JPH10239741A - Stroboscopic device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stroboscopic device for camera capable of selecting whether stroboscopic photographing is to be performed or not, and capable of rapidly coping with shutter chance by shortening the preparing time for charge in the case of the stroboscopic photographing. SOLUTION: When a stroboscopic discharge tube 38 emits light, a preliminary charge start circuit 43 operates to input a signal to the point (a) of a power source latch circuit 41, and a battery 24 and a charge circuit are connected to start the preliminary charge for a main capacitor 36. When the voltage level of the main capacitor 36 reaches a voltage level V1 , the signal is inputted to the point (c) of the circuit 41 connected to a preliminary charge stop circuit 44, the power supply to the charge circuit from the battery 24 is stopped, and the preliminary charge is stopped. When charge switch 30 is pressed, the charge circuit is operated to charge the capacitor 36, and the voltage level reaches V2 . Then, the signal is inputted to the point (b) of the circuit 41 connected to a full charge stop circuit 57, the power supply to the charge circuit from the battery 24 is stopped, and the charge is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe device for a camera, and more particularly, to a strobe device capable of selecting whether or not to perform strobe photographing and capable of promptly responding to strobe photographing. It is.

[0002]

2. Description of the Related Art A film unit with a lens, which is one of the simple cameras, is a unit body having a simple photographing mechanism, in which an unexposed photographic film cartridge is built in in advance. Is also widely used because it is inexpensive and easy to use, and various kinds of lens-equipped film units are also sold by the present applicant. In addition, such a film unit with lens,
A camera with a built-in simple strobe device is also sold by the present applicant so that shooting can be easily performed indoors or at night.

By the way, the above-mentioned film unit with a lens and a strobe device built in an inexpensive camera require a photographer to operate a charge switch to emit light from a strobe discharge tube when performing strobe shooting. The main capacitor is charged to an appropriate voltage level.

However, as described above, if the main condenser is charged by operating the charging switch of the flash unit every time flash photography is performed, for example, in the case of a moving subject, the shutter needs to be replaced. I often missed a chance. In addition, when flash photography is performed continuously, such as at a wedding or party venue, there are many mistakes that flash photography is not performed due to forgetting to press the charge switch.

[0005] In order to eliminate the trouble of operating the charging switch of the strobe device, and to prevent a shutter chance from being missed due to a waiting time due to charging,
There is also provided a film unit with a lens having a built-in strobe device in which a main condenser is charged in advance for the next photographing in conjunction with light emission of a strobe discharge tube.

[0006]

However, in the case of using a flash device in which the main capacitor is charged in advance as described above, the flash is always emitted simultaneously with the shutter release. Conversely, the subject becomes overexposed, and a problem arises in that shooting is not performed in an appropriate exposure state. Also, there is a problem that the flash device emits light when photographing in places such as art museums where the use of flash is prohibited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to select whether or not to perform flash photography, and to shorten the preparation time for charging when performing flash photography, thereby providing a shutter. It is an object of the present invention to provide a camera strobe device that can quickly respond to a chance.

[0008]

In order to achieve the above object, a strobe device for a camera according to the present invention comprises a precharge start circuit for starting charging a main capacitor in synchronization with light emission of a strobe discharge tube; A pre-charge stop circuit that stops charging the main capacitor within the voltage range that does not reach the voltage level required for light emission from the discharge tube, and a full charge stop circuit that stops charging the main capacitor when the voltage level exceeds the voltage required for light emission from the strobe discharge tube And a power supply latch circuit for turning on a charge switch or turning on power according to a signal from the pre-charge start circuit, and turning off power according to a signal from the pre-charge stop circuit or the full charge stop circuit. It is.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, as an embodiment of a strobe device of the present invention, a strobe device built in a film unit with a lens will be exemplified. FIG. 2 is an external perspective view showing a film unit with a lens having a built-in flash device of the present invention, and FIG. 3 is an exploded perspective view thereof. The film unit with lens 1 includes a main body 3 and the main body 3.
A unit body 2 including a photographing mechanism 4, a strobe device 5, a front cover 6 and a rear cover 7 covering these from front and rear, an exterior body 31 and a photographic film cartridge 32 covering a part of the unit body 2. It is composed of

The photographing mechanism 4 includes a well-known shutter device 8,
Photographing lens 9, viewfinder 11, and number-of-photographs display plate 1
2 etc. are provided. An opening for exposing the photographing lens 9, the finder 11 and the like is provided on the front surface of the front cover 6, and a charging completion display window 16 for confirming the completion of flash charging is also provided. A switch operating member 13 for operating the switch contact piece 25 of the strobe device 5 is integrally provided at a lower portion of the front surface of the front cover 6.

