JPH02291698A - Lighting device for discharge lamp and method of lighting it - Google Patents

Abstract

PURPOSE:To start lighting without causing any damage to the switching element of a lighting circuit due to high voltage by starting a discharge lamp with pulse voltage applied to the discharge lamp to cause glow discharge prior to output of the lighting circuit. CONSTITUTION:A discharge lamp 15 is connected to one end of a lighting circuit. A starting circuit 24 is connected in parallel to the discharge lamp 15 and in a direction opposite to the lighting circuit. The starting circuit consists of a resistance 28, a condenser 29, a pulse transformer 23, and a semiconductor switch 30. A series circuit formed by the resistance 28 and the condenser 29 is connected to a DC power supply 25 via a transistor 26 and a resistance 27 connected to each other in series. With voltage applied to the transistor 26, the starting circuit 24 is connected to the power source 25 and it starts its operation, causing a high-potential pulse to be applied to the discharge lamp 15. This in turn causes the discharge lamp 15 to start glow discharge and retain it. After glow discharge is started, the lighting circuit starts its operation with the lapse of a specified time, to proceed to arc discharge. Then, with the lapse of a specified time, the starting circuit 24 stops its operation.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a discharge lamp lighting device and a lighting method thereof.

(Prior art) Conventionally, as a discharge lamp lighting device, for example, Japanese Patent Application Laid-Open No. 63-1
The one found in Japanese Patent No. 50892 is known. As shown in FIG. 14, four transistors Q1, Q2 . Q3. An inverter circuit IN provided with Q4 is connected to form a lighting circuit, and a discharge lamp LM is connected to an output terminal of the lighting circuit via a choke coil L and a secondary winding N2 of a pulse transformer PT. The primary winding N1 of the pulse transformer PT includes a thyristor Sl, a constant voltage conduction element S2, and a capacitor C,,C.
2, C4, and a starting circuit constituted by resistors R, , R2, and a pulse voltage is supplied from this starting circuit.

In this device, when the power supply V is turned on, the inverter circuit IN starts oscillating operation, and the starting circuit is operated by the output of the inverter circuit IN. That is, the constant voltage conduction cable S2 turns on and off, and thereby the thyristor S1 turns on and off. And the secondary winding N2 of the pulse transformer PT
A high voltage pulse is generated and applied across the discharge lamp LM. The discharge lamp LM is started and lit by this high-voltage pulse, and thereafter is lit by the output of the inverter circuit IN. In addition, by connecting a capacitor C shown by a dotted line in the figure, the discharge lamp L M l. : ljl-The supplied voltage has a waveform in which a high frequency is superimposed on a low frequency.

When the discharge lamp LM is turned on, the voltage across the discharge lamp LM decreases, so that the operation of the starting circuit is stopped.

(Problem to be Solved by the Invention) However, in the case where the secondary winding N2 of the pulse transformer PT is inserted between the output terminal of the lighting circuit and the discharge lamp LM, one of the secondary windings N2 Since one is directly connected to the discharge lamp LM and the other is connected to the discharge lamp LM via the lighting circuit, the high voltage pulse generated in the secondary winding N2 is reduced by the lighting circuit, so the pulse voltage of the high voltage pulse is required. It needed to be higher than that.

Furthermore, there was a risk that the high voltage pulses and pulse current generated in the secondary winding N2 would enter the lighting circuit and destroy switching elements such as transistors.

In particular, when the discharge lamp LM is lit with a high frequency or a lighting waveform in which a high frequency is superimposed, there is a problem that the inductance value of the secondary winding N2 becomes very large, making it impossible to supply appropriate power to the discharge lamp. For this reason, it is possible to reduce the inductance value, but if this is done, a sufficient high-voltage pulse cannot be obtained at the time of starting, making it impossible to start and light the lamp.

