JPS623237A - camera film feeding device - Google Patents

Abstract

PURPOSE:To prevent the overlapping exposure of a film and to refeed a film in an incomplete feed state by inhibiting releasing operation in the incomplete film feed state, and stopping temporarily powering on a motor by a feeding indicating means which indicates the refeeding of the film. CONSTITUTION:When the film can not be driven during film rewinding operation, the lighting of a light emitting element 35 and releasing operation are not allowed, so it is indicated that the film is not rewound completely, and such trouble that a film which is already exposed is damaged is eliminated. Further, a user knows that the film is not rewound completely by an alarm display and electromotive force enough to rewind the film is recovered after elapsing the time when the operation of a rewind switch SW 3 is started. Therefore, the film is rewound to the end.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to an improvement in a film feeding device for a camera that automatically winds and rewinds a film.

(Background of the Invention) In recent years, cameras have become increasingly automated, and a type of camera that automatically winds and rewinds the film and also detects the feeding status from the rotational status of the film feeding motor or a sprocket that is linked to the movement of the motor. There is a camera. In such a camera, if the capacity of the power supply battery becomes low, for example, the motor will stop rotating before the film has been completely rewound to the end. When the camera stops, the user mistakenly assumes that the film has been rewound and opens the back cover or presses the release button carelessly, causing problems such as re-exposing the film that has already been shot. . Furthermore, as described above, if the film rewind operation is stopped in the middle of the film rewinding operation, the next photographic preparation operation cannot be carried out smoothly.

(Object of the Invention) An object of the present invention is to provide a film feeding device that can solve the above-mentioned problems, prevent overexposure of the film, and refeed the film that has not been fed yet. That's true.

(Characteristics of the Invention) In order to achieve this object, the present invention provides a state detection means for detecting whether the film has been fed to a normal position or film feeding has not been completed; A release inhibiting means for prohibiting the release operation when an incomplete state is detected, and a release inhibiting means that prohibits the release operation when an incomplete state of film feeding is detected.
Output state holding means outputs an energization prohibition signal to the motor and a release prohibition signal to the release prohibition means and holds the output state, and the output state holding means maintains the output state by the film refeeding operation. and a feeding instructing means for instructing the film to be re-fed to the position where the film feeding by the motor is completed, thereby prohibiting the release operation and energizing the motor when the film feeding is not completed. The present invention is characterized in that the film is fed again by utilizing the return of the electromotive force of the power supply voltage that occurs when the film is temporarily stopped.

(Embodiments of the Invention) The present invention will be explained in detail below based on the illustrated embodiments.

The figure is a block diagram showing one embodiment of the present invention. SWt
is a release switch, SW2 is a sprocket switch that turns on and off repeatedly as the film moves, SW3 is a rewind switch used to wind the film at the discretion of the operator, and SW4 is turned on when the camera back is opened.

The back cover switch is turned off when it is closed. SW5 is a film presence switch that is turned on when the film is located on the exposure surface and turned off when it is not. SW6 is the zoom switch. 1 to 6 are pull-up resistors. 7 to 11 1 is an inverter that outputs a high-level signal when each of the switches is turned on; 12 is an AND gate; 13 is an exposure control circuit;
4 is an inverter that outputs an inverted signal of the signal input from the AND gate 12; 15 is an AND gate; 16 is an inverter that outputs a film winding start instruction when a high level signal is input from the AND gate 15, and a high level signal from the OR gate 17; a winding circuit that instructs the motor drive circuit 18 to complete film winding upon input of a signal;
19 is a film feeding motor, 20 is a Nant gate,
21. 22 is a Nant gate that constitutes a latch circuit, 23
24.25 is a one-shot circuit; 26 is an OR gate; 27 is an AND gate; An oscillation circuit, 29 is an OR gate, and 30 is a frequency dividing circuit that divides the frequency of the pulse from the oscillation circuit 28, which outputs a high level signal from the output terminal Qi after a certain period of time, and is not reset within the certain period of time. As a result, a high level signal is output from the output terminal Qj. 3
1 is a Nandt gate, 32.33 is a Nandt gate that constitutes a latch circuit, and is set by inputting a high level signal from the Nandt gate 31;
It is reset by inputting a higher level signal. Reference numeral 35 denotes a light-emitting element that lights up when the latch circuit consisting of the Nant gates 32 and 33 is set, that is, when the motor 19 stops during film rewinding, and displays a warning that film rewinding is not yet completed. , 36 is an AND gate, 37 is a three-person AND gate, 38 is a three-person gate (7'F'-), and 39 is a motor drive circuit that instructs a film rewind start when a high level signal is input from the OR gate 38. This is a rewinding circuit for 18.

