JP5795233B2 - Discharge lamp lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device.

  Conventionally, a discharge lamp lighting device for lighting a discharge lamp in which one or more kinds of gases are sealed has been proposed (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 disclose a discharge lamp lighting device for lighting an excimer lamp which is a kind of discharge lamp.

Japanese Patent No. 3355976 Japanese Patent No. 3820791

  The discharge lamp lighting devices disclosed in Patent Documents 1 and 2 cause an excimer lamp to perform streamer discharge. In this streamer discharge, since the discharge current locally flows in the discharge lamp, the portion where the discharge current locally flows is significantly deteriorated, and the life of the discharge lamp is short. Further, in the streamer discharge, the light emission distribution is non-uniform, resulting in uneven irradiation.

  In view of the above-described problems, an object of the present invention is to provide a discharge lamp lighting device that can extend the life of a discharge lamp and suppress the occurrence of uneven irradiation.

The present invention proposes the following items in order to solve the above-described problems.
(1) The present invention is a discharge lamp lighting device (for example, equivalent to the discharge lamp lighting device 1 in FIG. 1) for lighting a discharge lamp (for example, equivalent to the discharge lamp Lamp in FIG. 1) in which one or more kinds of gases are sealed. And after applying a predetermined specific voltage to the electrode of the discharge lamp (for example, corresponding to the first electrode ELT1 in FIG. 1), applying a glow discharge voltage lower than the specific voltage, The specific voltage is greater than or equal to a voltage necessary for causing dielectric breakdown in the discharge lamp, and the glow discharge voltage is greater than or equal to a voltage necessary for causing the discharge lamp being lit to glow discharge. A discharge lamp lighting device is proposed.

  According to the present invention, first, a specific voltage is applied to the electrode of the discharge lamp. Further, the specific voltage is set to be equal to or higher than a voltage necessary for causing dielectric breakdown in the discharge lamp. For this reason, when the discharge lamp is turned off, a specific voltage is applied to the electrode of the discharge lamp to cause dielectric breakdown in the discharge lamp, so that the discharge lamp can be turned on.

  Moreover, after applying a specific voltage to the electrode of the discharge lamp, a glow discharge voltage lower than the specific voltage is applied. Further, the glow discharge voltage is set to be equal to or higher than the voltage necessary for glow discharge of the discharge lamp that is lit. For this reason, after starting the lighting of the discharge lamp, the discharge lamp can be glow-discharged. In this glow discharge, since the discharge current flows substantially uniformly in the discharge lamp, local deterioration of the discharge lamp is suppressed. In glow discharge, the light emission distribution is substantially uniform. Therefore, the life of the discharge lamp can be extended and the occurrence of uneven irradiation can be suppressed.

  (2) The present invention includes a light detection means (for example, corresponding to the light detection unit 20 in FIG. 1) for detecting whether or not light is emitted from the discharge lamp in the discharge lamp lighting device of (1). When the light detection means does not detect that light is emitted from the discharge lamp, the specific voltage is applied to the electrode of the discharge lamp, and light is emitted from the discharge lamp. When the light detecting means detects this, a discharge lamp lighting device is proposed in which the glow discharge voltage is applied to the electrode of the discharge lamp.

  According to this invention, in the discharge lamp lighting device of (1), the light detection means for detecting whether or not light is emitted from the discharge lamp is provided. When the light detection means has not detected that light is emitted from the discharge lamp, the above-described specific voltage is applied to the electrode of the discharge lamp. On the other hand, when the light detection means detects that light is emitted from the discharge lamp, the above-described glow discharge voltage is applied to the electrode of the discharge lamp. For this reason, it is possible to prevent the above-described glow discharge voltage from being applied to the electrode of the discharge lamp even though the discharge lamp has not started lighting, and to reliably start the discharge lamp and perform the glow discharge. realizable.

  (3) The present invention relates to the discharge lamp lighting device of (1) or (2), one end of the primary winding (for example, equivalent to the primary winding W1 in FIG. 1) and the secondary winding (for example, FIG. 1 (corresponding to the transformer T in FIG. 1) connected to one end of the secondary winding W2 and a power source (eg, FIG. 1) for applying a voltage to the other end of the primary winding. DC power source Vin), one end of the primary winding and one end of the secondary winding, and a reference potential source (for example, corresponding to the reference potential source GND in FIG. 1). A switching element (for example, corresponding to the switching element Q in FIG. 1) and a control means (for example, corresponding to the control unit 10 in FIG. 1) for controlling the switching element, and at the other end of the secondary winding Is connected to the electrode of the discharge lamp, and the control means applies the specific voltage to the electrode of the discharge lamp. In the case of applying, the on width of the switch element is controlled to the first on width, and when the glow discharge voltage is applied to the electrode of the discharge lamp, the on width of the switch element is set to the first on width. The discharge lamp lighting device is characterized in that the second on-width is controlled to be narrower than that.