Therefore, the present invention provides a discharge lamp that can supply a discharge lamp without reducing the pulse voltage, and also prevents the supply of high-voltage pulses and pulse current to the lighting circuit at startup, thereby preventing damage to the switching elements of the lighting circuit. The aim is to introduce lighting devices and lighting methods.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a discharge lamp connected to an output terminal of a lighting circuit;
This discharge lamp is provided with a secondary winding of a pulse transformer that is connected in parallel on the side opposite to the lighting circuit and supplies a pulse voltage to the discharge lamp prior to output from the lighting circuit.

Another object of the present invention is to first maintain a glow discharge in the discharge lamp by supplying power from a pulse transformer, and then to switch from glow discharge to arc discharge by supplying power from a lighting circuit for lighting.

Further, the present invention provides a discharge lamp connected to an output terminal of a lighting circuit, an impedance element on the opposite side of the discharge lamp from the lighting circuit, and a pulse voltage supplied to the discharge lamp prior to output from the power source and the lighting circuit. A series circuit consisting of a pulse 1 and a secondary winding of a lance is provided, and the discharge lamp is connected to a power source through an impedance element and a secondary winding of a pulse transformer in series.

Furthermore, the present invention is to maintain DC discharge of an arc by first supplying power to the discharge lamp from a pulse transformer, and then supplying necessary power from a lighting circuit.

(Function) In the present invention having such a configuration, first, the pulse voltage from the secondary winding of the pulse transformer is supplied to the discharge lamp to start and light the discharge lamp and maintain the glow discharge of the discharge lamp. Thereafter, the output from the lighting circuit is supplied to the discharge lamp to cause the discharge lamp to shift from glow discharge to arc discharge, thereby lighting the discharge lamp.

Further, in the present invention, first, a pulse voltage of 1J1 from the secondary winding of the pulse transformer is supplied to the discharge lamp to maintain DC discharge of an arc in the discharge lamp. Thereafter, necessary power is supplied from the lighting circuit to maintain the lighting state of the discharge lamp.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a lighting circuit is configured by connecting an inverter circuit 12 for high frequency output to a first DC power supply 11,
A capacitor 13 and a choke coil 1 are connected to the output terminal of the lighting circuit, that is, the output terminal of the inverter circuit 12.
A discharge lamp, for example, a high-pressure discharge lamp 15, is connected through 4 in series.

The inverter circuit 'J' 612 includes two MOS type transistors 16.17 and each transistor 16.1.
7, and a transistor 19 that controls the operation of this drive circuit 18.

Note that the transistor 19 is connected to the drive circuit 18 via a power source 20. This tiger? The register 19 controls ON/OFF of the drive circuit 18, that is, the operation and non-operation of the inverter circuit 11 (lighting circuit). Furthermore, diodes 21.22 are connected in parallel to each of the transistors 16.17.

A starting circuit 24 in which a secondary winding 232 of a pulse transformer 23 is connected in parallel is connected to the discharge lamp 15 on the side opposite to the lighting circuit side.

The starting circuit 24 includes a series circuit including a resistor 28 and two capacitors, and the primary S line 231 of the pulse transformer 23 is connected in parallel to the two capacitors via a semiconductor switch 30. The secondary winding 2 of the pulse transformer 23 is connected to the series circuit of the resistor 28 and capacitor 29.
3■ are connected in parallel.

A series circuit of a resistor 28 and a capacitor 29 of the starting circuit 24 is connected to a second DC power supply 25 via a transistor 26 and a resistor 27 in series.

Incidentally, are the first power supply 11 and the second power supply 25 common? There may be.

A force pressure is applied between the base and the emitter of one of the transistors between c and c' at the timing shown in FIG. 2(a). ? l:! B is connected between the base and emitter of the L-transistor 26 at the timing shown in FIG. 2(b).
, b' is applied.

In this embodiment having such a configuration, first, at 1o, a voltage between b and b' is applied between the base and emitter of the transistor 26, and the transistor 26 is turned on. The starting circuit 24 is then connected to the second DC power supply 25 via the resistor 27 and starts operating. When the starting circuit 24 operates, a pulse current periodically flows through the primary winding 23+ of the pulse transformer 23, and a high voltage pulse is generated in the secondary winding 23■. This high voltage pulse is applied across the discharge lamp 15, and the discharge lamp 15 is started and lit. Then, the discharge lamp 15 starts to emit glow and is maintained.