On the upper surface of the front cover 6, a release button 14 for operating the shutter device 8 is integrally provided, and a photographing number display window 15 for exposing a part of the photographing number display plate 12 is provided. I have.

An aperture 17 serving as an exposure optical path is provided at the center of the main body 3, and a cartridge chamber 18 and a film roll chamber 19 are formed at both ends thereof. In the cartridge chamber 18 and the film roll chamber 19, a photographic film cartridge 32 and a photographic film 33a drawn from the photographic film cartridge 32 are rolled up. Furthermore, in the upper part of the cartridge chamber 18,
A winding knob 21 for rotating the spool 34 of the photo film cartridge 32 to wind the photo film 33a is provided.

On the upper front part of the main body 3, a strobe device 5 is provided.
Is attached. As shown in FIG.
The printed circuit board 22 on which various components necessary for forming a strobe circuit such as a main capacitor 36 and a charge completion lamp 37 are soldered on a pattern, and the strobe discharge tube 3
The flash unit includes a strobe light emitting unit 23 including a reflector 8 and a reflector 39, a protector 10 for covering the front surface of the strobe light emitting unit 23, a switch contact 25, a battery 24 for supplying power to the strobe device 5, and the like.

The switch contact piece 25 is a switch operating member 1.
3 together with a strobe charging switch 30, which contacts the contacts 35a and 35b formed on the printed circuit board 22 by pressing the switch operating member 13, and short-circuits the contacts 35a and 35b, thereby strobe charging. The switch 30 is turned on.

FIG. 1 is a circuit diagram showing an outline of a circuit of a strobe device of the present invention. The strobe device 5 includes a power supply latch circuit 41, a transformer 42 for boosting a voltage, a main capacitor 36, a synchro switch 45 that is turned on in conjunction with a shutter release, a trigger capacitor 46, a charging completion lamp 37, a preliminary charging start circuit 43, Charge stop circuit 4
4, a strobe discharge tube 38, and a battery 24 serving as a main power supply for these.

The precharge circuit 43 comprises a resistor 51 and a capacitor 52, and starts a precharge, which will be described later, in conjunction with light emission of the strobe discharge tube 38 (discharge of the main capacitor 36).

The pre-charge stop circuit 44 comprises a zener diode 53, a transistor 54, a capacitor 55, and several resistors 56.
, The voltage level of the pre-charging of the main capacitor 36 started is detected, and when the voltage level of the main capacitor 36 reaches the voltage level V ₁ shown in the waveform diagram of FIG. This is a circuit for stopping charging.

The full charge stop circuit 57 is composed of a zener diode, detects the voltage level of full charge to the main capacitor 36 started when the charge switch 30 is turned on, and changes the voltage level of the main capacitor 36 to the waveform shown in FIG. reaches the voltage level V ₂ shown in, the Zener diode is operated, a circuit for stopping the full charge.

The power supply latch circuit 41 includes a precharge start circuit 43, a full charge stop circuit 57, and a precharge stop circuit 4.
4 are connected to each other (a, b, c in FIG. 1).
A charging circuit including a charging switch 30, a transformer 42, and the like;
And the battery 24. This power supply latch circuit 41
Connects the battery 24 and the charging circuit and turns on the charging circuit by turning on the charging switch 30 or inputting a signal to a point a connected to the pre-charging start circuit 43, and Point b connected to the stop circuit 57,
Alternatively, a latch circuit that cuts off the battery 24 and the charging circuit and turns off the charging circuit when a signal is input to a point c connected to the preliminary charging stop circuit 44.

