JP2009289684A - High pressure discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device which certainly lights a high pressure discharge lamp connected by wiring of 3 m or more of cabling distance and prevents an error operation and damages due to leakage of a high pressure pulse. <P>SOLUTION: The lighting device for high pressure discharge lamp includes a starting part 4 which includes a pulse transformer 31 and generates pulse voltage for starting the high pressure discharge lamp connected by wiring of 3 m or more of cabling distance; a lighting circuit 30 which is connected to the starting part and drives the started high pressure discharge lamp; a pulse bypass capacitor C1 which is connected between the output ends of the lighting circuit; and capacitors for grounding C2, C3 which are connected between the output end of the lighting circuit and the reference potential point. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high pressure discharge lamp lighting device including a starter that generates a high pressure pulse for starting a high pressure discharge lamp.

  Conventionally, a high pressure discharge lamp lighting device for lighting a high pressure discharge lamp has a built-in starter for generating a high voltage pulse voltage for starting the high pressure discharge lamp. When this type of high-pressure discharge lamp lighting device is placed close to the high-pressure discharge lamp and the wiring length (wiring distance) between the starter and the high-pressure discharge lamp is small, the high-pressure pulse voltage is not attenuated and the high-pressure discharge lamp is Since it is applied, there is no problem in startability. However, the length of the wiring between the starting device and the high pressure discharge lamp may be increased due to the installation of equipment. In such a case, the stray capacitance, inductance component, etc. increase with the extension of the wiring length, and the attenuation of the high voltage pulse voltage increases, making it difficult to start the high pressure discharge lamp.

Therefore, in Patent Document 1, a first starter is provided at a position separated from the discharge lamp, and a second starter is provided at a position close to the discharge lamp, whereby the first starter in the high pressure discharge lamp lighting device is provided. There has been proposed a technique for reliably starting a high-pressure discharge lamp at a position separated from one starting device.
JP 2005-215722 A

  However, the device of Patent Document 1 has the disadvantages that it is necessary to provide two starting devices, which increases the circuit configuration and costs.

  In consideration of the attenuation of the high-voltage pulse voltage, an apparatus that generates a very high-level high-voltage pulse voltage is also conceivable. However, the generated high-pressure pulse may leak through a conductive pipe such as a metal pipe that houses the wiring from the starting device to the high-pressure discharge lamp. The leaked high-pressure pulse flows into the circuit of the high-pressure discharge lamp lighting device from the conductive pipe through the ground line and the grounding capacitor. Thus, the leaked pulse energy may cause a malfunction in the circuit in the high pressure discharge lamp lighting device, and the circuit components may be destroyed.

  The present invention has been made in view of such a problem, and even when the wiring length between the starting device and the high pressure discharge lamp is relatively long, the high pressure pulse is prevented from leaking and has a simple configuration. An object of the present invention is to provide a high pressure discharge lamp lighting device capable of reliably starting a high pressure discharge lamp.

  The high-pressure discharge lamp lighting device according to claim 1, further comprising: a starting unit that has a pulse transformer and generates a pulse voltage for starting a high-pressure discharge lamp connected by a wiring having a wiring length of 3 m or more; A lighting circuit for driving the high-pressure discharge lamp that has been started and connected; a pulse bypass capacitor connected between the output terminals of the lighting circuit; and a connection between the output terminal of the lighting circuit and a reference potential point And a grounding capacitor to be provided.

  In addition, the high pressure discharge lamp lighting device according to claim 2 includes a pulse transformer, and a starting unit that generates a pulse voltage for starting a high pressure discharge lamp connected by a wiring having a wiring length of 3 m or more; A lighting circuit connected to the starting unit and driving the started high-pressure discharge lamp; a filter circuit connected to a power supply side of the lighting circuit; connected between an input terminal of the filter circuit and a reference potential point And a grounding capacitor.

  The high pressure discharge lamp lighting device according to claim 3 is characterized in that a capacitor that suppresses the attenuation of the pulse voltage is connected between the output terminals of the starting unit.

  According to the present invention, even when the wiring length between the starter and the high-pressure discharge lamp is relatively long, high-pressure pulses are leaked, the circuit is prevented from malfunctioning, and the circuit components are prevented from being destroyed. With this configuration, the high pressure discharge lamp can be reliably started.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a high pressure discharge lamp lighting device according to a first embodiment of the present invention.

