JPS5840170B2 - Electric film winding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric film winding device.

Generally, the film is run by starting the drive of an electric motor, and when a certain amount of film corresponding to frames has been wound, the drive of the electric motor is stopped and the film is automatically wound one by one frame by frame. An electric film winding device is known.

When a certain amount of film equivalent to one frame in these electric film winding devices is wound, the drive of the electric motor is stopped by a machine using a cam or the like that links the power supply circuit of the electric motor to the drive of the electric motor. Some methods have been implemented in which the bottom is opened by means of physical means and the drive of the electric motor is stopped.

However, as mentioned above, most of this is done by mechanical means, and it is difficult to wind a fixed amount of film equivalent to one frame each time the film is wound due to mechanical operation delays and other factors. There is a drawback that the amount of film shift is accumulated.

In order to eliminate the above-mentioned drawbacks, the present invention is directed to an electric film winding device that automatically winds up the film frame by frame by the drive of an electric motor, and detects perforations in the film that is traveling by the drive of the electric motor. The present invention provides an electric film winding device that counts the number of pulse signals emitted by the camera and stops driving the electric motor when the number reaches a predetermined number.

An embodiment of the electric film winding device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an electric film winding device according to an embodiment of the present invention, in which E is a battery power source, M is a motor, SWl is a first switch, and 8th is a second switch. and 1 is a counting circuit.

The electric motor M drives a film winding mechanism via a transmission train constituted by gears (not shown) to wind the film.

The first switch Sw1 is closed by an operation from outside the camera, or in the case of continuous shooting, for example, in the case of an eye reflex camera, the first switch Sw1 is closed when the reflector is lowered or the rear curtain of the shutter finishes running, and the counting circuit is closed. By resetting the value 1, the counting output of this counting circuit becomes zero, that is, the output voltage becomes a low potential, and the driving of the electric motor M is started.

The second switch holder is opened and closed by the perforation of the film which is driven by the electric motor M, and emits a pulse signal, which is then supplied to the counting circuit 1.

That is, the second switch is closed when the movable contact of the second switch falls into the perforation of the film, and opens when the movable contact of the second switch is moved out of the perforation of the film. The device is configured to detect perforations.

Therefore, the number of pulse signals applied to the counting circuit 1 matches the number of perforations.

The counting circuit 1 is composed of n inverse counting circuits, where n is the number of perforations in one frame, and is, for example, a ring counting circuit composed of a plurality of flip-flop circuits, and the first switch sw1 is closed. The number of pulse signals emitted from the second switch ξ is reset when the signal is pressed, and when the number reaches a predetermined number n, a counting output is generated, that is, a high potential is output, and the output drives the motor. The power supply to M is cut off and the drive of electric motor M is stopped.

Here, the activation of the electric film winding device when using a film having perforations at a ratio of 8 perforations/1 frame will be explained below based on the principle diagram shown in FIG.

FIG. 2 is a principle diagram for explaining the activation of this electric film winding device. At time T1, when the first switch Sw1 is closed, a counting circuit (four cascade-connected three inverse counting circuits) is connected. Since the counting circuit 1 (consisting of a T-type flip-flop) is reset, the output of the counting circuit 1 becomes a low potential and starts driving the electric motor M to run the film.

Further, by detecting the perforation of the running film and continuously opening and closing the second switch 8 at time T2, the counting circuit 1 calculates the number of pulse signals by supplying a pulse signal to the counting circuit 1 which has been reset in advance. Count.

As described above, the counting circuit 1 outputs a high potential at time T3 when the number of supplied pulse signals is counted as "8", cuts off the power supply to the electric motor M, and stops driving the electric motor M.

That is, when using a film having perforations at a ratio of 8 perforations/1 frame, the electric film winding device closes the first switch Sw1 at time T1 to drive the electric motor M. The second switch 8 is started and the film is run, and the number of pulse signals emitted by the second switch 8, which is opened and closed by the perforations of the running film, is a predetermined number of 1.
At time T3 when the film reaches "8", the drive of the electric motor is stopped via the counting circuit 1, and one frame of film is wound.

Furthermore, if the first switch SW is set to be closed again when one frame of photography is completed, then sequentially -
It is possible to automatically wind the film frame by frame, allowing continuous shooting.

By the way, the film used in the electric film winding device constructed as described above is not only a film having perforations at a ratio of 8 perforations/1 frame as described above, but also a film in which the number of pulse signals is It is also possible to use a film with perforations at a ratio of 6 perforations/1 frame if the motor is set to stop driving when the perforation reaches 6".

As is clear from the above, the electric film winding device according to the present invention includes a pulse generator that detects perforations in a film traveling by driving an electric motor and generates a pulse signal, and a pulse generator that counts the number of pulse signals and drives the electric motor. A counting circuit for controlling the operation of the motor, and a switch for resetting the counting circuit and starting the driving of the electric motor,
The drive of the motor is stopped when the number of pulse signals reaches a predetermined number, and the perforations of the film are converted into pulse signals and the number of pulse signals is counted to drive the motor. Since the film is stopped, the film can be automatically wound frame by frame accurately and sequentially.

Therefore, it can be said that the drawback of conventional electric film winding apparatuses, that the amount of deviation of the film is accumulated each time the film is wound, can be solved by the electric film winding apparatus of the present invention.

In addition, since the drive of the motor is stopped by electrical means using the counting output of a counting circuit that counts pulse signals generated by perforation detection, it is very advantageous in terms of design and mechanism.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an electric film winding device according to an embodiment of the present invention, and FIG. 2 is a principle diagram for explaining the activation of the electric film winding device. 1... Counting circuit, M... Electric motor, Sw
l...First switch, SW,...Second switch.

Claims (1)

[Claims] 1. In an electric film winding device that automatically winds up a film having a plurality of perforations per frame one frame at a time by the drive of an electric motor, the perforations of the traveling film are detected by the drive of the electric motor. A pulse generator that emits a pulse signal using a pulse generator, a counting circuit that counts the number of pulse signals and controls the drive of the motor based on the counting output, and a reset switch that resets the counting circuit and makes the counting output zero. , wherein the counting circuit is configured to start the electric motor upon activation of the reset switch, and to stop the electric motor when counting of the pulse signals corresponding to the number of perforations in one frame is completed. Electric hoisting device.