JPH07209692A - Camera provided with multiple exposure preventing mechanism - Google Patents

Abstract

PURPOSE:To effectively prevent multiple exposure and to excellently open/close a shutter even when film is ended in the middle of one frame and new film is set in a camera other than an automatic rewinding type which opens/closes the shutter independently. CONSTITUTION:This camera is provided with a set cam 10 rotating interlocked with feeding the film, a frame stop lever 12, a 1st switch So detecting the set state of the set cam 10, a cam ring 20 setting the lens by the rotation of the set cam 10, and a 2nd switch Ss detecting the lens set state. Only in the case of detecting a film set completing state and a lens set completing state, shutter operation is executed. Thus, the multiple exposure is effectively prevented. Since only feeding the film is executed when an state other than the above states is detected and a shutter button is depressed, the initializing is performed at the time of loading the film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera provided with a multiple exposure preventing mechanism, and more particularly, to a mechanism and control for preventing multiple exposure of a camera which can be opened and closed regardless of film feeding and which is manually rewound. Regarding

[0002]

2. Description of the Related Art In a camera, it is necessary to feed a film of one frame each time one photographing is completed. The film is fed automatically by a motor or manually. It will be. The shutter release (opening / closing) at the time of photographing is performed by a mechanically charged spring force in conjunction with the film feeding, but is also electrically performed by an electromagnetic actuator. According to this electric shutter release, there is an advantage that a mechanical structure interlocking with film feeding is unnecessary.

Further, when the filming is completed up to the last frame, the film will be rewound, but this rewinding is done automatically (auto rewind type) or with a low-priced camera or the like manually. is there. That is, in the manual type, the film is rewound by the motor by pushing the rewind button by manual operation (manual rewind type), or the film is manually rewound.

[0004]

However, as described above, in the camera of the type in which the shutter opening / closing (release) operation can be performed by the electromagnetic actuator regardless of the film feeding, even when the film cannot be fed one frame,
There is a problem that the shutter can be opened and closed, and multiple exposure is performed. In order to prevent this multiple exposure, the fact that one frame of film has been fed is detected, for example, at the position of a set cam connected to the film winding shaft, and when this set cam is in a predetermined set completion state. First, the shutter release can be set.

However, in this case, there is the following problem in a camera other than the auto rewind type camera. That is, if the film is stretched (completely wound up) when the last one frame is just wound up, the set cam comes to a predetermined position where the shutter can be opened and closed. Then, in this state, the set cam remains as it is even after one shooting, so that the shutter can be opened and closed next time, and multiple exposure is allowed.

Also, when the film is stretched by winding up the last frame halfway, the shutter cannot be opened and closed, so the film is rewound and a new film is loaded. However, at this time, the set cam that detects the set state of the film is stopped midway, and the film set state is not completed, so the shutter cannot be released.

The present invention has been made in view of the above problems, and an object thereof is to prevent multiple exposure in a camera other than an auto-rewind type camera capable of independently opening and closing the shutter. (EN) Provided is a camera having a mechanism, and further, a camera having a multiple-exposure prevention mechanism that can open and close a shutter satisfactorily when a new film is set even when the film is finished in the middle of one frame. .

[0008]

In order to achieve the above object, a camera having a multiple exposure prevention mechanism according to the first aspect of the present invention comprises a film feeding mechanism for feeding a predetermined amount of film each time a film is taken, A first detector for detecting the set state of the fed film, a lens set mechanism for setting the photographing lens in a predetermined state in association with the film feeding, and a second set for detecting the lens set state by the lens set mechanism. In order to prevent multiple exposure from the detection unit, the first detection unit detects the film setting completion state, and when the second detection unit detects the lens setting completion state, controls to permit the shutter operation. And a control unit. According to the second aspect of the invention, when the shutter button is pressed when the first detecting section detects that the film setting is not completed or the second detecting section detects that the lens setting is not completed. It is characterized in that only film feeding is executed.

[0009]

According to the above construction, the first detecting section detects whether or not the film has been set, that is, the one-frame advance is completed, and the second detecting section moves the film for focusing or zoom photographing. It is detected whether the lens to be set is in the completed state. Since this lens setting mechanism is executed in conjunction with the actual feeding of the film, it is possible to surely determine whether or not the next one frame has been completely fed by detecting the set state. Therefore, the shutter operation is allowed when the frame advance completion state and the lens setting completion state are detected, and the shutter is opened and closed by operating the shutter button at this time.

