WO2015040853A1

WO2015040853A1 - Illumination device, and imaging device

Info

Publication number: WO2015040853A1
Application number: PCT/JP2014/004749
Authority: WO
Inventors: 優太高橋; 裕昭前田
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2013-09-19
Filing date: 2014-09-16
Publication date: 2015-03-26

Abstract

This illumination device has: a first capacitor (6) that stores a charge; a flash discharge tube (8) that emits light by consuming the charge stored by the first capacitor (6); and a first trigger capacitor (14) that applies a trigger voltage for causing the flash discharge tube (8) to emit light. Moreover, the illumination device has: a trigger circuit comprising a trigger transformer (15); a light emission control element (10) that is serially connected to the flash discharge tube (8); a control circuit (34) that controls the trigger circuit and the light emission control element (10) and that obtains light emission information of the flash discharge tube (8); and a temperature information acquisition unit (24) that obtains temperature information of the flash discharge tube (8). Thus, the occurrence of light emission defects that accompany rises in the temperature of the flash discharge tube (8), etc., can be prevented.

Description

Illumination device and imaging device

The present invention relates to a light emission control circuit for an illumination device, and more particularly, to an illumination device and an imaging device provided with a light emission control circuit that can emit light repeatedly and at high speed even with a large amount of light and capable of emitting light for the first time without so-called “light-out defects”. About.

Conventionally, a strobe device and an imaging device that cause a flash discharge tube to emit light by the following operation have been disclosed as an illumination device used at the time of taking a photograph (for example, see Patent Document 1).

A conventional strobe device is composed of a flash discharge tube as a light source, a light emission control element, a booster circuit, a control circuit, and the like. The light emission control element includes, for example, an insulated gate bipolar transistor (hereinafter abbreviated as IGBT) and is connected in series with the flash discharge tube to control the light emission operation of the flash discharge tube.

Specifically, when the flash discharge tube is caused to emit light, first, in response to the light emission start signal of the control circuit, the operation of the drive voltage supply system to the gate terminal of the IGBT is started to turn on the IGBT. At the same time, a known trigger operation is performed to start light emission from the flash discharge tube.

On the other hand, when the flash discharge tube light emission is stopped, the operation of the drive voltage supply system is stopped in response to the light emission stop signal of the control circuit, and the IGBT is turned off by short-circuiting between the gate terminal and the emitter terminal of the IGBT. To do. This stops the light emission of the flash discharge tube.

Hereinafter, the operation of the light emission control circuit of the strobe device described in Patent Document 1 will be described with reference to FIG. FIG. 9 is a diagram showing a light emission control circuit of a conventional strobe device.

As shown in FIG. 9, the conventional light emission control circuit first stores electric charge in the main capacitor 6 via a power source 1 such as a commercial power source and a booster circuit 2 such as a DC-DC converter 2. At this time, the charging voltage of the main capacitor 6 is monitored by inputting the voltage divided by the

resistors

4 and 5 to the MON terminal of the control circuit 34. When the charging voltage of the main capacitor 6 reaches a predetermined voltage, the operation of the booster circuit 2 is stopped and charging is completed.

Similarly, the first trigger capacitor 14 for applying the trigger voltage to the flash discharge tube 8 is charged to the same voltage as the main capacitor 6 with the polarity shown through the resistor 12, the diode 13, and the trigger transformer 15.

When the flash discharge tube 8 is caused to emit light, a high level (hereinafter referred to as Hi level) signal from the IT terminal of the control circuit 34 is applied to the gate terminal of the IGBT 10. At the same time, the first trigger switch element 16 is turned on by a signal from the TR1 terminal of the control circuit 34. As a result, the charge of the first trigger capacitor 14 flows through the first trigger switch element 16, the IGBT 10, and the trigger transformer 15. Then, a high trigger voltage is generated on the secondary side of the trigger transformer 15 to excite the flash discharge tube 8. As a result, a current flows through the flash discharge tube 8 and light emission starts.

On the other hand, in order to stop the light emission of the flash discharge tube 8, a low level (hereinafter referred to as “low level”) signal from the IT terminal of the control circuit 34 is applied to the IGBT 10. Thereby, IGBT10 will be in an OFF state. As a result, the current flowing through the flash discharge tube 8 is also stopped and light emission is stopped.

However, in the configuration of the light emission control circuit, when the flash discharge tube 8 is caused to emit light continuously, the load capacity of the flash discharge tube 8 changes as the temperature of the flash discharge tube 8 rises. Therefore, even if the amount of charge flowing to the primary side of the trigger transformer 15 is constant, a phenomenon occurs in which the voltage at the secondary side output of the trigger transformer 15 gradually decreases. As a result, there is a problem that the flash discharge tube 8 does not emit light, so-called “missing light emission” occurs.

When the flash discharge tube 8 is caused to emit light continuously, the charging voltage of the first trigger capacitor 14 is almost the same as the charging voltage of the main capacitor 6. At this time, if the flash discharge tube 8 is caused to emit light continuously at a high speed, the charging time of the main capacitor 6 may be shortened, and at the same time, the charge amount of the first trigger capacitor 14 may be reduced. Therefore, similarly to the above, the output on the secondary side of the trigger transformer 15 is reduced, and “light emission failure” occurs.

In order to solve the above problem, there is a method of using a large-capacity capacitor for the first trigger capacitor 14. As a result, it is possible to secure a trigger voltage that can emit light even if the output on the secondary side of the trigger transformer decreases. However, in this case, since the initial trigger voltage is high, a trigger transformer that can withstand a high voltage is required. Further, in some cases, the trigger voltage applied to the flash discharge tube 8 may decrease due to sparking between the trigger transformer and the ground line. Therefore, there is a possibility that the “missing light emission” cannot be solved reliably.

Further, when the flash discharge tube 8 is caused to emit light continuously with a certain amount of light, the temperature of the flash discharge tube 8 rises as described above. The state inside the flash discharge tube 8 generated at this time will be described with reference to FIG. 8A.

FIG. 8A is a diagram showing an operation timing chart of a light emission control circuit of a conventional flash discharge tube.

That is, as shown in FIG. 8A, as light is emitted, impurities deposited from the glass tube of the flash discharge tube 8 adhere to the pellets that emit electrons inside the flash discharge tube 8 by applying a trigger voltage. Therefore, even when no light is emitted for a long time or when no impurities are adhered to the pellet, the flash discharge tube 8 starts to emit light of an internal rare gas when left in the dark for a certain time or longer. Electrons that tend to contribute are significantly reduced. For this reason, the flash discharge tube 8 in the above-described state sometimes does not emit light and “missing light emission” may occur.

JP 2001-66671 A

The present invention increases the charge amount of the trigger capacitor or increases the voltage applied to the primary side of the trigger transformer, and controls the light emission control element to be non-conductive so that it does not emit flash light, and then the trigger voltage is flashed. Provided are an illuminating device and an imaging device that prevent “missing light emission” from being applied to a tube.

