JPS6057576B2 - motor drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor drive device,
In particular, this invention relates to improvements in the film winding mechanism.

As is well known, there are various motor drive devices that incorporate a motor and use the driving force of the motor to wind the film, but there are two types depending on the winding mechanism of the camera to which it is applied.
It is broadly divided into

That is, one is applicable to a camera that can be wound in small steps, and the other is applicable to a camera that can be wound only in one operation.
The present invention is directed to a motor drive device for use in a camera that only requires one winding operation. Generally, the configuration and functions required of a motor drive device include a motor and a gear system that transmits the driving force of the motor;
It also has a function to stop the motor when a predetermined amount of film has been wound.

Furthermore, in cameras that cannot be wound in small steps, the winding drive shaft is returned to the predetermined starting position by a return member installed inside the camera, so the gear system must be adjusted during this return process. It is desirable to provide a clutch mechanism in the motor to disconnect it from the motor. Such a latch mechanism is embodied, for example, in the prior art shown in FIG. In FIG. 1, 1 is a drive gear rotated via a motor 3 and an appropriate transmission system (not shown), and 2 is a winding gear rotated by the drive gear 1, which is a film winding drive shaft on the camera side. shall be rotated integrally.

Therefore, if the film winding drive shaft on the camera side needs to rotate by an angle α to feed one frame of film and charge the shutter, the winding gear 2 also needs to rotate by an angle α.

A toothless portion 1a is formed in the drive gear 1, and meshing with the drive gear 2 can be selectively released. This part has the clutch function described above. The clutch operation in Fig. 1 will be explained below. Fig. 1A is just before the hoisting operation, and when the motor 3 is rotating at this time, the drive gear 1 is decelerated and rotated by the transmission system (not shown), and thus the hoisting operation is performed. Gear 2 rotates to feed the film.

FIG. 1B shows the state immediately after winding of the film is completed.

Assuming that the winding gear 2 has been rotated by an angle α necessary for film feeding and shutter charging, at this point a switch means (not shown) generates a rotation stop signal for the motor. Then, due to inertia, time lag, etc., the toothless portion 1a of the motor 3 or the drive gear 1 is brought to the meshing portion between the drive gear 1 and the winding gear 2, and the drive gear 1 is stopped. At the same time, the winding gear 2 is brought under the action of the returning behavior of the film winding drive shaft on the camera side, so that it returns to the predetermined starting position as shown in FIG. 1C. From FIG. 1B to FIG. 1C, the drive gear 1 is in a stopped state. It's dark.
If the operation of the motor drive device continues further,
Film advance is complete (shutter charge is also complete).

), the shutter release is performed, and film winding is started again in response to the shutter release completion signal for the next photographing operation. That is, the motor 3 starts rotating from the state shown in FIG. 1C in order to start winding the film for the next time. However, since the drive gear 1 has a tooth-missing portion 1a, even if the motor 3 rotates in response to the film winding start signal, the film will not wind until the drive gear 1 rotates by the angle β in FIG. 1C. The game was not started, resulting in loss time.

The degree of this loss time is approximately 0.1 to 0. Although it is a hoe,
In high-speed continuous shooting such as motor drive, this value becomes a value that cannot be ignored. In order to eliminate this loss time, it is extremely difficult to adjust the timing of signal generation such as when the motor 3 stops and starts driving. This cannot be said to be an appropriate method due to error factors. ) The present invention provides a novel motor drive device that avoids the above-mentioned drawbacks that could not be solved with the prior art.

In other words, the present invention is effective as it can completely eliminate the loss time that existed between the end of exposure and film winding, thereby improving responsiveness. Furthermore, the clutch mechanism is also equipped with a switch means for a motor stop signal when film winding is completed, thereby simplifying the configuration and realizing a switching means that does not require timing adjustment. An embodiment of the present invention will be described in detail below based on the accompanying drawings starting from FIG.