After that, at t1, a voltage between C and c' is applied between the base and emitter of one transistor, and that t? Injista 1
9 turns on. The drive circuit 18 then starts operating, the transistors 16 and 17 alternately switch, and high-frequency power is supplied to the discharge lamp 15 from the inverter circuit 12 via the capacitor 13 and the choke coil 14.

In this way, the discharge lamp 15 shifts from glow discharge to arc discharge and comes into steady lighting operation. Then, at timing t2, the transistor 26 is turned off and the operation of the starting circuit 24 is stopped.

In this way, the starting circuit 24 is first operated to cause the discharge lamp 15 to glow discharge and maintain it for a certain period of time, and then the lighting circuit is operated to cause the discharge lamp 15 to transition from glow discharge to arc discharge. The switching loss of the transistors 16 and 17 of the circuit does not become large, and the transistors 16 and 17 can be operated in a safe region.

Also, at the time of starting, the secondary winding 23 of the pulse transformer 23
The high voltage pulse generated in (2) is reduced by the discharge lamp 15, so even if the lighting circuit is in operation? There is no risk of damaging the transistors 16 and 17 even if the transistors 16 and 17 are penetrated.

In addition, the secondary winding 232 of the pulse transformer 23 has a high impedance to the high frequency output from the lighting circuit, so there is no risk of power loss in the secondary winding 23, and the discharge lamp 15 is lit with proper power. It will be operated.

Further, in this embodiment, the operation timing of the lighting circuit is determined by the ON/OFF operation of the transistor 19, but the power supply 11
The same effect can be obtained even if the operation timing of the lighting circuit is determined by turning the lighting circuit itself ON/OFF.

Next, other embodiments of the present invention will be described with reference to the drawings. Note that the same parts as in the previous embodiment are given the same reference numerals and detailed explanations will be omitted.

What is shown in Fig. 3 is a choke coil 14 and an hk lamp 1.
5 is connected in series with another choke coil 31 having a relatively large inductance.
The normally open contact 32m of the first relay 32 is connected in parallel to
That first relay 32? The first relay drive circuit 33 turns on and off at the timing shown in FIG. 4(a).

Further, the starting circuit 24 is connected to the second DC power supply 25 through the normally open contact 34m of the second relay 34 and the resistor 27 in series, and the second relay 34 is connected by the second relay drive circuit 35. The on/off operation is performed at the timing shown in FIG. 4(b).

Further, the timing circuit of the lighting circuit, such as the control transistor 19 of the drive circuit 18 connected to the power source 20, is eliminated.

In this circuit, first t. At this timing, the second relay 34 is turned on by the second relay drive circuit 35, and its normally open contact 34[n is closed.

Therefore, the starting circuit 24 operates first and the pulse transformer 2
The discharge lamp 1 is activated by high voltage pulses from the secondary winding 23■ of 3.
5 is started and lit, and the discharge lamp 15 glow discharges.

Also, the lighting circuit is activated, but what about the output of that lighting circuit? There are two choke coils 14.31 between the terminal and the discharge lamp 15.
are interposed in series, the combined impedance of the coil 14.31 with respect to the high frequency output from the lighting circuit is large, and therefore the high frequency power supplied to the discharge lamp 15 is small, and at this point the discharge lamp 15 shifts to arc discharge. Never.

Thereafter, at timing t1, the first relay 32 is operated by the first relay drive circuit 33, and its normally open contact 32m
When the choke coil 31 is closed, the choke coil 31 is short-circuited.
Appropriate high frequency power is supplied to the discharge lamp 15, and the discharge lamp 15
The lamp shifts from glow discharge to arc discharge and becomes a steady lighting operation.

Then, at timing t2, the second relay 34 is turned off and the operation of the starting circuit 24 is stopped.