In other words, the lighting device of the present invention applies the first capacitor for accumulating electric charge, the flash discharge tube that emits light by consuming the electric charge accumulated in the first capacitor, and the trigger voltage for causing the flash discharge tube to emit light. It has a trigger circuit including one trigger capacitor and a trigger transformer. Furthermore, it has a light emission control element connected to the flash discharge tube, a control circuit that acquires light emission information of the flash discharge tube, and a temperature information acquisition unit that acquires temperature information of the flash discharge tube.

According to this configuration, when the flash discharge tube is continuously emitting light, the trigger circuit and the light emission control element are controlled based on temperature information and light emission information in the vicinity of the flash discharge tube.

This allows the flash discharge tube to emit light without “missing light emission”. As a result, an illumination device suitable for an imaging device that performs continuous shooting can be realized.

Also, the imaging device of the present invention is equipped with the lighting device. Thereby, it is possible to realize suitable photography without causing the lighting device to lack light emission during continuous photography.

FIG. 1 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing a light emission control circuit of the illumination device according to Embodiment 2 of the present invention. FIG. 3 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 3 of the present invention. FIG. 4 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 4 of the present invention. FIG. 5 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 5 of the present invention. FIG. 6 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 6 of the present invention. FIG. 7 is a perspective view of the imaging device according to each embodiment of the present invention. FIG. 8A is a diagram showing an operation timing chart of a light emission control circuit of a conventional flash discharge tube. FIG. 8B is a diagram showing an operation timing chart of the light emission control circuit in each embodiment of the present invention. FIG. 9 is a diagram showing a light emission control circuit of a conventional strobe device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
Hereinafter, an illumination device and an imaging device according to Embodiment 1 of the present invention will be described with reference to FIG. As an example of the lighting device of the present embodiment, a strobe device can be given as an example. The same applies to the following embodiments.

FIG. 1 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 1 of the present invention.

As shown in FIG. 1, the light emission control circuit of the lighting device of the present embodiment includes at least a booster circuit 2, a first capacitor 6 constituting a main capacitor 6, and a xenon discharge tube (Xe discharge tube), for example. A flash discharge tube 8, a first trigger capacitor 14, a trigger circuit including a trigger transformer 15, a light emission control element 10, a second trigger capacitor 20, a temperature information acquisition unit 24, a control circuit 34, etc. Yes. The first capacitor 6 accumulates electric charges that cause the flash discharge tube 8 to emit light. The first trigger capacitor 14 accumulates the charge applied to the flash discharge tube 8 via the trigger transformer 15 of the trigger circuit as a trigger voltage for causing the flash discharge tube 8 to emit light. The light emission control element 10 includes, for example, an insulated gate bipolar transistor (hereinafter abbreviated as IGBT), and is connected in series with the flash discharge tube 8 to turn on / off light emission. The temperature information acquisition unit 24 acquires temperature information in the vicinity of the flash discharge tube 8.

Further, the control circuit 34 controls the trigger circuit and the light emission control element 10 and acquires the light emission information of the flash discharge tube 8. Further, the control circuit 34 includes a voltage determination unit 45, a trigger output value prediction unit 46, and the like. The voltage determination unit 45 determines the charging voltage of the first trigger capacitor 14 and the like. The trigger output value prediction unit 46 predicts a trigger output value such as a trigger voltage to be applied to the flash discharge tube 8 based on the temperature information of the flash discharge tube 8 and the determined charging voltage of the first trigger capacitor 14.

As described above, the light emission control circuit of the lighting apparatus according to the present embodiment is configured.

Hereinafter, the operation of the light emission control circuit will be described with reference to FIG.

The light emission control circuit of the present embodiment first stores electric charge in the first capacitor 6 via the power source 1 such as a commercial power source and the booster circuit 2 such as the DC-DC converter 2. At this time, the charging voltage of the first capacitor 6 is monitored at the MON terminal of the control circuit 34 by the resistance voltage division of the

resistors

4 and 5. Note that the charging voltage of the first capacitor 6 input to the MON terminal is determined by the voltage determination unit 45 of the control circuit 34. When the voltage reaches a predetermined voltage, the control circuit 34 stops the operation of the booster circuit 2 and completes the charging of the first capacitor 6.

At this time, the first trigger capacitor 14 for applying the trigger voltage to the flash discharge tube 8 has substantially the same voltage (the same voltage as the first capacitor 6) with the polarity shown through the resistor 12, the diode 13, and the trigger transformer 15. Charged).

Similarly, the second trigger capacitor 20 is also charged to substantially the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown through the resistor 12, the diode 13, the diode 21, and the trigger transformer 15. Therefore, similarly to the charging voltage of the first capacitor 6, the charging voltages of the first trigger capacitor 14 and the second trigger capacitor 20 are also determined by the voltage determination unit 45 of the control circuit 34.

The second trigger capacitor 20 constitutes a trigger capacitor for increasing the capacity of the trigger capacitor for applying the trigger voltage as necessary, for example, by being connected in parallel with the first trigger capacitor 14. Therefore, the anode of the second trigger capacitor 20 is connected to the cathode terminal of the diode 21, and the cathode of the second trigger capacitor 20 is connected to the cathode of the first trigger capacitor 14.

Further, in order to form a discharge loop, the second trigger switch element 22 is connected between the anode of the second trigger capacitor 20 and the first trigger switch element 16. Thereby, if the 1st trigger switch element 16 and the 2nd trigger switch element 22 will be in a conduction state, it will become equivalent to connecting the 1st trigger capacitor 14 and the 2nd trigger capacitor 20 in parallel. However, in the initial state of the lighting device, the second trigger switch element 22 is set in a non-conductive state by a signal from the TR2 terminal of the control circuit 34.

Further, a temperature detection device 24 such as a thermistor constituting the temperature information acquisition unit 24 is disposed in the vicinity of the flash discharge tube 8, and the detected temperature information is emitted from the control circuit 34 when the flash discharge tube 8 emits light. Output to the TMP terminal.

Note that it is not particularly necessary to use the temperature information detected by the temperature detection device 24 as the temperature information of the flash discharge tube 8. For example, data of light emission information including the light emission interval, the light emission amount of the past flash discharge tube, and the position information of the flash discharge tube at the time of light emission is recorded in a storage device such as a semiconductor memory (not shown). Based on the current state of the flash discharge tube 8, the temperature is calculated and predicted from the stored light emission information data. Then, the predicted value may be output to the control circuit 34 as temperature information of the flash discharge tube 8, and the light emission control circuit may be controlled based on this to cause the flash discharge tube 8 to emit light.

