JPH02287449A - Stroboscopic device - Google Patents

Abstract

PURPOSE:To simplify a driving system of an insulating gate type bipolar transistor by providing a switch means that operates a trigger circuit and a gate means, and a control element that turns off the insulating gate bipolar transistor by means of turning on. CONSTITUTION:The switch means 17 is connected to a gate through a resistance 25 of an SCR 22 as the trigger switch element of the trigger circuit 20. By turning on the switch, a transistor 26 turns off the insulating gate type bipolar transistor I.G.B.T., and the transistor 26 is connected between the gate and emitter of I.G.B.T. as its control element. When a high level pulse signal having an extremely short time interval is impressed on a base terminal 18a of a transistor 18 for the switch means 17, this transistor 18 is turned on, and a current runs through the gate means 14 and the switch means 17 and a flash discharge tube Xe consumes electric charges of a main capacitor CM and emits light. Therefore the stroboscopic device that has the simplified driving system of the insulating gate bipolar transistor is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an insulated gate bipolar transistor (I
nsulated Gate Bipolar Tra
The present invention relates to a strobe device connected to an insulated gate type bipolar transistor, and particularly to a strobe device having a drive system of an insulated gate bipolar transistor.

BACKGROUND OF THE INVENTION Various types of strobe devices have been proposed in which a high-power transistor is connected in series with a flash discharge tube as a light emission control element, and a device using the above-mentioned insulated gate bipolar transistor is also disclosed in Japanese Patent Laid-Open No. 1983-1999. It is disclosed in Japanese Patent No. 47033.

As shown in FIG. 4, the device disclosed in this publication supplies a constant voltage to a power source 1, which is, for example, a well-known DC-DC converter circuit, and a light emission control circuit 5, which is attached to the power source 1 and will be described later. A trigger command signal is connected to the constant voltage circuit 2, a known trigger circuit 3 for triggering the flash discharge tube Xe, and a control means 7 in the camera body, and is used to send and receive various signals to operate the trigger circuit 3. A control circuit 4 that generates equal output signals, an insulated gate bipolar transistor connected in series with the flash discharge tube Xe; G.
B, T.

The light emitting control circuit 5 controls the on/off of the discharge tube Xe and controls the light emission of the discharge tube Xe, and the voltage doubler circuit 6 applies double pressure to the discharge tube Xe.

In this device, when switch Sv is turned on now,
The power supply 1, which is a DC-DC converter circuit, starts operating, and the main capacitors C and A and the voltage doubler capacitor CI are connected to the secondary winding S of the oscillation transformer T1.

The capacitor CI, which acts as an operating power source for the control circuit 4, is charged by a low voltage power source E. At the same time, charging of the capacitor C3 of the constant voltage circuit 2 connected to the other secondary winding S2 of the oscillation transformer T1 via the diode D is also started.

Therefore, power is supplied to the control circuit 4 and the light emission control circuit 5, the control circuit 4 starts operating, and the light emission control circuit 5
is ready to emit light.

When a light emission start signal is input to the control circuit 4 from the control means 7 in a state where the main capacitor 0M etc. is charged,
The control circuit 4 outputs a high-level trigger signal from the terminal 01 for a predetermined period taking into account the maximum light emission time of the flash discharge tube Xe, and supplies it to the transistor Q+ of the light emission control circuit 5.

Transistor Qr turns on in response to the trigger signal, which turns on transistor Q2, and the charging voltage of capacitor C1 of constant voltage generation circuit 2 increases to transistor Q2.
Insulated gate bipolar transistor 1. G
, B, T, and the insulated gate bipolar transistor 1. G, B, and T will be turned on.

It goes without saying that at this time, the terminal Q of the control circuit 4 is maintained at a low level, and the transistor Q3 is turned off.

Insulated gate bipolar transistor 1. G, B,
T.