  According to the present invention, in the discharge lamp lighting device of (1) or (2), a voltage is applied to the transformer in which one end of the primary winding and one end of the secondary winding are connected, and the other end of the primary winding. A power source for applying the switch, a switch element, and a control means for controlling the switch element are provided. The switch element was provided between one end of the primary winding and one end of the secondary winding and the reference potential source, and the other end of the secondary winding was connected to the electrode of the discharge lamp. When the control means applies a specific voltage to the electrode of the discharge lamp, the on width of the switch element is controlled to the first on width, and when the glow discharge voltage is applied to the electrode of the discharge lamp, The on-width of the element is controlled to a second on-width that is narrower than the first on-width. According to this, an effect similar to the effect mentioned above can be produced.

  (4) In the discharge lamp lighting device according to (3), the present invention is connected to one end of the primary winding and one end of the secondary winding to absorb surge voltage (for example, , Which corresponds to the surge voltage absorber 30 in FIG. 1).

  According to this invention, in the discharge lamp lighting device of (3), the surge voltage absorbing means for absorbing the surge voltage is connected to one end of the primary winding and one end of the secondary winding. For this reason, it can prevent that a surge voltage is applied to the electrode of a discharge lamp, and can implement | achieve the stable implementation of glow discharge.

  (5) The present invention proposes a discharge lamp lighting device according to (4), wherein the surge voltage absorbing means is a snubber circuit.

  According to the present invention, the surge voltage absorbing means is constituted by a snubber circuit. For this reason, a surge voltage can be absorbed by the surge voltage absorbing means, and the same effect as described above can be obtained.

  (6) In the discharge lamp lighting device according to any one of (3) to (5), the present invention includes a current measuring unit that measures a current flowing through the discharge lamp (for example, corresponding to the current measuring unit 40 in FIG. The discharge lamp lighting device is characterized in that the control means controls the second ON width based on a measurement result by the current measurement means.

  According to the present invention, in the discharge lamp lighting device according to any one of (3) to (5), the above-described second on-width is controlled based on the current flowing through the discharge lamp. For this reason, when the current flowing through the discharge lamp fluctuates due to various factors such as the temperature and deterioration state of the discharge lamp, the on-width of the switch element during the lighting of the discharge lamp is appropriately controlled to further stabilize the glow discharge. It can be realized accurately.

  According to the present invention, the life of the discharge lamp can be prolonged and the occurrence of uneven irradiation can be suppressed.

1 is a circuit diagram of a discharge lamp lighting device according to a first embodiment of the present invention. It is a circuit diagram of the discharge lamp lighting device concerning a 2nd embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the constituent elements in the following embodiments can be appropriately replaced with existing constituent elements, and various variations including combinations with other existing constituent elements are possible. Accordingly, the description of the following embodiments does not limit the contents of the invention described in the claims.

<First Embodiment>
[Configuration of Discharge Lamp Lighting Device 1]
FIG. 1 is a circuit diagram of a discharge lamp lighting device 1 according to a first embodiment of the present invention. The discharge lamp lighting device 1 lights a discharge lamp Lamp in which one or more kinds of gases are sealed. The discharge lamp lighting device 1 includes a transformer T, a DC power supply Vin, a switch element Q, a diode D1, a control unit 10, and a surge voltage absorption unit 30. The surge voltage absorption unit 30 includes a capacitor C, a diode D2, and a resistor R, and constitutes a so-called snubber circuit.

  One end of the primary winding W1 of the transformer T and one end of the secondary winding W2 of the transformer T are connected to the anode of the diode D1 and the anode of the diode D2.

  The cathode of the diode D1 is connected to the collector of a switching element Q composed of an IGBT (Insulated Gate Bipolar Transistor). The reference potential source GND is connected to the emitter of the switch element Q, and the control unit 10 is connected to the gate of the switch element Q.

  A reference potential source GND is connected to the cathode of the diode D2 via a resistor R. A capacitor C is connected to the resistor R in parallel.

  The other end of the primary winding W1 is connected to the positive electrode of the direct current power source Vin, and the negative electrode of the direct current power source Vin is connected to the reference potential source GND. A first electrode ELT1 of the discharge lamp Lamp is connected to the other end of the secondary winding W2, and a reference potential source GND is connected to the second electrode ELT2 of the discharge lamp Lamp.

[Operation of discharge lamp lighting device 1]
The discharge lamp lighting device 1 having the above configuration performs different operations when starting to turn on the discharge lamp Lamp and when glow discharge is performed on the discharge lamp Lamp being lit.

<When lighting starts>
First, the operation of the discharge lamp lighting device 1 when starting the lighting of the discharge lamp Lamp will be described.