As shown in FIG. 5, a strobe discharge tube 38 is provided.
When the voltage level of the main capacitor 36 becomes equal to or higher than _VL , the synchro switch 45 is turned on to emit light (discharge).
I do. Then, the voltage level of the main capacitor 36 is set to V
By charging up to ₂ , a specified amount of strobe light is emitted. Therefore, even if the pre-charge is started by the pre-charge start circuit 43 and the main capacitor 36 is charged up to the voltage level V ₁ , the voltage level is equal to or lower than V _L , so that the synchro switch 45 is turned on (shutter release operation). ), The strobe discharge tube 38 does not emit light.

When the charging switch 30 of the power supply latch circuit 41 is pressed, the charging circuit operates and the main capacitor 3
6 is charged, and when the voltage level eventually reaches V ₂ , the power supply latch circuit 4 connected to the full charge stop circuit 57
A signal is input to point b of 1 and the power supply from the battery 24 to the charging circuit is cut off to stop charging. When the voltage level is charged to V ₂ higher than V _L , the flash switch 38 emits light and emits a predetermined amount of flash light when the synchro switch 45 is turned on.

Next, the operation of the flash device having such a configuration will be described. FIG. 6 is a flowchart simply showing the flow of the operation of the flash device of the present invention. When using the film unit with a lens purchased by the user for the first flash photography,
1 is wound up to the first frame, and the charge switch 30
Press. When the charge switch 30 is pressed, the power supply latch circuit 41 operates, the battery 24 and the charging circuit are connected, and the main capacitor 36 whose voltage level is 0 is charged.

When the voltage level of the main capacitor 36 reaches V ₂ , a signal is input to the point b of the power supply latch circuit 41 connected to the full charge stop circuit 57, and the power supply from the battery 24 to the charging circuit is cut off. Charging stops. At the same time, the trigger capacitor 46 is charged, and the charging completion lamp 37 is turned on.

The photographer confirms the photographing range with the viewfinder 11 or the like, and presses the release button 14 to release the shutter device 8.
Operates to perform exposure for one frame. At this time, the synchronization switch 45 is turned on in conjunction with the operation of the shutter device 8. Since the voltage level of the main capacitor 36 has been charged to V ₂ higher than V _L , the main capacitor 36 is discharged, the strobe discharge tube 38 emits light, and the subject is irradiated with a specified amount of strobe light. It should be noted that the above process is only the first operation of flash charging, and is shown in a range surrounded by a dotted line in the flowchart of FIG.

When the strobe discharge tube 38 emits light and the main capacitor 36 discharges, the precharge start circuit 43 operates to input a signal to the point a of the power supply latch circuit 41, and the battery 24 and the charging circuit are connected. Precharge of the main capacitor 36 is started. When the pre-charging of the main capacitor 36 is being performed, the pre-charging stop circuit 44 detects the voltage level of the main capacitor 36, and the voltage level of the main capacitor 36 becomes the voltage level V ₁ shown in the waveform diagram of FIG. Upon reaching, the zener diode 53 operates. Then, a signal is input to the point c of the power supply latch circuit 41 connected to the pre-charge stop circuit 44, and the power supply from the battery 24 to the charging circuit is cut off to stop the pre-charge.

When taking a picture again, if there is sufficient brightness, for example, outdoors in the daytime, the strobe device is not used so that the exposure is not excessive. In this case, the photographer presses the release button 14 without pressing the charge switch 30. Then, when one frame of exposure is performed by operating the shutter device 8, the synchro switch 45 is turned on in conjunction with the operation of the shutter device 8, but the voltage level of the main capacitor 36 is lower than _VL. since only up to V ₁ is not charged, not that the main capacitor 36 is discharged, thus the flash discharge tube 38 does not emit light, shooting without flash is performed.

On the other hand, when flash photography is performed again,
The photographer presses the charge switch 30. Then, the charging circuit charges the main capacitor 36 is performed by operating, eventually the voltage level reaches V _2, the full charging stop circuit 57
, A signal is input to the point b of the power supply latch circuit 41, the power supply from the battery 24 to the charging circuit is cut off, and the charging is stopped.

