JPS6041440B2 - discharge lamp lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp lighting device, and in particular, when starting a discharge lamp, it is started and lit using a voltage that is a combination of a high-frequency oscillation voltage and a pulse voltage, and after the discharge lamp is lit, it is lit using only the oscillation voltage. The present invention relates to a discharge lamp lighting device that maintains a discharge lamp.

The present applicant has previously discovered that, in addition to improving efficiency, it has become possible to reduce the size and weight of current limiting chokes, and to reduce high-frequency and high-frequency signals at the beginning of each half cycle of an AC We proposed a discharge lamp lighting method (hereinafter referred to as the "every-cycle start lighting method") in which the discharge lamp is re-ignited using a voltage, and after being re-ignited, the discharge lamp is kept lit using an AC power source.

FIG. 1 is an electrical circuit diagram showing a discharge lamp lighting device using an every-cycle start lighting method, which is the background of the present invention.

In the configuration, 1 is a commercial frequency AC power supply, a current limiting choke as an example of a current limiting device, 2 and a discharge lamp 3.
series circuit is connected. An intermittent high frequency high voltage generating circuit (hereinafter referred to as a high voltage circuit) 4 is connected to the non-power supply side of the filaments 31 and 32 of the discharge lamp 3. The high voltage circuit 4
is a high-frequency high-voltage generating circuit (
This is a circuit in which a capacitor 6 for intermittent oscillation is connected in series to a booster circuit 5.

As long as the high-voltage circuit 4 performs intermittent high-frequency oscillation, it may be replaced with a high-voltage generating circuit using a gated thyristor such as a triac, or even an inverter.

The operation of the configuration shown in FIG. 1 will be explained below. When the power supply 1 is turned on, the power supply voltage is applied to the discharge lamp 3 via the current limiting choke 2, and the power supply voltage is also applied to the high voltage circuit 4. In the high voltage circuit 4, the power supply voltage is applied to the thyristor 52 via the intermittent oscillation capacitor 6,
In order to cause this thyristor 52 to break over, the booster circuit 5 starts an oscillation operation. This oscillation operation would continue without the intermittent oscillation capacitor 6, but as the booster circuit 6 oscillates, the intermittent oscillation capacitor 6 is gradually charged, and the intermittent oscillation capacitor 6 in parentheses is
As the terminal voltage of the thyristor 52 cancels out the power supply voltage, the thyristor 52 remains off after a certain period of time, and the booster circuit 5 stops its oscillation operation. Therefore, an intermittent oscillation output is generated from the high voltage circuit 4 at each predetermined phase of each half cycle of the AC power supply voltage. This oscillation output is superimposed on the power supply voltage and applied to the discharge lamp 3.

At the same time, during the oscillation period of the high voltage circuit 4, the input current if of the high voltage circuit 4 flows through the path of power supply 1 - current limiting choke 2 - filament 31 - high voltage circuit 4 - filament 32 - power supply 1, and the filaments 31 and 32 It gets heated. When the filaments 31, 32 are thus sufficiently preheated, the discharge lamp 3, which is triggered by the oscillation output from the high voltage circuit 4, is started.

When the discharge lamp 3 is started and lit, the voltage across the discharge lamp 3 drops to the tube voltage, so the high voltage circuit 4 stops its oscillation operation. Thereafter, each thyristor of the power source 1 of the discharge lamp 3 is re-ignited by the intermittent oscillation output of the high voltage circuit 4, and is maintained lit by the power source voltage.

According to the above-mentioned every-cycle start lighting method, the discharge lamp 3 is re-ignited by the intermittent oscillation output of the high-voltage circuit 4, so compared to the conventional lighting method in which the discharge lamp is re-ignited by the power supply voltage. Therefore, the voltage difference between the power supply voltage and the tube voltage of the discharge lamp becomes smaller.
The current-limiting choke 2 that shares this differential voltage can be made into a 4-shape.