Therefore, in this embodiment, the discharge moon 15 can be maintained in glow discharge for a certain period of time and then can be shifted to arc discharge. Further, the high voltage pulse generated in the secondary winding 23.2 of the pulse transformer 23 is also reduced by the discharge lamp 15 and also by the choke coil 31.14.

Therefore, in this embodiment as well, the effect of the same measures as in the previous embodiment is enhanced.

Note that in this embodiment, the drive circuit 18 connected to the power supply 20
Although the timing circuit of the lighting circuit such as the control transistor 19 is omitted, this circuit may be included. By providing this circuit, the operation timing of the lighting circuit can be made similar to that of the embodiment shown in FIG.

The one shown in FIG. 5 has two terminals in which the anode and cathode of a diode bridge circuit 41 are connected to both ends of the choke coil 31, instead of the first relay 32 and first relay drive circuit 33 shown in FIG. The collector and emitter of the transistor 42 are connected between the terminal where the cathodes of the diode bridge circuit 41 are connected and the terminal where the anodes are connected. An amplifier 43 is connected between the base and emitter of the transistor 42.
The amplifier 43 is driven and controlled by a timer 45 connected to a third DC power supply 44.

Further, the base and emitter of the transistor 26 are connected to the collector and emitter of a phototransistor 46a of a photocoupler 46. The light emitting diode 46b of the photocoupler 46 is connected to the output terminal of an amplifier 47, and the amplifier 47 is driven and controlled by a timer 49 connected to a fourth DC power source 48.

The voltage between a and a' is applied from the amplifier 43 between the base and emitter of the transistor 42 at the timing shown in (;1) in FIG.
7 through the photocoupler 46 between the base and emitter of the transistor 26.
This is done at the timing shown in (b) of the figure.

In this embodiment, the amplifier 47 is first driven by the timer 49 at timing to, and the transistor 2
6 is turned on and the starting circuit 24 is driven. As a result, a high voltage pulse is generated from the secondary winding 232 of the pulse transformer 23, and the discharge lamp 15 is started and lit, causing the discharge lamp 15 to glow discharge. At this time, the lighting circuit is also operated, but since two choke coils 14 and 31 are interposed in series between the output terminal of the lighting circuit and the discharge lamp 15, the coil 14 is connected to the high frequency output from the lighting circuit. The combined impedance of .31 is large, so the high frequency power supplied to the discharge lamp 15 is small, and the discharge lamp 15 does not shift to arc discharge at this point.

Thereafter, at timing t1, the amplifier 43 is driven by the timer 45 and the transistor 42 is turned on. As a result, the choke coil 31 is short-circuited via the diode bridge circuit 41, and appropriate high-frequency power is supplied to the discharge lamp 15 from the lighting circuit, so that the discharge lamp 15 shifts from glow discharge to arc discharge and performs steady lighting operation.

Therefore, in this embodiment, the same effects as in the previous embodiment can be obtained.

In each of the embodiments shown in FIGS. 1, 3, and 5, the starting circuit includes a pulse transformer 23 having one primary winding and one secondary winding, a resistor 28, a capacitor 29, and a semiconductor switch 30. Consists of? However, the present invention is not limited thereto, and a starting circuit 71 shown in FIG. 7 may also be used.

This starting circuit 71 has two primary windings 7 2 1 1+
721■ and one secondary winding 72. A pulse transformer 72 is provided, and one end of the primary winding 72z of the pulse transformer 72 is connected to the connection point of the resistor 73 and the capacitor 74 in a series circuit of the resistor 73 and the capacitor 74, and the other end is It is connected to the anode of a unidirectional three-terminal thyristor 75. Further, one end of the other primary winding 721■ of the pulse transformer 72 is connected to a resistor 76, a capacitor 77 and a resistor 7.
It is connected to a connection point between a resistor 76 and a capacitor 77 in a series circuit of No. 8, and the other end is connected to one end of a semiconductor switch 79. Further, the gate of the thyristor 75 is connected to the connection point between the capacitor 77 and the resistor 78. Then, one end of each of the secondary winding 722 and the resistor 73, 76 is connected to the discharge lamp 15.
is connected to one end of the capacitor 74, the resistor 78 and the semiconductor switch 79, and the cathode of the thyristor 75? It is connected to the other end of the discharge lamp 15.

