JPH0244695A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To reduce pulse voltage at the time of restarting while shortening a rising time of a light output by impressing a high frequency electromagnetic field on a discharge lamp. CONSTITUTION:In addition to that power is supplied to an electricity-proof lamp 4 from a power supply device 14, a high-frequency electromagnetic field is always impressed thereon from a high-frequency electromagnetic generation device 15. Thereby, atoms of sealed gas inside a luminous tube of a discharge lamp 4 are in an excited state while coming to a state liable to start so that it suffys to make up required energy for moving to a state being able to start discharge from the excited state by a high-tension pulse to be generated in a high-tension pulse generation device 3 in order to start immediately after putting out the discharge lamp 4 so that the height of the high-tention pulse necessary for restarting can be lowered. Further, the high-tention pulse generation device 3 stops its output by a control device 16 after starting of the discharge lamp 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a discharge lamp lighting device that facilitates restarting.

2. Description of the Related Art Conventionally, as a discharge lamp lighting device of this type, one shown in FIG. 8 is known. In FIG. 8, 1 is a commercial AC power supply, 2 is a ballast, 3 is a high voltage pulse generator, 4 is a discharge lamp, and 5 is a control device for controlling the output of the high voltage pulse generator 3. The high voltage pulse generator 3 includes a pulse transformer 6, a spark gap 7, a capacitor 8, and a charging circuit 9. Further, the charging circuit 9 includes a transformer 10 and a resistor 11. Note that the commercial AC power supply 1 is connected to a ballast 2, and a high voltage pulse generator 3 is connected between the input terminals of the ballast 2 via a control device 5, forming a part of the high voltage pulse generator 3. It is connected to the discharge lamp 4 via the secondary winding 12 of the pulse transformer 6. In the discharge lamp lighting device configured in this manner, the high voltage pulse generator 3 is operated by the control device 5 at the time of starting and restarting. That is, charging of the capacitor 8 is started from the commercial AC power supply 1 through the charging circuit 9, and when the voltage of the capacitor 8 reaches the breakover voltage of the spark gap 7, the spark gap 7 becomes conductive. This operation causes the primary winding A of the pulse transformer 6! 1.3, the electric charge stored in the capacitor 7 is discharged, and a high pulse voltage is generated in the secondary winding 12 of the pulse transformer 6, and is applied to the discharge lamp 4. Note that such a discharge lamp lighting device is configured to be able to generate high-voltage pulses necessary for restarting in a high-temperature state at any time. However, when the discharge lamp 4 starts, the high voltage pulse generator 3
The control device 5 operates to stop the generation of high voltage pulses. In addition, the discharge lamp 4 is connected to a commercial AC power source 1 at the lighting center.
Power is supplied through the ballast 2 and the secondary winding 12 of the pulse transformer 6 to maintain lighting.

Problems to be Solved by the Invention However, in conventional discharge lamp lighting devices, immediately after the discharge lamp is turned off, the arc tube is in a high temperature state, so the discharge starting voltage is higher than during normal starting, and it is difficult to immediately restart the discharge lamp. For this purpose, it is necessary to apply a higher pulse voltage to the discharge lamp.

Therefore, there are problems such as the lighting device becoming large due to the need for insulation against high voltage, and the spark gap that constitutes the high voltage pulse generator being susceptible to deterioration.

Means for Solving the Problems The present invention provides a discharge lamp, a power supply device that supplies power to the discharge lamp, a high voltage pulse generator that applies a high voltage pulse to the discharge lamp at least at the time of restarting, and This discharge lamp lighting device includes a high-frequency electromagnetic field generator that applies a high-frequency electromagnetic field to the lamp, and a control device that controls the output of the high-voltage pulse generator.

By applying a working high frequency electromagnetic field, the pulse voltage required during restart is reduced.

