JPH10232433A - Stroboscopic unit and film unit with lens provided with built-in stroboscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stroboscopic unit where a neon tube is prevented from being lit by static electricity. SOLUTION: An oscillating transistor Q101 whose emitter is connected to the negative pole of a battery B, a transistor Q102 whose collector is connected to the positive pole of the battery B and whose emitter is connected to the base of the transistor Q101, an oscillating transistor TRA whose terminal on a primary winding side is connected to the positive pole of the battery B and the collector of the transistor Q101 and whose terminal on a secondary winding side is connected to a rectifying device and the base of the transistor Q102, and a main switch MSW whose either terminal is connected to the positive pole of the battery B and which is turned on only in the midst of operation are provided. Then, a 1st resistance R101 whose either terminal is connected to the other terminal of the main switch MSW and whose other terminal is connected to the base of the transistor Q102 and a capacitor C102 whose either terminal is connected to the other terminal of the 1st resistance R101 and whose other terminal is connected to the negative pole of the battery B are provided, and a 2nd resistance R102 is provided in parallel with the capacitor C102; whereby a circuit is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a strobe unit,
The present invention relates to a film unit with a built-in strobe, and is suitable for use in a film unit with a lens.

[0002]

2. Description of the Related Art Conventionally, film units with a lens having a built-in strobe are commercially available from various companies. Since the strobe circuit requires a higher current than other electronic circuits, leaving the main switch turned on for charging will drain the battery severely, and the recycle time will be longer than allowable or built-in Before the shooting of all the frames of the film is completed, the use of the strobe becomes impossible. In the case of a film unit with a lens, the user cannot replace the battery, so that special consideration must be given to battery consumption.

For this reason, the main switch of the strobe is devised by various companies, such as a structure in which the operating member of the main switch is constantly pressed with the fingertip during charging, or the operating member of the main switch is used as a sliding member, and the charging is performed while the charging is performed. A configuration is used in which the member is protruded to the side, and the user can visually recognize that the battery is being charged from the other five surfaces excluding only the side surface opposite to the side surface from which the slide member is protruded.

[0004] However, the former has a trouble that the operating member must be constantly pressed during charging, and the latter has a problem that when the battery is stored in a bag or the like without noticing the state in which the slide member is protruded, the battery becomes exhausted. There is a problem of exhaustion.

[0005] In order to solve such a problem, a film unit with a lens employing an automatic charging stop strobe similar to a strobe used in a lens shutter camera has begun to be marketed.

A one-touch diaphragm type switch suitable for a main switch of a strobe is commercially available.

[0007]

First, referring to FIG. 1, which is a typical circuit diagram of the above-described automatic charging stop strobe,
The strobe circuit will be described.

When the flash photography mode is performed, the main switch MSW is turned on. The main switch MSW is a diaphragm switch and is turned on only when an operation button (not shown) is pressed. When the main switch MSW is turned on, a base current is supplied to a transistor Q102 which is an NPN-type second transistor through a first resistor R101, and a collector current of the transistor Q102 is supplied to an oscillation transistor Q101 which is an NPN-type first transistor. Since it is supplied as the base current, the oscillation transistor Q101 is turned on, and a current flows through the primary coil of the oscillation transformer TRA. As a result, a large current according to the winding ratio flows through the secondary coil of the oscillation transformer TRA, and the diode D101 as a rectifying element
Main capacitor C101 by the current rectified by
Is charged.

When the current of the secondary coil increases, the base current of the oscillating transistor Q101 also increases via the transistor Q102, and accordingly, the collector current further increases, and the oscillating transistor Q101 enters an oscillating state. Oscillation is continued by the back electromotive force. Once in the oscillation state, the oscillation of the oscillation transistor Q101 continues even if the main switch MSW is turned off, and the main capacitor C101 is charged.

When the main capacitor C101 is charged and the voltage of the neon tube Ne reaches 260 to 270 V, the neon tube Ne is turned on. Further, the main capacitor C101
When the charging of the resistor R103 proceeds, the voltage across the resistor R103 increases, and when the voltage reaches a predetermined voltage, the Zener diode D10
2, a zener current flows, a base current of the third transistor Q103, which is a third transistor, flows, turning on the transistor Q103 and turning off the transistor Q102. As a result, the oscillation transistor Q
101 is also turned off to stop the oscillation, and the current of the battery B as the power supply is also cut. Therefore, it is possible to prevent a voltage drop of the battery due to forgetting to turn off the main switch as in a conventional strobe.

As described above, once the main switch MSW is pressed, the oscillation continues until the charging voltage required for flash photography is reached, and the oscillation is stopped when the predetermined voltage is reached. .

