JPH0376444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera clutch mechanism, and more particularly to a camera clutch mechanism that converts rotation of a rotary drive unit into direct motion to switch and connect clutch gears of a camera drive system and a lens drive system. .

In a camera with a built-in motor drive, a drive motor installed in the mirror box is rotated in the forward direction to raise the mirror and perform focusing operations, and rotated in the opposite direction to restore the mirror, feed film, and charge the shutter.

If such a camera is further equipped with an automatic focus adjustment function, the same motor must be used to advance the lens toward close range or toward infinity. and the lens drive system must be switched.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a camera clutch mechanism that allows reliable switching in a short period of time.

In order to achieve the above object, the camera clutch mechanism according to the present invention connects the driving force from the motor built in the camera body to the gear of the first or second drive system by switching the clutch gear. a rotational drive mechanism; a motion conversion mechanism that converts rotation of the rotational drive mechanism into linear motion; and a motion conversion mechanism that displaces the clutch gear by the linear motion of the motion conversion mechanism and drives the clutch gear with the first or second drive. A slide plate that meshes with a gear of the system, and a position of the slide plate to detect that the clutch gear has been switched to the gear of the first or second drive system and send a drive signal to the rotary drive mechanism. It consists of a detection switch that stops the operation.

According to the above structure, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 1 is a mechanical diagram showing an embodiment of a camera clutch mechanism according to the present invention.

Pinion 2 installed on the output shaft of motor 1
The rotation is transmitted to the clutch gear 6 through the gear 4, the pinion 3 coaxially provided with the gear 4, and the idle gear 5 that meshes with the pinion 3. The clutch gear 6 can mesh with the gear 8 or 12 by moving the clutch shaft 7 in the vertical direction. When the clutch gear 6 meshes with the gear 8, it connects to a pinion 9 provided coaxially with the gear 8, a gear 11 meshing with the pinion 9, a pinion 10 provided coaxially with the gear 11, and the driving force is transmitted to the camera. It is transmitted to drive system A. When the clutch gear 6 meshes with the gear 12, the clutch gear 6 is connected to a pinion 13 provided coaxially with the gear 12, a gear 14 meshed with the pinion 13, and a pinion 15 provided coaxially with the gear 14, and the driving force is transmitted to the lens. It is transmitted to drive system B.

A clutch shaft 7 on which a clutch gear 6 is provided
A small diameter portion 16 is provided below and engages with a groove portion of a slide plate 17. Slide plate 17
are provided with guide grooves 18 and 19, and the pin 2
1 and 20, it can be slid up and down.

A U-shaped holding portion 22 is provided on the right side of the slide plate 17, and holds a roller 23 therebetween. The roller 23 is installed eccentrically with respect to the rotation axis of the ratchet gear 24.

A feed pawl 26 is pivotally supported at the tip of the feed lever 25 and biased clockwise by a spring 27, and the rear end is pivotally supported by a fixed portion and biased clockwise by a spring 29. The feed lever 25 is provided with a contact piece 28, which can be attracted by a magnet 30. A pawl 32 biased clockwise by a spring 31 meshes with the ratchet gear 24 and prevents the ratchet gear 24 from reversing.

A projecting piece 33 is provided on the left side of the slide plate 17, and an upper position detection switch 34 detects that the clutch gear 6 is engaged with the gear 8 or 12 by upward or downward movement of the slide plate 17. , a lower position detection switch 35 are provided, and these position detection switches 34, 3
5, the sending of the pulse signal to the magnet 30 is stopped.

Next, the operation of the camera clutch mechanism according to the present invention will be explained.

FIG. 1 shows a state in which it is connected to a camera drive system A. If you want to switch the driving force of motor 1 from camera drive system A to lens drive system B,
It is sufficient to move the clutch gear 6 downward to disengage it from the gear 8 and at the same time engage it with the gear 12 of the lens drive system.

Now, when a pulsed excitation current is continuously applied to the coil of the magnet 30, when the excitation current is flowing, the contact piece 28 of the feed lever 25 is attracted, and when the excitation current is not flowing, the feed lever 25 is moved by the action of the spring 29. The lever 25 continues to be returned.
Therefore, when the magnet 30 attracts the contact piece 28, the claw of the feed pawl 26 at the tip of the feed lever 25 meshes with the gear 24, causing the ratchet gear 24 to rotate intermittently in the direction of the arrow. The pawl 32 is pressed against the ratchet gear 24 by a spring 31, and prevents the ratchet gear 24 from reversing when the gear 24 is intermittently fed by the feed pawl 26.

