JP4144526B2 - Discharge lamp lighting device, lighting device, projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve start-up characteristics in a direct-current lighting device of a high-pressure discharge lamp. <P>SOLUTION: This discharge lamp lighting device is constituted of a chopper circuit including a switching element Q1 to carry out switching intermittently on a DC power supply 1 at high frequency, an inductor L1, and a capacitor C1, a pair of switching elements Q2, Q3 connected to the DC power supply 1 in parallel, a series circuit of the inductor L2 and the capacitor C2 connected between a connecting point of the pair of switching elements Q2, Q3 and an output of the chopper circuit, and the discharge lamp 2 connected to the capacitor C2 in parallel. At start-up, it is controlled so that a first switching element Q1 is made in an interrupted state, and a second and a third switching elements Q2, Q3 are switched on alternately. At a steady state, it is so controlled that while one of the second and the third switching elements Q2, Q3 is made in an interrupted state, the other is made in a conducted state, and the first switching element Q1 is made to switch ON/OFF. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a technique for supplying an alternating current to a DC lighting high-pressure discharge lamp at the time of start-up and lighting the DC lamp by supplying a direct current in a steady state.

  FIG. 18 is a circuit diagram showing a general lighting device for a high pressure discharge lamp such as a metal halide lamp. The voltage supplied from the DC power source 1 is controlled by the down converter 7, and a DC voltage is applied to the discharge lamp 2 with a fixed pulse width at the start. At that time, a high voltage pulse is supplied by the igniter 8 to break down between the electrodes of the discharge lamp 2 and start discharging. After the discharge is started, the output current is detected by the current detection circuit 3, the output voltage is detected by the voltage detection circuit 4, the calculation is performed by the calculation circuit 5, and is fed back to the down converter 7 via the pulse width modulation circuit 6. The pulse width is controlled so that a constant power can be supplied after the discharge lamp 2 is stabilized.

  The starting voltage for breaking down the discharge lamp 2 is an output voltage of the down converter 7 and a high voltage pulse by the igniter 8. The output voltage of the down converter 7 is substantially the same as the DC power supply voltage. Requires a high-pressure pulse of several KV to several tens of KV by the igniter 8. The high-voltage pulse required at the time of starting causes a malfunction to the own circuit and the peripheral circuit, and starting with a low pulse is preferred.

In Patent Document 1 (Japanese Patent Laid-Open No. 10-144488), the output of a DC power supply is converted into a voltage by a step-down chopper circuit to charge a smoothing capacitor, and the polarity of the output of the smoothing capacitor is inverted by a full bridge inverter circuit. Although the configuration applied to the high-pressure discharge lamp is disclosed, the technique disclosed in Patent Document 1 turns on the switching element of the step-down chopper circuit at the timing when the current flowing through the inductor of the step-down chopper circuit becomes zero during steady lighting. This is intended to reduce the stress on circuit components, and is not a technique for improving the starting performance.
Japanese Patent Laid-Open No. 10-144488

  The present invention provides a high-pressure discharge lamp direct current lighting device that operates at an alternating current at the time of starting to improve the start-up performance of the low pulse and suppress the electrode deterioration of the discharge lamp. Is an issue.

  According to the present invention, in order to solve the above problem, as shown in FIG. 1, a DC power source 1, a first switching element Q1 having one end connected to one end of the DC power source 1, and a DC power source as one end. A first capacitor C1 connected to the other end of the first capacitor C1; a first inductor L1 connected between the other end of the first capacitor C1 and the other end of the first switching element Q1; A diode D1 connected between the other end and the other end of the first switching element Q1 so as to be opposite to the forward direction of the first switching element Q1 and a second connected between both ends of the DC power supply 1. And a second circuit L2 connected between the connection point of the second and third switching elements Q2, Q3 and the other end of the first capacitor C1, and the second switching circuit Q2, Q3. A series circuit of two capacitors C2 and The discharge lamp 2 connected in parallel to the second capacitor C2 and the second and third switching elements Q2 and Q3 are controlled to be alternately turned on at the start-up, and the second or third switching element Q2 is controlled at the steady state. , Q3, and a control means for controlling the first switching element Q1 to be turned on / off with the other (Q2) in the shut-off state and the other (Q3) in the conductive state.