When the photographer confirms that the charging completion lamp 37 is lit, and then presses the release button 14, the shutter device 8 is operated to perform one frame of exposure, and at the same time, the synchro switch 45 is turned on. Turn on. The voltage level of the main capacitor 36, since it is charged to a high V ₂ than V _L, flash discharges discharge tube 38 to main condenser 36 is discharged, flash light of the provisions of the amount of light is irradiated to the object, the flash Shooting is performed.

Then, after the flash photography is performed, the pre-charge start circuit 43 operates again in conjunction with the emission of the flash discharge tube 38, and a signal is input to the point a of the power supply latch circuit 41, and the battery 24 and the preliminary charging of the main capacitor 36 to a voltage level V ₁ is performed and the charging circuit is connected.

As described above, the voltage is applied to the main capacitor 36.
Level V₁By always carrying out preliminary charge until
As shown in FIG. 5, the voltage level becomes
Ra V _TwoTime T required to charge until_ThreeVoltage level
Bell 0 to V₁Time T required to charge until₁Only the minute
Short time T_TwoJust wait and start flash photography
Can be Therefore, if the subject is moving
When shooting at a party venue or wedding ceremony,
The voltage level V is applied to the main capacitor 36 in advance.₁Up to reserve
When the charge switch 30 is pressed for a short time
Interval T_TwoJust wait and miss a photo opportunity
Flash photography can be performed quickly without using a flash.

[0031] On the other hand, the voltage level of the pre-charging of the main capacitor 36, so it is up to low V ₁ than V _L, such as outdoors during the day, exposure and shooting of a sufficient environment, the use of strobe museums When taking a picture in a prohibited place, unless the charge switch 30 is pressed, the main capacitor 36 will not be discharged due to a shortage of the voltage level. No overexposure or annoying shooting location.

In the above-described embodiment, the preliminary charging is performed in synchronization with the light emission of the strobe discharge tube. In addition, the preliminary charging is performed in conjunction with the operation of the synchro switch and the shutter blade. You may do so.

In the above-described embodiment, an example is shown in which the strobe device of the present invention is incorporated in a film unit with a lens. However, it is needless to say that the present invention can be applied to an ordinary camera.

[0034]

As described above in detail, according to the camera strobe device of the present invention, a pre-charge start circuit for starting charging the main capacitor in synchronization with light emission of the strobe discharge tube, and a strobe discharge tube A pre-charge stop circuit that stops charging the main capacitor within a voltage range that does not reach the voltage level required for light emission of the flashlight, a full charge stop circuit that stops charging the main capacitor when the voltage level required for light emission of the strobe discharge tube is exceeded, A power supply latch circuit that turns on a charge switch or turns on power by a signal from the pre-charge start circuit and turns off power by a signal from the pre-charge stop circuit or the full charge stop circuit is provided.
It is possible to provide a camera strobe device that can select whether or not to perform strobe shooting, shortens the preparation time for charging when performing strobe shooting, and can quickly respond to a photo opportunity.

[Brief description of the drawings]

FIG. 1 is an example of a circuit diagram of a strobe device of the present invention.

FIG. 2 is an external perspective view of a film unit with a lens incorporating a flash device of the present invention.

FIG. 3 is an exploded perspective view of FIG. 2;

FIG. 4 is an external perspective view of the strobe device of the present invention.

FIG. 5 is a waveform diagram showing a change in a voltage level of a main capacitor in the strobe device of the present invention.

FIG. 6 is a flowchart showing the operation of the flash device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Film unit with lens 5 Strobe device 24 Battery 36 Main capacitor 38 Strobe discharge tube 41 Power supply latch circuit 43 Precharge start circuit 44 Precharge stop circuit 45 Sync switch 57 Full charge stop circuit

Claims (1)

[Claims] 1. A strobe device for a camera having a power supply, a main capacitor, a charge switch, a strobe discharge tube, etc., wherein the main capacitor starts charging in synchronization with light emission of the strobe discharge tube. A pre-charge start circuit; a pre-charge stop circuit for stopping the charging of the main capacitor within a range not reaching a voltage level required for light emission of the strobe discharge tube; A full charge stop circuit for stopping the charging of the main capacitor, and turning on the power by a signal from the precharge start circuit or turning on the charge switch;
And a power supply latch circuit for turning off the power supply in response to a signal from the preliminary charge stop circuit or the full charge stop circuit.