Even if this starting circuit 71 is used, two of the pulse transformers 72
Since a high voltage pulse is generated in the next winding 72■, it performs the same function as the starting circuit 24 described above.

The one shown in FIG. 8 configures a lighting circuit by connecting an inverter circuit 55 provided with four transistors 51, 52, 53, and 54 as switching elements to a first power source 11, and an output terminal of the lighting circuit. A discharge lamp 15 is connected to the discharge lamp 15 via a choke coil 14. The discharge lamp 15 is connected to the secondary wire 23■ of the pulse transformer 23 in parallel. The primary winding 23 of the pulse transformer 23. is connected to the output terminal of the starting circuit 56. The starting circuit 5
The input terminal 6 is connected to the second DC power supply 25 via a resistor 27 and a transistor 26 in series, and is also connected in parallel to the discharge lamp 15.

The starting circuit 56 connects a capacitor 57 in parallel to the second DC power supply 25, and connects the capacitor 57 to the second DC power supply 25 in parallel. resistance 58 to 7
A capacitor 59 is connected in parallel through the capacitor 59. A constant voltage conductor 61 is connected in parallel to the capacitor 59 via the primary winding 231 of the pulse transformer 23 and the capacitor 60 in series. Each of the transistors 5
Surge absorbing diodes 62.63 and 64.65 are connected in parallel to 1.52 and 53.54, respectively.

In the inverter circuit 55, transistors 51 and 52 are turned on and off at low frequencies, and transistors 53 and 5 are turned on and off at low frequencies.
It is designed to be turned on and off at a high frequency.

In this embodiment, first, a voltage is applied between b and b' to turn on the transistor 26 and operate the starting circuit. A high-voltage pulse is generated from the secondary winding 23 of the pulse transformer 23 and applied to the discharge lamp 15. As a result, the discharge lamp 15 is started and lit and emits a glow. When this glow discharge is maintained for a certain period of time, the drive circuit (not shown) of the inverter circuit 55 starts operating, and the transistor 5
Transistors 1 and 52 perform switching operations at low frequencies, and transistors 53 and 54 perform switching operations at high frequencies.

In this way, the inverter circuit 55 supplies the discharge lamp 15 with a lighting waveform in which a high frequency wave is superimposed on a low frequency wave, and the discharge lamp 15 shifts from glow discharge to arc discharge.

Therefore, this embodiment also has the same effect as the previous embodiment.
＜＞It is something that can be done.

Further, in this embodiment, when the discharge lamp 15 is lit steadily, a lighting waveform in which a high frequency is superimposed on a low frequency is supplied from the inverter circuit 55, so that acoustic resonance can be prevented, and The load characteristics of lighting circuits will also be revised.

The circuit shown in FIG. 9 is obtained by removing the diodes 62, 63, 64, 65 connected in parallel to the transistors 51, 52, 53, 54 of the inverter circuit 55 in FIG. Each transistor 51.52
．． 53 and 54 are turned on and off at low frequencies, respectively. That is, the transistors 51, 53 and 52, 54 alternately perform switching operations.

Even in the case where the inverter circuit 55 is driven at a low frequency in this way, the discharge lamp 15 is initially maintained in glow discharge by the starting circuit 56, and then the lighting circuit is operated to shift the discharge lamp 15 from glow discharge to arc discharge. Therefore, the same effects as in the embodiment described above can be obtained.

The system shown in FIG. 10 is a system in which the discharge lamp 15 is maintained at arc direct current discharge without glow discharge during startup, and then the power necessary for lighting the discharge lamp 15 is supplied by the power supply from the lighting circuit. This is an example.