When turned on, the trigger capacitor C4 of the trigger circuit 3,
Capacitor C4 via the primary winding of trigger transformer T2
A charging current of T2 flows, and a trigger pulse is generated in the secondary winding of the transformer T2. At the same time, the positive side of capacitor C3 of voltage doubler circuit 6 is grounded via resistor R5 and insulated gate bipolar transistors I, G, B, T, and the charging voltage of capacitor C2 is connected to main capacitor CM.
is applied to the flash discharge tube Xe superimposed on the charging voltage. As a result, the flash discharge tube Xe has a main capacitor C
It consumes the charge of M and emits light.

When an appropriate amount of light is obtained by emitting light from the flash discharge tube Xe,
For example, a light emission stop pulse is formed by a photometric circuit included in the control means 7, inputted to the control circuit 4, and output as a high-level light emission stop signal from its terminal 02.

This light emission stop signal is supplied to transistors Q3 and Q4, turning them on, thereby connecting the base-emitter of transistor Q+ and the insulated gate bipolar transistors 1. The gates and emitters of G, B, and T are shorted, transistor Q+, and insulated gate bipolar transistor 1. G, B, and T are turned off.

As a result, transistor Q2 turns off and capacitor C
1 is prevented, and at the same time, the discharge current that was flowing through the flash discharge tube Xe stops flowing, and light emission stops.

The basic operation of the device shown in Figure 4 is as described above.
Compared to a system in which light emission is stopped using a commutating capacitor, there is no over-emission of light, and it is possible to repeatedly emit light at high speed.

In addition, the constant voltage circuit 2 is eliminated, and the insulated gate bipolar transistor 1. The previous proposal also discloses a configuration as shown in FIG. 5 in which the driving power for G, B, and T is obtained from the high voltage side, that is, from the main capacitor CM.

In FIG. 5, elements corresponding to those of the apparatus shown in FIG. 3 are given the same reference numerals.

In this configuration, the previous transistor Q+ is the main capacitor C
High potential side terminals of M, ■, ■, and insulated gate bipolar transistor 1. The transistor Q is connected between the gates of the transistors G, B, and T, and the base of the transistor Q is connected between the transistor Q and the insulated gate bipolar transistor 1. Zener diodes Z and D are connected between the connection point with the gates of G, B, and T, and the ground. Therefore, as mentioned earlier, when the trigger signal is output from the control circuit 4 and the transistor QI is turned on,
The transistor Q is turned on, and the charging voltage of the main capacitor CM is regulated by the Zener diodes Z and D, and a predetermined voltage is applied to the insulated gate bipolar transistor 1. G
, B, and T, and this insulated gate bipolar transistor 1. G, B,
T is turned on, and the flash discharge tube Xe emits light as in the previous device.

As described above, insulated gate bipolar transistor 1
．． By obtaining the driving power for G, B, and T from the high voltage side, there is no need to configure the constant voltage circuit 2 as described above. Therefore, it is possible to expect the effect that it is not necessary to keep the DC-DC converter circuit, which is the power supply 1, in an operating state all the time, and that there is no need to pay much attention to its operation management.

In other words, in the constant voltage circuit 2, the insulated gate bipolar transistor 1. When obtaining driving power for G, B, and T, the charging voltage of the capacitor C3 is always connected to the insulated gate bipolar transistor 1. Since it is necessary to control G, B, and T to values sufficient to turn them on, great care must be taken in setting the number of turns of the secondary winding S and in maintaining the operation of the DC-DC converter circuit. However, if the configuration is as shown in FIG. 5, the above-mentioned precautions will not be necessary.

Problems to be Solved by the Invention As mentioned above, strobe devices in which an insulated gate bipolar transistor is connected in series with a flash discharge tube are well known, and the driving power source for the insulated gate bipolar transistor is also connected to a constant voltage circuit or a main capacitor. The use of an output voltage, etc. is disclosed in the above device.

On the other hand, looking at the drive system of the insulated gate bipolar transistor in the above device, it is configured such that the above drive power is supplied in response to the operation of the transistor Q+ which is turned on in response to a trigger signal. That is, it is a condition for supplying driving power that the transistor Ql is in an on-operation, and therefore the trigger signal continues to be output from the control circuit for a predetermined period of time taking into account the total light emission time of the flash discharge tube.