According to the present invention, in a DC lighting device for a high-pressure discharge lamp, by performing a lighting operation with AC at the time of starting, it is possible to improve starting performance and to suppress electrode deterioration of the discharge lamp. Further, even when an igniter is used in combination, the energy of the start pulse can be reduced, so that the possibility of malfunction of the peripheral circuit is reduced, which is particularly suitable as a lighting device for an HID lamp such as a projector.
According to the second aspect of the present invention, since the second inductor has a transformer structure, it becomes easy to secure a high voltage necessary for starting the discharge lamp.
According to the invention of claim 3, at the time of starting, the resonance current can be reduced to reduce the stress of the circuit element, and after the lamp is lit, the ripple of the lamp voltage can be reduced to reduce the flicker of light. effective.

According to the sixth to tenth aspects of the present invention, since the frequency of the high-frequency switching operation at the time of starting is changed continuously or in multiple steps, even if there are variations in the constants of the inductor and the capacitor, sufficient starting There is an advantage that voltage can be secured.
According to the eighth aspect of the invention, there is an advantage that the inductor and the capacitor can be reduced in size by switching near the odd frequency of the resonance frequency of the inductor and the capacitor at the time of starting.
According to the invention of claim 11, since the transition from the glow discharge to the arc discharge can be smoothly performed, there is an effect that the disappearance at the start can be reduced.

(Embodiment 1)
FIG. 1 is a circuit diagram of Embodiment 1 of the present invention. One end of the first switching element Q1 is connected to the positive electrode of the DC power supply 1. The other end of the first switching element Q1 is connected to the cathode of the diode D1. The anode of the diode D1 is connected to the negative electrode of the DC power supply 1. One end of the capacitor C <b> 1 is connected to the negative electrode of the DC power source 1. One end of an inductor L1 is connected to a connection point between the switching element Q1 and the cathode of the diode D1. The other end of the inductor L1 is connected to one end of another inductor L2 and to the other end of the capacitor C1. The other end of the inductor L2 is connected to one end of the discharge lamp 2. A capacitor C2 is connected to the discharge lamp 2 in parallel. The other end of the discharge lamp 2 is connected to one end of each of the switching elements Q2, Q3. The other end of the switching element Q2 is connected to the positive electrode of the DC power source 1. The other end of the switching element Q3 is connected to the negative electrode of the DC power supply 1 through a current detection circuit 3 made of a small resistance R.

  FIG. 2 shows the operation of each switching element Q1, Q2, Q3 of the present embodiment. The switching elements Q2, Q3 are controlled by the output of the pulse generation circuit 9 so that they are alternately turned on when the discharge lamp 2 is started. At this time, the switching element Q1 is controlled to be in a cut-off state (OFF). The pair of switching elements Q2 and Q3 are alternately switched to convert the DC power source 1 into AC and apply it to the discharge lamp 2.

  On the other hand, at the time of steady lighting of the discharge lamp 2, the switching element Q2 is controlled to be in a cut-off state (OFF), and the switching element Q3 is controlled to be in a conductive state (ON). Further, the switching element Q1 is ON / OFF controlled by the output of the pulse width modulation circuit 6 so that the DC power supply 1 is intermittently switched at a high frequency with a predetermined pulse width when the discharge lamp 2 is steadily lit.

  The voltage across the capacitor C1 is detected by a voltage detection circuit 4 including resistors R1 and R2, and is input to the arithmetic circuit 5. The supply current from the capacitor C1 to the discharge lamp 2 is detected by the current detection circuit 3 including the small resistance R and is input to the arithmetic circuit 5. The arithmetic circuit 5 calculates lamp power based on the detection outputs of the voltage detection circuit 4 and the current detection circuit 3, and calculates an error voltage corresponding to the difference from the target power. The pulse width modulation circuit 6 feedback-controls the pulse width of the switching element Q1 so that the error voltage becomes zero.

