JPS6242492B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film feed device for an electric camera.

It is well known that in cameras using cartridge-filled film, it is necessary to load the film and then empty-feed the first two or three frames. In order to avoid the trouble of repeating the film winding and shutter release operations for each frame during this blank feed, a cam that rotates together with the film counter is provided, and every frame is moved while the counter moves from the start scale S to 1. Cameras are known in which the film winding stopper is disabled or the link between film winding and shutter charge is cut off so that the film can be wound continuously without having to press the shutter button each time.

In order to perform this type of blank feed in an electric winding camera, there is a first switch in the motor circuit that is turned on by the shutter release and turned off when winding is complete, and a switch from S that is linked to the film counter. 1, and a second switch that is turned off during the rest of the scale range, so that the second switch continuously rotates the motor when loading the film.
Furthermore, in order to prevent the above-mentioned idle feeding from occurring before the back cover is closed, it is necessary to provide a third switch that is linked to the opening and closing of the back cover, which increases the number of switches and complicates the circuit configuration. Also, even with this configuration, if you accidentally touch the third switch while the camera back is open, the motor will rotate and the counter will not operate and the film will be fed all the way to the end, leaving the risk that the entire film will be exposed. It was hot.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a film feeding device which has a simple structure and eliminates the above-mentioned drawbacks.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows the motor control circuit in the device of the present invention, where 1 is the motor and SW ₁ is the motor 1.
A switch E is a power supply that controls the power supply to the power supply.
Switch SW ₁ is designed to energize the motor and rotate it when the contact C is connected to the a side, and to shoot both ends of the motor to cut off the energization and apply braking when the contact C is connected to the b side. FIG. 2 is a perspective view showing the configuration of the main parts of the present invention, in which 1 is the aforementioned motor, and 2 is a film take-up spool, which is driven by the motor 1 via a gear train (not shown).

3 is a sprocket that rotates following the film.
When the film is advanced one frame, it rotates once.
4 is the film counter scale plate, S...12...
...It is equipped with 36 scales, is fixed to a well-known ratchet wheel, and is set to advance by one scale for each revolution of the sprocket by means of a feed pawl, and automatically returns to the starting position S by a spring (not shown) when the back cover is opened. do.
When the back cover of the counter is open, the feed claw does not operate and the scale does not advance regardless of the rotation of the sprocket. 5 is an index. A cam plate 6 rotates together with the scale plate 4 and is provided with a protrusion 6a. Reference numeral 11 denotes an indexing cam that is driven by the motor 1 via a shutter charging gear train (not shown) and is provided with a notch 11a. Reference numeral 9 denotes a switch lever that can be rotated around an axis 9C, and is biased to rotate counterclockwise by a spring 10 so that its tip 9a comes into contact with the outer periphery of the indexing cam, and the other arm 9b has the above-mentioned switch lever. The movable contact piece C of the switch SW ₁ is held, and this contact piece slides on the fixed contact pieces a and b as the lever 9 rotates. Reference numeral 7 denotes a free feed lever that can be rotated around an axis 7C, and the tip 7 is moved by a spring 8.
a is rotationally biased in the direction in which it contacts the cam 6, and has a bent portion 7b at the other end to be engaged with the arm 9b of the switch lever 9. The tip 7a is located very close to the slope of the protrusion 6a of the cam 6 when the counter is in the S position. Reference numeral 12 denotes a release member of the switch lever, which is interlocked with a shutter (not shown) and moves in the direction of arrow A when the shutter is charged, and moves in the direction of arrow B when the shutter completes its operation.

The operation of this device will be explained below.

Figure 2 shows the state with no film loaded.
The shutter is charged, and the tip 9a of the switch lever 9 has fallen into the notch 11a of the indexing cam 11. In this state, the contact piece C of the switch _SW1 is connected to the b side, and the motor 1 is stopped. At this time, the start scale S of the counter 4 matches the index 5.

