JPH02242594A - Apparatus for lighting discharge lamp - Google Patents

Abstract

PURPOSE:To electronize and downsize a whole lighting apparatus by a method wherein one of switching elements is chopper-operated at the time of lighting a lamp after start-up to have a high voltage pulse generating circuit inactivated while the lamp is lit with a direct current supplied to a discharge lamp. CONSTITUTION:This apparatus comprises a high voltage pulse generating circuit 4 comprising a DC power source VDC, two switching elements S1, S2, a voltage raising circuit 7 and an oscillating circuit 8, a capacitor C8 for cutting direct current, capacitors C9, C10, etc. At the time of start-up, the switching elements S1, S2 alternatively perform on/off inverter operation to operate the high voltage pulse generating circuit 4 to apply high voltage pulses to a discharge lamp, while at the time of lighting the lamp one of the switching elements S1, S2 is chopper-operated to have the high voltage pulse generating circuit inactivated so that high voltage pulses can be stopped without an exclusive switch. Since lighting of the discharge lamp is thus performed by chopper-operation, the whole lighting apparatus can be electronized and compacted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a discharge lamp lighting device for starting and lighting a discharge lamp by generating a high-voltage pulse through a switching operation of a semiconductor switching element.

[Prior art] The discharge lamp lighting device shown in FIG.
This method is described in Japanese Patent No. 999, in which a high voltage is applied to a high-pressure discharge lamp, and the lamp is instantaneously started for commercial lighting. The discharge lamp 2 is connected to the AC power source via the current limiting inductance L and the secondary side of the transformer T2,
Further, a capacitor C is connected in parallel to a series circuit of the discharge lamp 2 and the transformer T2.

The second circuit operates as follows. That is, switch S. When turned on, the voltage from the AC power source 1 (G) is boosted by the transformer T, and this boosted voltage is applied to the discharge gear G.
When the discharge starting voltage is reached, the capacitor C2, the discharge cap G, and the primary loop of the transformer 'F2 are discharged.

This discharge generates a high-voltage pulse in the output of the trasis 1~2g (-100 KV even in conditions where it is difficult to restart)
It can be lit instantaneously using high voltage (-). The switch So is on when a high-voltage pulse is generated, and when the discharge lamp 2 is lit, the high-voltage pulse is unnecessary, and after confirming the lighting, the switches S and l are turned off.

FIG. 11 shows another conventional example, published in Japanese Patent Application Laid-Open No. 59196594.
This is what is stated in the publication No.

In the second circuit, a high frequency is output from the AC power supply 1 by the inverter circuit 3. The output of this inverter circuit 3 is rectified by a tie-down valve D B l, and the output of the discharge lamp 2 is
Direct current flows through. At startup, the voltage is increased by the transformer 'F, and when the discharge starting voltage of the discharge gear G is reached in the same way as described above, a high voltage pulse is generated from the I-lance T to light the discharge lamp 2. Also, switch S. As in the conventional example above, the lamp is turned on when starting, and turned off once it lights up.

[Problems to be Solved by the Invention] In the circuit shown in FIG. 10, the I-lance T1 has a voltage of 100 V.
Or, when inputting a voltage of 200 cm and generating a voltage of several thousand cm on the secondary side, the step-up ratio becomes sharper, the number of secondary windings becomes very large, and the high voltage There is a problem in that the transformer T1 or very large F is damaged when the power is turned on. Also 5
When the discharge lamp 2 is turned on, the switch S is turned on. must be turned off to stop generating high voltage pulses.

In addition, in the circuit 1.111!1 in 1), the transformer '2'3 operates at a high frequency, so it can be made smaller, but it is necessary to provide the switch S1 in the same manner as above.

In this way, conventionally, in order to stop the high-pressure pulse,
There was a problem that both required a dedicated switch So.

The present invention has been provided in view of the above-mentioned points, and an object of the present invention is to stop the high-voltage pulse when a discharge lamp is lit, and to stably light the discharge lamp without providing a dedicated switch to stop the high-voltage pulse. The present invention provides a discharge lamp lighting device.