Next, we will discuss the operation. First, a case will be described in which the voltage of the power supply battery is sufficiently high and film rewinding is possible. When you open the back cover to load film,
The back cover switch SW4 is turned on and the output of the inverter 10 becomes a high level signal. As a result, the output of the NOR gate 34 also becomes a high level signal, so the output of the NAND gate 33 forming the latch circuit becomes a high level signal.

When the film is loaded, the film presence/absence switch SW5 changes from on to off, and the NAND game) 21.22
The output of the latch circuit consisting of the following becomes a low level signal.

In this state, when a release button (not shown) is pressed and the release switch SWl is turned on, the output of the inverter 7 becomes a high level signal, and this signal is input to one input terminal of the AND gate 12. At this time, since a high-level signal is input from the Nant gate 33 to the other input terminal of the AND gate 12, the output of the AND gate 33 becomes a high-level signal, which causes the exposure control circuit 13 of the next stage to
is excited and performs the exposure control operation on the film, and
Upon completion of exposure, a high level signal is output to one input terminal of the AND gate 15. The release switch SW
1 is turned off, the output of the inverter 7 is inverted to a low level signal, and this signal is input as a high level signal to the other input terminal of the AND gate 15 via the AND gate 12 and the inverter 14. The output of the gate 15 becomes a high level signal, and the hoisting circuit 16 is excited. Therefore, the motor drive circuit 18 operates, and the motor 1
9 begins to rotate in the winding direction, and winding of the film is started.

As described above, when film winding starts, as the film moves, the sprocket switch f SW 27
3 (on/off is repeated, and this on/off signal is input to the counter 23 via the inverter 8. The counter 23 counts the number of input on/off times, and when it reaches a predetermined number (a number corresponding to - the number of frames fed), (Noa game) Outputs a high level signal to 17. At this time, since the output of the AND gate 12 is a low level signal due to the release switch SWI being turned off, the reset of the counter 23 is released and the count is enabled.

When the output of the NOR gate 17 becomes a high level signal, the output of the winding circuit 16 is inverted to a low level signal, and the film winding operation is stopped.

On the other hand, each time the sprocket switch SW2 changes from off to on, the one-shot circuit 24 momentarily outputs a high-level signal to one input terminal of the AND gate 27. During film winding or rewinding, the output of the OR gate 26 is a no-level signal, and therefore, the AND gate 27 outputs one pulse at a time when the SPRO switch SW2 changes from OFF to ON. The frequency divider circuit 30 is reset via the signal. During film winding, the sprocket switch SW2 no longer turns on and off repeatedly due to film tension, etc., and the frequency dividing circuit 30 is reset for a predetermined period of time.
When the output terminal Qi stops, a high level signal is output from the output terminal Qi, the output of the NAND gate 20 becomes a low level signal, and the output of the latch circuit consisting of NAND gates 21 and 22 becomes a high level signal. This signal is input to one input terminal of the AND gate 37, and since the film is loaded at this time, the film presence/absence switch SW5 is off and its output is a high level signal, and the output of the NOR gate 33 is also a high level signal. Therefore, the AND gate 3
7 becomes a high level signal, and this signal is input to the rewinding circuit 39 via the NOR gate 38. This energizes the rewind circuit 39. Therefore, the motor drive circuit 18
is operated, the motor 19 starts rotating in the rewinding direction, and rewinding of the film is started. At this time, since a high level signal is simultaneously input via the NOR gate 17, the operation in the winding direction by the winding circuit 16 is stopped.