That is, a starting circuit 81 is connected to the discharge lamp 15. This starting circuit 81 includes first and second pulse transformers 82.8
3. Semiconductor switch 84, unidirectional 3-terminal thyristor 8
5, a resistor 86, a capacitor 87, and a resistor 88 are connected in series, and a resistor 89 and a capacitor 90 are connected in series. The discharge lamp 15 is connected to the power source 25 through a transistor 26, a resistor 27, a secondary winding 83■ of the second pulse transformer 83, and a secondary winding 82■ of the first pulse transformer 82 in series. ing.

The first series circuit and the second series circuit are connected to the second DC power supply 25 via the transistor 26 and the resistor 27 in series. One end of the primary winding 82 of the first pulse transformer 82 is connected to the connection point between the resistor 86 and the capacitor 87 of the first series circuit, and the other end is connected to the second end through the semiconductor switch 84. DC power supply 2
It is connected to the negative terminal of No.5. Further, one end of the primary winding 83 of the second pulse transformer 83 is connected to the connection point between the resistor 89 and the capacitor 90 of the second series circuit, and the other end is connected to the second series circuit through the thyristor 85. DC power supply 2
It is connected to the negative terminal of No.5.

A voltage between C and C' is applied between the base and emitter of the transistor 19 at the timing shown in FIG. 11(a), and the base and emitter of the transistor 26 are applied. A voltage between b and b' is applied between the transmitters at the timing shown in (l1) in FIG.

In this example, first t. At this point, a b, b' voltage is applied between the base and emitter of the transistor 26, turning on the transistor 26. The starting circuit 81 is then connected to the second DC power supply 25 via the resistor 27 and starts operating.

In the starting circuit 81, capacitors 87 and 90 are charged, and first the semiconductor switch 84 is turned on and the capacitor 87 is turned on.
is discharged via the primary winding 821 of the first pulse transformer 82 and the semiconductor switch 84. As a result, a high voltage pulse is generated in the secondary winding 822 of the first pulse transformer 82 and applied to the discharge lamp 15. Subsequently, the cyrisk 85 conducts and the capacitor 90 becomes the second pulse 1 lance 8'3.
The primary winding 83. and is discharged via the cyrisk 85. As a result, the secondary winding 8 of the second pulse transformer 83
3■ Discharge from discharge lamp 15 to 91F! A high-voltage pulse with sufficient energy to cause the discharge lamp 15 is generated and supplied to the discharge lamp 15. In this way, the discharge lamp 15 is maintained in direct current arc discharge by the starting circuit 81.

After that 1. When this occurs, a voltage between c and c' is applied between the base and emitter of transistor 19, and transistor 19 is turned on. The drive circuit 18 then starts operating, the transistors 16 and 17 alternately switch, and the high frequency power necessary to maintain lighting is supplied from the inverter circuit 12 to the discharge lamp 15 via the capacitor 13 and choke coil 14. Become.

Then, at timing t2, the transistor 26 is turned off and the operation of the starting circuit 81 is stopped.

In this manner, the discharge lamp 15 is maintained in direct arc emission without being subjected to glow discharge, and then enters the lit state.

Therefore, it is possible to prevent the phenomenon of fading, which often occurs when transitioning from glow hk electricity to arc discharge. In addition, the lamp voltage of the discharge lamp 15 is high during glow discharge, so in order to connect the discharge lamp 15 to the lighting circuit in the glow discharge state, it is necessary to set the withstand voltage of the switching element of the lighting circuit to be high. In this case, since the discharge lamp 15 is connected to the lighting circuit in an arc discharge state, a switching element of the lighting circuit does not need to have such a high withstand voltage. In other words, the switching elements of the lighting circuit can be more effectively prevented from being destroyed.

It should be noted that the configuration of the starting circuit is not limited to that of this embodiment, and may be one shown in FIGS. 12 and 13, for example.

The starting circuit 91 shown in FIG. 12 includes one primary winding 92,
A pulse transformer 92 consisting of a secondary winding 92 and a secondary winding 92 is provided, and one end of the primary winding 921 is connected to a resistor 93 and a capacitor 94.
The other end of the resistor 93 is connected to the other end of the discharge lamp 15 via the semiconductor switch 95, and the other end of the resistor 93 is connected to the discharge lamp 15 via the secondary winding 92 of the pulse transformer 92. It is connected to one end of the electric lamp 15, and the other end of the capacitor 94 is connected to the pond end of the discharge lamp 15.