In FIG. 2, 10 is a winding drive shaft on the camera side.

An operating plate 12 having a protrusion 12a and a pin 12b fixed thereto, and a connecting plate 14 having two recesses 14a are integrally attached to the winding drive shaft 10. The winding drive shaft 10 is connected to the convex piece 12a of the actuating plate 12 and the stopper 16,1.
It can be rotated within the range of contact with the stopper 18, and by rotating clockwise until the convex piece 12a and the stopper 18 come into contact, one frame of film is wound up and the shutter is charged. When the protruding piece 12a and the stopper 16 come into contact with each other, the protruding piece 12a and the stopper 16 stop. 20 is a motor that is a driving source of the motor drive device;
A motor drive device (not shown) is connected to a power supply and an appropriate switch, etc., and stops during shutter release, rotates in the direction of arrow A when the shutter release completion signal is received, and stops when the film 1 frame advance completion signal is received. .

22 is a gear system that reduces and transmits the rotation of the motor 20, and its reduction ratio is adjusted according to the camera side winding drive mechanism.

A drive gear 24 is rotated counterclockwise by the transmission gear system 22, and has a recess 24a in a part thereof.

A ball 25 biased upward by a spring (not shown) is loosely fitted into the recess 24a. Reference numeral 26 denotes an inertia plate having a pin 26a planted on its bottom surface, and counterclockwise rotation of the drive gear 24 is transmitted to the inertia plate 26 via the ball 25 and pin 26a.

The ball 25 and pin 26a here function as a torque limiting clutch mechanism as described later. The inertia plate 26 has a protruding piece 26b on a part thereof, a clutch pawl 28 is pivotally attached to the protruding piece 26b, and the clutch pawl 28 is attached to a spring 29.
is subjected to a counterclockwise rocking force under the action of 30
is a clutch gear whose teeth are formed to act as a one-way clutch together with the clutch pawl 28, and the inertia plate 2
The counterclockwise rotation of 6 is transmitted as is, and the coupler 32, which rotates integrally with the clutch gear 30, is rotated.

If the connecting piece 32a of the coupler 32 is engaged with the recess 14a of the connecting plate 14 on the camera side, the winding drive shaft 10 on the camera side is rotated in the film winding direction. To explain the operation of the above configuration, when a switch means (not shown) is operated in response to a release end signal and the motor 20 is rotationally driven in a counterclockwise direction, the drive gear 24 is decelerated and rotated counterclockwise by the transmission gear system 22. be moved. Therefore, the ball 25 rotates the inertia plate 26 counterclockwise via the pin 26a. The coupler 32 is a one-way clutch. It rotates via the clutch pawl 28 and clutch gear 30, and the winding drive shaft 10 on the camera side is rotated. When one frame of film feeding and shutter charging are completed, the convex piece 12a of the actuating plate 12 touches the stopper 18.
comes into contact with. Therefore, since a load is applied in the winding direction, the coupler 32, clutch gear 30, and inertia plate 26 are forcibly stopped, but since the motor 20 is rotating, the driving gear 24 is given rotational force in the counterclockwise direction. There is. Therefore, at the contact portion between the ball 25 and the pin 26a, the ball 25 is pressed against the stopped pin 26a. The ball 25 is pushed against the pin 2 against the elastic force of a spring (not shown) that urges the ball 25 upward.
6a and is inserted into the recess 24a. By detecting the downward movement of the ball 25 and using it as a signal to stop the motor, the end of one frame advance of the film is detected and the motor is stopped. Therefore, when the ball 25 passes over the pin 26a, the motor stops and all transmission systems stop. At the same time, the winding drive shaft 10 on the camera side is rotated back clockwise by the spring 19. This rotation is transmitted to the connecting plate 14, coupler 32, clutch gear 30, clutch pawl 28, and inertia plate 26.
The inertia plate 26 will be brought to a position where the hoisting drive shaft 10 is stopped by the stopper 16. but,
When the clutch gear 30 rotates clockwise and stops due to the contact between the convex piece 12a of the actuating plate 12 and the stopper 16,
Since the inertia plate 26 has the inertia to rotate clockwise, the clutch pawl 28 continues to rotate clockwise together with the inertia plate while sliding on the clutch gear 30.