[Means for Solving the Problems 1] The present invention (J, a DC power source, at least two switch/chink elements connected in series connected in parallel with the DC power source, and a switching output of the switching element L) a discharge lamp that is started and lit by the lamp; a DC supply means that mainly supplies direct current to the discharge lamp; a high-voltage pulse generation circuit that receives the output of the switching element and applies a high-voltage pulse to the discharge lamp at the time of starting; A DC cutting capacitor provided between the pulse generation circuit and an inverter is operated to alternately turn on and off the switching elements at least when starting the discharge lamp, and when lighting, only one of the switching elements is operated as a chopper. It is equipped with a control circuit.

[Function] With the above means, when starting the discharge lamp, the control circuit alternately turns on and off the switching elements to operate the inverter, and inputs this output to the high-voltage pulse generation circuit to generate high-voltage pulses. This high-voltage pulse is used to start the discharge lamp, and when the lamp is turned on after starting, the switch is turned on.
One of the elements is operated as a chopper, and the DC current is cut through the capacitor to disable the high-voltage pulse generation circuit, and at the same time, DC is supplied to the discharge lamp via the DC supply means to light the discharge lamp. I try to let them do it. .

[Embodiment 11] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention operates a high-voltage pulse generation circuit by performing inverter operation of at least 2-) switching elements alternately turning on and off during startup, applies high-voltage pulses to the discharge lamp, and at least one switching element operates during lighting. By operating the chopper, the high-voltage pulse generation circuit is immobilized and the high-voltage pulse can be stopped without the need for a dedicated switch. Here, the high-voltage pulse generation circuit can be stopped by switching from the inverter operation to the collar operation I\, and the capacitor of the high-voltage pulse generation circuit is made immobile by cutting off the direct current. Since the discharge lamp is lit using rectangular wave lighting or direct current lighting (chopper operation that turns it on and off at high frequency), the current-limiting interface can be made smaller.

FIG. 4 is a basic hook circuit diagram of the present invention. DC power supply VD, -, and two switching elements S, ,
S2, a vibration circuit 5, a load 6, a high-voltage pulse generation circuit/1 consisting of a booster circuit 7 and a vibration circuit 8, a DC power/isolation condenser C8, and a capacitor C9+ CI 11
Composed to etc.! It's heavy. Note that, as will be described later, switching elements 83. S,
There are also cases where it is used.

In an inverter operation that applies high voltage pulses to the load (discharge lamp) 6, switching elements S1 and 82 are turned on and off alternately, and an oscillating current flows through the oscillating circuit 8 of the high voltage pulse generating circuit 4, passing through the booster circuit 7 to the load. A high voltage pulse is applied to 6. When the discharge lamp is lit, the switching element S or S
2 turns on and off (chopper operation), and the vibration circuit 5
Then, only the load 6 becomes operational. For example, the capacitor C8 is turned on and off by the switching element 81 (S2 is in the off state).
When the voltage is on, the vibration circuit 8 and the booster I port 7 remain stationary because they are charged with the polarity shown in FIG.

With this configuration, a dedicated switch is not required and the high voltage pulse can be stopped.

Figure 1 shows a specific circuit diagram, with a tie auto bridge that rectifies the AC power supply +) connected in series to the output end of B2.
I transistors Q+ and Q2, which are switching elements, are connected in parallel, and a capacitor C9+ is connected in series.
CIO is connected in parallel with transistors Q,,C2. A series circuit including an inductance I77, a transformer TG, and a discharge lamp 2 is connected between the connection point of the transistors Q, . . . , Q2 and the connection point of the capacitor CD111. Furthermore, diodes D, D, are connected to the transistors Q, Q2, respectively. The high voltage pulse generating circuit 4 is comprised of a capacitor C8, transformers Ta, T'r, capacitors C4, C5, diodes I), B2, a discharge gear G, and the like. The control circuit 9 controls on/off of the transistor QQ2, and at the time of starting, the transistors Q1. Q2 is turned on and off alternately to operate the inverter, and when lighting, only one transistor Q or C2 is operated as a chopper to disable the high voltage pulse generation circuit 4 and the discharge lamp 2 is turned on and off. It is designed to supply direct current.

Further, by detecting the current flowing through the discharge lamp 2, it is determined whether the discharge lamp 2 is started or turned on, and the control circuit 9 detects the transistor Q1. I am trying to control Q2.