  As shown in FIG. 1, the high-pressure discharge lamp lighting device 2 is supplied with a power supply voltage from a commercial AC power supply 1. The AC voltage from the commercial AC power supply 1 is output to the rectifier circuit 11 via the filter circuit 10. The filter circuit 10 removes high frequency components of the lighting circuit 3 described later. The rectifier circuit 11 converts the AC voltage from the filter circuit 10 into a DC voltage and outputs it to the lighting circuit 30.

  The lighting circuit 30 has one output end connected to the output end O1 via the starter 4, and the other output end connected to the output end O2. The high pressure discharge lamp 3 is connected between the output terminals O1 and O2 via the wiring 5. The starting unit 4 including the pulse transformer 31 generates a pulse voltage that starts the high-pressure discharge lamp 3. In the present embodiment, the wiring length of the wiring 5 is assumed to be a sufficiently long length, for example, 3 m or more, and the starting unit 4 is capable of releasing high voltage even when the pulse voltage is attenuated by the wiring 5 of 3 m or more. A pulse voltage having a level sufficient to light the electric lamp 3 can be generated.

  In the present embodiment, a pulse bypass capacitor C1 is connected between the positive output terminal and the negative output terminal of the lighting circuit 30, and the grounding capacitor C3 is connected to the positive output terminal. The negative output terminal is connected to the reference potential point via the grounding capacitor C2. A capacitor C4 is connected between the output terminals O1 and O2.

  FIG. 2 is a circuit diagram showing an example of a specific configuration of the high pressure discharge lamp lighting device 2 of FIG.

  As shown in FIG. 2, a commercial AC power supply 1 is connected to an input terminal of a rectifier circuit 11 configured by a diode bridge and performing full-wave rectification, and a capacitor 12 is connected in parallel to an output terminal of the rectifier circuit 11. A series circuit of a MOS-type first FET (field effect transistor) 14 and a first current detection element 15 is connected in parallel via a first inductor 13. A smoothing capacitor 17 including a forward diode 16 and an electrolytic capacitor is connected in parallel to a series circuit of the first FET 14 and the first current detection element 15.

  A step-up chopper circuit 19 is configured by the first inductor 13, the first FET 14, the diode 16, and the smoothing capacitor 17. The step-up chopper circuit 19 has a chopping control unit 18. The chopping control unit 18 is given an input voltage from the rectifier circuit 11, an output voltage generated across the smoothing capacitor 17, and an output voltage from the first current detection element 15 to control the FET 14 on and off. The turn-off timing is controlled.

  A polarity inversion circuit / regulator circuit 20 is connected between the output terminals of the step-up chopper circuit 19, that is, between both ends of the smoothing capacitor 17. The polarity inversion circuit / regulator circuit 20 includes MOS-type second, third, fourth, and fifth FETs 21, 22, 23, and 24, second and third inductors 25 and 26, and a starting unit 4. Yes.

  That is, the second FET 21, the second inductor 25, and the third FET 22 are connected in series, the drain terminal of the second FET 21 is connected to the positive terminal of the smoothing capacitor 17, and the source terminal of the third FET 22 is the first terminal. The second current detection element 27 is connected to the negative terminal of the smoothing capacitor 17.

  The fourth FET 23, the third inductor 26, and the fifth FET 24 are connected in series, the drain terminal of the fourth FET 23 is connected to the positive terminal of the smoothing capacitor 17, and the source terminal of the fifth FET 24 is the second terminal. The current detection element 27 is connected to the negative terminal of the smoothing capacitor 17.

  The diode 28 is connected in parallel to the series circuit of the second inductor 25 and the third FET 22 with the opposite polarity to the third FET 22, and the series circuit of the third inductor 26 and the fifth FET 24. In addition, the diode 29 is connected in parallel with the reverse polarity of the fifth FET 24.

  The connection point between the second inductor 25 and the third FET 22 is connected to one terminal O2 that connects the high pressure discharge lamp 3, and the connection point between the third inductor 26 and the fifth FET 24 is the start unit 4. Is connected to the other terminal O1 to which the high pressure discharge lamp 3 is connected via the secondary winding of the pulse transformer 31 constituting the.

  The starting unit 4 has a series circuit of a diode 32, a resistor 33, and a capacitor 34 connected in parallel to the fifth FET 24. The series circuit of the primary winding of the pulse transformer 31 and the bidirectional two-terminal thyristor 35 is connected to the capacitor 34. Are constituted by pulse voltage generation circuits connected in parallel.