As a result, the above device requires a pulse generation circuit that generates a pulse having a predetermined period of pulse width in order to form a trigger signal in the control circuit, which complicates the circuit configuration and is disadvantageous in terms of energy consumption. This results in the inconvenience of becoming.

The present invention has been made with this point in mind, and is a strobe light that does not have a special pulse generation circuit and is equipped with a simple drive circuit that obtains the drive power for the insulated gate bipolar transistor from the high voltage side. The purpose is to provide equipment.

Means for Solving the Problems The strobe device of the present invention comprises a main capacitor connected to both ends of a DC high voltage power supply and charged, a flash discharge tube and an insulated gate bipolar transistor connected in series,
A first series connection body connected to both ends of the main capacitor, a switch element, and a constant voltage element are connected in series. A second series connection body connected to the gate, a gate means connected to both ends of the flash discharge tube and turning on the switch element when operated, and a second series connection body connected to both ends of the insulated gate bipolar transistor and operated. a trigger circuit for exciting the flash discharge tube and a switch means for operating the gate means; and a control element to control the operation.

Operation Since the strobe device of the present invention is configured as described above, when the switch means operates, the trigger circuit and gate means operate, the flash discharge tube is excited, and the switch element is turned on. Become. Therefore, the charging voltage of the main capacitor is set to a predetermined voltage by the constant voltage element and supplied to the gate of the insulated gate bipolar transistor, which turns on, and as a result, the flash discharge tube emits light. In addition, the gate means continues to operate via the insulated gate bipolar transistor in the on state, and keeps the switching element on. When the control element is turned on in this state, the insulated gate bipolar transistor is turned off. However, when the flash discharge tube stops emitting light, if the switch means is in an inactive state, the gate means becomes inactive and the switch element is turned off, and the device returns to its initial state, that is, - times of emitting light. The operation is completed.Therefore, the trigger signal required to turn on the insulated gate bipolar transistor may be a very short pulse signal for operating the switch means.

Embodiments Hereinafter, embodiments of a strobe device according to the present invention will be described with reference to the drawings.

[Example 1] FIG. 1 is an electrical circuit diagram of the main part of the first embodiment.

In the figure, elements having the same functions as those of the conventional example shown in FIG. 4 are given the same reference numerals.

As shown in the figure, a main capacitor CM is connected to both ends of the DC high voltage power supply 8, and a flash discharge tube Xe and an insulated gate bipolar transistor 1. A first series connection body 9 formed by connecting G, B, and T in series, and a transistor 11 which is a switch element. Resistance 12. A second series connection body 10 is connected in which Zener diodes 13, which are constant voltage elements, are connected in series.

Resistor 12 of transistor 11 and Zener diode 13
A connection point A is connected to the gates of insulated gate bipolar transistors LG, B, and T.

Both ends of the flash discharge tube Xe consist of resistors 15 and 16,
A transistor 11 whose connection point B is a switch element.
The gate means 14 of the switch element connected to the control pole (base) of is connected. Insulated gate bipolar transistor 1. A transistor 18, which is a switching element, and a resistor 19 are connected in series at both ends of G, B, and T, and a connection point C between the transistor 18 and the resistor 19 is a trigger switch element of a trigger circuit 20, which will be described later. A switch means 17 is connected to the gate of 5CR22 via a resistor 25. Tori is circuit 20
is a trigger capacitor 23 charged via a resistor 21
, a trigger switch element 5CR22 which discharges the charge in the trigger capacitor 23 via the trigger transformer 24 when turned on, and a resistor 25 for protecting the 5CR22.

Insulated gate bipolar transistor 1. G, B,
Between the gate and emitter of T, an insulated gate bipolar transistor 1. G, B,
A transistor 26, which turns off T, is connected as its control element.

Note that the base terminal 18 which is the control pole of the transistor 18
a and the base terminal 2 which is the control pole of the transistor 26
A trigger signal for starting light emission and a stop signal for stopping light emission are respectively supplied to 6a.

