JPH06202196A - Stroboscope controller - Google Patents

Abstract

PURPOSE:To excellently execute photographing with strobe light by inhibiting the re-emission of the light of a stroboscope caused by chattering in the case of opening action when a synchro switch is opened/closed and the chattering occurs. CONSTITUTION:When the shutter is totally opened, the synchro switch 1 is closed and a chattering signal is generated, and by the first chattering signal, a pulse which is a little longer than the chattering time is generated from an inverter 11, and then a transistor 7 is turned on and a stroboscopic device 8 emits the light. When the synchro switch 1 is opened and the chattering signal is generated, the pulse which is a little longer than the chattering time, is generated by the first chattering signal from the inverter 11, and then the on-state of the transistor 7 is kept and the light re-emission of the stroboscope 8 by the chattering signal is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe control device for a camera.

[0002]

2. Description of the Related Art In a camera, as a method for photographing a strobe, a method is generally used in which a strobe is operated by the operation of a synchro contact synchronized with shutter operation.

Generally, the strobe is shown in FIG.
The configuration as shown in FIG. 7 of Japanese Patent No. 65434 has been adopted. The operation of FIG. 5 will be specifically described. The trigger capacitor 202 is discharged by closing the synchro contact 201 accompanying the opening operation of the shutter.
The trigger electrode of 03 is displaced, and the electric charge charged in the main capacitor 204 flows into the main discharge tube 203 to emit light. In the figure, 205
Is a booster circuit for charging the main capacitor 204,
206 is a diode, 207 is a resistor, 208 is a transformer, 209 is a battery, and 210 is an operation switch of the booster circuit 205.

[0004]

The above-mentioned problems are currently
Due to the improvement of the booster circuit, the main capacitor 202 is rapidly recharged within a time of several msec. Therefore, the recharging of the main capacitor 202 proceeds rapidly immediately after the light emission ends, and the chattering that occurs when the synchro contact opens at the end of the shutter operation causes the light emission again, resulting in a properly photographed photograph. There is a problem that stroboscopic light is superposed and defective photography occurs.

An object of the present invention is to perform good stroboscopic photography.

[0006]

The present invention achieves the above object by providing a re-flashing prohibition means for prohibiting re-flashing of a strobe by a chattering signal generated when a synchro switch is turned off. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on an embodiment shown in the drawings.

In FIG. 1, 1 is a synchro switch,
One end is connected to the low potential side and the other end is connected to the high potential side via the resistor 2, and in this example, the shutter (not shown) is closed for a predetermined time in synchronization with the full opening. 3 is a stroboscopic light emitting means, which is composed of an inverter 4, a capacitor 5, an OR gate 6, and a transistor 7, and outputs a stroboscopic light emission signal from the terminal A to the strobe device 8. Reference numeral 9 is a re-light emission prohibiting means, which is an inverter 4 ', a NOR gate 10, an inverter 1
1 and a capacitor 12 and a resistor 13 forming a differentiating circuit, and in this example, a one-shot pulse generating circuit for generating a pulse having a pulse width of a predetermined time is used.

Next, the operation will be described with reference to FIG.

It is now assumed that the synchro switch 1 is open. At this time, the point a becomes "1", and the inverter 1
Since the output d of 1 is "0", the output b of the NOR gate 10
Becomes "1", which is a stable state.

When a shutter switch (not shown) is operated and the shutter is fully opened, the synchro switch 1 is closed. At this time, chattering causes chattering signals such as the pulses P1, P2, and P3 shown in FIG.
Enter each in ´.

Since the output d of the inverter 11 input to the NOR gate 10 is "0", the rising edge of the pulse P1 inverted by the inverter 4'is inverted and passes through the NOR gate 10 like the pulse P4 of FIG. 2b. .

The potential of the capacitor 12 at the point c once becomes "0" as shown in FIG. 2c due to the fall of the pulse P4. As a result, the output d of the inverter 11 becomes "1" as shown in FIG. 2d. Therefore, the output b of the NOR gate 10
Becomes "0" until the output d of the inverter 11 becomes "1".

Since the potential at the point c, which becomes "0", is connected to the high potential side through the resistor 13, the potential gradually rises as the capacitor 12 is charged, and the constant time is maintained. After a lapse of time, the voltage exceeds the reference voltage Vr and returns to "1".

Therefore, the output d of the inverter 11 is "1" for a certain period of time. That is, a pulse P5 having a pulse width of a fixed time is generated as shown in FIG. 2d.

The potential at the point c changes from "0" to the reference voltage V
The time to recover to r can be set by the capacitance of the capacitor 12 and the resistance value of the resistor 13, and in this example, it is set to be slightly longer than the generation time of the chattering signal generated due to the opening / closing of the synchro switch 1. . That is, the inverter 11 generates a pulse having a pulse width of a predetermined time by the falling signal when the synchro switch 1 is closed.

The pulse P5 is input to the OR gate 6 and the NOR gate 10.

The pulse P5 input to the OR gate 6 is O
It passes through the R gate 6 and turns on the transistor 7. Therefore, the strobe light emission signal is output from the terminal A as shown in FIG. 2A, and the strobe device 8 operates to emit light once.
At this time, the signal shown in FIG. 2A is inverted by the inverter 4 and delayed by the capacitor 5 is input to the OR gate 6.

When chattering is completed when the synchro switch 1 is closed, the potential at point a stabilizes at "0". Therefore, since "1" is input to the OR gate 6 via the inverter 4, the transistor 7 is kept on even after the input of the pulse P5 is completed.

At this time, since the potential at the point a of the NOR gate 10 becomes "0", it becomes "1" at the end of the pulse P5.
Becomes stable.