When the oscillation of the oscillation transistor Q101 stops and the discharge of the electric charge of the main capacitor C101 advances and the voltage drops, the voltage of the neon tube Ne also drops after 5 to 15 minutes, and the neon tube Ne turns off. When the neon tube Ne is turned off at the time of photographing, the main switch MSW may be turned on again.

When the shutter release is performed with the film unit with the lens toward the subject in a state where the neon tube Ne is lit, the trigger switch TS is opened by the shutter opening operation.
W is turned on, the trigger capacitor C103 is discharged through the primary coil of the trigger coil TRI, and the trigger coil T103 is discharged.
A high voltage is generated in the secondary coil of the RI, and the xenon tube Xe, which is a flash tube, emits light. When the xenon tube Xe emits light, the base current of the oscillation transistor Q101 flows instantaneously due to the circuit voltage fluctuation due to the light emission current of the main capacitor C101, and re-oscillates. That is, continuous light emission can be performed without turning on the main switch MSW.

The resistor R104 is a trigger capacitor C
The capacitor C102 is a charging resistor for the capacitor 103, and prevents the capacitor C102 from re-inadvertently re-oscillating due to disturbance noise other than the emission current, for example, from a motor or a relay near the lens-fitted film unit.

In a film unit with a lens incorporating a strobe unit having the above-described circuit configuration, the following problems occur, though rarely. That is, the film unit with the lens housed in a bag or the like may be rubbed by vibration or the like, static electricity may be charged on the resin exterior member or the unit body, and oscillation may start due to discharge noise. In a dry winter or the like, static electricity charged on a human body may be discharged to a film unit with a lens. As described above, even if the main switch MSW is not turned on, oscillation may occur due to electrostatic discharge noise, and as a result, the main capacitor C101 may be charged and the neon tube Ne may be lit. Unnecessarily illuminating the neon tube Ne in this way is not preferable because it wastes battery power and strobe photography is performed against user's intention. In addition, when a film is loaded in a dark room in the manufacturing process of the film unit with a lens, if the neon tube Ne is turned on carelessly, there is a problem that an unexposed film is exposed.

SUMMARY OF THE INVENTION In view of such a problem, a first object of the present invention is to propose a strobe unit in which a neon tube is not turned on by electrostatic discharge noise.

Further, when the above-described automatic charging stop strobe is incorporated, a transistor and a diode are added to the conventional strobe. Also, these additional components are not very small. For this reason, in a commercially available film unit with a built-in flash having a built-in automatic charging stop strobe, an outer wall of a photographing unit for exposing a film by a photographing lens to form a photographing screen and an outer wall of a roll film chamber for winding the film in advance. And a space formed by a battery chamber for storing batteries and the inner wall of the front cover is provided in a relatively large size, and most of the flash components are mounted in this space. As a result, the dimensions of the film unit with a lens are enlarged, and the miniaturization is hindered. Further, there is a film unit with a lens using a double-sided board as a printed board for mounting each strobe component, and in this case, the cost is particularly increased.

The present invention has been made in view of such a problem, and even if an automatic charging stop circuit is added to a strobe, the electric components are efficiently arranged so that miniaturization is not hindered and the built-in strobe is inexpensive. A second object is to propose a film unit with a lens.

[0019]

A first object of the present invention is to provide a battery as a power supply for a strobe circuit, an NPN-type first transistor having an emitter terminal connected to a negative electrode of the battery, and a collector terminal connected to the battery. And a second transistor of an NPN type having an emitter terminal connected to the base terminal of the first transistor, and one terminal on the primary winding side connected to the positive electrode of the battery and the other terminal connected to the other terminal. Is connected to the collector terminal of the first transistor, one terminal of the secondary winding is connected to the rectifying element, and the other terminal is connected to the base terminal of the second transistor. A transformer, one terminal is connected to the positive electrode of the battery, a main switch that is turned on only during operation, and one terminal is connected to the other terminal of the main switch. A first resistor connected in series with the main switch, the other terminal being connected to a base terminal of the second transistor, and one terminal being connected to the other terminal of the first resistor. In a strobe unit having a capacitor connected in series with the first resistor and having the other terminal connected to the negative electrode of the battery, a strobe unit provided with a second resistor in parallel with the capacitor is solved. .