During film rewinding, the frequency dividing circuit 30 is reset by turning on and off the sprocket switch SW2, similarly to during film winding.

When rewinding is performed normally, the output of the Nantes gate 31 remains at a high level because it is reset before a high level signal is output from the output terminal QJ of the frequency dividing circuit 30, and therefore the Nantes gate 31 remains at a high level. The output of the gate 33 remains a high level signal.

When all the film is wound up in a cartridge (not shown),
Film presence/absence switch SW5 is turned on and AND gate 2 is activated.
4 becomes a low level signal, and this signal is input to the rewinding circuit 39 via the OR gate 38, so the motor 19 stops.

In this state, the output of the Nant gate 33 remains latched to the I\I level signal, so the release is not inhibited.

Next, a case will be described in which the voltage of the power supply battery decreases and the film cannot be rewound to the end.The operation from the 0-winding state to the rewinding state is the same as described above. The rotation of the motor 19 gradually slows down, and the timing of repeating on/off of the sprocket switch SW2 linked to the rotation becomes slow, until it remains in the on or off state (motor 19 no longer rotates wB).
The frequency divider circuit 30 is no longer reset and its output terminal Q
A signal with a higher level than 1 is output. The frequency dividing circuit 3
When a high level signal is output from the output terminal Qj of 0, the output of the Nant gate 34 is inverted to a low level signal (
At this time, a high level signal is input from the rewinding circuit 39), and the output of the Nant gate 32 becomes a high level signal, and the light emitting element 35 lights up, indicating a warning that film rewinding is not yet completed. will be done. On the other hand, since the output of the Nant gate 33 is inverted to a low level signal,
The output of the AND gate 24 is forcibly set to a low level signal, and the power supply to the motor 19 is stopped via the motor drive circuit 18, thereby stopping the film rewinding operation. At the same time, the output - of the AND gate 12 is also forcibly set to a low level signal, so that the release is locked. Furthermore, in this embodiment, a configuration is assumed in which the lens barrel can be moved by the rotational force in the rewinding direction of the motor 19 to perform zooming to the telephoto side or wide side, and normally, by turning on the zoom switch SW6. Zooming in any direction is possible, but even if the zoom switch SW6 is operated in this state and the output of the inverter 11 becomes a high level signal, the AND gate 3
Since the output of the Nandt gate 33, which is one input of the AND gate 36, is a low level signal, the output of the AND gate 36 remains a low level signal, and the motor 19 is not energized regardless of the operation of the zoom switch SW6. In this state, only the rewind switch SW3 is valid. When the rewind switch SW3 is turned on, the output of the inverter 9 becomes a high level signal, so the output of the OR gate 38 also becomes a high level signal, the rewind circuit 39 is excited, and the motor 1
9 begins to rotate in the rewinding direction, and the rewinding operation of the remaining film is resumed. The subsequent operations are the same as described above.

In addition, in such a state, there is no switch other than the rewind switch SW3 that can directly operate the camera, but indirectly by opening the back cover, you can operate the camera back switch SW4.
is turned on, and as a result, the output of the inverter 10 becomes a high level signal, the output of the NOR gate 34 becomes a low level signal, and the output of the Nant gate 33 is latched to a high level signal, so the release switch SWI and zoom Switch SW6 becomes effective. However, as described above, the light emitting element 35 lights up and the release is locked, allowing the user to know that the film has not been completely rewound and that rewinding is necessary. As can be easily understood, the release switch SW1 and zoom switch SW6 are not enabled because the back cover is not opened, and the release switch SW1 and zoom switch SW6 are not enabled when the back cover is opened. The reason is.

This is to enable the camera to return to normal operation at any time after removing the film.

In addition, as mentioned above, the operation of the rewind switch SW3 becomes effective even though the voltage of the power supply battery has decreased. This is because it utilizes the characteristic that the electromotive force (of the power supply battery) is restored to the extent that it can be rewound.