The accumulated energy and required inductance of the current limiting choke 2 are each 1/4 compared to the conventional glow lighting system.
and 1/the degree of the ear chamber, and the size can be reduced accordingly. Note that these reductions in size are even more remarkable when compared to a rabbit-start type ballast having a step-up transformer configuration.

Furthermore, according to such a lighting method, the phase difference between the power supply voltage and the tube current is smaller than that in the conventional lighting method, so a power factor correction capacitor is not necessary or the capacitance can be made extremely small.

In this case, the tube voltage becomes a rectangular wave with rest periods due to intermittent oscillation periods, and its effective value is slightly lower than that of the conventional lighting system.

In addition, the intermittent input current of the high voltage circuit 4 is caused by the current limiting choke 2.
By flowing through the tube, the waveform of the tube voltage is slightly increased due to the influence of the input current. The appearance phase of the input current is constant regardless of fluctuations in the power supply voltage, and therefore the rising phase of the tube current is kept constant regardless of fluctuations in the power supply voltage.
Furthermore, the input current has a characteristic that if the tube current increases due to an increase in the power supply voltage, the rear end of the tube current waveform falls into the appearance period of the input current in the next half cycle, so that it decreases. , has a negative coefficient of variation. These are the reasons why the fluctuation rate of the tube current in the every-cycle start lighting method is maintained well despite the decrease in stable impedance. As described above, the every-cycle start lighting method, which is the background of the present invention, has great advantages in terms of resource and energy savings.

By the way, if the oscillation output voltage of the high voltage circuit 4 is increased in the every-cycle start lighting method which is the background of this invention, a large oscillation energy can be obtained and the discharge lamp can be reliably started and lit. If the discharge lamp is subsequently re-ignited using this large oscillation output voltage, there is a problem in that the filament is relatively seriously damaged and the life of the discharge lamp is shortened.

Further, when the discharge lamp 3 is of a hot cathode type as shown in the illustrated example, there is a problem that the filament preheating current and the lamp lighting efficiency conflict with each other.

That is, the every-cycle start lighting device shown in FIG.
2, the filament preheating current is likely to be insufficient.

In order to increase this filament preheating current, for example, the capacitance of the intermittent oscillation capacitor 6 may be increased to
It is conceivable to increase the intermittent oscillation period. However, if the capacitance of the intermittent oscillation capacitor 6 is simply increased, the intermittent oscillation period of the high voltage circuit 4 during lighting of the discharge lamp 3 will also become longer, and this will increase the non-emission period of the discharge lamp 3 due to the intermittent oscillation period. At the same time, power loss due to heating of the filament during the intermittent oscillation period also increases, causing a decrease in the luminous efficiency of the discharge lamp 3. Therefore, there is a demand to increase the capacity of the intermittent oscillation capacitor 6 in order to increase the filament thermal current at the time of starting the discharge lamp 3, and an intermittent oscillation capacitor 6 to increase the luminous efficiency during lighting of the discharge lamp 3. Because of the two conflicting demands of reducing the capacitance of the oscillation capacitor 6, the capacitance of the intermittent oscillation capacitor 6 has been set to a value that is a compromise between the two demands. Therefore, the capacitance of the intermittent oscillation capacitor 6 is too small from the perspective of filament preheating current, but too large from the perspective of luminous efficiency of the discharge lamp 3, leaving room for improvement. Therefore, the main object of the present invention is to start and light the discharge lamp with a voltage that is enriched with the pulse voltage of the oscillation voltage when starting the discharge lamp, and to restart the discharge lamp with only the oscillation voltage after lighting the discharge lamp. Therefore, it is an object of the present invention to provide an inexpensive discharge lamp lighting device which can prevent the application of pulse voltage (high voltage) to the filament after the discharge lamp is started and lit, thereby extending the life of the discharge lamp.

FIG. 2 is a block diagram showing the principle of the invention.