Now, in a state where the main capacitor CM and the Riga capacitor 23 are charged by the DC high voltage power supply 8, a high level pulse signal having an extremely short duration is applied to the base terminal 18a of the transistor 18 of the switching means 17. , this transistor 18 is turned on, and the resistor 15 of the gate means 14 is turned on.
．． 16 and through the resistor 19 of the switch means 17 a current will flow. Therefore, resistor 15 and resistor 19
The voltage drop across transistors 11 and 5CR
22 is turned on, the charged voltage of the main capacitor CM is applied to the Zener diode 13, and the charged charge of the trigger capacitor 23 is discharged via the trigger transformer 24, and the flash discharge tube Xe is excited. That is, the trigger circuit 20 performs a well-known trigger operation. Therefore, a predetermined voltage is output to the connection point A, and the insulated gate bipolar transistor 1. As a result, the insulated gate bipolar transistor 1. G, B, T,
is turned on, and the flash discharge tube Xe consumes the charge in the main capacitor CM to emit light.

Insulated gate bipolar transistor 1. G, B,
T.

When turned on, gate means 14. The current flowing through the switch means 17 is transferred to the gate means 14. Insulated gate bipolar transistor 1. G, B, and T. Therefore, the on state of the transistor 11 is maintained regardless of the state of the transistor 18 of the switching means 17, and of course the insulated gate bipolar transistor 1. Supply of driving power to main capacitor CM to G, B, and T will also continue.

That is, the transistor 18 of the switch means 17 is configured so that the trigger operation of the flash discharge tube Xe is performed from the supply of the signal, and the transistor 18 of the switch means 17 is an insulated gate bipolar transistor 1. G
, B, and T only have to remain on for a period of time until they turn on. Of course, that period is extremely short, so in this embodiment, the trigger signal is a pulse signal with an extremely short width as described above. That's fine.

At an appropriate time in the above-mentioned state, for example, the flash discharge tube Xe
When the amount of light emitted by the transistor 26 reaches the appropriate amount of light, a high-level pulse signal having a predetermined pulse width is applied to the base terminal 26a of the transistor 26 from, for example, a photometric circuit (not shown), and the transistor 26 is turned on. , insulated gate bipolar transistor 1. The gates and emitters of G, B, and T are shorted, so that the insulated gate bipolar transistor 1. G, B,
T is off.

Insulated gate bipolar transistor 1. G, B,
T.

When turned off, the discharge current flowing through the flash discharge tube Xe is cut off, and the base current of the transistor 11 flowing through the gate means 14 is also cut off. stops emitting light, transistor 11 is also turned off, and the insulated gate bipolar transistors I, G, B, of the main capacitor CM
The supply of driving power to T is stopped. That is, the light emitting device returns to the initial state before emitting light, and one light emitting operation ends at this point.

Although it is actually rare, insulated gate bipolar transistors1. When G, B, and T are off,
If transistor 18 is still on, gate means 1
4. Although current flows through the switch means 17, no particular problem occurs if the on period of the transistor 26 is set to a predetermined period longer than the on period of the transistor 18.

Furthermore, when a trigger signal is applied to the base terminal 18a of the transistor 18, the insulated gate bipolar transistor 1.
If the turning on of G, B, and T is delayed or not performed for some reason, a large current will flow through the flash discharge tube Xe and the gate of 5CR22 via the switch means 17, but the resistance value of the resistor 25 By setting appropriately,
No particular problem arises.

Furthermore, the above-mentioned insulated gate bipolar transistor 1. The delay in turning on G, B, and T, in other words, the fact that the trigger circuit 20 operates first and the flash discharge tube It goes without saying that this can be prevented by connecting the gate and cathode of 5CR22 to slightly delay the turning-on point of 5CR22 from the turning-on point of transistor 18. That is, by turning on the transistor 18, the insulated gate bipolar transistor 1. After G, B, and T are sufficiently turned on, 5CR22 turns on, and the trigger circuit 20
Therefore, the trigger operation of the flash discharge tube Xe can be performed by the following.