Further, as described above, the control circuit 34 includes a trigger output value prediction unit 46 inside. The trigger output value prediction unit 46 determines the current condition based on the temperature information of the flash discharge tube 8 detected by the temperature information acquisition unit 24 and the determination result of the charging voltage of the first trigger capacitor 14 determined by the voltage determination unit 45. Below, the trigger output value which is the trigger voltage which can be output is estimated.

When the predicted trigger output value is less than or equal to the specified value, a signal for turning on the second trigger switch element 22 is output from the TR2 terminal of the control circuit 34. At the same time, a signal for turning on the first trigger switch element 16 is output from the TR1 terminal of the control circuit 34. Further, a Hi level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to make the IGBT 10 conductive. Here, the specified value means at least a trigger voltage (trigger output value) necessary for exciting the rare gas in the flash discharge tube 8. Therefore, the prescribed value is determined and set for each flash discharge tube 8 to be used, based on the type of the flash discharge tube 8 and the pressure of a gas such as an enclosed rare gas.

Thereby, the electric charge of the first trigger capacitor 14 flows through the first trigger switch element 16 and the trigger transformer 15. Furthermore, the electric charge of the second trigger capacitor 20 flows through the second trigger switch element 22 and the trigger transformer 15. As a result, the charge of the second trigger capacitor 20 is added to the charge of the first trigger capacitor 14 and flows to the primary side of the trigger transformer 15. Then, a high output trigger voltage is generated on the secondary side of the trigger transformer 15. As a result, the rare gas in the flash discharge tube 8 is excited, and a current flows to the flash discharge tube 8 through the first capacitor 6. As a result, the flash discharge tube 8 starts to emit light.

On the other hand, when the light emission of the flash discharge tube 8 is stopped, a Low level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10. Thereby, IGBT10 will be in an OFF state. As a result, the current flowing through the flash discharge tube 8 is stopped and light emission is stopped.

That is, as described above, when the strobe device 42 constituting the illumination device mounted on the imaging device 44 shown in FIG. 7 is used, depending on the temperature state of the flash discharge tube 8 and the charge amount of the first trigger capacitor 14, In some cases, the trigger output value, which is the trigger voltage output from the secondary side of the trigger transformer 15, falls below a specified value. Therefore, in the present embodiment, in addition to the charge amount of the first trigger capacitor 14, the charge amount of the second trigger capacitor 20 is simultaneously discharged on the discharge loop on the primary side of the trigger transformer 15. Thereby, the trigger output value on the secondary side of the trigger transformer 15 is set to a state exceeding the specified value. As a result, the rare gas in the flash discharge tube 8 can be excited to cause the flash discharge tube 8 to emit light.

On the other hand, when trying to cause the flash discharge tube 8 to emit light, the control circuit 34 determines that the predicted value of the trigger output value exceeds the specified value only with the charge amount of the first trigger capacitor 14 determined by the voltage determination unit 45. If predicted, the second trigger switch element 22 is held in a non-conductive state. Thereby, the flash discharge tube 8 can be made to emit light only by the charge amount of the first trigger capacitor 14.

With the above configuration, it is possible to realize a strobe device 42 suitable for the imaging device 44 that can continuously emit light without causing the flash discharge tube 8 to be “missing light emission”.

(Embodiment 2)
Hereinafter, an illumination device and an imaging device according to Embodiment 2 of the present invention will be described with reference to FIG.

FIG. 2 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 2 of the present invention.

The light emission control circuit of the illumination device of the present embodiment is the light emission control circuit of the first embodiment in that a third trigger capacitor 25, a third trigger switch element 28, a diode 26, and a signal resistor 27 are further provided. And different. The third trigger capacitor 25 is in parallel with the first trigger capacitor 14 and the second trigger capacitor 20 as long as the first trigger switch element 16, the second trigger switch element 22, and the third trigger switch element 28 are conductive. Configured to be connected. Since other components and their operations / actions are the same as those in the first embodiment, description thereof is omitted.

That is, as shown in FIG. 2, the third trigger capacitor 25 that applies the trigger voltage to the flash discharge tube 8 similarly has the polarity shown via the resistor 12, the diode 13, the diode 21, the diode 26, and the trigger transformer 15. Thus, the first capacitor 6, the first trigger capacitor 14, and the second trigger capacitor 20 are charged to substantially the same voltage (including the same voltage).

That is, like the second trigger capacitor 20, the third trigger capacitor 25 constitutes a trigger capacitor for increasing the capacity of the trigger capacitor for applying the trigger voltage as necessary. Therefore, the anode of the third trigger capacitor 25 is connected to the cathode terminal of the diode 26, and the cathode of the third trigger capacitor 25 is connected to the cathode of the first trigger capacitor 14. As a result, when the first trigger switch element 16, the second trigger switch element 22, and the third trigger switch element 28 become conductive, the third trigger capacitor 25 is in parallel with the first trigger capacitor 14 and the second trigger capacitor 20. Configured to be connected to.

In order to form a discharge loop, the third trigger switch element 28 is connected between the anode of the third trigger capacitor 25 and the first trigger switch element 16.

Then, similarly to the second trigger switch element 22, the third trigger switch element 28 is controlled by a signal from the TR 3 terminal of the control circuit 34. As a result, the charge amount of the third trigger capacitor 25 is added to the charge amounts of the first trigger capacitor 14 and the second trigger capacitor 20 and can be discharged on the discharge loop on the primary side of the trigger transformer 15. It becomes. As a result, the trigger output value, which is the trigger voltage on the secondary side of the trigger transformer 15, can be further increased as necessary to prevent the flash discharge tube 8 from lacking light emission.

Also in the above configuration, when the trigger output value on the secondary side of the trigger transformer 15 predicted by the trigger output value predicting unit 46 exceeds the specified value, the third trigger switch element 28 may be maintained in the non-conductive state. Good. As a result, only the charge amount of the first trigger capacitor 14 and the second trigger capacitor 20 can be discharged.

In the first and second embodiments, the second trigger capacitor 20 and the third trigger capacitor 25 are connected in parallel as the trigger capacitor connected to the first trigger capacitor 14. Not limited to. For example, in addition to the second trigger capacitor 20 and the third trigger capacitor 25, a plurality of trigger capacitors may be provided and connected to the first trigger capacitor 14 in parallel. Thereby, the charge amount supplied to the primary side of the trigger transformer 15 can be further increased. The control circuit 34 controls each of the plurality of trigger capacitors. Thereby, the charge amount supplied to the primary side of the trigger transformer 15 can be arbitrarily adjusted according to the state where the trigger output value of the trigger transformer 15 is equal to or less than the specified value. As a result, the flash discharge tube 8 can be excited with a more optimal trigger output value.

(Embodiment 3)
Hereinafter, an illumination apparatus and an imaging apparatus including the illumination apparatus according to Embodiment 3 of the present invention will be described with reference to FIG.