To explain the outline of the present invention with reference to FIG. 2, an oscillation circuit 5', which is an example of a high-frequency voltage generating means, has an oscillation voltage that is the voltage required to re-ignite the discharge lamp 3 every half cycle, that is, the re-ignition voltage. For example, the first
A booster circuit 5 shown in the figure is used. The pulse generation circuit 7, which is an example of the pulse generation means, generates a pulse voltage with a high peak value, and the peak value of the superimposed voltage obtained by superimposing the pulse voltage and the oscillation voltage of the oscillation circuit 5' is the initial starting voltage of the discharge lamp 3. The generated pulse voltage is selected so that it is equal to or higher than ESt. The pulse generating circuit 7 includes a switch means 8 which is closed when the discharge lamp 3 is started and is opened after the discharge lamp 3 is turned on to disable the pulse generating circuit 7. When the discharge lamp is started, the switch means 8 is closed, so that the pulse voltage generated by the pulse generation circuit 7 and the oscillation voltage generated by the oscillation circuit 5' are superimposed and the discharge lamp 3 is Supplied at both ends. Therefore, the discharge lamp 3 is started and lit by a high voltage that is higher than the required starting voltage, which is a combination of the pulse voltage and the oscillation voltage. After lighting the discharge lamp 3, the switch means 8
is opened, and the pulse generation circuit 7 is disabled. For this reason, after the discharge lamp 3 is lit, only the oscillation circuit 5' operates in oscillation, so that the discharge lamp 3 is turned on again every half cycle of the AC power supply 1 by the oscillation voltage of the oscillation circuit 5', and is turned on by the power supply voltage. It remains lit. Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a specific circuit diagram of a discharge lamp lighting device according to an embodiment of the present invention.

In the configuration, an AC power source 1 is connected in series with a current limiting choke 2 as an example of a current limiting device and a hot cathode discharge lamp 3 as an example of a discharge lamp. A series circuit consisting of an intermittent oscillation capacitor 6, a secondary winding 92 of a pulse transformer 9, and an oscillation circuit 5' is connected in parallel to the non-power supply side ends of the filaments 31 and 32 of the discharge lamp 3. This oscillation circuit 5' is constructed on the same circuit as the booster circuit 5 shown in FIG. 1 described above. Further, the oscillation circuit 5' and the intermittent oscillation capacitor 6 constitute an intermittent high frequency generation means 4'. A primary winding 91 of a pulse transformer 9 and a series circuit of a thyristor 8, which is an example of a switching means, are connected in parallel to the intermittent oscillation capacitor 6.
This intermittent oscillation capacitor 6, primary winding 91, thyristor 8, and secondary winding 92 constitute a pulse generating circuit 7A. FIG. 4 is a waveform diagram of each part to explain the operation of FIG. b shows the intermittent oscillation voltage Vo of the oscillation circuit 5' after the discharge lamp is turned on.

Next, the specific operation of this embodiment will be explained with reference to FIGS. 3 and 4.

First, the operation of the discharge lamp 3 at startup will be explained.

When the AC power supply 1 is turned on, the oscillation capacitor 51 is charged along the path of current limiting choke 2 - filament 31 - intermittent oscillation capacitor 6 - secondary winding 92 - oscillation capacitor 51 - filament 32. When the terminal voltage of the oscillation capacitor 51 exceeds the breakover voltage of the thyristor 52, the thyristor 52 becomes conductive, and the oscillation capacitor 51 and boost inductor 53 cooperate to perform a high frequency oscillation operation. The discharge lamp 3 cannot be started and lit only with the oscillation voltage Vo of the oscillation circuit 5'. During the oscillation operation of the oscillation circuit 5', the intermittent oscillation capacitor 6 is charged by the input current to the oscillation circuit 5', and the filaments 31, 32
is preheated. As the oscillation circuit 5' oscillates, the intermittent oscillation capacitor 6 is gradually charged, and when its terminal voltage exceeds the breakover voltage of the thyristor 8, the thyristor 8 becomes conductive. A discharge current of 6 flows through the closed circuit of the intermittent oscillation capacitor 6, the thyristor 8, and the primary winding 91-6. For this reason, 2
A boosted pulse voltage Vp is induced in the next winding 92.
This pulse voltage Vp and the oscillation voltage Vo of the oscillation circuit 5' are superimposed and applied to the discharge lamp 3. This discharge lamp 3
At the time of starting lighting, the intermittent oscillation capacitor 6 charges and discharges as described above, so the oscillation circuit 5' continuously oscillates as shown in FIG. 4a.