  When the switching element Q1 is turned on during steady lighting of the discharge lamp 2, a current flows from the positive electrode of the DC power supply 1 through the switching element Q1, the inductor L1, the capacitor C1, and the negative electrode of the DC power supply 1, and the capacitor C1 is turned on. Charged. When the switching element Q1 is turned off, the regenerative current flows through the path from the inductor L1 to the inductor L1 via the capacitor C1 and the anode and cathode of the diode D1 due to the energy stored in the inductor L1.

  Further, since the switching element Q3 is turned on, the discharge lamp 2 is connected to both ends of the capacitor C1 via a low-pass filter composed of a series circuit of the inductor L2 and the capacitor C2, and becomes a load on the capacitor C1. ing. Therefore, by making the ON width of the switching element Q1 variable, the charging voltage of the capacitor C1 can be made variable, and the power supplied to the discharge lamp 2 can be controlled. That is, the switching element Q1, the inductor L1, the diode D1, and the capacitor C1 constitute a step-down chopper circuit (down converter). Each switching element Q1, Q2, Q3 uses a switching element with a built-in body diode. For example, since the power MOSFET has a reverse diode built in between the drain and source, it is used as the switching elements Q1, Q2, and Q3. In addition, bipolar transistors having diodes connected in antiparallel may be used as the switching elements Q1, Q2, and Q3.

(Embodiment 2)
FIG. 3 is a circuit diagram of the second embodiment of the present invention. The basic circuit configuration is the same as in FIG. 1, but the circuit in FIG. 3 includes an inductor L2 ′ in which the inductor L2 in FIG. 1 has a transformer structure, and connects one end of the primary side and the secondary side of the transformer. A series circuit of the primary side of the transformer and the capacitor C2 is connected between a connection point of the switching elements Q2 and Q3 and the other end of the capacitor C1, and a series circuit of the secondary side of the transformer and the discharge lamp 2 is connected to the capacitor. It is connected in parallel with C2. The configuration and operation other than the inductor L2 ′ are the same as those in FIG.

  In the present embodiment, by including the inductor L2 ′ having a transformer structure, the resonant voltage generated by the resonance between the primary side of the inductor L2 ′ and the capacitor C2 is applied to the secondary side of the inductor L2 ′ according to the turns ratio. It is easy to secure the starting voltage to be applied to the discharge lamp 2.

  1 or 3, the switching element Q1 is turned on / off by the output of the pulse width modulation circuit 6 so that the DC power supply 1 is intermittently switched at a high frequency with a predetermined pulse width even at the start. Control may be performed. Each switching element Q1, Q2, Q3 uses a switching element with a built-in body diode. For example, since the power MOSFET has a reverse diode built in between the drain and source, it is used as the switching elements Q1, Q2, and Q3. In addition, bipolar transistors having diodes connected in antiparallel may be used as the switching elements Q1, Q2, and Q3.

(Embodiment 3)
FIG. 4 shows the operation of each switching element Q1, Q2, Q3 according to the third embodiment of the present invention. The circuit diagram is the same as in the first embodiment (FIG. 1) or the second embodiment (FIG. 3). Further, since the operation at the time of start is the same as that of the first embodiment (FIG. 2), description thereof is omitted. In the present embodiment, the switching element Q3, which is always in the conductive state in the first embodiment (FIG. 2) at the time of steady state, is turned on / off in synchronization with the switching element Q1. Each switching element Q1, Q2, Q3 uses a switching element with a built-in body diode. For example, since the power MOSFET has a reverse diode built in between the drain and source, it is used as the switching elements Q1, Q2, and Q3. In addition, bipolar transistors having diodes connected in antiparallel may be used as the switching elements Q1, Q2, and Q3. By connecting reverse diodes in parallel to the switching elements Q1, Q2, Q3, the regenerative current of the inductors L1, L2 can flow even when the switching elements Q1, Q3 are simultaneously turned off.