FIG. 3 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 3 of the present invention.

As shown in FIG. 3, the light emission control circuit of the lighting apparatus of the present embodiment includes a second trigger capacitor 20 that increases the voltage applied to the primary side of the trigger transformer 15, and the fourth trigger switch element 30 is interposed therebetween. The first trigger capacitor 14 is connected in series. That is, the anode of the second trigger capacitor 20 is connected to the anode of the diode 31 and the fifth trigger switch element 33. The cathode of the second trigger capacitor 20 is connected to the anode of the first trigger capacitor 14 via the fourth trigger switch element 30. Further, a resistor 32 is connected between the cathode of the second trigger capacitor 20 and the trigger transformer 15. A path for charging the second trigger capacitor 20 is configured through the resistor 32, the resistor 12, the diode 13, the resistor 32, and the trigger transformer 15.

The control circuit 34 includes a TR4 terminal and a TR5 terminal that control conduction of the fourth trigger switch element 30 and the fifth trigger switch element 33.

Note that other components and their operations / actions are the same as those in the first and second embodiments.

The light emission control circuit of the present embodiment first stores electric charges in the first capacitor 6 constituting the main capacitor via the power source 1 such as a commercial power source and the booster circuit 2 such as the DC-DC converter 2. At this time, the charging voltage of the first capacitor 6 is monitored at the MON terminal of the control circuit 34 by the resistance voltage division of the

resistors

At this time, the first trigger capacitor 14 for applying the trigger voltage to the flash discharge tube 8 has substantially the same voltage (the same voltage as the first capacitor 6) with the polarity shown through the resistor 12, the diode 13, the diode 31, and the trigger transformer 15. Are charged).

Similarly, the second trigger capacitor 20 is also charged to substantially the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown through the resistor 12, the diode 13, the resistor 32, and the trigger transformer 15. Therefore, similarly to the charging voltage of the first capacitor 6, the charging voltages of the first trigger capacitor 14 and the second trigger capacitor 20 are also determined by the voltage determination unit 45 of the control circuit 34.

At this time, in the initial state of the lighting device, the fourth trigger switch element 30 and the fifth trigger switch element 33 are set in a non-conduction state by signals from the TR4 terminal and the TR5 terminal of the control circuit 34.

Then, when the flash discharge tube 8 is caused to emit light, the trigger output value prediction unit 46 of the control circuit 34 is discriminated by the temperature information output from the temperature information acquisition unit 24 to the control circuit 34 and the voltage discrimination unit 45. Based on the determination result of the charging voltage of the trigger capacitor 14, a trigger output value corresponding to the trigger voltage that can be output is predicted under the current conditions.

At this time, if the predicted trigger output value falls below the specified value, a signal for turning off the first trigger switch element 16 is output from the TR1 terminal of the control circuit 34. Further, a signal for turning on the fourth trigger switch element 30 is output from the TR4 terminal. Similarly, a signal for turning on the fifth trigger switch element 33 is output from the TR5 terminal.

Further, a Hi level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to make the IGBT 10 conductive. As a result, the anode of the first trigger capacitor 14 and the cathode of the second trigger capacitor 20 are connected. A voltage obtained by summing the charging voltage of the first trigger capacitor 14 and the charging voltage of the second trigger capacitor 20 is applied to the discharge loop on the primary side of the trigger transformer 15. As a result, a high trigger voltage is generated on the secondary side of the trigger transformer 15 to excite the rare gas in the flash discharge tube 8, and a current flows through the flash discharge tube 8. As a result, the flash discharge tube 8 starts to emit light.

That is, as described above, when the strobe device 42 constituting the illumination device mounted on the imaging device 44 shown in FIG. 7 is used, a trigger is generated depending on the temperature state of the flash discharge tube 8 and the charging voltage of the first trigger capacitor 14. In some cases, the trigger output value output from the secondary side of the transformer 15 does not excite the flash discharge tube 8 and lack of light emission occurs. Therefore, in the present embodiment, the second trigger capacitor 20 is connected in series to the first trigger capacitor 14. Thereby, the voltage applied to the primary side of the trigger transformer 15 is increased, and the trigger output value that is the trigger voltage on the secondary side of the trigger transformer 15 is increased. As a result, the rare gas in the flash discharge tube 8 can be excited to cause the flash discharge tube 8 to emit light.

In the present embodiment, when the flash discharge tube 8 is caused to emit light, the control circuit 34 uses only the charging voltage of the first trigger capacitor 14 determined by the voltage determination unit 45 so that the predicted value of the trigger output value is less than the specified value. If the trigger output value does not cause “missing light emission”, the fourth trigger switch element 30 and the fifth trigger switch element 33 are held in a non-conductive state. Then, the first trigger switch element 16 is turned on. As a result, the discharge loop on the primary side of the trigger transformer 15 is mainly formed by only the first trigger capacitor 14. As a result, it is possible to generate a trigger voltage on the secondary side of the trigger transformer 15 using only the voltage of the first trigger capacitor 14 and apply the trigger voltage to the flash discharge tube 8.

In the present embodiment, similarly to the second trigger capacitor 20, a switching element, a diode, and the like are further added to provide a plurality of trigger capacitors, and the first trigger capacitor 14 may be connected in series. Needless to say. Thereby, the voltage applied to the primary side of the trigger transformer 15 can be arbitrarily adjusted. As a result, the trigger output value, which is the trigger voltage output from the secondary side of the trigger transformer 15, can be adjusted in more detail according to the state of the flash discharge tube 8.

In each of the above embodiments, a description is given of an example in which a plurality of trigger capacitors including a second trigger capacitor and a third trigger capacitor are connected in parallel or in series on the discharge loop on the primary side of the trigger transformer. However, it is not limited to this. For example, the above configurations may be combined and configured in series-parallel connection. Thereby, it is possible to control the trigger output value in further detail. As a result, power consumption and the like can be suppressed.

(Embodiment 4)
Hereinafter, an illumination device and an imaging device according to Embodiment 4 of the present invention will be described with reference to FIG.

FIG. 4 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 4 of the present invention.

First, the second trigger capacitor 20 of the light emission control circuit of the lighting apparatus according to the present embodiment is a trigger capacitor for increasing the voltage applied to the primary side of the trigger transformer 15 as in the third embodiment. Therefore, the anode of the second trigger capacitor 20 is connected to the anode terminal of the diode 37, the anode terminal of the diode 31, and the fifth trigger switch element 33. Further, the cathode of the second trigger capacitor 20 is connected to the anode of the first trigger capacitor 14 via the fourth trigger switch element 30, and is connected to the primary side terminal of the trigger transformer 15 via the resistor 32. .