Due to the continuous oscillation operation of the oscillation circuit 5', the preheating current of the filaments 31 and 32 increases significantly. Thus, when the filament is sufficiently heated, the discharge lamp 3 is started and lit by a high voltage that exceeds the required starting voltage, which is the sum of the oscillation voltage Vo and the pulse voltage Vp. When the discharge lamp 3 is started and lit, a tube current flows through the discharge lamp 3, and the tube voltage of the discharge lamp 3 decreases.

Therefore, the intermittent oscillation capacitor 6 is not charged until it reaches the breakover voltage of the thyristor 8, and the pulse generation circuit 7A stops the pulse generation operation. In the next half cycle, the intermittent oscillation capacitor 6 is gradually charged with the oscillation operation of the oscillation circuit 5', but before the terminal voltage of the intermittent oscillation capacitor 6 reaches the breakover voltage of the thyristor 8, the discharge lamp 3 is re-ignited by the oscillation output voltage of the oscillation circuit 5', the oscillation circuit 5' thereafter oscillates intermittently every predetermined phase of each half cycle of the power supply voltage. Intermittent oscillation voltage Vo at this time
Since ' is selected to be greater than the restriking voltage rst of the discharge lamp 3, the discharge lamp 8 is kept lit by the power supply voltage while being restriked every half cycle of the AC power supply 1 by the intermittent oscillation voltage Vo'. Ru. With this configuration, compared to the conventional high-voltage circuit of the every-cycle start ignition method, it is possible to reduce the applied energy when starting and re-igniting the discharge lamp 3, and damage to the filaments 31 and 32 is reduced. , there is an advantage that the discharge lamp 3 has a long life.

Further, since the pulse generating circuit 7A uses the intermittent oscillation capacitor 6, it has the advantage of having a simple circuit configuration.
Furthermore, in the hot cathode type discharge lamp 3, since the intermittent oscillation capacitor 6 is substantially short-circuited by the thyristor 8 at the time of starting, the filament preheating current can be made sufficiently large even if the capacitance of the intermittent oscillation capacitor 6 is smaller than that of the secondary. can.

Furthermore, since the capacitance of the intermittent oscillation capacitor 6 is small after the discharge lamp 3 is started and lit, the intermittent oscillation period of the oscillation circuit 5' can be shortened, reducing filament loss and improving luminous efficiency. There is also the advantage of being able to In addition, as a modification of this embodiment, the secondary winding 92 is
The positions of the cross marks in the diagram, that is, the intermittent oscillation capacitors 6 and 1
It may be connected between the connection points of the next winding 91 or between the connection points of the AC power source 1 and the filament 32. Furthermore, instead of serially superimposing the pulse voltage Vp and the oscillation voltage yo, the secondary winding 92 and the capacitor 74 are connected in series, and the series circuit is connected in parallel to the power supply side ends of the filaments 31 and 32 of the discharge lamp 3. By this, the oscillation voltage Vo and the pulse voltage Vp
may be superimposed in parallel.