The inertia plate 26 includes pins 26 implanted in the inertia plate 26.
a comes into contact with the ball 25 and stops. Therefore, during the next film winding, the loss time when the ball 25 and the pin 26a engage with each other is completely eliminated, and the responsiveness during film winding can be improved. As described above, it is composed of the coupling 32 and the torque limiting clutch (ball 25 and pin 26a).

) By providing a one-way clutch between the two, the loss time at the start of winding can be eliminated, and various one-way clutches can be used. Further, in the present invention, the clutch release operation of the torque limiting clutch itself is used as a signal source for stopping the motor.

In FIGS. 3 and 4, parts equivalent to those in FIG. A plate spring 40 having a semicircular arc shape is fixed to the drive gear 24 with screws or the like.

Further, it is assumed that the inertia plate 26 and the drive gear 24 can only rotate about the central axis of rotation, and their movement in the axial direction is restricted by a stopper 70 or the like. No. Signal plate 4 loosely fitted to the flange portion of the drive gear 40 to be located below the leaf spring 40
The lever 2 is provided to be slidable in the axial direction, and the lever 50 has one end always in contact with the signal plate 42. At the other end of the lever 50, a switching means 60 that contributes to a signal to stop driving the motor is arranged. This operation is explained as follows.

When the rotation of the inertial plate 26 is regulated as the film winding is completed and the drive gear 24 is still driven, the ball 25 biases the leaf spring 40 downward, passes over the pin 26a, and returns to the old position. The displacement of the leaf spring 40 at this time is the signal plate 4
2 is lowered and immediately raised. The switching means 60 are therefore short-circuited and opened via the lever 50. The ON-OFF state of the switching means 60 is used as a motor drive stop signal. As described in detail above, the present invention takes advantage of the characteristics of the camera winding mechanism that cannot be wound in small steps, and uses the return behavior of the winding drive shaft on the camera side to eliminate the loss time when the motor drive starts winding. be.

The configuration can be realized by simply adding a one-way clutch to a conventional motor drive device. As a more desirable configuration, if a pin-ball clutch is used as the torque limiting clutch, it can be easily linked with a one-way clutch to eliminate loss time, and it can also be used as a motor drive stop signal source, allowing accurate motor drive stop control. is possible.

[Brief explanation of drawings]

FIGS. 1A, B, and C are explanatory diagrams of the operation of the prior art.

Claims (1)

[Scope of Claims] 1. A coupling member that is applied to a camera in which a winding drive shaft is rotated back to a predetermined position after film winding is completed, and that is connected to and drives the winding drive shaft, and the coupling member and the motor, and transmits the driving force of the motor to the coupling member during film winding, and disconnects the motor and the coupling member due to an increase in torque load on the winding drive shaft upon completion of film winding. In a motor drive device comprising a torque limiting clutch and a switch means for driving and stopping the motor in response to a film winding completion signal, the winding driving force from the motor is applied to the coupling member between the coupling member and the torque limiting clutch. A motor drive device characterized by being provided with a one-way clutch that engages in the direction of transmission. 2. In the motor drive device according to claim 1, the torque limiting clutch is provided between first and second rotary plates that are opposed devices and have a common rotation center. A convex portion fixed to the first rotary plate and a hole bored in a part of the second rotary plate are loosely fitted into the convex portion, and a biasing force is applied in the direction of the first rotary plate. A motor drive device consisting of a ball and a ball. 3. In the motor drive device according to claim 2, the hole bored in the second rotary plate is formed as a through hole, and the switching is performed by detecting the movement of the ball through the through hole. A motor drive device configured to control means.