On the other hand, the third trigger capacitor 25 is a trigger capacitor for increasing the capacity. Specifically, the third trigger capacitor 25 is connected to the first trigger capacitor 14 or the trigger capacitor in which the first trigger capacitor 14 and the second trigger capacitor 20 are connected in series to the discharge loop on the primary side of the trigger transformer 15. Connected in parallel above. That is, the anode of the third trigger capacitor 25 is connected to the cathode terminal of the diode 31 and further connected to the third trigger switch element 28. The cathode of the third trigger capacitor 25 is connected to the cathode of the first trigger capacitor 14.

Note that other components and their operations / actions are the same as those in the first to third embodiments.

resistors

At this time, the first trigger capacitor 14 that applies the trigger voltage to the flash discharge tube 8 has substantially the same voltage (the same voltage as the first capacitor 6) with the polarity shown through the resistor 12, the diode 13, the diode 37, and the trigger transformer 15. Are charged).

Similarly, the second trigger capacitor 20 is also charged to substantially the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown through the resistor 12, the diode 13, the resistor 32, and the trigger transformer 15.

Furthermore, the third trigger capacitor 25 is also charged to the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown in the figure via the resistor 12, the diode 13, the diode 31, and the trigger transformer 15. Therefore, similarly to the charging voltage of the first capacitor 6, the charging voltages of the first trigger capacitor 14, the second trigger capacitor 20, and the third trigger capacitor 25 are also determined by the voltage determination unit 45 of the control circuit 34.

In the following, the first trigger capacitor 14, the second trigger capacitor 20, and the third trigger capacitor 25 are used as an example in the case where a series-parallel circuit is formed on the discharge loop on the primary side of the trigger transformer 15. The operation of the light emission control circuit will be described.

First, a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16, and the first trigger switch element 16 is turned off. At the same time, a signal is output from the TR4 terminal of the control circuit 34 to the fourth trigger switch element 30 to make the fourth trigger switch element 30 conductive. As a result, the anode of the first trigger capacitor 14 and the cathode of the second trigger capacitor 20 are brought into conduction through the fourth trigger switch element 30.

In addition, a signal is output from the TR5 terminal of the control circuit 34 to the fifth trigger switch element 33, and the fifth trigger switch element 33 is turned on. As a result, a discharge loop is formed on the primary side of the trigger transformer 15 by the first trigger capacitor 14 and the second trigger capacitor 20.

Further, a signal is output from the TR3 terminal of the control circuit 34 to the third trigger switch element 28, and the third trigger switch element 28 is turned on.

Also, a Hi level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to make the IGBT 10 conductive.

As described above, first, the first trigger capacitor 14 and the second trigger capacitor 20 are connected in series on the discharge loop on the primary side of the trigger transformer 15. Further, a third trigger capacitor 25 is connected in parallel to the series connection of the first trigger capacitor 14 and the second trigger capacitor 20. Thereby, the trigger output value corresponding to the trigger voltage on the secondary side of the trigger transformer 15 is increased, and the flash discharge tube 8 can be excited. As a result, a current flows through the flash discharge tube 8 and the flash discharge tube 8 starts to emit light.

On the other hand, when the light emission of the flash discharge tube 8 is stopped, a Low level signal is applied from the IT terminal of the control circuit 34 to the IGBT 10. Thereby, IGBT10 will be in an OFF state. As a result, the current flowing through the flash discharge tube 8 is stopped and light emission is stopped.

That is, each trigger capacitor described above is connected in series and parallel with a parallel connection constituted by conduction and non-conduction of the first trigger switch element 16 to the fifth trigger switch element 33, thereby connecting a plurality of trigger capacitors in series and parallel. Is possible.

In this embodiment, the example in which the series-parallel circuit is formed by combining the connection of a plurality of trigger capacitors has been described. However, the present invention is not limited to this. For example, a primary discharge loop of the trigger transformer 15 may be formed by only the first trigger capacitor 14. Further, a primary discharge loop of the trigger transformer 15 may be formed by connecting the first trigger capacitor 14 and the second trigger capacitor 20 in series. Further, a discharge loop on the primary side of the trigger transformer 15 may be formed by connecting the first trigger capacitor 14 and the third trigger capacitor 25 in parallel.

(Embodiment 5)
Hereinafter, an illumination device and an imaging device according to Embodiment 5 of the present invention will be described with reference to FIGS. 5 and 8B.

FIG. 5 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 5 of the present invention. FIG. 8B is a diagram showing an operation timing chart of the light emission control circuit in each embodiment of the present invention.

As shown in FIG. 5, the light emission control circuit of the lighting apparatus of the present embodiment includes at least the booster circuit 2, the first capacitor 6, the flash discharge tube 8, and the light emission control circuit described in the first embodiment. A first trigger capacitor 14, a trigger circuit including a trigger transformer 15, a light emission control element 10, a control circuit 34, and the like are provided. Furthermore, the light emission control circuit of the present embodiment includes a first temperature information acquisition unit 40, a second temperature information acquisition unit 41, and the like. The first temperature information acquisition unit 40 includes a first temperature detection device 40 such as a thermistor, for example, and is disposed in the vicinity of the flash discharge tube 8. The first temperature information acquisition unit 40 acquires temperature information of the flash discharge tube 8 and outputs it to the TMP1 terminal of the control circuit 34. The second temperature information acquisition unit 41 includes a second temperature detection device 41 such as a thermistor. The second temperature information acquisition unit 41 measures a temperature such as the environmental temperature and outputs it to the TMP2 terminal of the control circuit 34. The data acquired by the second temperature information acquisition unit 41 is stored in a storage device such as a semiconductor memory.

Further, the control circuit 34 controls the trigger circuit and the light emission control element 10 and acquires the light emission information of the flash discharge tube 8. Further, the control circuit 34 includes a light emission interval measurement recording unit (not shown), an elapsed time measurement recording unit 47, and the like. The light emission interval measurement recording unit measures and stores the amount of light emitted from the flash discharge tube 8, the number of times of light emission, and the light emission interval. The elapsed time measurement recording unit 47 measures and stores the elapsed time since the flash discharge tube 8 last emitted light.

The other components and their operations / actions are the same as those in the first to fourth embodiments.

Hereinafter, the operation of the light emission control circuit will be described with reference to FIG. 5 and FIG. 8B.

resistors

4 and 5. Note that the charging voltage of the first capacitor 6 input to the MON terminal is determined by the voltage determination unit 45 of the control circuit 34. When the voltage reaches a predetermined voltage, the control circuit 34 stops the operation of the booster circuit 2 such as the DC-DC converter 2 and completes the charging of the first capacitor 6.

At this time, the first trigger capacitor 14 for applying the trigger voltage to the flash discharge tube 8 has substantially the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown through the resistor 12, the diode 13, and the trigger transformer 15. It is charged until.