As another modification, a bias coil 54 may be magnetically coupled to the boost inductor 53, and the bias coil 54 may be inserted into the open circuit of the intermittent oscillation capacitor 6-thyristor 8-primary winding 91-6. This has the advantage that the oscillation voltage at the time of pulse voltage generation, that is, at the time of starting the discharge lamp 3, can be increased without increasing the capacity of the circuit components. As another modification, the oscillation capacitor 51 may be connected in parallel to the power supply side ends of the filaments 31 and 32. In this way, the filament 31,
32 can be preheated by the oscillation current of the oscillation circuit 5'. Further, the terminal on the intermittent oscillation capacitor 6 side of the syristor 8 may be connected to the power source side of the filament 31. In this way, the filament 31 can be heated by the discharge current of the intermittent oscillation capacitor 6. FIG. 5 is a circuit diagram of a discharge lamp lighting device according to another embodiment of the present invention.

This embodiment differs from FIG. 3 in that the pulse generation circuit 78
was constructed as follows. That is, the non-power supply side end of the filament 31 of the discharge lamp 3 and the filament 3
A series circuit consisting of the secondary winding 92 of the filament transformer 9, the oscillation circuit 5', the primary winding 91, and the intermittent oscillation capacitor 6 is connected between the power supply side end of the filament transformer 9 and the filament 32. A series circuit consisting of a bias coil 54, a thyristor 81, and a diode 82 is connected between the non-power supply side end of the bias coil 54 and the non-power supply side end. In this circuit, an open circuit is formed by the intermittent oscillation capacitor 6, the primary winding 91, the bias coil 54, the thyristor 81, the diode 82, and the filament 32, and the discharging of the intermittent oscillation capacitor 6, that is, the generation of the pulse voltage Vp, is performed. , is performed only during one polarity (ie, half cycle) of the power supply voltage e. Since the operation of this embodiment is substantially the same as that shown in FIG. 3 after the discharge lamp 3 is turned on, only the operation at the time of starting the discharge lamp 3 will be described here.

When the AC power source 1 is turned on, the oscillating condenser 51 is charged. When the terminal voltage of the oscillation capacitor 51 exceeds the breakover voltage of the thyristor 52, the thyristor 52
becomes conductive, and the oscillation circuit 5' operates in oscillation. During the oscillation period of the oscillation circuit 5', the intermittent oscillation capacitor 6 is charged by the input current to the oscillation circuit 5. In the illustrated polarity of the AC power supply 1, when the terminal voltage of the intermittent oscillation capacitor 6 exceeds the breakover voltage of the thyristor 81, the thyristor 81 becomes conductive, so the intermittent oscillation capacitor 6
A discharge current flows in the closed circuit of the primary winding 91, the bias coil 54, the thyristor 81, the diode 82, and the filament 32-6. Due to this discharge current, a boosted pulse voltage Vp is generated in the secondary winding 92, and the pulse voltage Vp is multiplied by the bias coil 54 in the oscillation circuit 5.
' is applied to both ends of the discharge lamp 3 in a superimposed manner with the oscillation voltage Vo. On the other hand, when the power supply voltage of the AC power supply 1 becomes a polarity opposite to that shown in the figure, the diode 82 becomes reversed even if the intermittent oscillation capacitor 6 is charged with the opposite polarity to that shown in the figure, due to the oscillation operation of the oscillation circuit 5'. Since the direction is inserted, the thyristor 81 is not conductive, and therefore the pulse generating circuit 7B does not generate a pulse voltage.

Thereafter, similarly, a voltage obtained by multiplying the pulse fin pressure Vp and the multiplied oscillation voltage Vo is generated for each polarity of the power supply voltage e, and only the oscillation voltage Vo is generated for the opposite polarity.
Then, at one side of the power supply voltage e, a pulse voltage Vp
When the discharge lamp 3 is started and lit by a voltage that is a combination of the oscillation voltage Vo and the oscillation voltage Vo, the pulse generating circuit 7B stops the pulse generating operation in the same manner as in the embodiment shown in FIG. 3 described above. Thereafter, the discharge lamp 3 is kept lit by the power supply voltage e while being re-ignited every half cycle of the AC power supply by the intermittent oscillation voltage yo' caused by the action of the oscillation circuit 5' and the intermittent oscillation capacitor 6. Note that various other modifications can be made by changing the switch means 8 consisting of a series circuit of a thyristor 81 and a diode 82 shown in FIG. 5.