The second object is to store a photographing section for exposing a film by a photographing lens to form a photographing screen and a roll film in which the film is wound up in advance or a patrone in which the film is wound up for each photographing. A roll film chamber to be provided, and a battery chamber for accommodating a battery for a strobe power supply are sequentially arranged, and the subject side in the photographing unit, the roll film chamber and the battery room is covered with a front cover, and the photographing unit An outer wall, an outer wall of the roll film chamber,
And a first space formed by an inner wall of the front cover, an outer wall of the roll film chamber, an outer wall of the battery chamber,
And a strobe built-in lens in which a printed circuit board on which a wiring pattern is arranged only on the front cover side is arranged in a second space formed by an inner wall of the front cover, and a component of an automatic charging stop strobe is mounted on the printed circuit board In a film unit with a strobe, at least an oscillation transformer is disposed above the first space, and at least a trigger coil is disposed in the second space.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment for preventing a neon tube from being turned on by electrostatic discharge noise, which is a first problem, will be described with reference to FIG.

FIG. 2 is a circuit diagram of an automatic charging stop strobe which is substantially the same as that of FIG.
In that a second resistor R102 is added in parallel with FIG.

For example, a spike noise is applied to the ground line due to electrostatic discharge, and a beard-like voltage is generated at the base of the transistor Q102.
102 turns on. Also, the transistor Q1
Since the impedance of the transistor Q10 is high due to the influence of external relay noise or dielectric noise,
2 turns on. For this purpose, the second resistor R1
02, the impedance of the transistor Q102 is lowered to reduce the influence of the transistor Q102.
02 flows in the base terminal of the transistor Q1.
02 is turned on, charging is started, and the neon tube is prevented from lighting up.

Although a new battery has a voltage of about 1.6 V, the voltage drops while a strobe is used. In order for charging to be possible even when the voltage of the battery B drops to 1.2 V, the base voltage of the transistor Q102 must be 1.1 V
It is necessary. As a result, the resistance of the first resistor R101 is 1 kΩ or more, and the resistance of the second resistor R102 is 1 MΩ.
In the following, the resistance value of the second resistor R102 is
It is desirable that the resistance value of the resistance 101 be 10 times or more.

Originally, in order to operate one transistor, a voltage between the base and the emitter of 0.6 V or more was required. Therefore, to operate two Darlington-connected transistors, a voltage of 1.1 V or more is empirically required. Therefore, it is necessary to make the resistance value of the second resistor R102 ten times or more the resistance value of the first resistor R101. As a result, even when the voltage of the battery B becomes 1.2 V, the oscillation starts. can do.

Next, FIG. 3 shows a view of the strobe unit on which the circuit diagram shown in FIG. 2 is mounted as viewed from the rear side. Explaining the arrangement of the main components, the printed board 21 is a single-sided board on which a wiring pattern is provided on the back side of the paper surface, a light-emitting portion made of a xenon tube Xe or the like is located at the upper left, and the reflector 22 is located at a substantially left center. Trigger coil TRI and lead wire 23
Connected by The reason why the lead wire 23 was used is as follows.
This is because the arc discharge was prevented by the high voltage. Further, a first resistor R101 is arranged at the upper right of the trigger coil TRI, and a second resistor R102 is arranged at the lower left of the trigger coil TRI. In the center, a diaphragm-shaped flat main switch MSW is arranged on the back side of the drawing. A neon tube Ne and an oscillation transformer TRA are arranged at the upper right, and a main capacitor C101 is arranged at the lower right.

The other parts are denoted by the same reference numerals as in FIG. 2, and 24 is a jumper wire.

A state in which this strobe unit is incorporated in a film unit with a lens will be described with reference to a sectional view of FIG.

In FIG. 4, 1 is a unit body,
Although not shown, various mechanisms for photographing are mounted. The front of the unit body 1 is covered with a front cover 2 and the rear is covered with a rear cover 3 in a light-tight state. Reference numeral L denotes a photographing lens, which forms an image of the subject light on the film F when the shutter 4 is opened and exposes the film. The place where the photographing is performed in this manner is referred to as a photographing unit 5 in the present embodiment.

In a film unit with a lens,
The unexposed film F is wound on the spool 6 in advance in the manufacturing process, and is wound up one frame at a time in each photographing in the arrow direction. The portion where the film F is wound up is referred to as a roll film chamber 7 in the present embodiment.

Next to the roll film chamber 7, there is provided a battery chamber 8 for accommodating a battery B which is a power source of the strobe.

As described above, the photographing unit 5, the roll film chamber 7 and the battery chamber 8 are arranged in this order, and in the space surrounded by the front and the inner wall of the front cover 2, the strobe component is mounted on the printed circuit board 21. Implemented and deployed. Here, the outer wall 1a of the photographing unit 5 and the outer wall 1 of the roll film chamber 7
The inverted triangular space formed by b and the inner wall 2a of the front cover 2 is referred to as a first space 11. The space formed by the outer wall 1b of the roll film chamber 7, the outer wall 8a of the battery chamber 8, and the inner wall 2a of the front cover 2 is referred to as a second space 12.