  Further, the high frequency component of the voltage applied to the high pressure discharge lamp 3 is smoothed between the connection point between the second inductor 25 and the third FET 22 and the connection point between the third inductor 26 and the fifth FET 24. In this manner, a pulse bypass capacitor C1 functioning as a filter is connected.

  The polarity inversion circuit / regulator circuit 20 further includes a switching control unit 37. The switching control unit 37 takes in the output voltage from the second current detection element 27 and switches the second, third, fourth, and fifth FETs 21, 22, 23, and 24 so that the flowing current becomes constant. It comes to control.

  The switching control at this time is performed at a high frequency of several tens KHz for the second and fourth FETs 21 and 23, is performed at a low frequency of 100 Hz for the third and fifth FETs 22 and 24, and The second and fourth FETs 21 and 23 are provided with an off period in which high-frequency switching is not performed in synchronization with the third and fifth FETs 22 and 24. That is, the second FET 21 performs a high-frequency switching operation in synchronization with the period during which the fifth FET 24 is on, and the second FET 21 also stops the high-frequency switching operation during the period during which the fifth FET 24 is off. The state continues and the fourth FET 23 performs a high-frequency switching operation in synchronization with the period during which the third FET 22 is on, and the fourth FET 23 also stops the high-frequency switching operation during the period during which the third FET 22 is off. And the off state is continued.

  Next, lighting control by the high pressure discharge lamp lighting device 2 will be described.

  The power supply voltage is boosted by the on / off operation of the first FET 14, and the boosted DC voltage is charged in the smoothing capacitor 17, and this DC voltage becomes the power source of the polarity inversion circuit / regulator circuit 20. As described above, in the polarity inversion circuit / regulator circuit 20, the third FET 22 and the fifth FET 24 are alternately turned on / off in the low frequency cycle, and the second FET 21 is turned on by the fifth FET 24 being turned on. The high frequency switching operation is performed only during a certain period, and the fourth FET 23 performs the high frequency switching operation only during the period during which the third FET 22 is on.

  Then, before the high pressure discharge lamp 3 is turned on, when the fourth FET 23 is turned on, the fourth FET 23 → the third inductor 26 → the diode 32 → the resistor 33 → the capacitor 34 → the second from the positive terminal of the smoothing capacitor 17. Current sensing element 27 → the charging current flows from the negative terminal of the smoothing capacitor 17 to charge the capacitor 34. This charging is repeated every time the fourth FET 23 is turned on. When the charging voltage of the capacitor 34 eventually reaches the breakover voltage of the bidirectional two-terminal thyristor 35, the bidirectional two-terminal thyristor 35 becomes conductive.

  When the bidirectional two-terminal thyristor 35 is turned on, a discharge current from the capacitor 34 instantaneously flows in the primary winding of the pulse transformer 31, and a high pulse voltage of several KV is generated in the secondary winding of the pulse transformer 31, Applied to the high pressure discharge lamp 3.

  In this case, when the wiring length of the wiring 5 is relatively large, the high pulse voltage is easily influenced by the stray capacitance and inductance component of the wiring 5. However, in the present embodiment, the starting unit 4 has power to apply a sufficient level of pulse voltage to the high-pressure discharge lamp 3. Thereby, even if the wiring length of the wiring 5 is 3 m or more, the high-pressure discharge lamp 3 can be reliably turned on.

  FIG. 3 shows a high voltage pulse generated by the starter 4 with time on the horizontal axis and voltage on the vertical axis. The lower part of FIG. 3 shows the time axis of the upper rectangular area extended.

  In this way, the high pressure discharge lamp 3 starts to be turned on soon. After the high-pressure discharge lamp 3 is lit, the lamp voltage of the high-pressure discharge lamp 3 drops from, for example, about 200 V to about 100 to 130 V, so that the charging voltage of the capacitor 34 becomes the breakover voltage of the bidirectional two-terminal thyristor 35. The pulse voltage output from the starting unit 4 is stopped. That is, after the high pressure discharge lamp 3 is turned on, the generation of the pulse voltage can be stopped reliably.

  Further, during the period when the fifth FET 24 is on, when the second FET 21 is turned on, the secondary FET 21 → the inductor 25 → the high-pressure discharge lamp 3 → the secondary of the pulse transformer 31 starts from the positive terminal of the smoothing capacitor 17. When a current flows through the winding → the fifth FET 24 → the second current detecting element 27 → the negative terminal of the smoothing capacitor 17 and the second FET 21 is turned off, the inductor 25 → the high pressure discharge lamp 3 → the pulse transformer 31 2 A current flows from the next winding → the fifth FET 24 → the diode 28 → the inductor 25, and this is repeated every time the second FET 21 is turned on / off.