Embodiment A block diagram of a first embodiment of a discharge lamp lighting device according to the present invention is shown in FIG. In Fig. 1, 4 is a discharge lamp;
14 is a power supply device, 3 is a high voltage pulse generator, 15 is a high frequency electromagnetic field generator, and 16 is a control device for controlling the output of the high voltage pulse generator 3. The power supply device 14 is connected to the discharge lamp 4 via the high voltage pulse generator 3 and supplies power to keep the discharge lamp 4 lit.

However, a control device 16 is connected between the power supply device 14 and the high voltage pulse generator 3, thereby operating the high voltage pulse generator 3t and controlling its output. Further, this power supply device 14 includes a high frequency electromagnetic field generating device 1
It also supplies power to operate 5. That is,
In this embodiment, in addition to being supplied with power from the power supply device 14,
A high frequency electromagnetic field is constantly applied to the discharge lamp 4 from the high frequency electromagnetic field generator 14 . Generally, when the discharge lamp 4 is stably turned on and then turned off once, the discharge lamp 4 is in a high temperature state, so it is more difficult to start than in the case of a normal cold start. However, since the high-frequency electromagnetic field is constantly applied to the discharge lamp 4, the atoms of the gas filled in the arc tube of the discharge lamp 4 are in an excited state, making it easier to start than when no high-frequency electromagnetic field is applied. . Therefore, in order to restart the discharge lamp 4 immediately after extinguishing it, the energy required to transition from this excited state to a state where discharge can be started can be supplemented by the high voltage pulses generated by the high voltage pulse generator 3. good.

As a result, the height of the high voltage pulse required to instantaneously restart the discharge lamp 4 can be lowered compared to a conventional restart method that does not apply a high frequency electromagnetic field. Note that the high voltage pulse generator 3 is controlled in part by the control device 16.
After the discharge lamp 4 is started, its output is stopped. however,
The effect of lowering the height of the high voltage pulse required for restart is
The effect differs depending on the intensity of the applied high-frequency electromagnetic field, the position of the discharge lamp 4 in the high-frequency electromagnetic field, etc. As a result of a simple experiment, 25. We confirmed that by placing an OW type metal halide lamp in a 2.45GHz high frequency electromagnetic field, the height of the high voltage pulse required to immediately restart the lamp after it has been turned off can be reduced to 1/3 or less. ing.

It goes without saying that the starting method according to this embodiment can also be applied to normal cold starting.

This prevents deterioration of the spark gap that constitutes the high voltage pulse generator, and also simplifies insulation measures, making it possible to downsize the device. Furthermore, in this embodiment, since the electrodes of the discharge lamp 4 are not used to apply a high frequency electromagnetic field, an excessive high frequency electromagnetic field can be applied to the discharge lamp 4 at the time of starting. As a result, the rise of the optical output during the starting period becomes faster, and it becomes possible to shorten the time required to reach stable lighting. As the control device 16 for controlling the output of the high voltage pulse generator 3, for example, a timer circuit may be used to stop the generation of high voltage pulses after a certain period of time has passed after the power is turned on. That is, any device may be used as long as it can stop supplying power to the high voltage pulse generator after the discharge lamp 4 is started. It doesn't matter if it is. In this embodiment, the high voltage pulse generator 3 is configured to operate without distinction between normal startup and restart in a high temperature state, but depending on the magnitude of the applied high frequency electromagnetic field energy, It is also possible to configure the high voltage pulse generator 3 to operate only at the time of starting. That is, during normal starting, the energy required for starting is smaller than when restarting in a high temperature state, and depending on the magnitude of the high frequency electromagnetic field energy to be applied, starting can be performed without applying a high voltage pulse. This results in
The frequency with which the high voltage pulse generator 3 is operated is reduced, making it possible to prevent deterioration of the life of the spark gap.

Next, FIG. 2 shows a block diagram of a second embodiment of the present invention in which the discharge lamp is an electrodeless discharge lamp. In FIG. 2, 17 is an electrodeless discharge lamp, 18 is a power supply device, 3 is a high voltage pulse generator, 15 is a high frequency electromagnetic field generator, and 16 is a control device for controlling the output of the high voltage pulse generator 3. Note that the power supply device 18 is connected to the high voltage pulse generator 3 via the control device 16.