  The light detection unit 20 detects whether light is emitted from the discharge lamp Lamp and transmits the detection result to the control unit 10.

  When the light detection unit 20 does not detect that light is emitted from the discharge lamp Lamp, the control unit 10 sets the switch element Q so that the ON width of the switch element Q becomes the first ON width. Switch. According to this, an electromotive force is generated in the secondary winding W2, and a voltage is applied to the first electrode ELT1 of the discharge lamp Lamp.

  Here, a voltage applied to the first electrode ELT1 of the discharge lamp Lamp when the switch element Q is switched with the first on-width is referred to as a specific voltage. Further, the specific voltage is assumed to be equal to or higher than a voltage necessary for causing dielectric breakdown in the discharge lamp Lamp.

  For this reason, when the switching element Q is switched with the first ON width, dielectric breakdown occurs in the discharge lamp Lamp, and lighting of the discharge lamp Lamp is started.

<During glow discharge>
Next, the operation of the discharge lamp lighting device 1 when glow discharge is performed on the discharge lamp Lamp being lit will be described.

  When the light detection unit 20 detects that light is emitted from the discharge lamp Lamp, the control unit 10 determines that the ON width of the switch element Q is smaller than the first ON width described above. The switching element Q is switched so that According to this, an electromotive force is generated in the secondary winding W2, and a voltage is applied to the first electrode ELT1 of the discharge lamp Lamp.

  Here, a voltage applied to the first electrode ELT1 of the discharge lamp Lamp when the switch element Q is switched with the second on-width is referred to as a glow discharge voltage. Then, the glow discharge voltage becomes lower than the above-mentioned specific voltage because the ON width of the switch element Q is narrowed. However, the glow discharge voltage is assumed to be equal to or higher than the voltage necessary for glow discharge of the lighting discharge lamp Lamp.

  When a glow discharge voltage is applied to the first electrode ELT1 of the lighting discharge lamp Lamp, the discharge lamp Lamp starts glow discharge. For this reason, when the switching element Q is switched with the second on-width while the discharge lamp Lamp is in the on state, glow discharge of the discharge lamp Lamp is started.

  According to the discharge lamp lighting device 1 described above, the following effects can be obtained.

  The discharge lamp lighting device 1 can apply a specific voltage to the first electrode of the discharge lamp Lamp, cause dielectric breakdown inside the discharge lamp Lamp, and start lighting the discharge lamp Lamp.

  Further, the discharge lamp lighting device 1 can glow discharge the discharge lamp Lamp by applying a glow discharge voltage to the first electrode ELT1 of the discharge lamp Lamp being lit. In this glow discharge, since the discharge current flows substantially uniformly inside the discharge lamp Lamp, local deterioration of the discharge lamp Lamp is suppressed. In glow discharge, the light emission distribution is substantially uniform. Therefore, the life of the discharge lamp Lamp can be prolonged and the occurrence of uneven irradiation can be suppressed.

  In addition, the discharge lamp lighting device 1 includes a light detection unit 20 that detects whether or not light is emitted from the discharge lamp Lamp, and the light detection unit 20 indicates that light is emitted from the discharge lamp Lamp. If not detected, a specific voltage is applied to the first electrode ELT1 of the discharge lamp Lamp. On the other hand, when the light detection unit 20 detects that light is emitted from the discharge lamp Lamp, a glow discharge voltage is applied to the first electrode ELT1 of the discharge lamp Lamp. For this reason, it is possible to prevent the glow discharge voltage from being applied to the first electrode ELT1 of the discharge lamp Lamp even though the lighting of the discharge lamp Lamp has not started, and to start the lighting of the discharge lamp Lamp and the glow discharge. Implementation can be realized reliably.

  Further, in the discharge lamp lighting device 1, a surge voltage absorption unit 30 configured by a snubber circuit is connected to one end of the primary winding W1 and one end of the secondary winding W2. For this reason, it is possible to prevent a surge voltage from being applied to the first electrode ELT1 of the discharge lamp Lamp, and a stable implementation of glow discharge can be realized.

Second Embodiment
[Configuration and Operation of Discharge Lamp Lighting Device 1A]
FIG. 2 is a circuit diagram of a discharge lamp lighting device 1A according to the second embodiment of the present invention. The discharge lamp lighting device 1 </ b> A is different from the discharge lamp lighting device 1 according to the first embodiment of the present invention shown in FIG. 1 in that it includes a current measuring unit 40 and a control unit 10 </ b> A instead of the control unit 10. And is different. In the discharge lamp lighting device 1A, the same components as those in the discharge lamp lighting device 1 are denoted by the same reference numerals, and description thereof is omitted.