Figure 2 shows the on/off tights of transistors Q, Q2.
The chart (a) shows the inverter operation when a high voltage pulse is generated, and the chart (1) shows the chopper operation. FIG. 3 shows the voltage across the discharge lamp 2 (2), FIG. 3(a) shows the inverter operation, and FIG. 3(1)) shows the chip operation. In the figure (a), a high voltage pulse is superimposed, and in the figure (L), a rectangular wave voltage is obtained, the transistor Q operates during 'F1, and the transistor Q2 operates during T2, alternating at a low frequency.

Next, we will explain the dynamic f1.7 First, at the time of starting when a high voltage pulse is applied, the following operation occurs. AC power supply l is full-wave rectified by diode bridge DB2, and capacitor C9
+ Obtain DC voltage smoothed by CIO. As shown in Fig. 2, when the transistors Q, Q2 are turned on and off at high frequency (inverter operation),
A high frequency voltage is applied to the next side, and the boosted voltage is applied to the discharge gap G. When a voltage higher than the discharge starting voltage of the discharge gap G is applied, a high-voltage pulse is generated on the secondary side of the lance 'F6, and the high-voltage pulse is applied to the discharge lamp 2 in a closed circuit of the transformer T6, the capacitor C6, and the discharge lamp 2. applied,
It is possible to start the discharge lamp 2. When started, the main current to the discharge lamp 2 flows through the inductance L2 to the discharge lamp 2.
It will flow to

Next (*), the case of lighting will be explained. When the discharge lamp 2 starts, the transistor Q or C2 shifts to chopper operation, and only one of the transistors 1 to Q1 or C2 operates for a predetermined period < TI or 1 2) Turns on at high frequency as shown in FIG. 2 (Il). 1 to Lance 'r7 are capacitors C
8, no high frequency voltage is applied, so there is no operation. The discharge lamp 2 has a waveform as shown in FIG. 3 (1), and can be stably lit. That is, the high frequency component is bypassed by the capacitor C, and the DC component flows to the discharge lamp 2.

Note that the switching frequency of 1 helangister Q+, Q, and z is several tens of kHz, and the low frequency (1,, /To) is several hundred kHz.
(z) Since the transistors Q, . . . , Q2 are turned on at high frequencies, the inductance -42, capacitors C6 and C8, and transformer T7 are small and lightweight.

In addition, the discharge lamp 2 has an inductance L2, a contereza C6, etc.
7 mainly constitutes a series supply means 2 for supplying direct current.

[Embodiment 2] FIG. 5 shows Embodiment 2, which differs from FIG. 1 in the high-voltage pulse generation circuit 4 and is otherwise the same as FIG. 1.

In addition, a to (l in the figure indicate the connection points. In FIG. 1, a discharge cap G was used, but in FIG. 5, a bidirectional two-terminal thyristor Q3 is used. The operation is as follows. 1, when the voltage of the capacitor C5 reaches the breakover voltage of the thyristor Q3, it turns on and applies a high voltage pulse to the discharge lamp 2 via the transformer 'F6.The operation of the capacitor C1 is also as follows. It is the same as the figure. Unlike the discharge cap G, this embodiment does not wear out and can be used semi-permanently, and the breakover voltage can be easily set.
Alternatively, a three-terminal cyrisk may be used.

(Third Embodiment) FIG. 6 shows a third embodiment, in which the circuit configuration is the same as that in FIG. 1, and the operation of the l-run risk QQ2 is set by the control circuit 9 as shown in FIG. When a high voltage pulse is generated, the periods T3 and T (same as in Fig. 2(a)), that is, when the transistors Q1 and Q2 are alternately turned on and off, the periods T and 1 and 2 are the same. As in FIG. 2 (1)), the capacitor C8 cuts the direct current, so the high voltage pulse generating circuit 4 does not operate.

When the light is turned on and the operation shown in FIG. 6 is performed, T3. During the period 'T', the discharge gap G is selected to have a value between 1 and no operation.

FIG. 7 shows the waveforms at both ends of the discharge lamp 2 at this time. This embodiment has the advantage that the required number of high-voltage pulses can be set freely, rather than generating high-voltage pulses over the entire area. Further, the same effect can be obtained even if the circuit shown in FIG. 5 is used as the high voltage pulse generating circuit 4.