According to this embodiment, when the film cannot be driven during film rewinding, the light emitting element 35 is turned on,
Since the release operation is not accepted, it is possible to notify the user that the film has not been completely rewound, thereby preventing the camera back from being opened, the release button being pressed inadvertently, or the release button being pressed. This eliminates the possibility that the camera will hit something and release the camera, which eliminates the inconvenience of damaging the film that has already been shot. Furthermore, if the film cannot be driven while the film is being rewound, the power to the motor 19 is immediately stopped, and a warning message is displayed to ensure that the film is completely rewound. The user realizes that there is no rewind switch SW3.
After a period of time long enough for the operation to start, the electromotive force sufficient to rewind the film will be restored (of the power supply battery).
By taking advantage of these characteristics, the capacity of the power source battery can be utilized to its full potential.

Further, as described above, by lighting the light emitting element 35 and locking the release, the user can be prompted to operate the rewind switch SW3, so that the user can be prompted to operate the rewind switch SW3. You can expect it. Therefore, the remaining film is rewound to the end, making it possible to smoothly perform the next shooting preparation operation (for example, film exchange). Furthermore, since only the operation of the rewind switch SW3 is effective, damage to the film that has already been shot can be prevented.

(Correspondence between the invention and the embodiment) In this embodiment, the sprocket switch SW2, the inverter 8, the one-shot circuit 24, the AND gate 27,
The OR gate 29, the frequency dividing circuit 30, and the Nant gate 31 serve as the state detection means of the present invention, the AND gate 12 serves as the release inhibiting means, the Nant gates 32 and 33 serve as the output state holding means, and the rewind switch SW3. The inverter 9 corresponds to a feeding instruction means.

(Modified Example) In this example, the explanation was given regarding film rewinding, but
Not only when rewinding the film, but also when the power battery becomes weak and the film cannot be driven while the film is being wound after a frame has been photographed, a warning message will be displayed. At the same time, for example, when the wind switch is operated, the piece is moved to the end.
In other words, it is also possible to create a structure in which winding can be performed until the next frame is at the proper exposure position (for example, in order to smoothly perform the photographing operation of the next frame).

(Effects of the Invention) As explained above, according to the present invention, there is provided a state detection means for detecting whether the film has been fed to a normal position or film feeding has not been completed; A release inhibiting means for prohibiting the release operation when an incomplete state is detected, and a release inhibiting means that prohibits the release operation when an incomplete state of film feeding is detected.
Output state holding means outputs an energization prohibition signal to the motor and a release prohibition signal to the release prohibition means and holds the output state, and the output state holding means maintains the output state by the film refeeding operation. and a feeding instructing means for instructing the film to be re-fed to the position where the film feeding by the motor is completed, thereby prohibiting the release operation and energizing the motor when the film feeding is not completed. Since the film is fed again by utilizing the electromotive force recovery of the power supply voltage that occurs when the film is temporarily stopped, it is possible to prevent overexposure of the film and also to re-feed the film that has not been fed yet. It becomes possible to do so.

[Brief explanation of drawings]

The figure is a block diagram showing one embodiment of the present invention. 7-11...Inverter, 12...Ant gate, 16...Hoisting circuit, 18...
... Motor drive circuit, 19 ... Motor, 21
．． 22. Old... Nantes Gate, 24.25...
One-shot circuit, 3o... frequency dividing circuit, 32.
33...Nant gate, 35...Display element, 39...Rewinding circuit, SWI...
Release switch, SW2... Sprocket switch, SW3... Rewind switch.

Claims (1)

[Claims] 1. In a film feeding device that feeds a film using a motor, a state detection means for detecting whether the film has been fed to a normal position or film feeding has not been completed, and a film feeding device. a release prohibition means for prohibiting the release operation when an incomplete state is detected; and a release prohibition means for disabling the release operation when an incomplete state of film feeding is detected;
The output state holding means holds the output state while outputting each, and the output state holding means releases the output state holding by the film refeeding operation, and the film is replayed to the film feeding completion position by the motor. 1. A film feeding device for a camera, comprising a feeding instruction means for issuing a feeding instruction.