(Embodiment 4)
FIG. 5 shows operations of the switching elements Q1, Q2, and Q3 according to the fourth embodiment of the present invention. The circuit diagram is the same as in the first embodiment (FIG. 1) or the second embodiment (FIG. 3). In addition, the steady-state operation is the same as that of the first embodiment (FIG. 2), and thus the description thereof is omitted. In the present embodiment, as a start-up operation, switching is performed so that the switching elements Q2 and Q3 are alternately turned on at a high frequency of approximately the resonance frequency determined by the inductor L2 and the capacitor C2, and a resonance voltage is applied to the discharge lamp 2. The starting voltage of the discharge lamp 2 is ensured.

  As an example, the starting voltage of the discharge lamp 2 can be secured by setting the inductor L2 to 600 μH, the capacitor C2 to 3300 pF, and operating the switching elements Q2 and Q3 at a substantially resonant frequency of 115 KHz determined by the inductor L2 and the capacitor C2.

  Thereafter, after the discharge lamp 2 is turned on, the switching element Q2 is turned off (OFF), the switching element Q3 is turned on (ON), and the switching element Q1 is intermittently switched at a high frequency, and the switching element Q1, diode D1 , Inductor L1 and capacitor C1 are operated only, the DC power is supplied, and the discharge lamp 2 is turned on.

  At this time, the resonance current at the time of resonance can be suppressed by setting the capacitance of the capacitor C2 to be smaller than the capacitance of the capacitor C1. Further, the ripple current of the discharge lamp 2 that is dc-lighted can be reduced due to the large capacity of the capacitor C1 during the chopper operation.

(Embodiment 5)
In the present embodiment, the high-frequency switching frequency in the start-up operation of the above-described fourth embodiment is set to about one-third of the resonance frequency determined by the inductor L2 and the capacitor C2, and is described in the fourth embodiment. Therefore, a starting voltage applied to the discharge lamp 2 can be secured.

  For example, the inductor L2 is set to 100 μH and the capacitor C2 is set to 2200 pF as an example, and the switching elements Q2 and Q3 are switched at 115 KHz, which is approximately one third of the resonance frequency determined by the inductor L2 and the capacitor C2. The starting voltage substantially the same as the example given in Form 4 can be obtained. Further, the inductor L2 and the capacitor C2 can be reduced in size. If the switching frequency is approximately an odd number of a resonance frequency determined by the inductor L2 and the capacitor C2, substantially the same effect can be obtained even at 1/5 and 1/7.

(Embodiment 6)
FIG. 6 is a waveform diagram showing a switching operation of each switching element Q1, Q2, Q3 in Embodiment 6 of the present invention, and FIG. 7 is a waveform diagram showing a resonance voltage generated at that time. The circuit configuration of this embodiment is the same as that shown in FIG.

  In the present embodiment, the high-frequency switching frequency in the above-described fourth and fifth embodiments is swept at a frequency that passes through a resonance frequency (or an odd fraction of the resonance frequency) determined by the inductor L2 and the capacitor C2. Thus, it is possible to stably obtain a resonance voltage substantially the same as the resonance voltage described in the fourth and fifth embodiments without being affected by variations in the resonance frequency due to variations in the inductor L2 and the capacitor C2. It is possible to secure a starting voltage applied to the.

  As an example, with respect to the example of the resonant frequency of 115 KHz given in the fourth embodiment, the switching frequency is swept through the switching elements Q2 and Q3 at 50 KHz to 160 KHz passing through the resonant frequency. As a result, the resonance voltage changes as shown in FIG. 7, so that the discharge lamp 2 can be started regardless of variations between the inductor L2 and the capacitor C2.

(Embodiment 7)
FIG. 8 is a waveform diagram showing the switching operation of each switching element Q1, Q2, Q3 in the seventh embodiment of the present invention. The circuit configuration of this embodiment is the same as that shown in FIG.

  In the present embodiment, the operating frequency of switching elements Q2 and Q3 is changed stepwise in the high-frequency operating section at the start. When the first frequency is f1, the second frequency is f2, and the third frequency is f3, f1> f2> f3 and the respective frequencies are resonant frequencies determined by the inductor L2 and the capacitor C2, or The resonance frequency is set to approximately an odd number, and when the discharge lamp 2 is not broken down, a voltage required for starting is secured, and when it is broken down, the frequency is switched step by step. The current flowing through the discharge lamp 2 is increased to shift from glow discharge to arc discharge.