[Embodiment 4] Fig. 8 shows Embodiment 11, and the difference from Fig. 1 is that instead of the capacitors C9, C, o, 1 herensis Q2°,
The point is that Q,2 is used. Transistor Qll+
The operations of Q,2, Q2+, Q,z□ are similar to transistors Q, Q2 in FIG. In other words, the transistor Q l+ + Q l 2 corresponds to the transistor Q1 and the transistor Q211Q22 to the transistor Q2, respectively. In Figure 1, capacitor C9+ CI. The voltage is divided by the DC power supply V. 1. A voltage of 17/2 is applied between a and ci, but in FIG. 8, since a transistor is used, the DC power source . C or just a-
(It will be applied between 1 and 2, and is effective when the DC power supply
This is the same as in the case of FIG.

[Example 5] FIG. 9 shows Example 5. The difference from FIG. 1 is in the presence of a capacitor C9, but the other operations are the same as in FIG. When transistor Q1 turns on, DC power supply ■. C
When the transistor Q2 is turned on, the capacitor C3° becomes the power source. Therefore, the capacitance of =1 tensor C4U is from several dimensions to several hundred μF. The overall operation is the same as in FIG.

Alternatively, the operation shown in FIG. 6 may be used.

[Effects of the Invention] As described above, the present invention includes a DC power supply, at least two switching elements connected in series that are connected in parallel with the DC power supply, and a radiation source that is started and lit by the switching output of the switching element. between the electric lamp, a direct current supply means that primarily supplies direct current to the discharge lamp, a high-voltage pulse generation circuit that receives the output of the switching element and applies a high-voltage pulse to the discharge lamp at the time of starting, and the switching element and the high-voltage pulse generation circuit. It is equipped with a condenser → no switch for direct current cut provided, and a control circuit that operates an inverter to alternately turn on and off the switching elements at least when the discharge lamp is started, and operates only one of the switching elements as a chopper when the discharge lamp is lit. Therefore, when starting a discharge lamp, the switching elements are alternately turned on and off in the wholesale circuit to operate the inverter, and this output is input to the high-voltage pulse generation circuit to generate high-voltage pulses. This high-voltage pulse is used to start the discharge lamp, and when the lamp is turned on after starting, one of the switching elements is activated to cut the DC current through the capacitor. At the same time, DC is supplied to the discharge lamp via a DC supply means to light the discharge lamp. Therefore, for example, a step-up transformer that generates high-voltage pulses in a high-voltage pulse generation circuit is used for high-frequency Since it is a transformer of
This eliminates the need for a dedicated stop switch as in the past, and furthermore, since the entire lighting device is electronic, it has the effect of significantly downsizing and reassignment. .

[Brief explanation of drawings]

FIG. 1 is a specific circuit diagram of an embodiment of the present invention, FIG. 2 is a time chart 1 shown above, FIG. 3 is an operation waveform diagram shown above,
The figure is the basic circuit diagram of the same as above, Fig. 5 is the main circuit diagram of the second embodiment of the same, and Fig. 0 is the tights and chart of the third embodiment of the above.
Figure 7 is an operation waveform diagram of the same as above, and Figure S (embodiment of the same as above)
1 is a circuit diagram, FIG. 9 is a circuit diagram of Embodiment 5, and FIG.
Figure IJ: A circuit diagram of the rM conventional example. Figure 11 is a circuit diagram of another conventional example. 4 is a high-voltage pulse generation circuit, 9 is a control circuit, QQ1 transistor, and C8 is a :1 antenna. Agent Patent Attorney Ishi 1) Long 7~0

Claims (1)

[Claims] (1) a DC power source and at least two switching elements connected in series that are connected in parallel with the DC power source;
a discharge lamp that is started and lit by the switching output of the switching element; a DC supply means that primarily supplies direct current to the discharge lamp; and a high-voltage pulse generation circuit that receives the output of the switching element and applies high-voltage pulses to the discharge lamp at the time of starting. , a capacitor for direct current cut provided between the switching element and the high-voltage pulse generation circuit, and at least when starting the discharge lamp, an inverter is operated to alternately turn on and off the above-mentioned switching element, and when lighting the lamp, one of the switching elements is connected. A discharge lamp lighting device characterized by comprising: a control circuit for chopper operation of a discharge lamp.