JPH067214B2 - Clutch interlocking mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a clutch motion mechanism that engages and disengages by mechanical motion.

[Conventional technology]

In recent compact cameras, stepping motors, servo motors, DC motors, and the like have been used as drive sources for shutter operation mechanisms, lens extension mechanisms for extending the image pickup lens, and the like. For example, in a system in which such a lens extension mechanism is used in connection with a distance measuring device, a focus adjustment ring is rotated by a stepping motor, and the imaging lens is extended in conjunction with this. Then, the focus adjustment ring is stopped when the focus signal is detected from the distance measuring device, and thereby the imaging lens is stopped at the focus position.

By the way, when stopping the above-mentioned focus adjustment ring, it is difficult to obtain accuracy simply by stopping the driving of the stepping motor itself due to the influence of operation delay due to inertia. The locking member is engaged and mechanically locked, and the clutch mechanism is released to disconnect the focus adjustment ring from the stepping motor. In order to obtain such an action, conventionally, the locking member is operated by a magnet, a plunger or the like.

[Problems to be solved by the invention]

However, like the focus adjustment ring described above, a locking member for stopping a driven ring driven by a motor through a clutch mechanism at a predetermined position is operated by using an electromagnetic device such as a magnet or a plunger. In this case, the electromagnetic device must be installed in parallel near the locking member, which not only increases the cost burden but also is disadvantageous in space and hinders the compactness of the camera. Absent.

The present invention has been made in view of such a conventional technique,
An object of the present invention is to provide a clutch interlocking mechanism that mechanically operates a locking member for locking a driven ring at a predetermined position and accurately between a locking position and a locking release position.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a drive ring driven by a motor with a clutch member, and when the clutch member is in the engagement position, the driven ring is driven by the drive ring. Further, in order to hold the driven ring in a predetermined position, the engagement of the clutch member is released and the locking member is operated at the same time, thereby locking the driven ring and the rotation. The engaging / disengaging operation of the locking member is configured to be controlled in association with the mechanical displacement of the clutch member.

According to a preferred embodiment of the present invention, the drive ring is used as a shutter drive ring for actuating a shutter, and the driven ring is used as a focus adjustment ring that determines the extended position of the imaging ring. In addition to the locking member for locking the focus adjusting ring, the clutch member is also mechanically interlocked with the focus adjusting ring. Therefore, the focus adjustment and the operation of the shutter necessary for photographing are performed in an orderly manner as a mechanical series by one motor for rotating the shutter drive ring, and other electromagnetic drive devices such as magnets are used. It is not necessary to use it.

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

〔Example〕

A first example of an autofocus device using the present invention
In the figure, a sleeve 2 is projectingly provided on the shutter substrate 1. The sleeve 2 is formed with two stages of outer peripheral surfaces 2a and 2b having different outer diameters. The large diameter outer peripheral surface 2a is provided with a shutter drive ring 3 and the thin outer peripheral surface 2b is provided with a focus adjusting ring 5. It is movably attached. The focus adjustment ring 5 is in contact with the front surface 2c of the outer peripheral surface 2a having a large diameter and is always rotated within a constant plane. Further, the thickness of the outer peripheral surface 2 a having a large diameter is larger than the thickness of the shutter drive ring 3, and a gap is formed between the shutter drive ring 3 and the focus adjustment ring 5.

A clutch lever 7 rotatable around a shaft 6 is attached to a part of the shutter drive ring 3 and is biased counterclockwise by a spring 8. A pin 9 is planted in the clutch lever 7. Shutter drive ring 3
Tooth rows 11 and 12 are formed on the outer periphery of the. A gear 16 driven by a stepping motor 13 via gears 14 and 15 meshes with the tooth row portion 11, and a gear 18 integrated with a disc 17 meshes with the other tooth row portion 12. ing.

Pins 19 are planted in the disc 17. The pin 19 swings the interlocking lever 20 in the counterclockwise direction in the process of rotating the disk 17 together with the gear 18 in the clockwise direction. By rotating the interlocking lever 20 in the counterclockwise direction, the shutter drive pin 23 implanted in the interlocking lever 20 penetrates the slot 24 formed in the shutter substrate 1 to operate the shutter blade drive mechanism 25. It has become.

A cam surface 28 whose height gradually increases toward the front surface side is formed on the front surface side of the focus adjustment ring 5 which is rotated in a constant plane with the front end surface 2c of the outer peripheral surface 2a having a large diameter as an opposition.
Further, clutch teeth 29 are formed on the outer periphery of the focus adjustment ring 5, and a projection 30 having a tapered slope 30a connected to the optical axis side is provided. A locking claw 33 of a locking lever 32 pivotally mounted on a support shaft 31 planted in the shutter base plate 1 is engaged with the clutch teeth 29. The clutch teeth 29 and the locking claws 33 form a one-way clutch, and the locking claws 33 prevent the focus adjusting ring 5 from being returned in the clockwise direction by the bias of the spring 35.