  Further, during the period when the third FET 22 is on, when the fourth FET 23 is turned on, the fourth FET 23 → the inductor 26 → the secondary winding of the pulse transformer 31 → the high voltage discharge from the positive terminal of the smoothing capacitor 17. When a current flows to the negative terminal of the lamp 3 → the third FET 22 → the second current detection element 27 → the smoothing capacitor 17 and the fourth FET 23 is turned off, the inductor 26 → the secondary winding of the pulse transformer 31 → the high voltage A current flows through the discharge lamp 3 → the third FET 22 → the diode 29 → the inductor 26, and this is repeated every time the fourth FET 23 is turned on and off.

  In this way, the high pressure discharge lamp 3 maintains lighting at a low frequency of about 100 Hz. Further, the voltage waveform supplied from the polarity inversion circuit / regulator circuit 20 to the high pressure discharge lamp 3 during lighting is a low-frequency rectangular wave. Then, the high frequency component placed on the rectangular wave is removed by the filter function of the capacitor C1.

  Thus, the high pressure discharge lamp lighting device 2 generates a high pressure pulse from the starter 4 at the time of start-up to turn on the high pressure discharge lamp 3, and after the high pressure discharge lamp 3 is turned on, a rectangular wave of 100 Hz is applied to the high pressure discharge lamp 3. The low-frequency power is supplied to continue lighting. The low frequency power is not necessarily limited to a rectangular wave, and may be a sine wave. Further, the power frequency is not limited to 100 Hz, and may be high frequency power.

  By the way, when the wiring length of the wiring 5 is relatively long, the high pulse voltage is easily affected by the stray capacitance and inductance component of the wiring 5. For this reason, as described above, it is necessary to generate a high voltage pulse having an extremely high voltage in the starting unit 4. In the present embodiment, in order to reduce the voltage that must be generated in the starting unit 4, a capacitor C <b> 4 is provided for suppressing the attenuation of the high-voltage pulse voltage due to the influence of the wiring 5. The capacitor C4 is provided between the terminals O1 and O2, and suppresses loss due to stray capacitance and inductance components of the wiring 5.

  FIG. 4 shows the change in pulse voltage due to the difference in the capacitance of the capacitor C4, with the horizontal axis representing the wiring length and the vertical axis representing the pulse voltage supplied to the high pressure discharge lamp 3. When the peak length of the pulse voltage is set to be the same regardless of the capacitance of the capacitor C4 when the wiring length is 0 m, the larger the capacitance of the capacitor C4, the higher the voltage of the pulse voltage. It can be seen that it is supplied to the electric lamp 3.

  FIG. 5 shows the change of the pulse voltage when the capacitance of the capacitor C4 is 1000 pF, with the wiring length on the horizontal axis and the pulse voltage supplied to the high pressure discharge lamp 3 on the vertical axis.

  As shown in FIG. 5, when a capacitor having a capacitance of 1000 pF is used as the capacitor C4, a pulse voltage having a peak voltage of about 4.5 kV can be obtained up to a wiring length of about 5 m. In this case, it can be seen that a pulse voltage having a peak voltage of 3 kV can be obtained even when the wiring length is 35 m.

  Since a general high-pressure discharge lamp is lit by a high-pressure pulse of about 3 kV, the high-pressure discharge lamp can be reliably lit even when the wiring length is longer than 3 m by using the starting unit 4 in the present embodiment. I can see that

  Currently, commercialized high pressure discharge lamp lighting devices may not be able to supply a sufficient pulse voltage for starting when the wiring length exceeds about 2 m. In this embodiment, a pulse voltage having a sufficient peak voltage can be easily generated by using an appropriate capacitance for the capacitor C4.

  Next, the operation when the high-pressure pulse leaks will be described with reference to FIG.

  The wiring 5 is capacitively coupled to a conductive pipe 41 such as a metal pipe that accommodates the wiring 5 via stray capacitances C12 and C13. For this reason, the high voltage pulse transmitted by the wiring 5 may leak into the conductive pipe 41 through the stray capacitances C11, C12, and C13. When the lighting circuit 30 side of the secondary winding of the pulse transformer 31 of the starter 4 is positive, the leakage pulse voltage is represented by a pulse bypass capacitor C1 and a grounding capacitor C2 as shown by solid line arrows in FIG. Then, it flows to the negative polarity side of the secondary winding of the pulse transformer 31 through the casing of the high pressure discharge lamp lighting device 2, the conductive pipe 41, and the stray capacitances C11, C12, and C13. When the output terminal O1 side of the secondary winding of the pulse transformer 31 of the starter 4 is positive, the leakage pulse voltage is caused by the stray capacitances C11 and C12 and the conductive piping 41 as shown by the broken line arrows in FIG. It flows to the negative polarity side of the secondary winding of the pulse transformer 31 through the housing of the high pressure discharge lamp lighting device 2, the grounding capacitor C3, and the pulse bypass capacitor C1.