The power supply device 18 also supplies power to operate the high frequency electromagnetic field generator 15, and the high frequency electromagnetic field is constantly applied to the electrodeless discharge lamp 17 from the high frequency electromagnetic field generator 15. That is, at the time of starting, the high voltage pulse generator 3 connected to the power supply device 18 is operated while a high frequency electromagnetic field is applied to the electrodeless discharge lamp 17, and a high voltage pulse is generated from the outside of the electrodeless discharge lamp 17. The voltage is applied to start the electrodeless discharge lamp 17. Note that the high voltage pulse generator 3 is an electrodeless discharge lamp 17.
After starting, the control device 16 stops its operation.

In this case as well, depending on the strength of the applied high-frequency electromagnetic field, it is possible to configure the high-voltage pulse generator 3 to operate only at restart. Furthermore, in the case of this configuration, as in the first embodiment, deterioration of the spark gap can be prevented, the device can be downsized, and the rise time of the optical output during the starting period can be shortened.

Next, a block diagram of a third embodiment of the discharge lamp lighting device according to the present invention is shown in FIG. The difference from the first embodiment of the discharge lamp lighting device shown in FIG. 3 is that the lighting device includes a timer circuit 19, and when a certain period of time has passed after the discharge lamp 4 is started, this timer circuit 19 is activated. The output of the high frequency electromagnetic field generator 15 is controlled by In the first embodiment of the present invention, since the power supply device 14 always supplies power to keep the discharge lamp 4 lit, it is not necessary to apply a high-frequency electromagnetic field after the discharge lamp 4 is lit. . In this embodiment, when a certain period of time has elapsed after the discharge lamp 4 was started, the timer circuit 19 operates to stop applying the high-frequency electromagnetic field.

This makes it possible to prevent wasteful power consumption during stable lighting, and to reduce the adverse effects on the human body and peripheral devices due to leakage of high-frequency electromagnetic fields.

Note that if a measure such as shielding the discharge lamp 4 with a metal mesh is used to prevent leakage of the high-frequency electromagnetic field, the loss of light output due to this can be prevented by removing the shield during stable lighting.

Next, a block diagram of a fourth embodiment of the discharge lamp lighting device according to the present invention is shown in FIG. The difference from the second embodiment of the discharge lamp lighting device shown in FIG. A control device 2 that controls the output of the high-frequency electromagnetic field generator 15 based on signals from the
1 was established. In this embodiment, as in the case of the third embodiment of the present invention, application of the high frequency electromagnetic field is stopped after stable lighting of the discharge lamp 4. This prevents wasted power consumption during stable lighting, and reduces the negative impact on the human body and peripheral equipment due to leakage of high-frequency electromagnetic fields. If the light source 4 is shielded with a metal mesh, by removing the shield during stable lighting, it is possible to prevent loss of light output due to this. However, since this embodiment includes a detection unit 20 that detects stable lighting of the discharge lamp 4, more reliable detection is possible compared to the second embodiment of the present invention using a timer circuit. .