A protrusion 7a provided as a striking portion at one end of the clutch lever 7 disengages from the protrusion 30. That is,
When the posture of the clutch lever 7 is in a state in which the lower edge 7b thereof is restricted by the boss 31a in which the support shaft 31 is planted, the projection 7a engages with the projection 30, and the clutch 7 is urged by the biasing force of the spring 8. When rotated clockwise, the protrusion 7a
Is retracted to the inside of the protrusion 30 to release the engagement.

A pin 38 embedded in the lens barrel 36 is pressed against the cam surface 28 of the focus adjustment ring 5. The lens barrel 36 carries a taking lens 39 and is biased rearward by a spring 40. Note that the lens barrel 36 is moved along the optical axis 42 without play by a conventionally known guide mechanism (not shown), and is not rotated around the optical axis 42.

The operation of the above configuration is performed as follows. First, when the shutter release is performed, the controller 50 shown in FIG. 2 operates, and the stepping motor 13 rotates in the forward direction via the motor drive circuit 51. As a result, the gear 14 is rotated in the clockwise direction, and the shutter drive ring 3 is rotated in the counterclockwise direction, which is the initial position shown in FIG. At this initial position, the projection 7a of the clutch lever 7 is in contact with the projection 30 and rotates together with the shutter drive ring 3. Then, the focus adjustment ring 5 is inserted through the engaging portion between the protrusion 7a and the protrusion 30.
Also, the spring 35 is driven counterclockwise to rotate against the spring 35. The clutch lever 7 is urged inward by the spring 34, but the protrusion 7 a causes engagement friction with the protrusion 30,
Also, since the rocking is restricted by the slope 30a connected to the protrusion 30a, the engagement between the protrusion 7a and the protrusion 30 is maintained as it is.

When the shutter drive ring 3 rotates in this way by a predetermined amount, the pin 9 planted in the clutch lever 7 unlocks the locking lever 32, so that the locking lever 32 swings by the spring 34, and the locking claw 33 causes the clutch. Touch the tooth 29. However, since the locking claw 33 and the clutch teeth 29 form a one-way clutch, when the focus adjusting ring 5 rotates counterclockwise following the shutter drive ring 3, the rotation is blocked. Continue without. While the disk 17 is also rotated via the gear 18 during this period, the pin 19 does not come into engagement with the interlocking lever 20, so the shutter blade drive mechanism 25 is not operated.

By rotating the focus adjustment ring 5 counterclockwise in this way, the lens barrel 36 is gradually extended by the cam surface 28. In parallel with this, the distance measuring device 52 (FIG. 2) performs the focus detection operation. When the distance measuring device 52 detects the focus position, it outputs a focus signal to the controller 50. That is, in the time chart shown in FIG. 3, the shutter driving ring 3 gradually rotates in the forward direction from the shutter release timing T _1, and the focus signal is output at the timing T ₂ . Of course, the timing T
₂ differs depending on the timing at which the focusing signal is obtained from the distance measuring device 52.

The controller 50 slightly reverses the stepping motor 13 until timing T ₃ by inputting the focus signal.
As a result, the shutter drive ring 3 rotates in the opposite direction, so that the projection 7a of the clutch lever 7 is attached to the focus adjustment ring 5.
Is momentarily separated from the protrusion 30 of. At this time, the focus adjustment ring 5 tries to return by the bias of the spring 35, but remains in that position by the engagement of the locking claw 33 and the clutch tooth 29.

When the projection 7a of the clutch lever 7 is separated from the projection 30 by rotating the shutter drive ring 3 in the clockwise direction, the clutch lever 7 moves the shaft 6 by the urging force of the spring 8 as shown in FIG. Further, it swings counterclockwise around the center, enters the inside of the protrusion 30, and is stopped by a stopper (not shown). Konrora 50, the timing T ₃ later, the stepping motor 13 is rotated forward again through the motor drive circuit 51. However, timing T ₃
When the shutter drive ring 3 is subsequently rotated, the clutch lever 7 is moved to the disengaged position with respect to the focus adjustment ring 5, so that the protrusion 7a moves inside the protrusion 30 as shown in FIG. Then, the focus adjustment ring 5 remains stopped at the position where the photographing lens is extended to the in-focus position.

In the process in which the shutter drive ring 3 rotates, the gear 16
The disk 17 rotates via the. Then, the timing T ₄
When the time point is reached, the pin 19 implanted in the disc 17 rotates the interlocking lever 20. When the shutter drive pin 23 moves counterclockwise in the slot 24 by the rotation of the interlocking lever 20, the known shutter blade drive mechanism 2
The shutter blade 48 is opened via 5, and exposure is started. The controller 50 is connected to an exposure control unit 54 that determines exposure from brightness information obtained from a known photometry unit 53 that measures subject brightness and information such as film sensitivity, and shutter blades are output by signals obtained from the exposure control unit 54. Timing T ₅ for closing 48 is determined.