  The current measuring unit 40 is provided between the second electrode ELT2 of the discharge lamp Lamp and the reference potential source GND. The current measuring unit 40 measures the current flowing through the discharge lamp Lamp.

  10 A of control parts switch not only the detection result by the light detection part 20, but the measurement result by the current measurement part 40, and switches the switch element Q.

  Specifically, when the light detection unit 20 does not detect that light is emitted from the discharge lamp Lamp, the control unit 10A sets the switch element Q to the above-described manner similarly to the control unit 10 of FIG. The first ON width of the switching is performed.

  On the other hand, when the light detection unit 20 detects that light is emitted from the discharge lamp Lamp, the control unit 10A determines the ON width of the switch element Q based on the measurement result by the current measurement unit 40. A certain second ON width is controlled. Specifically, if the current flowing through the discharge lamp Lamp when the discharge lamp Lamp is stably performing glow discharge is referred to as a reference current, the control unit 10A stores the reference current. Then, as the current flowing through the discharge lamp Lamp measured by the current measuring unit 40 becomes larger than the reference current, the control unit 10A sets the second on-width to be narrower. Further, as the current flowing through the discharge lamp Lamp measured by the current measuring unit 40 becomes smaller than the reference current, the control unit 10A sets the second on-width as described above wider. Then, the control unit 10A switches the switch element Q with the set second ON width. According to this, the glow discharge voltage decreases as the current flowing through the discharge lamp Lamp increases as compared with the reference current, and the glow discharge voltage increases as the current flowing through the discharge lamp Lamp decreases.

  According to the above discharge lamp lighting device 1A, in addition to the above-described effects that can be achieved by the discharge lamp lighting device 1, the following effects can be achieved.

  The discharge lamp lighting device 1A controls the second on-width described above based on the current flowing through the discharge lamp Lamp. For this reason, when the current flowing through the discharge lamp Lamp fluctuates due to various factors such as the temperature and deterioration state of the discharge lamp Lamp, the on-width of the switch element Q during lighting of the discharge lamp Lamp is appropriately controlled to stabilize the glow discharge. Can be implemented more accurately.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made without departing from the gist of the present invention.

  For example, in the second embodiment described above, the control unit 10A reduces the second on-width as the current flowing through the discharge lamp Lamp increases and the first current as the current flowing through the discharge lamp Lamp decreases as compared with the reference current. Although the 2 on width is increased, the present invention is not limited to this. For example, when the current flowing through the discharge lamp Lamp rises to a predetermined first threshold value, the second on-width is narrowed by a predetermined width and lowered to a predetermined second threshold value. The second ON width may be widened by a predetermined width.

DESCRIPTION OF SYMBOLS 1, 1A; Discharge lamp lighting device 10, 10A; Control part 20; Light detection part 30; Surge voltage absorption part 40; Current measurement part C; Capacitor D1, D2; Diode ELT1; First electrode ELT2; Discharge lamp Q; Switch element R; Resistance T; Transformer Vin; DC power supply

Claims (5)

A discharge lamp lighting device for lighting a discharge lamp enclosing one or more kinds of gas,
A transformer in which one end of the primary winding and one end of the secondary winding are connected;
A power supply for applying a voltage to the other end of the primary winding;
A switching element provided between one end of the primary winding and one end of the secondary winding, and a reference potential source;
Control means for controlling the switch element,
The other end of the secondary winding is connected to the electrode of the discharge lamp,
The control means, the ON width of the switching element is controlled to the first ON width, after applying a certain voltage defined pre Me to the electrodes of the discharge lamp, the first on the ON width of the switching element A glow discharge voltage lower than the specific voltage is applied to the electrode of the discharge lamp by controlling to a second on-width narrower than the width ;
The specific voltage is equal to or higher than a voltage necessary for causing dielectric breakdown in the discharge lamp,
The discharge lamp lighting device, wherein the glow discharge voltage is equal to or higher than a voltage necessary for glow discharge of the discharge lamp being lit. Photodetection means for detecting whether light is emitted from the discharge lamp,
The control means includes
When the light detection means does not detect that light is emitted from the discharge lamp, the specific voltage is applied to the electrode of the discharge lamp,
2. The glow discharge voltage is applied to the electrode of the discharge lamp when the light detection means detects that light is emitted from the discharge lamp. Discharge lamp lighting device.   3. The discharge lamp lighting device according to claim 1, further comprising a surge voltage absorbing unit that is connected to one end of the primary winding and one end of the secondary winding and absorbs a surge voltage. 4. .   The discharge lamp lighting device according to claim 3, wherein the surge voltage absorbing means is a snubber circuit.   Current measuring means for measuring the current flowing through the discharge lamp,
  5. The discharge lamp lighting device according to claim 1, wherein the control unit controls the second on-width based on a measurement result obtained by the current measurement unit.

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