As is clear from FIG. 4, the space defined by the center of the arc of the outer wall 1b of the roll film chamber 7 and the inner wall 2a of the front cover 2 is small. Except for the main switch MSW, mounting of general components is not possible. Have difficulty. However, the first space 11 and the second space 12 have enough space,
By appropriately arranging the components of the strobe unit in both spaces, miniaturization is not impaired even if an automatic charging stop function is added.

As described with reference to FIG. 3, components located on the right side of the main switch MSW are stored in the first space 11, and components located on the left side of the main switch MSW are stored in the second space 12. Is done. In particular, the oscillation transformer TR
By arranging A above the first space 11, even if the printed circuit board 21 is an inexpensive single-sided board instead of an expensive double-sided board, a strobe circuit having an automatic charging stop circuit as described above can be efficiently arranged. can do.

The roll film chamber 7 does not necessarily need to be a place where the film is wound in advance as described above, but may be a place where a cartridge or a cartridge for winding the film at the time of winding is stored.

[0036]

According to the strobe unit of the first and second aspects, oscillation occurs due to electrostatic discharge noise as in the conventional strobe unit, and as a result, unnecessary lighting of the neon tube Ne does not occur. The neon tube Ne is turned on carelessly when loading the film in a dark room during the manufacturing process of the film unit with the lens, as the battery is not consumed and the flash photography is not performed against the user's intention. Therefore, there is no problem that the unexposed film is exposed.

According to the film unit with a built-in strobe lens according to the third and fourth aspects, even if a strobe unit having an automatic charging stop circuit is used, the electric components are efficiently arranged, so that miniaturization is hindered. And it can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional automatic charging stop strobe.

FIG. 2 is a circuit diagram of an automatic charging stop strobe of the present invention.

FIG. 3 is a view of the strobe unit as viewed from the back.

FIG. 4 is a cross-sectional view in which a strobe unit is incorporated in a film unit with a lens.

[Explanation of symbols]

 B Battery Q101 Oscillation transistor Q102 Transistor TRA Oscillation transformer MSW Main switch R101 First resistor R102 Second resistor 11 First space 12 Second space 21 Printed circuit board

Claims (4)

[Claims] 1. A battery as a power supply of a strobe circuit, an NPN-type first transistor having an emitter terminal connected to a negative electrode of the battery, a collector terminal connected to a positive electrode of the battery, and an emitter terminal connected to the first terminal. An NPN-type second transistor connected to the base terminal of the first transistor; one terminal on the primary winding side connected to the positive electrode of the battery; and the other terminal connected to the collector terminal of the first transistor An oscillation transformer having one terminal connected to the secondary winding connected to the rectifier element and the other terminal connected to the base terminal of the second transistor; and one terminal connected to the positive electrode of the battery. And a main switch that is turned on only during operation, and one terminal is connected in series with the main switch by being connected to the other terminal of the main switch. A first resistor having the other terminal connected to the base terminal of the second transistor; and one terminal connected to the other terminal of the first resistor, so that the first resistor is connected in series with the first resistor. And a capacitor having the other terminal connected to the negative electrode of the battery, wherein a second resistor is provided in parallel with the capacitor. 2. The resistance of the first resistor is 1 kΩ or more,
2. The strobe unit according to claim 1, wherein the resistance value of the second resistor is 1 MΩ or less, and the resistance value of the second resistor is 10 times or more the resistance value of the first resistor. 3. 3. A photographing unit for exposing a film with a photographing lens to form a photographing screen, and a roll film chamber for storing either a roll film in which a film has been wound in advance or a patrone in which a film is wound for each photographing. A battery chamber for accommodating a battery for a strobe power supply, and a subject cover in the photographing unit, the roll film chamber and the battery chamber are covered with a front cover, an outer wall of the photographing unit, and the roll film. From the first space formed by the outer wall of the chamber and the inner wall of the front cover,
A printed circuit board having a wiring pattern disposed only on the front cover side is disposed in a second space formed by an outer wall of the roll film chamber, an outer wall of the battery chamber, and an inner wall of the front cover, Wherein a film unit with a built-in strobe is mounted with at least an oscillation transformer, and at least a trigger coil is arranged in the second space. Film unit with built-in strobe lens. 4. A film unit with a built-in strobe lens, wherein a reflector of a strobe light emitting unit disposed above the roll film chamber and the trigger coil are connected by a lead wire.