  If the discharge lamp 2 is to be broken down at the first frequency f1, the frequency after the second frequency f2 may be a resonance frequency determined by the inductor L2 and the capacitor C2 or a frequency other than a substantially odd number of the resonance frequency.

(Embodiment 8)
FIG. 9 is a waveform diagram showing the switching operation of each switching element Q1, Q2, Q3 and the resonance voltage at the start in the eighth embodiment of the present invention. The circuit configuration of this embodiment is the same as that shown in FIG. The present embodiment is characterized in that the operation of sweeping the frequency in the sixth and seventh embodiments continuously or in multiple stages is repeatedly performed. Thereby, the resonance voltage in the sixth and seventh embodiments can be repeated, and the starting voltage applied to the discharge lamp 2 can be ensured. As an example, if one cycle of variable frequency is about 400 μsec and the start voltage generation interval is 1 sec, about 2,500 cycles can be repeated, and a stable high start voltage is applied to the discharge lamp 2 to cause a break. Can be taken down.

  FIG. 10 is a waveform diagram showing the switching operation of one cycle of switching elements Q1, Q2, Q3 with variable frequency according to the present embodiment. The operating frequencies of the switching elements Q2 and Q3 are changed so that fa> fb, where fa is the initial frequency of one variable frequency cycle and fb is the final frequency. More preferably, the frequencies fa and fb are set so that a resonance frequency determined by the inductor L2 and the capacitor C2 or a frequency that is substantially an odd number of the resonance frequency passes during the frequency sweep.

  FIG. 11 shows an example of the current flowing through the discharge lamp and the applied resonance voltage when the discharge lamp is not lit (no load). FIG. 12 shows an example of the current flowing through the discharge lamp and the applied resonance voltage when the discharge lamp breaks down during the application of the starting voltage.

(Embodiment 9)
FIG. 13 is a diagram showing operations from the start time to the steady time in Embodiment 9 of the present invention. A section Tb for shifting the lamp from glow discharge to arc discharge is provided after a section Ta in which a voltage required for starting is generated by resonance of the second inductor L2 and the second capacitor C2. Further, the frequency of the section Tb for shifting from the glow discharge to the arc discharge is set lower than the frequency of the section Ta. As an example, a section Ta for generating a voltage necessary for starting is set to 115 KHz for 1 second, and a section Tb for shifting from glow discharge to arc discharge is set to 52 KHz for 0.5 second. This time is set with the time and frequency while observing the time required for the discharge lamp to break down and the state until the discharge lamp can stably shift from glow discharge to arc discharge.

  FIG. 14 shows an example of a current flowing through the discharge lamp and an applied resonance voltage when the discharge lamp is not lit. FIG. 15 shows an example of the current flowing through the discharge lamp and the applied resonance voltage when the discharge lamp breaks down during the application of the starting voltage.

(Embodiment 10)
FIG. 16 is a circuit diagram of the tenth embodiment of the present invention. The basic circuit configuration is the same as that of FIG. 1, but the circuit of FIG. 16 further includes an igniter 8. The configuration and operation other than the igniter 8 are the same as those in FIG. In each of the above embodiments, the discharge lamp 2 is turned on using the power source voltage and the resonance voltage of the DC power source 1 as applied voltages. However, in this embodiment, the igniter 8 is further provided to reduce the pulse. Start is possible.

  At the start-up operation, the switching elements Q2 and Q3 are alternately turned on and off at a high frequency of a substantially resonant frequency determined by the inductor L2 and the capacitor C2, and a resonance voltage is generated at both ends of the capacitor C2. The igniter 8 is operated, and a starting pulse that generates an electric field from the anode to the cathode at the time of starting is applied to the discharge lamp 2 from the pulse transformer PT of the igniter 8.