Further, the first temperature detection device 40 constituting the first temperature information acquisition unit 40 arranged in the vicinity of the flash discharge tube 8 outputs the detected temperature information of the flash discharge tube 8 to the TMP1 terminal of the control circuit 34. .

Note that it is not necessary to use the temperature information detected by the first temperature detection device 40 as the temperature information of the flash discharge tube 8 in particular. For example, the ambient temperature is acquired by the second temperature detection device 41 constituting the second temperature information acquisition unit 41, and past emission information such as the light emission interval and the amount of light emitted from the flash discharge tube 8 is not shown. Record in storage device. From the stored data, the current temperature of the flash discharge tube 8 is calculated and predicted. Then, the predicted value may be output as temperature information of the flash discharge tube 8 to the control circuit 34, and based on this, the light emission control circuit may be controlled to cause the flash discharge tube 8 to emit light.

Next, when the flash discharge tube 8 is caused to emit light, a Hi level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to make the IGBT 10 conductive. At the same time, a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16 to make it conductive. Therefore, the charge of the first trigger capacitor 14 flows through the first trigger switch element 16 and the trigger transformer 15. As a result, a high trigger voltage is generated from the secondary side of the trigger transformer 15. Then, by exciting the rare gas in the flash discharge tube 8, a current flows between the anode and the cathode of the flash discharge tube 8. As a result, the flash discharge tube 8 starts to emit light.

That is, an illumination device such as a normal strobe device repeatedly performs the light emission operation of the flash discharge tube 8 as described above.

However, an illuminating device such as a strobe device may be placed in a situation where the light emission is performed continuously at regular intervals, the light is emitted continuously for a short time, or the light is not emitted for a long time.

Therefore, in the present embodiment, the number of times of light emission performed in the past, light emission information such as the light emission interval and the amount of light emitted, the temperature of the flash discharge tube 8, the environmental temperature, and the past (last) light emission to the present. Information such as the elapsed time is acquired by the light emission interval measurement recording unit and the elapsed time measurement recording unit 47 of the control circuit 34 described above. Then, based on the acquired data, the control circuit 34 determines whether or not the set condition for the occurrence of “missing light emission” of the flash discharge tube 8 occurs before performing the light emission operation of the flash discharge tube 8.

That is, as shown in FIG. 8A and FIG. 8B, the “light emission deficiency” of the flash discharge tube 8 is caused by the state in which impurities deposited from the glass tube or the like constituting the flash discharge tube 8 are adsorbed on the pellet or left standing for a long time. It is determined whether or not the condition occurs.

At this time, when it is determined that the “light emission failure” of the flash discharge tube 8 occurs, a low level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to turn off the IGBT 10. At the same time, a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16 to make it conductive. Thereby, the electric charge of the first trigger capacitor 14 flows through the first trigger switch element 16 and the trigger transformer 15. As a result, a high trigger voltage is generated from the secondary side of the trigger transformer 15 and applied to the flash discharge tube 8.

That is, the illumination device of the present embodiment applies only the trigger voltage to the flash discharge tube 8 without causing a current to flow between the anode and the cathode of the flash discharge tube 8 in order to cause the flash discharge tube 8 to emit light. At this time, the trigger voltage is applied at least once based on the data of the light emission interval measurement recording unit and the elapsed time measurement recording unit 47 of the control circuit 34 until the number of times that it can be determined that “light emission failure” does not occur. The reason for this will be described with reference to FIG. 8B. That is, as shown in the operation timing chart of the light-emitting circuit in FIG. 8B, the impurities adsorbed on the pellet can be removed by applying the trigger voltage. As a result, it is possible to prevent the occurrence of “missing light emission” in the flash discharge tube 8 and maintain the light emission state.

However, normally, when power is not supplied to the control circuit 34 or the like for a long time, for example, when the power is turned off for a long time, the number of light emission performed in the past, the light emission interval, the light emission amount, and the light emission in the past (last) Information measured by a light emission interval measurement recording unit (not shown), the elapsed time measurement recording unit 47, or the like such as the elapsed time up to the present time may not be acquired from a storage device such as a semiconductor memory.

Therefore, in order to cope with the above situation, in the present embodiment, at the time of turning on the power, the low level signal is always applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 at least once. Turn off. At the same time, a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16, and the first trigger switch element 16 is turned on. Thus, only a trigger voltage is applied to the flash discharge tube 8 without flowing a current intended to emit light between the anode and the cathode of the flash discharge tube 8 to remove impurities in advance or for a long time. Release the gas that has been in a stable state where it is difficult to excite the sealed gas. As a result, the flash discharge tube 8 can always be maintained in a state capable of emitting light regardless of the past progress history of the strobe device. Thereby, “missing light emission” of the flash discharge tube 8 can be prevented in advance.

(Embodiment 6)
Hereinafter, an illumination apparatus and an imaging apparatus according to Embodiment 6 of the present invention will be described with reference to FIG.

FIG. 6 is a diagram showing a light emission control circuit of the lighting apparatus according to Embodiment 6 of the present invention.

The light emission control circuit of the strobe device according to the present embodiment includes a diode 21, a second trigger capacitor 20, a second trigger switch element 22, and a resistor 23, and the charge charge of the trigger capacitor on the primary loop of the trigger transformer 15. This is different from the light emission control circuit of the fifth embodiment in that two circuits for emitting light are configured. At this time, the capacity of the second trigger capacitor 20 is set to be smaller than the capacity of the first trigger capacitor 14. The other components and their operations / actions are the same as those in the fifth embodiment, and thus the description thereof is omitted.

The light emission control circuit of the present embodiment first stores electric charges in the first capacitor 6 constituting the main capacitor 6 via the power source 1 such as a commercial power source and the booster circuit 2 such as the DC-DC converter 2. At this time, the charging voltage of the first capacitor 6 is monitored at the MON terminal of the control circuit 34 by the resistance voltage division of the

resistors

4 and 5. Note that the charging voltage of the first capacitor 6 input to the MON terminal is determined by the voltage determination unit 45 of the control circuit 34. When the charging voltage of the first capacitor 6 reaches a predetermined voltage, the control circuit 34 stops the operation of the booster circuit 2 such as the DC-DC converter 2 and completes the charging of the first capacitor 6.

At this time, the first trigger capacitor 14 for applying the trigger voltage to the flash discharge tube 8 is up to substantially the same voltage (including the same voltage) as the main capacitor 6 with the polarity shown through the resistor 12, the diode 13, and the trigger transformer 15. Charged.

Also, the second trigger capacitor 20 is charged to the same voltage (including the same voltage) as the first capacitor 6 with the polarity shown in the figure via the resistor 12, the diode 13, the diode 21, and the trigger transformer 15. Further, as in the fifth embodiment, the control circuit 34 stores temperature information of the flash discharge tube 8 and ambient temperature information such as the first temperature information acquisition unit 40 and the second temperature information acquisition unit 41. Input from the acquisition unit to the TMP1 terminal and the TMP2 terminal, respectively.