Next, FIG. 5 shows a specific example of the configuration of a lighting device according to a fourth embodiment of the present invention. In FIG. 5, 1 is a commercial AC power supply, 2 is a ballast, 3 is a high voltage pulse generator,
4 is a discharge lamp, 15 is a high frequency electromagnetic field generator, and 5 is a control device for controlling the output of the high voltage pulse generator 3. Note that the high frequency electromagnetic field generating device 15 includes the high frequency oscillator 2
2. It is composed of a waveguide 23, a cavity resonator 24, and a photosensitive short body which is a detection section 20. Further, the commercial AC power supply 1 is connected to a ballast 2, and a high voltage pulse generator 3 is connected between the input terminals of the ballast 2 via a control device 5, forming a part of the high voltage pulse generator 3. Secondary winding of pulse transformer 6,
It is connected to the discharge lamp 4 via *12 and supplies power to keep the discharge lamp 4 lit. Note that the operation of the high voltage pulse generator 3 is controlled by a control device 16. In addition, the commercial AC power supply 1 includes a high frequency oscillator 2
It also supplies power to operate 2. In this embodiment, in addition to power being supplied from the commercial AC power source 1, a high frequency electromagnetic field is applied to the discharge lamp 4 from a high frequency electromagnetic field generator 15. That is, power is supplied from the commercial AC power supply 1 to the high frequency oscillator 22, and the generated high frequency electromagnetic waves are transmitted to the waveguide 2.
3 and is applied to the discharge lamp 4 located within the cavity resonator 24. Generally, when the discharge lamp 4 is stably turned on and then turned off once, the discharge lamp 4 is in a high temperature state, so it is more difficult to start than in the case of a normal cold start. However, since the high-frequency electromagnetic field is constantly applied to the discharge lamp 4, the atoms of the gas filled in the arc tube of the discharge lamp 4 are in an excited state and are more likely to start than when no high-frequency electromagnetic field is applied. be. Therefore, in order to restart the discharge lamp 4 immediately after extinguishing it, the energy required to transition from this excited state to a state where discharge can be started can be supplemented by the high voltage pulses generated by the high voltage pulse generator 3. As a result, the height of the high voltage pulse required to instantaneously restart the discharge lamp 4 can be lowered compared to a conventional restart method that does not apply a high frequency electromagnetic field. The high-voltage pulse generator 3 is controlled by the control device 16 to stop its output after the discharge lamp 4 has started, and when the discharge lamp 4 has started and the light output increases, the high-voltage pulse generator 3 stops the output of the high-voltage pulse generator 3 by the control device 16. When the short body detects the light output from the discharge lamp 4 and reaches stable lighting, the control device 21 operates to stop the operation of the high frequency electromagnetic field generating device 15. It goes without saying that the starting method according to this embodiment can also be applied to normal cold starting. Note that the photosensitive short body in this embodiment may be, for example, a photodiode, but other types may be used as long as they can detect light output and operate the control device. Further, the same effect can be obtained by using a method of detecting, for example, the temperature near the arc tube, lamp current, lamp voltage, etc. as a means for detecting stable lighting of the discharge lamp 4.

Next, a block diagram of a fifth embodiment of the discharge lamp lighting device according to the present invention is shown in FIG. The difference from the first embodiment of the discharge lamp lighting device shown in FIG. 7 is that the reflector 2 of the vehicle headlamp is
5 and a discharge lamp 26 used for a vehicle headlamp.

Conventionally, light bulbs have been used for vehicle headlights, but recently, the use of discharge lamps has been considered from the viewpoint of improving efficiency and light distribution controllability. At this time, it is difficult to immediately start the headlights, immediately restart them, and rapidly rise the luminous flux, which are necessary when driving a vehicle, and therefore, it is necessary to apply extremely high voltage pulses, and M! ! There have been cases where this has become a practical problem due to relatedness.

In this embodiment, a discharge lamp lighting device like the first embodiment of the present invention is incorporated into a vehicle headlamp. In this embodiment, the power supply device 14 is connected to a discharge lamp 2 disposed at a predetermined position of a reflecting mirror 25 via a high voltage pulse generator 3.
6 to supply power to keep the discharge lamp 26 lit.

