means to the first control means, control is performed so that the lamp current value does not decrease. A discharge lamp lighting device. 11. The discharge lamp lighting device according to claim 1, wherein the discharge lamp is a high-pressure discharge lamp. 12. The discharge lamp lighting device according to claim 11, wherein the high-pressure discharge lamp is a metal halide lamp. 13. The high pressure discharge lamp is M98 of ANSI standard.
The discharge lamp lighting device according to claim 11, wherein the discharge lamp lighting device is (70W) or M130 (35W). 14. The discharge lamp lighting device according to claim 11, wherein the arc tube of the high pressure discharge lamp is a ceramic arc tube.