  That is, even when a high-voltage pulse leaks from the wiring 5 through the stray capacitances C11, C12, and C13, the pulse voltage can be reliably prevented from flowing into the lighting circuit 30.

  Further, the capacitors C1 to C3 have a role as a functional ground that causes a noise component generated from the lighting circuit 30 to flow to the reference potential point. The capacitors C1 to C3 also have a function as protective ground.

  Thus, in this embodiment, even when the wiring length between the starter 4 and the high pressure discharge lamp 3 is long, reliable lighting is possible. In addition, the pulse voltage leaking from the wiring 5 does not flow into the lighting circuit, and malfunction and destruction of the circuit can be prevented.

(Second Embodiment)
FIG. 7 is a block diagram showing a second embodiment of the present invention. In FIG. 7, the same components as those in FIG.

  The discharge lamp lighting device 8 according to the present embodiment is only different from the first embodiment in the positions of the capacitors C1 to C3. A capacitor C1 is connected between one input end of the filter circuit 10 and the other input end, and one input end of the filter circuit 10 is connected to a reference potential point via a capacitor C3. The other input terminal is connected to a reference potential via a capacitor C2.

  Also in the embodiment configured as described above, the high voltage pulse voltage leaking from the wiring 5 flows into the filter circuit 10 from the casing of the discharge lamp lighting device 8 via the capacitors C2 and C3. The high voltage pulse voltage leaked by the filter circuit 10 is attenuated. Thereby, malfunction and destruction of the lighting circuit 30 can be prevented by the high voltage pulse voltage leaking from the wiring 5.

  Other operations and effects are the same as those of the first embodiment.

1 is a block diagram showing a high pressure discharge lamp lighting device according to a first embodiment of the present invention. The circuit diagram which shows an example of the specific structure of the high pressure discharge lamp lighting device 2 of FIG. The waveform diagram which shows the high voltage | pressure pulse which the start part 4 generate | occur | produces taking time on a horizontal axis and taking a voltage on a vertical axis | shaft. The graph which shows the change of the pulse voltage by the difference in the capacity | capacitance of the capacitor | condenser C4, taking the length of wiring in the horizontal axis and taking the pulse voltage supplied to the high pressure discharge lamp 3 on the vertical axis. The graph which shows the change of the pulse voltage in case the capacity | capacitance of the capacitor | condenser C4 is 1000 pF, taking the pulse length supplied to the high voltage | pressure discharge lamp 3 on the horizontal axis | shaft and the vertical axis | shaft. Explanatory drawing for demonstrating an effect | action when a high voltage | pressure pulse leaks. The block diagram which shows the 2nd Embodiment of this invention.

Explanation of symbols

2 ... High pressure discharge lamp lighting device 4 ... Starter 3 ... High pressure discharge lamp 5 ... Wiring 30 ... Lighting circuit 31 ... Starter C1-C4 ... Capacitor

Claims (3)

A starting unit that has a pulse transformer and generates a pulse voltage for starting a high-pressure discharge lamp connected by a wiring having a wiring length of 3 m or more;
A lighting circuit connected to the starting unit and driving the started high-pressure discharge lamp;
A pulse bypass capacitor connected between the output terminals of the lighting circuit;
A grounding capacitor connected between the output terminal of the lighting circuit and a reference potential point;
A high pressure discharge lamp lighting device comprising: A starting unit that has a pulse transformer and generates a pulse voltage for starting a high-pressure discharge lamp connected by a wiring having a wiring length of 3 m or more;
A lighting circuit connected to the starting unit and driving the started high-pressure discharge lamp;
A filter circuit connected to the power supply side of the lighting circuit;
A grounding capacitor connected between the input terminal of the filter circuit and a reference potential point;
A high pressure discharge lamp lighting device comprising: A capacitor for suppressing the attenuation of the pulse voltage is connected between the output terminals of the starter;
The high pressure discharge lamp lighting device according to claim 1 or 2.

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