In addition, when the frame feed completion state and the lens set completion state are not detected and the shutter button is pressed, the shutter opening / closing is not executed, but only the film feeding is executed. Therefore, when the last frame is rolled up halfway and the film is stretched and a new film is loaded after that, the film is fed and the one-frame feed is completed (initial set state). This allows the shutter to be opened and closed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a multiple exposure preventing mechanism in a camera according to an embodiment, and FIG. 2 shows a part of a control circuit of the camera. In FIG. 1, the set cam 10 is connected to a film winding shaft (not shown), and the set cam 10 is configured to rotate clockwise once for each frame of the film. In the locking groove 11 formed on the side surface of the set cam 10, the claw 1 of the top stopper lever 12 is
3 is locked, and this frame stop lever 12 contacts the side surface of the rotating set cam 10. Then, contact needles 14A and 14B are attached to the lower side of the frame stopper lever 12, and electrode portions 15A and 15B having different shapes are arranged at positions contacting the contact needles 14A and 14B. The first switch (first detection unit) So is composed of 14A, 14B and the electrode units 15A, 15B.
That is, according to the movement of the top stopper lever 12, the contact needle 1
4A moves between the electrode portions 15A and 15B, the contact needle 14B moves only the electrode portion 15B, and is turned on in the state shown in the figure to detect a film setting completion state (frame advance completion state). It will be.

An engaging pin 17 is provided on the upper surface of the set cam 10, and the engaging pin 17 engages with a projecting piece 19 of a driving body 18 which moves horizontally. This driver 18
Has a projecting piece 22 which is arranged to drive the cam ring 20 for setting (extending) the lens and which engages with the engagement pin 21 of the cam ring 20. The driving body 18 is urged to the right side in the drawing by the spring 24, and the cam ring 20 is urged in the clockwise direction by the spring 25. Therefore, when the set cam 10 rotates,
Is moved to the left in the drawing, the projecting piece 22 of the driving body 18 engages with the engaging pin 21 to rotate the cam ring 20 counterclockwise. At this time, the cam ring 20 is stopped at a predetermined charging completion position by a locking mechanism (not shown).

Although not shown, a three-dimensional cam mechanism for converting rotational movement into linear movement is formed outside the cam ring 20. Therefore, the rotation of the cam ring 20 causes the photographing lens 26 to be extended in the front-back direction by a predetermined amount, which allows the camera of the embodiment to perform a plurality of stages of autofocus from a short distance to a long distance.
Inside the cam ring 20, for example, the shutter blade 2
Two 8 are arranged, and an electromagnetic actuator 29 for independently driving the shutter blade 28 is provided.

Further, a projection 31 is attached to the cam ring 20, and a switch lever 32 rotated by the projection 31 is provided.
2 is biased counterclockwise by a spring 33. The switch lever 32 is provided with the first switch S
Similarly to o, the contact needles 34A and 34B are attached, and the electrode portions 35A and 35B are arranged at positions contacting the contact needles 34A and 34B. Therefore, the contact needles 34A and 34B and the electrode portions 35A and 35B are used to
The switch (second detection unit) Ss is configured,
It turns on in the state shown in the figure, which causes the cam ring 2
A lens set completion (charge completion) state of 0 is detected. In the embodiment, the second switch Ss and the first switch
The switches So are connected in series, and the operating states of the switches Ss and So are transmitted from the terminal 36 to the control unit.

A control circuit for such a camera is shown in FIG. 2, and the first switch So and the second switch Ss are connected in series to the control IC section 37. Therefore, in the embodiment, the control signal is transmitted to the control IC unit 37 when both the first switch So and the second switch Ss are turned on. A drive power source 38 is connected to the control IC section 37, and a first-stage switch SP1, a second-stage switch SP2, a manual rewind switch SMR, etc. of the shutter button are also connected.