6a and 6b are circuit diagrams of another embodiment of the switch means 8. FIG.

In FIG. 6a, a thyristor 83 is connected in series to a parallel circuit of a thyristor 81 and a diode 82.

In operation, the terminal voltage of the intermittent oscillation capacitor 6 is set to the thyristor 81 at one polarity of the AC voltage e.
and 83, a pulse voltage Vp is generated, and in the other polarity of the AC voltage e, when the terminal voltage of the intermittent oscillation capacitor 6 exceeds the breakover voltage of one thyristor 83, a pulse voltage Vp is generated. It is designed to generate a pulse voltage Vp. In FIG. 6b, a gated thyristor 84 is used as the switch means 8. In FIG. FIG. 7 is a circuit diagram of a fin lamp lighting device according to still another embodiment of the present invention.

In the configuration, the primary winding 2a of the current limiting choke 2, the discharge lamp 3, and the secondary winding 92 of the pulse transformer 9 are connected in series to the AC power supply 1. Filament 3 of discharge lamp 3
The secondary winding 2b of the current limiting choke 2, the oscillation circuit 5', the thyristor 81, and the diode 82 are connected to the non-power supply side ends of 1 and 32.
series circuit is connected. Further, a series circuit of an intermittent oscillation capacitor 6 and a primary winding 91 of a pulse transformer 9 is inserted between the oscillation circuit 5' and the power supply side end of the filament 32. Further, a high frequency pass capacitor 10 is connected in parallel to the AC power supply 1 as required. The operation of this embodiment is almost the same as that shown in FIG. 5, and can be easily understood with reference to FIG. 5, so a detailed explanation thereof will be omitted.

FIG. 8 is a circuit diagram of a discharge lamp lighting device according to another embodiment of the present invention, and particularly shows a case where two discharge lamps are lit in series.

In the configuration, an AC power supply 1 is connected in series with a current limiting choke 2 and discharge lamps 3a and 3b. A series circuit of a pulse generation circuit 7D and an oscillation circuit 5' is connected between the non-power supply side end of the filament 31a of the discharge lamp 3a and the non-power supply side end of the filament 32b of the discharge lamp 3b. The pulse generating circuit 7D connects the intermittent oscillation capacitor 6 in parallel with the primary winding 91 of the pulse transformer 9 and the series circuit of the triax 85, and connects the secondary winding 9 of the pulse transformer 9 in parallel.
The series circuit of 2 and capacitor 1 is connected to discharge lamps 3a and 3b.
It is commonly connected to the filaments 32a and 31b on the connection point side. Further, a filament winding 12 is wound around the primary winding 91, and both ends of the filament winding 12 are connected to the filaments 32a and 31M. Furthermore, if necessary, for the filaments 31b and 32b of the discharge lamp 3b,
The sequential starting capacitors 3 may be connected in parallel. It is assumed that the gate signal of the triac 85 is given from an appropriate gate circuit. In operation, the above 1
Similarly to the lamp lighting circuit, the intermittent oscillation capacitor 6 is charged during the oscillation operation period of the oscillation circuit 5'.