Furthermore, the resistor 25 may be replaced with a Zener diode.

[Example 2] FIG. 2 is an electrical circuit diagram of the main part of the second embodiment.

In the figure, elements having the same functions as those in the first embodiment are given the same reference numerals.

As is clear from FIG. 2, this embodiment uses the trigger circuit 20 as the switch means 17 explained in the first embodiment, that is, the switch means 17 which operates the trigger circuit 20 and the gate means 14 by operating.
This embodiment differs from the first embodiment in that the trigger switch element 27 is also used.

In addition, as a trigger switch element, the above-mentioned 5CR2
Needless to say, 2, transistors, etc. are conceivable.

Since the second embodiment is configured as described above, the insulated gate bipolar transistor 1. G, B, T,
The operation of the drive system etc. is as follows.

A trigger signal for starting light emission is sent to the trigger switch element 2.
When a trigger signal having an extremely short duration is now supplied to the terminal 27a, the trigger switch element 27 is turned on.

When the trigger switch element 27 is turned on, the charge in the trigger capacitor 23 is discharged via the trigger transformer 23, and a trigger operation is performed to excite the flash discharge tube Xe. A current flows through the insulated gate board bipolar transistor 1., turning on the transistor 11, and applying a predetermined voltage determined by the Zener diode 13 to the insulated gate board bipolar transistor 1. G,B
, T, and therefore the insulated gate bipolar transistor 1. G, B, T,
will turn on. Therefore, the flash discharge tube Xe consumes the charge in the main capacitor C8 to emit light, and the gate means 14 continues to operate as described above.

At an appropriate point in such a state, the transistor 26
When a stop signal to stop light emission is supplied to the base terminal 26a of the insulated gate bipolar transistor 1, the transistor 26 turns on and short-circuits the gates and emitters of the insulated gate bipolar transistors 1, G, B, and D. Transistor 1. Turn off G, B, and T.

Insulated gate bipolar transistors I, G, B,
When T is turned off, the current flowing through the flash discharge tube Xe or the gate means 14 is cut off.
Therefore, the flash discharge tube Xe stops emitting light, the transistor 11 is also turned off, and the device returns to its initial state before emitting light.

The above is a single light emitting operation in the second embodiment, and the circuit configuration is simpler than in the first embodiment because the trigger switch element 27 also serves as the switch means 17.

Note that the resistor 28 is a resistor for protecting the trigger switch element 27, and may of course be replaced with a Zener diode, for example.

Furthermore, when an SCR is used as the trigger switch element 27 as in the first embodiment, the resistor 28 also serves the function of preventing it from being kept on unnecessarily.

[Example 3] FIG. 3 is an electrical circuit diagram of the main part of the third embodiment.

In the figure, 1. Elements having the same functions as those in the second embodiment are given the same reference numerals.

In this embodiment, as is clear from FIG. In the second embodiment, the gate means 14, which was made up of resistors 15 and 16, is made up of a diode 29 that forms a series connection with the resistor 15 and the like, and further includes a connection point between the resistor 16 and the diode 29. A trigger circuit 20 including a trigger switch element 27 which is also the switch means 17 is connected to the trigger circuit 20 . That is, based on the second embodiment described above, the diode 29 is added and the insulated gate bipolar transistor 1. G, B, and T are connected through a diode 29.

The third embodiment is configured as described above, and includes an insulated gate bipolar transistor 1. The operation of the G, B, T drive systems, etc. is almost the same as in the second embodiment described above, and the trigger switch element 27 is activated by supplying a trigger signal.
When turned on, the trigger circuit 20 performs a well-known trigger operation, and the resistors 15, 16 . Current flows through diode 29, turning on transistor 11. Therefore, a predetermined voltage set by the Zener diode 13 is applied to the gates of the insulated gate bipolar transistors I, G, B, T, and the insulated gate bipolar transistors 1.
G, B, and T are turned on, the flash discharge tube Xe emits light, and the gate means 14 continues to operate.