Then, when the flash discharge tube 8 is caused to emit light, a Hi level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to make the IGBT 10 conductive. At the same time, a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16 to turn on the first trigger switch element 16, and the second trigger switch element 22 is turned off from the TR2 terminal of the control circuit 34. deep. At this time, the electric charge of the first trigger capacitor 14 flows through the first trigger switch element 16 and the trigger transformer 15. As a result, a high trigger voltage is generated from the secondary side of the trigger transformer 15. Then, a current flows between the anode and the cathode of the flash discharge tube 8 by exciting the rare gas in the flash discharge tube 8. As a result, the flash discharge tube 8 starts to emit light.

Further, similarly to the fifth embodiment, the number of times of light emission performed in the past, light emission information such as the light emission interval and the amount of light emitted, the temperature of the flash discharge tube 8, the environmental temperature, and the process from the previous light emission to the present. Information such as time is acquired by a light emission interval measurement recording unit (not shown) or an elapsed time measurement recording unit 47 of the control circuit 34. Then, based on the acquired data, the control circuit 34 determines whether or not the set condition for the occurrence of “missing light emission” of the flash discharge tube 8 occurs before performing the light emission operation of the flash discharge tube 8.

At this time, when it is determined that the “light emission failure” of the flash discharge tube 8 occurs, a low level signal is applied from the IT terminal of the control circuit 34 to the gate terminal of the IGBT 10 to turn off the IGBT 10. At the same time, a signal is output from the TR2 terminal of the control circuit 34 to the second trigger switch element 22 to be in a conductive state, and a signal is output from the TR1 terminal of the control circuit 34 to the first trigger switch element 16 to be in a non-conductive state. . As a result, the electric charge of the second trigger capacitor 20 flows through the second trigger switch element 22 and the trigger transformer 15. As a result, a high trigger voltage is generated from the secondary side of the trigger transformer 15 and applied to the flash discharge tube 8.

That is, the strobe device of the present embodiment applies only the trigger voltage to the flash discharge tube 8 without flowing current between the anode and the cathode of the flash discharge tube 8 to emit light. At this time, the trigger voltage is applied at least once, based on the data of the light emission interval measurement recording unit (not shown) and the elapsed time measurement recording unit 47 of the control circuit 34, up to the number of times that it can be determined that no “light emission failure” occurs. To do. Thereby, the occurrence of “missing light emission” in the flash discharge tube 8 can be prevented in advance.

Note that the light emission control circuit of the lighting device according to the present embodiment includes a trigger circuit configured by the second trigger capacitor 20 or the like in order to prevent lack of light emission, and an existing trigger circuit configured by the first trigger capacitor 14 or the like. Separately. At this time, as described above, a capacitor having a small capacity is used for the second trigger capacitor 20 with respect to the capacity of the first trigger capacitor 14. The reason for this is that when the flash discharge tube 8 lacks light emission, the impedance of the flash discharge tube 8 may change with respect to the state capable of light emission. Therefore, if the capacity of the second trigger capacitor 20 is the same as that of the conventional trigger capacitor, the trigger voltage on the secondary side of the trigger transformer 15 may become too large. In this case, a trigger transformer that can withstand high voltage is required. In some cases, a spark (discharge) may occur between the trigger transformer 15 and the ground line due to a high trigger voltage. As a result, the trigger voltage applied to the flash discharge tube 8 may drop below the required trigger voltage.

Therefore, in the present embodiment, a capacitor having a smaller capacity than the first trigger capacitor 14 is used for the second trigger capacitor 20. Thereby, even when the charging voltage of the second trigger capacitor 20 is high, the trigger output value that is the trigger voltage on the secondary side of the trigger transformer 15 can be suppressed.

On the other hand, when a trigger voltage is applied to cause the flash discharge tube 8 to emit light, the impedance of the flash discharge tube 8 changes as compared with the case where the light emission is lost. Specifically, it varies depending on the type (gas type, diameter, etc.) and state (temperature, etc.) of the flash discharge tube. For example, when light emission is possible, the peak output of the trigger voltage is 5 kV. Changes to about 8 kV. Therefore, even if the trigger voltage is applied by the first trigger capacitor 14 having a capacity larger than that of the second trigger capacitor 20, the trigger voltage on the secondary side of the trigger transformer 15 that sparks (discharges) between the trigger transformer 15 and the ground line. Is not output. As a result, an appropriate trigger voltage for causing the flash discharge tube 8 to emit light can be applied to the flash discharge tube 8.

According to the present embodiment, it is possible to realize a highly reliable illumination device and imaging device at low cost.

In each of the above embodiments, a strobe device is described as an example of a lighting device for taking a picture, but the present invention is not limited to this. For example, the present invention may be applied to an illumination device such as an endoscope using a flash discharge tube.

As described above, the lighting device according to the present invention includes a first capacitor that accumulates electric charge, a flash discharge tube that emits light by consuming the electric charge accumulated in the first capacitor, and a trigger that causes the flash discharge tube to emit light. A trigger circuit including a first trigger capacitor for applying a voltage and a trigger transformer is provided. Furthermore, the light emission control element connected to the flash discharge tube, the trigger circuit and the light emission control element are controlled, and the control circuit for acquiring the light emission information of the flash discharge tube, and the temperature information acquisition for acquiring the temperature information of the flash discharge tube And may have a part.

According to this configuration, when the flash discharge tube is continuously emitting light, the trigger circuit and the light emission control element are controlled based on the temperature information in the vicinity of the flash discharge tube.

This allows the flash discharge tube to emit light continuously without “missing light emission”. As a result, an illumination device suitable for an imaging device that performs continuous shooting can be realized.

In addition, the control circuit of the lighting device according to the present invention includes a voltage determination unit that determines a charging voltage of the first trigger capacitor, a temperature information acquisition unit, and temperature information of the flash discharge tube acquired from the voltage determination unit and the first trigger capacitor. And a trigger output value prediction unit that predicts a trigger output value based on the determination result of the charging voltage. And when a trigger output value is less than the predetermined value decided beforehand, it may have the connection composition which connects at least one trigger capacitor in parallel with the 1st trigger capacitor.

∙ According to this configuration, when the trigger output value can be predicted to be lower than the specified value, one or more trigger capacitors are added to increase the capacity, and a larger amount of current flows through the trigger transformer. As a result, the trigger output value can be maintained to exceed the specified value. As a result, the flash discharge tube can emit light continuously without “missing light emission”.

Further, the lighting device of the present invention has at least one of the first trigger capacitor and the first trigger capacitor when the trigger output value is determined to be lower than the specified value based on the determination result of the temperature information of the flash discharge tube and the charging voltage of the first trigger capacitor. It may have a connection configuration in which two or more trigger capacitors are connected in series to the primary side of the trigger transformer.