The high frequency electromagnetic field generator 15 has its output section connected to a reflecting mirror 25.
A coil is placed around the reflector itself. The power supply device 14, the high voltage pulse generator 3, and the high frequency electromagnetic field generator 15 are connected to the control device 27 at the same time. first,
When starting the discharge lamp 26, the output voltage of the power supply device 14 is applied to the discharge lamp 26 according to a signal from the control device 27, and at the same time, the high-frequency electromagnetic field generator 15 also outputs the high-frequency electromagnetic field. is applied, and the atoms of the gas sealed in the arc tube are excited, and at the same time, the high voltage pulse from the high voltage pulse generator 3 is applied to the discharge lamp 26.
to be applied. Therefore, the discharge lamp 26 is started immediately and transitions to arc discharge by the power from the power supply device 14. At the same time, the entire arc tube is heated by the high frequency electromagnetic field from the high frequency electromagnetic field generator 15. Therefore, the luminescent metal precipitated within the arc tube evaporates rapidly, increasing the vapor pressure within the arc tube. As the vapor pressure inside the arc tube gradually increases,
The energy of the high-frequency electromagnetic field from the high-frequency electromagnetic field generator 15 is gradually absorbed by the vapor in the arc tube, and positive feedback occurs that further increases the vapor pressure, resulting in a rapid increase in vapor pressure.

Since the luminous intensity increases in proportion to the vapor pressure, the luminous flux from the headlamp can also rise rapidly. Note that when the discharge lamp 26 shifts to arc discharge, the operation of the high voltage pulse generator 15 is stopped by a signal from the control device 27.

In addition, after the luminous flux of the discharge lamp 26 of the headlight becomes stable,
The high frequency electromagnetic field generating device 1 is activated by a signal from the control device 27.
5 stops operation.

Next, since the discharge lamp 26 is generally in a high temperature state at the time of restart, it is more difficult to start it than in the case of a normal cold start. However, in this case as well, a high frequency electromagnetic field is applied to the discharge lamp 26 by the same operation as at the time of starting, so the discharge lamp 26 immediately restarts and the luminous flux also rises rapidly. As a result, the height of the high-voltage pulse required to instantaneously restart the discharge lamp 26 can be lowered compared to a conventional restart method that does not apply a high-frequency electromagnetic field. After stable lighting, power is constantly supplied from the power supply device 14 to maintain lighting of the discharge lamp 26, and stable lighting continues.

As described above, in this embodiment, immediate starting, restarting, and rapid rise of the luminous flux are possible, and the voltage of the high voltage pulse can be lowered, so that the insulation level can be lowered. At the same time, the reflector 25 of the headlight is connected to the high frequency electromagnetic field generator 15.
It can be used not only as an output section but also as a cavity resonator, and noise leakage can be prevented. Further, by providing a means such as shielding the lens at the opening of the headlamp with a metal mesh, leakage of the high frequency electromagnetic field can be completely prevented. Furthermore, it can also protect the lens. Furthermore, a mechanism for removing the shield after stable lighting can be provided to prevent loss of light output due to this.

Next, a block diagram of the sixth actual flow side of the discharge lamp lighting device according to the present invention is shown in FIG. The difference from the fifth embodiment of the discharge lamp lighting device shown in FIG. 8 is that the high frequency electromagnetic field generating device 1
5 is guided to a reflecting mirror 25 and a discharge lamp 26 using a waveguide 23, and a vehicle igniter 28 supplies high voltage to the vehicle engine. In this embodiment, first, when starting the discharge lamp 26, the output voltage of the power supply device 14 is applied to the discharge lamp 26, and at the same time, it is also output from the high frequency electromagnetic field generator 15, and the output passes through the waveguide 23. It passes through and is manually applied to the reflecting mirror 25. Reflector 2
5 constitutes a cavity resonator for this incident wave, so that the high frequency electromagnetic field applied to the discharge lamp 26 can be increased and the efficiency is good.

Therefore, the atoms of the gas sealed in the arc tube have a higher excitation state. At the same time, a high voltage pulse generated by the vehicle igniter 28 is applied to the discharge lamp 26. That is, it is used as a high voltage pulse generator. Therefore, the discharge lamp 26 is started immediately and transitions to arc discharge by the power from the power supply device 14. At the same time, high frequency electromagnetic field generator 1
The entire arc tube is heated by the high frequency electromagnetic field from 5.

Therefore, the luminous flux from the headlight can also rise rapidly. Note that when the discharge lamp 26 shifts to arc discharge, the operation of the high voltage pulse generator 15 is stopped. Moreover, after the luminous flux of the discharge lamp 26 of the headlamp becomes stable, the high-frequency electromagnetic field generator 15 stops operating. The same applies when restarting.