When the synchro switch 1 is opened, chattering signals are generated again at the point a by chattering, and the chattering signals such as the pulses P6 and P7 shown in FIG. 2A are generated and input to the inverter 4 and the inverter 4 ', respectively.

Since the output d of the inverter 11 input to the NOR gate 10 is "0", the pulse P6 is inverted by the inverter 4'and input to the NOR gate 10 as shown in FIG.
It passes like the pulse P8 of b.

Subsequently, the capacitor 12 operates in the same manner as above by the fall of the pulse P8, the pulse P9 is generated from the inverter 11, and the OR gate 6 and the NOR gate 1 are generated.
Enter 0 and.

A signal (in this case, "1") obtained by inverting the signal shown in FIG. 2a by the inverter 4 and delaying it by the capacitor 5 is input to the OR gate 6, so that the input of the pulse P9 is completed. , The transistor 7 is held on.

Therefore, even if a signal including chattering generated by opening / closing the synchro switch 1 is input,
Since the strobe device 8 is supplied with one pulse having no chattering signal as shown in FIG. 2A, the strobe device 8 is triggered only once by its rise, and re-lighting by the chattering signal can be prohibited.

The capacitor 5 is provided to prevent the output of the NOR gate 6 from instantaneously becoming "0" due to the rising of the pulse P6 and the rising of the pulse P9 occurring at the same time.

Therefore, stroboscopic photography can be performed well.

Next, another embodiment will be described with reference to FIG.

In the figure, reference numeral 14 is an inverter, and 15 is a flip-flop which constitutes stroboscopic light emitting means.
Reference numeral 16 constitutes a re-flashing prohibiting means, and AND gates 17, N
It is composed of an OR gate 18 and flip-flops 19, 20, 21. The same numbers as in FIG. 1 are the same.

Next, the operation will be described with reference to FIG.

Now, it is assumed that the synchro switch 1 is opened and the flip-flop 15 is reset. Then, the flip-flops 19, 20, and 21 are triggered by the clock signal (FIG. 4b) input from the terminal B and output "0" respectively. In this example, the cycle of the clock signal is set to be slightly longer than the chattering occurrence time caused by the opening and closing of the synchro switch 1.

Similar to the above example, when the shutter switch (not shown) is operated and the shutter is fully opened, the synchro switch 1 is closed and a chattering signal like x in FIG. 4a is generated at point a. To do.

The flip-flop 15 is an inverter 14
Triggered by the rising edge of the first chattering signal inverted by, the strobe light emission signal is output to the strobe device 8 as shown in FIG. 4e. As a result, the flash device 8 is set to 1
Flashes twice.

The flip-flop 19 outputs "1" when triggered by the pulse P10 shown in FIG. 4b which is input first after the synchro switch 1 is closed. This output opens the AND gate 17.

Next, when the pulse P11 is generated as shown in FIG. 4b, the flip-flop 20 turns on.
The output “1” of 9 is taken in and “1” is output. At this time, the flip-flop 19 operates similarly to the above, and therefore outputs "1". Therefore, the output c of the AND gate 17
Becomes "1" as shown in FIG. 4c, and this output is input to the data input terminals of the NOR gate 18 and the flip-flop 21.

When the pulse P12 is generated as shown in FIG. 4b, the flip-flop 21 is triggered by this pulse P12 and fetches "1", and outputs "0" as an inverted output.
Is output to the NOR gate 18. The other input of the NOR gate 18 is supplied with "1" by the output of the AND gate 17 (Fig. 4c) and its output is held at "0" as in Fig. 4d. This state is maintained while the synchro switch 1 is closed.

When the sync switch 1 is opened, chattering of the sync switch 1 causes a chattering signal such as y in FIG. 4a.

After the synchro switch 1 is opened, FIG.
When the pulse P13 is input as the clock signal as shown by b, the flip-flop 19 takes in the output "0" inverted by the inverter 14 and outputs "0".

As a result, the output of the AND gate 17 becomes "0" and is input to the NOR gate 18.

At this time, since the inverted output of the flip-flop 21 is "0", the output of the NOR gate 18 becomes "1", the flip-flop 15 is reset, and the strobe light emission signal is stopped.

When the pulse P14 is generated as shown in FIG. 4b, the flip-flop 21 is triggered by this pulse P14, takes in the output "0" of the AND gate 17, and outputs "1" to the NOR gate 18 as an inverted output. .

By this input, the output of the NOR gate 18 becomes "0", and the reset of the flip-flop 15 is released.

Since the period of the clock signal is set to be slightly longer than the chattering time generated by opening and closing the synchro switch 1, the flip-flop 15
The reset time (pulse width in FIG. 4d) is longer than the chattering occurrence time, and it is possible to prevent the flash from re-flashing due to chattering when the sync switch 1 is opened and closed.

[0044]

According to the present invention, good stroboscopic photography can be performed by providing a prohibiting means for prohibiting the re-flash of the strobe due to the chattering signal generated when the synchro switch is turned off. Moreover, for example, in the case of a strobe capable of quick charging, it is possible to surely prevent the stroboscope from emitting light again due to a chattering signal generated when the sync switch is turned off.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of FIG.

FIG. 3 is an electric circuit diagram showing another embodiment of the present invention.

FIG. 4 is a timing chart for explaining the operation of FIG.

FIG. 5 is an electric circuit diagram showing a conventional strobe device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synchro switch 3 Strobe light emitting means 8 Strobe 9 Relighting inhibiting means 15 Strobe emitting means 16 Reflashing inhibiting means

Claims (1)

[Claims] 1. A synchro switch that is turned on in synchronization with the opening / closing operation of a shutter, a strobe light emitting unit that illuminates a strobe in synchronism with the on state of the synchro switch, and is generated when the synchro switch is turned off. A flash control device, comprising: a flash re-restriction means for restricting re-flash of the flash by a chattering signal.