Then, when the transistor 26 is turned on by supplying the stop signal, the insulated gate bipolar transistor 1.
G, B, T are off, so the flash tube Xe
The light emission stops, the operation of the gate means 14 also stops, and the transistor 11 is turned off, so that the device returns to its initial state and the -th light emission operation is completed.

Now, the function of the diode 29 will be described next.

This diode 29 has a cathode composed of a flash discharge tube Xe and an insulated gate bipolar transistor 1. G, B,
T.

Therefore, the flash discharge tube Xe
It is clear that it functions to block current from flowing from the side. Therefore, when the trigger switch element 27 is turned on, for some reason, the insulated gate bipolar transistor 1. Even if G, B, and T do not turn on,
A large current does not flow into the trigger switch element through the flash discharge tube Xe, and as a result, the trigger switch element 2
7 can be reliably protected.

Although the third embodiment is based on the second embodiment, it goes without saying that it can be constructed based on the first embodiment.

Also, between the anode of the diode 29 and the trigger switch element 27, a resistor 28 as described in the second embodiment,
Alternatively, it goes without saying that a protective element such as a Zener diode may be provided as appropriate.

Effects of the Invention The strobe device of the present invention is operated by a switch means that operates a trigger circuit by operating a gate means that controls the operation of a switch element for supplying a driving power source to an insulated gate bipolar transistor using a main capacitor. At the same time, since the operation can be maintained by turning on the insulated gate bipolar transistors provided at both ends of the flash discharge tube, a trigger signal having a time width that takes into account the total light emission time of the flash discharge tube is generated. There is no need to configure a special pulse generation circuit to form the insulated gate bipolar transistor, and the number of control switch elements can be reduced by using the trigger switch element of the circuit as the switch means. This has the effect of simplifying the drive system and also being advantageous in terms of energy consumption.

[Brief explanation of the drawing]

1 to 3 are electrical circuit diagrams of essential parts of an embodiment of a strobe device according to the present invention, and FIGS. 4 and 5 are circuit diagrams showing the configuration of a conventional strobe device, respectively. 8...DC high voltage power supply, 9...First series connection body, 10...Second series connection body, 11...
...transistor, 12.15,16,19,21.
25... Resistor, 13... Zener diode, 14... Gate means, 17...
- Switch means, 18...Transistor, 20
...Trigger circuit, 22...SCR, 2
3...Trigger capacitor, 24...Trigger transformer, 26...Transistor, 27...
...Trigger switch element, 28...Resistor, 29...Diode, 1. G, B, T
. ...Insulated gate bipolar transistor, x
e・・・・・・Flash tube agent name Patent attorney Shigetaka Awano Haka 1 person Figure 1 Figure RIG TOP

Claims (3)

[Claims] (1) A main capacitor connected to both ends of a DC high-voltage power supply to be charged, and a first series connection body consisting of a flash discharge tube and an insulated gate bipolar transistor connected in series, and connected to both ends of the main capacitor. , a second series connection body comprising a switch element and a constant voltage element connected in series, connected to both ends of the main capacitor, and a connection point of the series connection connected to the gate of the insulated gate bipolar transistor; a gate means connected to both ends of the flash discharge tube and turns on the switch element when operated; and a trigger connected to both ends of the insulated gate bipolar transistor and excited the flash discharge tube when operated. A circuit and a switch means for operating the gate means, and a control element connected between the gate of the insulated gate bipolar transistor and ground and turned on to turn off the insulated gate bipolar transistor. Strobe device. (2) A strobe device according to claim 1, wherein the switch means comprises a trigger switch element forming part of a trigger circuit. (3) The gate means includes a diode whose cathode is connected to the connection point between the flash discharge tube and the insulated gate bipolar transistor, and the switch means has one end connected to the anode of the diode and connects the insulating gate via the diode. The strobe device according to claim 1 or 2, wherein the strobe device is connected to both ends of a gate type bipolar transistor.