As described above, in this embodiment, immediate starting, restarting, and rapid rise of the luminous flux are possible, and the voltage of the high voltage pulse can be lowered, so that the insulation level can be lowered. At the same time, the reflector 25 of the headlamp can be used as a cavity resonator to achieve more efficient and rapid rise. Furthermore, since the vehicle igniter 28 is used as a high voltage pulse generator, the entire structure can be simplified, made small, and inexpensive.

In addition. In the embodiments described above, the discharge lamp 26 may be a high-pressure discharge lamp having a metal luminescent material, such as a metal halide lamp or a high-pressure sodium lamp, or may be another type, such as a gas luminescent lamp without a metal luminescent material. Furthermore, in the fifth and sixth embodiments, even if the reflecting mirror 25 is not the output part of the high-frequency electromagnetic field generating device 15, it is possible to apply a low pulse voltage by applying a high-frequency electromagnetic field at the time of mere optical counterstarting. It enables instantaneous restart of the discharge lamp, extremely shortens the rise time of light output when starting or restarting the discharge lamp, and reduces the spark gap that constitutes the high voltage pulse generator. It is possible to provide a discharge lamp lighting device that can prevent deterioration and realize miniaturization of the device.

[Brief explanation of the drawing]

1 is a block diagram of a first embodiment of a discharge lamp lighting device according to the present invention, FIG. 2 is a block diagram of a second embodiment of a discharge lamp lighting device according to the present invention, and FIG. 3 is a block diagram of a discharge lamp lighting device according to a second embodiment of the present invention. FIG. 4 is a block diagram of the eighth embodiment of the electric lamp lighting device, FIG. 4 is a block diagram of the fourth embodiment of the discharge lamp lighting device of the present invention, and FIG. 5 is a block diagram of the fourth embodiment of the discharge lamp lighting device of the present invention. FIG. 6 is a block diagram of a fifth embodiment of a discharge lamp lighting device according to the present invention; FIG. 7 is a block diagram of a sixth embodiment of a discharge lamp lighting device according to the present invention; FIG. 8 is a configuration diagram of a conventional discharge lamp lighting device. 3... High voltage pulse generator, 4... Discharge lamp,
14... Power supply device, 15... High frequency electromagnetic field generator, 16... Control device, 17... Electrodeless discharge lamp,
18...Power supply device, 19...Timer circuit, 20...
- Detection unit, 21... Control device, 22... High frequency oscillator, 23... Waveguide, 24... Cavity resonator, 25...
...reflector, cavity resonator, 26...discharge lamp,
27...Control device, 28...Vehicle igniter. Name of agent: Patent attorney Shigetaka Awano

Claims (6)

[Claims] (1) A discharge lamp, a power supply device that supplies power to the discharge lamp, a high-voltage pulse generator that applies a high-voltage pulse to the discharge lamp at least when restarting, and a high-frequency electromagnetic field that applies a high-frequency electromagnetic field to the discharge lamp. A discharge lamp lighting device comprising: a high-frequency electromagnetic field generating device; and a control device controlling an output of the high-voltage pulse generating device. (2) The discharge lamp lighting device according to claim 1, which includes a timer circuit and controls the output of a high-frequency electromagnetic field generator based on a signal from the timer circuit. (3) It has a detection part that detects stable lighting of the discharge lamp,
The discharge lamp lighting device according to claim 1, wherein the output of the high frequency electromagnetic field generator is controlled based on the signal from the detection section. (4) The discharge lamp lighting device according to claim 1, 2, or 3, wherein the discharge lamp is a discharge lamp incorporated in a vehicle headlamp. (5) The discharge lamp lighting device according to claim 4, wherein the high voltage pulse generator is a vehicle igniter. (6) The discharge lamp lighting device according to claim 4 or 5, wherein the reflector of the vehicle headlamp is an output cavity resonator of a high-frequency electromagnetic field generator.