  The configuration of the igniter 8 is not limited to the illustrated configuration, but here the capacitor C3 is charged via the diode D3 with the peak value of the high frequency voltage obtained in the resonance capacitor C2 during the starting operation. The charge stored in the capacitor C3 is supplied to the primary winding of the pulse transformer PT through the discharge gap G. When the charge voltage of the capacitor C3 exceeds the breakdown voltage of the discharge gap G, the charge of the capacitor C3 is discharged through the discharge gap G, and a pulsed current flows through the primary winding of the pulse transformer PT. Thereby, a high voltage pulse boosted according to the turn ratio is generated in the secondary winding of the pulse transformer PT. By applying this high voltage pulse to both ends of the discharge lamp 2 via the capacitor C2, the discharge lamp 2 breaks down and discharge is started.

  Both the resonant voltage and the voltage generated by the igniter 8 are applied to the discharge lamp 2, and the discharge lamp 2 can be broken down with a lower pulse voltage than when only a high voltage pulse is applied.

  Since the capacitor C3 of the igniter 8 is charged by the resonance voltage, the start pulse generated by the igniter 8 is generated only at the time of high-frequency operation at the start, and the pulse of the igniter 8 is generated at the time of steady DC lighting operation. Operation stops automatically.

  FIGS. 17A to 17C are diagrams showing arrangement examples of the pulse transformer PT of the igniter 8 according to the present embodiment. The other configuration is the same as that of FIG. Arrangement of the igniter 8 when applying a start pulse for generating an electric field from the cathode to the anode at the start to the discharge lamp 2 and applying a start pulse for generating an electric field from both the anode and the cathode at the start An example is shown. In these configurations, the same effects as those of the embodiment of FIG. 16 can be obtained.

  In this way, a configuration including an igniter that applies a start pulse for generating an electric field from the anode to the cathode at the start time to the discharge lamp, and a start pulse for generating an electric field from the cathode to the anode at the start time is applied to the discharge lamp. Either a configuration including an igniter or a configuration including an igniter that applies a start pulse for generating an electric field from both the anode and cathode directions to the discharge lamp at the time of start may be employed.

  In each of the above embodiments, the discharge lamp lighting device may be used for a purpose of lighting a discharge lamp that is a light source of the lighting device built in the lighting device, or a metal halide lamp as a light source for a projector, etc. It may be used as a lighting device for a high pressure discharge lamp. In particular, in a liquid crystal projector or the like, since a large number of precise electronic circuits are arranged around the lighting device, the reliability can be improved by reducing the influence of the high voltage pulse by the igniter.

It is a circuit diagram of Embodiment 1 of the present invention. It is a wave form diagram which shows operation | movement of each switching element of Embodiment 1 of this invention. It is a circuit diagram of Embodiment 2 of the present invention. It is a wave form diagram which shows operation | movement of each switching element of Embodiment 3 of this invention. It is a wave form diagram which shows operation | movement of each switching element of Embodiment 4 of this invention. It is a wave form diagram which shows operation | movement of each switching element of Embodiment 6 of this invention. It is a wave form diagram which shows the resonant voltage which generate | occur | produces at the time of the starting of the lighting device of Embodiment 6 of this invention. It is a wave form diagram which shows operation | movement of each switching element of Embodiment 7 of this invention. It is a wave form diagram which shows the operation | movement and resonance voltage of each switching element of Embodiment 8 of this invention. It is a wave form diagram which shows the operation | movement for 1 cycle of each switching element of Embodiment 8 of this invention. It is a wave form diagram which shows the resonant voltage applied to the discharge lamp at the time of no load of Embodiment 8 of this invention, and the electric current which flows into a discharge lamp. It is a wave form diagram which shows the resonance voltage applied to the discharge lamp from the time of starting to the state immediately after steady lighting, and the electric current which flows into a discharge lamp when a discharge lamp breaks down in the middle from the time of no load of Embodiment 8 of this invention. . It is a wave form diagram which shows operation | movement of each switching element of Embodiment 9 of this invention. It is a wave form diagram which shows the resonance voltage applied to the discharge lamp at the time of no load of Embodiment 9 of this invention, and the electric current which flows into a discharge lamp. It is a wave form diagram which shows the resonance voltage applied to the discharge lamp from the time of starting to the state immediately after steady lighting, and the electric current which flows into a discharge lamp when a discharge lamp breaks down on the way from the time of no load of Embodiment 9 of this invention. . It is a circuit diagram of Embodiment 10 of the present invention. It is a circuit diagram which shows the example of arrangement | positioning of the pulse transformer of Embodiment 10 of this invention. It is a circuit diagram of a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC power supply 2 Discharge lamp 3 Current detection circuit 4 Voltage detection circuit 5 Arithmetic circuit 6 Pulse width modulation circuit 9 Pulse generation circuit