When the timing T ₅ determined by the exposure control unit 54 is reached, the stepping motor 13 is rotated in the reverse direction. This causes the shutter drive ring 3 to rotate in the clockwise direction, so that the shutter drive pin 23 moves in the clockwise direction.
When the shutter drive pin 23 is rotated clockwise, the shutter drive mechanism 25 operates the shutter blade 48 in the closing direction. Accordingly, the exposure by the shutter blade 48 is performed between the timing T ₄ through T ₆ as shown in Figure 3. The timing T _5, that is, the timing at which the stepping motor 13 is rotated in the reverse direction and the shutter blade 48 is closed is set at the exposure controller 54 and the controller 50.
Automatically adjusted by. Then, the timing T ₅ is controlled so as to be advanced as the subject brightness increases.

When the shutter drive ring 3 is rotated in the reverse direction after the shutter blades 48 are closed at timing T ₆ due to the reverse rotation of the shutter drive ring 3, the lower edge 7 of the clutch lever 7 is rotated.
b contacts the boss 31a of the support shaft 31, and the clutch lever 7
Is swung clockwise against the spring 8. As a result, the projection 7 a of the clutch lever 7 is formed on the slope 3 that is continuous with the projection 30.
It will be moved within the trajectory of 0a. Further, at this time, the pin 9 implanted in the clutch lever 7 presses the upper edge 32a of the locking lever 32 and swings it clockwise,
The locking claw 33 is disengaged from the clutch teeth 29. As a result, it solved the engagement of the focusing ring 5, the focusing ring 5 from the time of the timing T ₇ is rotated back to the clockwise direction by the bias of spring 35.

When the focus adjustment ring 5 is returned in this manner, the slope 30a moves to the projection 7a of the clutch lever 7 as shown in FIG.
After pushing up, the protrusion 30 comes into contact with the protrusion 7a. Thereby, each of the clutch lever 7 and the focus adjustment ring 5 is always returned to a constant initial position when one photographing sequence is completed. Further, in this manner, in conjunction with the return of the focus adjustment ring 5 to the initial position, the lens barrel 36 is also returned to the most retracted position, and each mechanism is returned to the initial state.

In this way, when the locking lever 32 that holds the focus adjustment ring 5 at the predetermined stop position is unlocked in conjunction with the operation of the clutch lever 7, without using an electromagnetic device such as a magnet. The focus adjustment ring 5 can be returned to the initial position at the optimum timing in the mechanical sequence operation. Moreover, since the slope 30a formed on the focus adjustment ring 5 is used to accurately restore the clutch lever 7 to the initial position, the projection 30 connected to the slope 30a and the projection 7a of the clutch lever 7 are relatively opposed to each other. The mechanical contact position is always kept constant in the initial state, which is effective for maintaining accurate mechanical interlocking.

〔The invention's effect〕

As described above, according to the clutch interlocking mechanism of the present invention, the drive ring is provided with the locking member for locking the driven ring, which is driven by the drive ring driven by the motor, at a predetermined position. The clutch member is engaged and disengaged in association with mechanical displacement of a clutch member that is actuated to transmit drive between the ring and the driven ring. Therefore,
It is possible to accurately operate the locking member at a constant timing within one sequence of mechanical interlocking by rotation of the drive ring and the driven ring without using an electromagnetic device such as a magnet or a plunger as in the past. It is very effective in saving cost and space.

[Brief description of drawings]

FIG. 1 is an exploded view of essential parts showing an embodiment of the present invention. FIG. 2 is a block diagram showing an example of a circuit configuration used in the present invention. FIG. 3 is a time chart showing the operation of the embodiment shown in FIG. 4 to 7 are front views of the essential parts showing the process of operation of the embodiment shown in FIG. 1 ... Shutter substrate 3 ... Shutter drive ring 5 ... Focus adjustment ring 7 ... Clutch lever 13 ... Stepping motor 23 ... Shutter drive pin 25 ... Shutter blade drive mechanism 29 ... Clutch teeth 30 ..Projection 31..support shaft 32..locking lever 33..locking claw 36..lens barrel

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03B 13/36

Claims (1)

[Claims] 1. A drive ring rotated by a motor,
A clutch member that is swingably provided on the drive ring, an engagement portion that engages with the clutch member, and a driven ring that is rotated by being driven by the drive ring via the clutch member. Engages with the tooth row formed on the driven ring to allow the driven ring to rotate in the driven direction and prevent the driven ring from rotating in the opposite direction, releasing the engagement between the clutch member and the engaging portion. And a one-way locking claw for locking the driven ring at a predetermined position after being driven,
Clutch return means for returning the clutch member to the engagement position in conjunction with the return of the drive ring to the initial position by the reverse rotation of the motor, and the clutch member are provided integrally with the clutch member, and the clutch member is set to the initial position. A clutch interlocking mechanism comprising: a clutch pawl releasing member that moves the one-way locking pawl in a direction to disengage from the tooth row when returning.