When the intermittent oscillation capacitor 6 is charged to a predetermined voltage, the triac 85 is
When a gate signal is applied to the triac 85, the triac 85 is activated. In response, a pulsed discharge current flows from the intermittent oscillation capacitor 6 through the closed circuit of the primary winding 91 and the triac 85, and a stepped-up pulse voltage Vp is induced in the secondary winding 92. This pulse voltage Vp is applied via the capacitor 11 to the connection point between the discharge lamps 3a and 3b. At this time, a voltage is induced in the filament winding 12 by the discharge current flowing through the primary winding 91, and the filaments 32a and 31b are preheated by the colloquial electromotive voltage. As this operation is repeated, the filaments 31a and 32b are sufficiently preheated by the input current to the oscillation circuit 5', and the filaments 31a and 32b are
When a and 31b are sufficiently preheated by the induced power caused by the discharge current of the pulse generation circuit 7D, the discharge lamp 3a is started and lit by the superimposed voltage of the oscillation voltage Vo of the oscillation circuit 5' and the pulse voltage Vp of the pulse generation circuit 7D. be done. Subsequently, the discharge lamp 3b is started and lit by the superimposed voltage of the oscillation voltage Vo and the pulse voltage Vp. In this manner, when the discharge lamps 3a and 3b are started and lit, the gate signal of the triac 85 is no longer applied. Therefore, the intermittent oscillation capacitor is enabled and the power supply voltage e is canceled out, so that the oscillation circuit 5 is caused to oscillate intermittently at each predetermined phase of each half cycle of the power supply voltage e. As a result, the discharge lamps 3a and 3b output the intermittent oscillation output Vo' of the oscillation circuit 5'.
It is kept lit by the light. As described above, according to the present invention, when starting a discharge lamp, the necessary starting voltage is obtained by the superimposed voltage of the oscillation voltage and the pulse voltage to start and light the discharge lamp, and after lighting the discharge lamp, the discharge lamp is restarted. By re-igniting with only the oscillation voltage necessary for ignition, it is possible to prevent damage to the electrodes and extend the life of the discharge lamp without applying high voltage after starting the discharge lamp. The effect is produced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an every-cycle start lighting system which is the background of the present invention.

FIG. 2 is a block diagram showing the principle of the invention. FIG. 3 is a circuit diagram of a discharge lamp lighting device according to an embodiment of the present invention. FIG. 4 is a waveform diagram for explaining the operation of FIG. 3. FIGS. 5 and 7 are circuit diagrams of other embodiments of the invention. FIG. 6 is a circuit diagram showing a modification of the switch means of FIG. 5. FIG. 8 shows another embodiment 2 of this invention.
FIG. 2 is a circuit diagram of a discharge lamp lighting device when lighting lamps in series. In the figure, 1 is an AC power supply, 2 is a current limiting choke, 3, 3a, 3b are discharge lamps, 4' is an intermittent high frequency voltage generating means, 5' is an oscillation circuit, 51 is an oscillation capacitor, 52 is a current-controlled nonlinear resistance element (thyristor), 53 is a boost inductor, 54 is a bias coil, 6
7, 7A to 7D are pulse generating circuits, and 8 is a switching means.

Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. A discharge lamp is connected to a low-frequency AC power source via a current limiting device, and a series circuit of an oscillation capacitor, a current-controlled nonlinear resistance element, and a step-up inductor is connected in parallel with the discharge lamp. It includes an oscillation circuit connected in parallel and an intermittent oscillation capacitor connected in series to at least the current-controlled nonlinear resistance element, and generates a high frequency and high voltage at the beginning of each half cycle of the AC power source to power the discharge lamp. In a discharge lamp lighting device that is capable of restriking and maintaining lighting using only a low-frequency AC power supply voltage after the discharge lamp is restriked, at least a switch means is connected in parallel to the intermittent oscillation capacitor, comprising pulse voltage generating means for generating a pulse voltage that is superimposed on the high frequency high voltage of the intermittent high frequency voltage generating means and applied to the discharge lamp, the high frequency high voltage of the intermittent high frequency voltage generating means and the pulse of the pulse voltage generating means; A discharge lamp lighting device characterized in that a peak of a superimposed voltage with a voltage is set to be equal to or higher than a starting voltage of the discharge lamp. 2 The pulse voltage generating means includes one pulse transformer in a parallel circuit of the intermittent oscillation capacitor and the switch means.
Claim 1, wherein the secondary winding of the pulse transformer is connected to a location where the high frequency high voltage of the intermittent high frequency voltage generating means is superimposed on and applied to the discharge lamp. discharge lamp lighting device.