The embodiment is constructed as described above, and its operation will be described below with reference to FIGS. First, when the film is set in a steady state and shooting is performed one by one, the set cam 10 described with reference to FIG. 1 engages the claw 13 of the frame stop lever 12 with the locking groove 11 every one rotation. Since it stops, the first switch So is turned on. at the same time,
The engaging pin 17 of the set cam 10 engages with the projecting piece 19 to move the driving body 18 horizontally, so that the projecting piece 22
By engaging the engaging pin 21 with the cam ring 2
0 rotates counterclockwise and sets the lens to a predetermined position. At this time, since the protrusion 31 of the cam ring 20 rotates the switch lever 32 in the clockwise direction, the second switch Ss is also turned on. In this way, when both the first switches So and Ss are turned on, the control IC unit 37
Allows the shutter operation, and the shutter blade 28 is opened and closed by operating the shutter button, that is, the operation of the second stage switch SP2.

Then, when the last frame is wound up and the film has just reached the end of the frame and the film is stretched (completely wound up), when the last photographing is completed, the state shown in FIG. 3 is obtained. Become. Since the film cannot be wound up here, the set cam 10 does not rotate and the cam ring 20 cannot be set to the lens set state. However, in this state, the second switch Ss is turned off,
Since the opening and closing of the shutter is prohibited by the control IC unit 37, the multiple exposure of the final frame is prevented.

When the final frame is partially wound up and the film is stretched, the state shown in FIG. 4 is obtained. At this time, as shown in the figure, since the first switch So is turned off, opening and closing of the shutter is prohibited regardless of whether the second switch Ss is on or off.
Multiple exposure is prevented. Then, when the film already photographed is rewound by the operation of the manual rewind switch SMR of FIG. 2 and the next new film is loaded, the film is set in the state of FIG. 4 and the set completion state is I won't. However, when either the first switch So or the second switch Ss (or both of them) is in the off state, only the film is fed by operating the shutter button, so that the set cam 10 moves about 3/4 rotation amount. Stop. Therefore, even when the film stops in the middle of the final frame, the initial setting (the state of FIG. 1) when the film is loaded is executed, and the next shooting can be performed.

In the above-mentioned embodiment, the detecting portions are connected to the contact needles 14 and 3.
Although the first switch So and the second switch Ss of the combination of 4 and the electrode portions 15 and 35 are used, various other switches can be used as the detection portion.

[0020]

As described above, according to the invention of the first aspect, the first detecting section for detecting the set state of the film feeding and the second detecting section for detecting the lens set state by the lens setting mechanism. Is provided and the shutter operation is controlled only when the film setting completion state is detected by the first detection unit and the lens setting completion state is detected by the second detection unit. Multiple exposure can be effectively prevented in a camera other than the auto-rewind type camera capable of performing the above.

According to the second aspect of the present invention, when the shutter button is pressed when the condition other than the film setting completion condition and the lens setting completion condition is detected, the film is fed. Since only this is executed, when a new film is loaded, the film can be set to the steady state film setting position (initial setting state). Therefore, there is an advantage that the shutter can be opened and closed satisfactorily even when the film is finished in the middle of one frame.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a camera including a multiple exposure prevention mechanism according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a part of a control circuit of the camera of the embodiment.

FIG. 3 is a perspective view showing a state when the shutter is opened and closed after the final frame is just rolled up and the film is stretched in the embodiment.

FIG. 4 is a perspective view showing a state in which the final frame is wound up halfway and the film is stretched in the embodiment.

[Explanation of symbols]

 10 ... Set cam, 12 ... Frame stop lever, 14A, 14B, 34A, 34B ... Contact needle, 15A, 15B, 35A, 35B ... Electrode part, 18 ... Driving body, 20 ... Cam ring, 31 ... Protrusion, 32 ... Switch lever , So ... First switch, Ss ... Second switch.

Claims (2)

[Claims] 1. A film feeding mechanism that feeds a predetermined amount of film each time a photograph is taken, a first detection unit that detects the set state of the fed film, and a photographing lens that moves in conjunction with the film feeding to a predetermined amount. Lens setting mechanism for setting the state, a second detection section for detecting the lens setting state by this lens setting mechanism, and a film setting completion state detected by the first detection section for preventing multiple exposure, and Two
A camera provided with a multiple exposure prevention mechanism including: a control unit that controls a shutter operation when the lens setting completion state is detected by the detection unit. 2. When the shutter button is pressed when the first detector detects that the film setting is not completed, or when the second detector detects that the lens is not completed, the film feed is started. A camera provided with the multiple exposure prevention mechanism according to claim 1, wherein only the sending is executed.