At this time, the roller 23, which is installed at an eccentric position on the axis of the ratchet gear 24, rotates in the direction of the arrow, thereby eccentrically moving downward. For this reason,
The gripping portion 22 of the slide plate 17 allows the roller 2 to
3, the slide plate 17 moves downward. By moving the slide plate 17, the slide plate 1
7 is engaged with the small diameter portion 16 of the shaft 7 of the clutch gear 6, so the clutch shaft 7 pulls it downward, causing the clutch gear 6 to disengage from the gear 8 and mesh with the gear 12. , the camera drive system A can be switched to the lens drive system B.

Final position of switching, i.e. ratchet gear 2
4 has rotated half a revolution, the protruding piece 33 of the switch plate 17 comes into contact with the position detection switch 35, turning on the switch and stopping sending the intermittent excitation signal to the magnet 30.

Conversely, when switching from lens drive system B to camera drive system A, roller 2 of ratchet gear 24
3 needs to move upward from the lowest position.
In other words, start the intermittent feed again and start the ratchet 2.
4 further 180 degrees in the direction of the arrow, and remove roller 23.
When the slide plate 17 is moved to the uppermost position (the position shown in FIG. 1), the slide plate 17 moves upward, the upper positioning switch 34 is turned on, and the intermittent excitation signal to the magnet 30 is stopped to complete the movement.

In the present invention, an example of intermittent feeding using the magnet 30 has been described as the drive mechanism for the ratchet gear 24, but a modification in which the ratchet gear 23 is rotated using a motor is also possible.

As explained in detail above, according to the present invention, the slide plate is displaced by half a rotation of the rotary drive mechanism to switch between the two drive systems, so the switching time is short, and switching can be detected. Since a detection switch is provided to stop the rotational drive mechanism, the operation is reliable.

[Brief explanation of drawings]

FIG. 1 is a mechanical diagram showing an embodiment of a camera clutch mechanism according to the present invention. 1...Motor, 2, 3, 9, 10, 13, 15
... Pinyon, 4, 8, 11, 12, 14 ... Gear, 5 ... Idle gear, 6 ... Clutch gear,
7... Clutch shaft, 16... Small diameter portion, 17... Slide plate, 18, 19... Guide groove, 20, 21...
... Pin, 22 ... Holding part, 23 ... Roller, 24
... Ratchet gear, 25 ... Feed lever, 26
...Feed claw, 27...Spring, 28...Touch piece, 2
9, 31...Spring, 32...Claw, 33...Protruding piece, 34, 35...Position detection switch.

Claims (1)

[Scope of Claims] 1. In a camera clutch mechanism that connects a driving force from a motor built in the camera body to a gear of a first or second drive system by switching a clutch gear, the a motion conversion mechanism that converts rotation of the drive mechanism into linear motion; and a slide plate that displaces the clutch gear by the linear motion of the motion conversion mechanism and engages the clutch gear with the gear of the first or second drive system. and a detection switch that detects that the clutch gear has been switched to the gear of the first or second drive system based on the position of the slide plate and stops sending out the drive signal of the rotary drive mechanism. A camera clutch mechanism featuring: 2. The rotary drive mechanism includes a ratchet gear, a feed lever that is biased in a direction to separate from the ratchet gear, and a feed lever that has a ratchet gear and a feed pawl that engages and disengages from the ratchet gear, and a feed lever that holds the feed lever by suction and operates the feed pawl. The camera according to claim 1, further comprising a magnet engaged with the ratchet gear, and configured to rotate the ratchet gear by sending an intermittent excitation signal between the magnets. clutch mechanism. 3. The camera according to claim 1, wherein the motion converting mechanism is configured to linearly move the slide plate by means of a pin eccentrically provided on the rotating part of the rotational drive mechanism. Clutch mechanism. 4. The first drive system is a camera drive system that rotates in the forward direction to raise the mirror and perform a focusing operation, and rotates in the opposite direction to restore the mirror, feed the film, charge the shutter, etc. A camera clutch mechanism according to claim 1. 5. The camera clutch mechanism according to claim 1, wherein the second drive system is a lens drive system that extends the lens toward close range or infinity for automatic focus adjustment. .