When the shutter button (not shown) is pressed in this state, the shutter is released, and when the operation is completed, the release member 1
2 moves in the direction of arrow B and the switch lever arm 9
Press b. As a result, the switch lever 9 rotates clockwise, the tip 9a disengages from the notch 11a of the indexing cam 11, and the switch contact piece C switches to the fixed contact piece a, resulting in the state shown in FIG. energization to the motor begins. As the motor 1 rotates, a charge mechanism consisting of a cam and a lever provided in a gear train (not shown) is actuated to charge the shutter, and the index cam 11 also begins to rotate. Release member 1
2 gradually moves in the direction of arrow A according to the shutter charge, and when the notch 11a of the cam 11 completely escapes from the tip 9a of the switch lever 9, it separates from the arm 9b and leaves the lever 9 free. FIG. 4 shows this state. After the shutter charge is finished, index cam 1
When SW 1 rotates exactly once, the tip of the switch lever falls into the notch 11a of the cam 11 by the force of the spring 10, and the switch SW ₁ accordingly switches from the A side to the B side, and the motor 1 stops, as shown in Fig. 3. Return to state. The same action is repeated every time you press the shutter button. In this case, since no film is loaded, the sprocket does not rotate even if the spool rotates, and therefore neither the counter nor the idle feed lever 7 operates. Next, the operation when a film is loaded will be explained. In this case as well, following the shutter release, the motor starts rotating and the shutter is charged as described above, but as the spool rotates and the film is wound up, the sprocket rotates, and the state shown in Fig. 4 changes from the state shown in Fig. 3. Before returning to the state, the counter advances by one scale, so the cam 6 rotates in the direction of the arrow in FIG. Rotate counterclockwise around 7C. As a result, the bending portion 7
b is within the operating range of arm 9b of the switch lever,
The tip 9a is prevented from engaging with the notch 11a of the indexing cam 11. Therefore, the film is continuously wound without switching the switch _SW1 and the motor remains energized. When the counter scale approaches 1, the tip 7a of the idle feed lever 7 moves to the cam 6.
The lever 7 returns to its original state as shown in FIG. 6, and the bent portion 7b is in a position where it does not prevent the tip 9a of the switch lever 9 from falling into the notch 11a. When the notch 11a comes to the position of the tip 9a of the switch lever as the index cam 11 continues to rotate, the tip 9a falls into the notch _11a as shown in FIG.
When the motor switches to the side, the motor stops.

From then on, each time you press the shutter button, the film will advance one frame at a time.

In the above embodiment, the film is driven by a take-up spool, but a wind-up sprocket may be provided separately from the counter sprocket and driven by a motor. In this case, the indexing cam 11 may rotate once when the hoisting sprocket rotates by one frame.

As described above, the present invention provides a cam at the start position of the automatic restoring film counter, and when the counter is between the start position and the first scale mark 1, a switch is activated to open and close the motor circuit for each frame. Since it is configured to be held in the closed state by a cam, it is possible to continuously feed the film leader part with an extremely simple structure, and the counter always starts when the camera back is open. position, the cam does not hold the switch in the closed state, so even if the shutter button is pressed by mistake and the shutter is activated and the motor rotates to feed the film, it will stop after only one frame.
This prevents unnecessary exposure of the film.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a motor control circuit according to an embodiment of the present invention, Figs. 2 to 7 are perspective views showing various states of the embodiment, and Fig. 2 shows a film counter starting without film being loaded. Figure 3 shows the shutter release and the switch is in position, Figure 4 shows the shutter being driven by the motor and being charged, and Figure 5 shows the film being loaded and the counter operating. FIG. 6 shows a state in which the idle feed lever has been activated, FIG. 6 shows a state in which the idle feed lever has returned to its original position, and FIG. 7 shows a state in which idle feed has been completed. 1; Motor, 2; Film take-up spool,
3; Sprocket, 4; Counter, 6; Cam,
7; Idle feed lever, 9; Switch lever, 11;
Index cam, 12; release member, SW ₁ ; changeover switch.

Claims (1)

[Claims] 1. In a camera that uses the driving force of a motor to prepare for photographing, a switch that operates the motor by changing from a first state to a second state in response to completion of the camera photographing operation; a cam member that maintains the switch in the second state and returns the switch to the first state and stops the motor in response to the end of the photographing preparation operation;
At the initial position, the cam member allows the switch to return to the first state, and the film is displaced from the initial position by the movement of the film fed by the driving force of the motor, so that the film is fed a predetermined amount. 1. A film feed device for an electric camera, comprising: a film feed control member for inhibiting the cam member from returning the switch to the first state until the switch is completed.