According to this configuration, when the trigger output value can be predicted to fall below the specified value, the voltage is increased by adding one or more trigger capacitors, and a higher voltage is applied by the trigger transformer. Thereby, the trigger output value applied to the flash discharge tube can be maintained to exceed the specified value. As a result, the flash discharge tube can emit light continuously without “missing light emission”.

Further, in the lighting device of the present invention, the connection configuration may be a series connection, a parallel connection, or a series-parallel connection configuration of the first trigger capacitor and at least one trigger capacitor. As a result, the degree of freedom in designing the light emitting circuit for preventing the “light emission defect” of the flash discharge tube is improved. As a result, the trigger output value can be arbitrarily set as required.

Further, in the illumination device of the present invention, the light emission information may include the number of times of light emission of the flash discharge tube, the light emission amount light emission interval, and the position information of the flash discharge tube during light emission. Thereby, it is possible to more accurately prevent “missing light emission” of the flash discharge tube.

In addition, when it is determined from the acquired light emission information that the condition for causing the lack of light emission is satisfied, the control circuit of the lighting device of the present invention at least in the flash discharge tube while keeping the light emission control element non-conductive. One or more trigger voltages may be applied. As a result, removal of impurities adhering to the pellets or release of the stable state of the rare gas in the flash discharge tube after standing for a long period of time can be prevented, thereby preventing “missing light emission”.

Further, the lighting device of the present invention may acquire temperature information of the flash discharge tube by calculation from light emission information of the flash discharge tube.

According to this configuration, the trigger output value can be predicted without directly measuring the temperature of the flash discharge tube or the vicinity thereof. Therefore, a temperature measurement device or the like can be omitted. Thereby, cost reduction of an illuminating device, an imaging device, etc. is attained.

Further, the temperature information acquisition unit of the lighting device of the present invention may acquire the temperature of the flash discharge tube from the flash discharge tube or a temperature detection element arranged in the vicinity of the flash discharge tube.

According to this configuration, the temperature of the flash discharge tube that emits light continuously can be obtained more accurately. Thereby, the trigger output value can be predicted more accurately based on the temperature information of the flash discharge tube.

The control circuit of the lighting device of the present invention further includes an elapsed time measurement recording unit that acquires and records the elapsed time since the flash discharge tube last emitted light, and the elapsed time acquired by the elapsed time measurement recording unit. May be used as light emission information. Thereby, based on the progress history of the flash discharge tube, “missing light emission” of the flash discharge tube can be effectively prevented.

Moreover, the lighting device of the present invention may apply the trigger voltage to the flash discharge tube at least once while the light emission control element is kept non-conductive when the power is turned on.

Thereby, even when the lighting device is not used for a long time, it is possible to prevent “missing light emission” in advance regardless of the progress history of the flash discharge tube.

Moreover, the imaging device of the present invention may be equipped with the illumination device. Thereby, it is possible to realize suitable photography without causing the lack of light emission of the lighting device during continuous photography.

The present invention is useful as a lighting device such as a strobe device or an endoscope that handles a flash discharge tube because it does not cause so-called “missing light emission” even during continuous light emission or during initial light emission.

1 Power supply 2 DC-DC converter (Boost circuit)
4, 5, 12, 23, 32 Resistance 6 First capacitor (main capacitor)
8 Flash discharge tube 10 IGBT (light emission control element)
13, 21, 26, 31, 37 Diode 14 First trigger capacitor 15 Trigger transformer 16 First trigger switch element 20 Second trigger capacitor 22 Second trigger switch element 24 Temperature detection device (temperature information acquisition unit)
25 3rd trigger capacitor 27 Signal resistor 28 3rd trigger switch element 30 4th trigger switch element 33 5th trigger switch element 34 Control circuit 40 1st temperature detection device (1st temperature information acquisition part)
41 2nd temperature detection device (2nd temperature information acquisition part)
42 Strobe device 44 Imaging device 45 Voltage determination unit 46 Trigger output value prediction unit 47 Elapsed time measurement recording unit

Claims

A first capacitor for storing charge;
A flash discharge tube that emits light by consuming the charge accumulated in the first capacitor;
A first trigger capacitor for applying a trigger voltage for causing the flash discharge tube to emit light;
A trigger circuit including a trigger transformer;
A light emission control element connected in series with the flash discharge tube;
A control circuit that controls the trigger circuit and the light emission control element, and obtains light emission information of the flash discharge tube;
A temperature information acquisition unit for acquiring temperature information of the flash discharge tube;
A lighting device.
The control circuit includes a voltage determining unit that determines a charging voltage of the first trigger capacitor;
A trigger output value prediction unit that predicts a trigger output value based on the temperature information of the flash discharge tube and the determination result of the charge voltage of the first trigger capacitor, acquired from the temperature information acquisition unit and the voltage determination unit; In addition,
2. The lighting device according to claim 1, wherein when the trigger output value falls below a predetermined value, the lighting device according to claim 1, wherein at least one trigger capacitor is connected in parallel to the first trigger capacitor.
From the determination result of the temperature information of the flash discharge tube and the charging voltage of the first trigger capacitor, when the trigger output value is determined to be below the specified value,
The lighting device according to claim 1, wherein the lighting device has a connection configuration in which the first trigger capacitor and at least one trigger capacitor are connected in series to a primary side of the trigger transformer.
4. The lighting device according to claim 2, wherein the connection configuration is a series connection, a parallel connection, or a series-parallel connection configuration of the first trigger capacitor and at least one of the trigger capacitors. 5. .
The lighting device according to claim 1, wherein the light emission information includes the number of times of light emission of the flash discharge tube, the light emission amount and the light emission interval, and positional information of the flash discharge tube at the time of light emission.
When it is determined from the acquired light emission information that the control circuit satisfies a condition for causing a predetermined lack of light emission,
The lighting device according to claim 1, wherein a trigger voltage is applied to the flash discharge tube at least once while the light emission control element is in a non-conductive state.
The lighting device according to claim 1, wherein the temperature information of the flash discharge tube is obtained by calculating from the light emission information of the flash discharge tube.
The lighting device according to claim 1, wherein the temperature information acquisition unit acquires the temperature of the flash discharge tube from the flash discharge tube or a temperature detection element disposed in the vicinity of the flash discharge tube.
The control circuit further includes an elapsed time measurement recording unit that acquires and records an elapsed time since the flash discharge tube last emitted light,
The lighting device according to claim 1, wherein the elapsed time acquired by the elapsed time measurement recording unit is used as the light emission information.
The lighting device according to claim 1, wherein at the time of turning on the power, the trigger voltage is applied to the flash discharge tube at least once while the light emission control element is kept non-conductive.
An imaging device equipped with the illumination device according to claim 1.