The starting circuit 101 shown in FIG.
2++, 102+■ and one secondary winding? A pulse transformer 102 consisting of 022 is provided, and one primary winding 102
One end of ++ is connected to the connection point between the resistor 103 and the semiconductor switch 104, and the other end is connected to the capacitor 105 and the low resistor 106.
is connected in series to the other end of the discharge lamp 15, and one end of the other primary winding 102+■ is connected to the resistor 107 and the capacitor 1.
08, and the other end is connected to the end of the discharge lamp 15 via a unidirectional three-terminal thyristor 109.

Further, the other ends of the resistors 103 and 107 are connected to one end of the discharge lamp 15 via the secondary winding 1022 of the pulse transformer 102, and the other ends of the semiconductor switch 104 and the capacitor 108 are connected to the other end of the discharge lamp 15. and connect the gate of the cyrisk 109 to the capacitor 105.
and the resistor 106.

The circuit for direct arc discharge at startup is shown in Figure 10.
If the starting circuit shown in Figures 12 and 13 is used, the third
The present invention can also be applied to the lighting circuits shown in FIGS.

[Effects of the Invention] As detailed above, according to the present invention, pulse voltage can be supplied to the discharge lamp without reducing it, and the lighting circuit can be improved by preventing the supply of high-voltage pulses and pulse current to the lighting circuit at startup. It is possible to provide a discharge lamp lighting device and a lighting method thereof that can prevent destruction of switching elements.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a circuit diagram, FIG. 2 is a voltage waveform diagram showing operation timing, and FIGS. 3 and 4 are diagrams showing an embodiment of the present invention. Fig. 3 is a circuit diagram, Fig. 4 is a timing waveform diagram showing the operation timing of the relay, and Figs. 5 and 6 show other embodiments of the present invention. , Figure 5 is a circuit diagram, Figure 6 is a voltage waveform diagram showing operation timing, Figure 7 is Figure 1,
FIGS. 3 and 5 are circuit diagrams showing other embodiments of the starting circuit in the embodiment shown in FIGS. 11 and 11 show still another embodiment of the present invention, FIG. 10 is a circuit diagram, FIG. 11 is a voltage waveform diagram showing operation timing,
12 and 13 are circuit diagrams showing other embodiments of the starting circuit in the embodiment shown in FIG. 10, and FIG. 14 is a circuit diagram showing a conventional example. 12.12', 55... Inverter circuit, 15...
・Discharge lamp, ]8...Drive circuit, 19,26.42...Transistor, 23,72,8
2.8B, 92, 102... Pulse transformer, 24, 56, 71, 81, 91, 101... Starting circuit. Applicant's agent Patent attorney Takehiko Suzue

Claims (4)

[Claims] (1) A discharge lamp connected to the output terminal of a lighting circuit, connected in parallel to the discharge lamp on the side opposite to the lighting circuit, and supplying a pulse voltage to the discharge lamp prior to output from the lighting circuit. A discharge lamp lighting device comprising a secondary winding of a pulse transformer. (2) Discharge lamp lighting characterized in that the discharge lamp is first maintained in glow discharge by supplying power from a pulse transformer, and then switched from glow discharge to arc discharge by supplying power from a lighting circuit. Method. (3) A discharge lamp connected to the output terminal of the lighting circuit, an impedance element on the opposite side of the discharge lamp from the lighting circuit, a power supply, and a pulse voltage applied to the discharge lamp prior to output from the lighting circuit. A discharge lamp lighting device characterized in that a series circuit comprising a secondary winding of a pulse transformer to be supplied is provided, and the discharge lamp is connected to the power source through the impedance element and the secondary winding of the pulse transformer in series. . (4) A method for lighting a discharge lamp, which comprises first supplying power to the discharge lamp from a pulse transformer to maintain DC discharge of an arc, and then supplying necessary power from a lighting circuit.