Claims (14)

DC power supply, a first switching element having one end connected to one end of the DC power supply, a first capacitor having one end connected to the other end of the DC power supply, the other end of the first capacitor and the first switching A first inductor connected between the other ends of the element, and a connection between the other end of the DC power source and the other end of the first switching element so as to be opposite to the forward direction of the first switching element. A diode, a series circuit of second and third switching elements connected between both ends of the DC power supply, and a connection point between the connection point of the second and third switching elements and the other end of the first capacitor. A series circuit of the second inductor and the second capacitor, a discharge lamp connected in parallel to the second capacitor, and the second and third switching elements at the time of start-up are controlled to be turned on alternately. Sometimes the second or third While the cut-off state of the switching element, a discharge lamp lighting apparatus, characterized in that it comprises a control means for controlling to turn on / off the first switching element and the other conductive. 2. The transformer according to claim 1, wherein the second inductor has a transformer structure, the primary side of the transformer and one end of the secondary side are connected, and the secondary side of the transformer and the series circuit of the discharge lamp are connected in parallel with the second capacitor. A discharge lamp lighting device comprising a series circuit of a primary side of a transformer and a second capacitor connected between a connection point of the second and third switching elements and the other end of the first capacitor. 3. The discharge lamp lighting device according to claim 1, wherein the second capacitor has a smaller capacity than the first capacitor. 4. The method according to claim 1, wherein the first switching element that is turned on / off in a steady state and the switching element that is in a conductive state among the second and third switching elements are turned on / off in synchronization. A discharge lamp lighting device characterized by The discharge lamp lighting device according to any one of claims 1 to 4, wherein high-frequency alternating current lighting is performed at start-up, and direct-current lighting is performed during normal operation. 6. The discharge lamp lighting device according to claim 5, wherein the frequency of the high-frequency switching operation at the time of starting is changed continuously or in multiple stages. 7. The discharge lamp according to claim 5, wherein the second and third switching elements are switched in the vicinity of the resonance frequency of the second inductor and the second capacitor at the start, and the resonance of the second inductor and the second capacitor causes the discharge lamp to resonate. A discharge lamp lighting device that generates a starting voltage. 7. The method according to claim 5, wherein the second and third switching elements are switched in the vicinity of an odd-numbered frequency of the resonance frequency of the second inductor and the second capacitor at the time of start-up. A discharge lamp lighting device that generates a starting voltage of a discharge lamp by frequency division resonance of a capacitor. 9. The frequency according to any one of claims 6 to 8, wherein the frequency to be changed is continuously or multistagely changed from the first frequency to the second frequency, and the variable frequency is defined as one cycle, and the frequency variable cycle is repeated. The discharge lamp lighting device characterized by performing. The discharge lamp lighting device according to claim 9, wherein the first frequency is higher than the second frequency. 11. The method for transferring a lamp from glow discharge to arc discharge after a first period in which a voltage required for starting is generated by resonance of a second inductor and a second capacitor. A discharge lamp lighting device comprising a second section. 12. The discharge lamp lighting device according to claim 11, wherein the frequency of the second section is set lower than the frequency of the first section. An illumination device comprising: a high-pressure discharge lamp that is turned on by the discharge lamp lighting device according to claim 1 as a light source. A projector comprising: a high-pressure discharge lamp that is turned on by the discharge lamp lighting device according to claim 1 as a light source.

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