JPS6319632A - Clutch interlocking mechanism - Google Patents

Abstract

PURPOSE:To enable accurate operation between a locking position and an unlocking position by providing a clutch member to a driving ring which is driven by a motor and driving the driven ring by the driving ring when a clutch member is at the locking position. CONSTITUTION:When shutter releasing operation is performed, a controller 50 operates to rotate a stepping motor 13 forward through a motor driving circuit 51 and a gear 14 rotates clockwise, so the shutter driving ring 3 rotates counterclockwise from its initial position. At the initial position, the projection 7a of a clutch lever 7 contacts a projection 30 and rotates along with the shutter driving ring 3. A slanting surface 30a formed on a focus adjusting ring 5 is utilized to return the clutch lever 7 accurately to the initial position, so the relative contacting position between the projection connecting with the slanting surface 30a and the projection 7a of the clutch lever 7 is held constant in the initial state, so mechanical interlocking operation is accurately maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a clutch interlocking mechanism that engages and disengages through mechanical interlocking.

[Conventional technology]

2. Description of the Related Art In recent compact cameras, stepping motors, servo motors, DC motors, and the like have been used as drive sources for shutter operating mechanisms and lens extension mechanisms for extending and operating photographic lenses.

For example, in a system in which such a lens extending mechanism is used in conjunction with a distance measuring device, a stepping motor rotates a focusing ring, and in conjunction with this, the photographing Y lens is extended. Then, when a focus signal is detected from the distance measuring device, the focus adjustment ring is stopped, thereby stopping the photographing lens at the focus position.

By the way, when stopping the focus adjustment ring mentioned above, simply stopping the driving of the stamping motor itself is difficult to achieve accuracy due to effects such as operation delay due to inertia. A locking member is engaged with the focusing ring to mechanically lock the focusing ring, and the clutch mechanism is released to disconnect the focusing ring from the focusing motor. and,
In order to obtain such an effect, conventionally, the locking member is operated by a magnet, a plunger, or the like.

[Problem that the invention seeks to solve]

However, like the focus adjustment ring mentioned above, a locking member for stopping a driven ring driven by a motor via a clutch mechanism at a predetermined position is actuated using an electromagnetic device such as a magnet or a plunger. If we do this, we will have to install electromagnetic devices in parallel near the locking member, which not only increases the cost burden (it also becomes disadvantageous in terms of space and prevents the camera from becoming more compact). It's possible.

The present invention has been made in view of such prior art,
It is an object of the present invention to provide a clutch interlocking mechanism in which a locking member for locking a driven ring at a predetermined position is mechanically operated accurately between a locking position and a locking release position.

[Means for solving problems]

In order to achieve the above object, the present invention provides a clutch member on a drive ring driven by a motor, and causes a driven ring to follow the drive ring when the clutch member is in an engaged position. Furthermore, in order to hold the driven ring in a predetermined position, the locking member is actuated at the same time as the clutch member is disengaged, thereby locking the rotation of the driven ring. The locking/disengaging operation of the locking member is controlled in conjunction with the mechanical displacement of the clutch member.

According to a preferred embodiment of the present invention, the driving ring is used as a shutter driving ring for shutter operation, and the driven ring is used as a focusing ring for determining the extending position of the photographic lens. In addition to the locking member for locking the focus adjustment ring, the clutch member is also mechanically interlocked to engage and disengage the focus adjustment ring. Therefore, the focus adjustment and shutter operation necessary for photographing are now performed in an orderly mechanical sequence by a single motor for rotating the shutter drive ring, and other electromagnetic drive devices such as magnets are used. There is no need to use it.

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

〔Example〕

A first example showing an example of an autofocus device using the present invention
In the figure, a sleeve 2 is provided protruding from a shutter substrate 1. This sleeve 2 is formed with two stages of outer circumferential surfaces 2a and 2b having different outer diameters, a shutter drive ring 3 is provided on the outer circumferential surface 2a with a large diameter, and a focus adjustment ring 5 is provided on the outer circumferential surface 2b with a small diameter. It is attached so that it can move freely. The focal point joint ring 5 is in contact with the front surface 2c of the large-diameter outer circumferential surface 2a, and is always rotated within a fixed plane. Further, the thickness of the large-diameter outer peripheral surface 2a is greater than the thickness of the shutter drive ring 3, so that a gap is formed between the shutter drive ring 3 and the focus adjustment ring 5.

A latch lever 7 is pivotally attached to a portion of the shutter drive ring 3 and is rotatable about a shaft 6, and is biased counterclockwise by a spring 8. Further, a pin 9 is implanted in the thalassotile lever 7. Shutter drive ring 3
A tooth row portion 11.12 is formed on the outer periphery of the tooth. A gear 16 driven by a stamping moke 13 is engaged with the gear 14 and 15, and a gear 18 integrated with a disc 17 is engaged with the other gear 12. are doing.

A pin 19 is implanted in the disc 17.

This pin 19 swings the interlocking lever 20 counterclockwise while the circle Fi 17 is rotated clockwise together with the gear 18. When the interlocking lever 20 is rotated counterclockwise, the shutter drive pin 23 embedded in the interlocking lever 20 passes through the slot 24 formed in the shutter board l and operates the shutter blade drive mechanism 25. It has become.

A cam surface 28 whose height gradually increases toward the front side is formed on the front side of the focusing ring 5, which is rotated within a constant plane with the front end surface 2c of the large-diameter outer peripheral surface 2a as an opposite end. .

Clutch teeth 29 are formed on the outer periphery of the focusing ring 5, and a protrusion 30 with a tapered slope 30a connected to the optical axis side is provided. A locking pawl 33 of a locking lever 32 that is pivotally attached to a support shaft 31 implanted in the shutter base plate 1 is engaged with the clutch teeth 29 . The clutch teeth 29 and the locking pawl 33 constitute a one-way clutch, and the locking pawl 33 prevents the focusing ring 5 from returning clockwise under the bias of the spring 35.

A projection 7a provided as a rising portion at one end of the clutch lever 7 is engaged with the projection 30. That is,
When the posture of the clutch lever 7 is such that its lower edge 7b is regulated by the boss 31a on which the support shaft 31 is installed, the protrusion 7a engages with the protrusion 30, and the clutch 7 is moved by the bias of the spring 8. When rotated counterclockwise, the protrusion 7a
is retracted inside the protrusion 30 and the engagement is released.

A pin 38 embedded in a lens barrel 36 is pressed against the cam surface 28 of the focusing ring 5. The lens barrel 36 carries a photographic lens 39 and is biased rearward by a spring 40. The lens barrel 36 is moved along the optical axis 42 without play by a conventionally well-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 shirt release is performed, the controller 50 shown in FIG. 2 is activated, and the motor drive circuit 5
1, the stepping motor 13 rotates normally. As a result, the gear 14 is rotated clockwise, so that the shutter drive ring 3 is rotated counterclockwise from the initial position shown in FIG. 4.

In this initial position, the protrusion 7a of the clutch lever 7
is in contact with the protrusion 30 and rotates together with the shutter drive ring 3 as it is. The focus adjustment ring 5 also engages the spring 3 through the engagement portion between the protrusion 7a and the protrusion 30.
5 and is driven to rotate counterclockwise. Note that the clutch lever 7 is biased inward by the spring 34, and the protrusion 7a has an engagement friction with the protrusion 30 and the protrusion 3
Since the rocking movement is restricted by the slope 30a continuous to 0a, the engagement between the protrusion 7a and the protrusion 30 is maintained as it is.

When the shutter drive ring 3 rotates a predetermined amount in this way, the pin 9 embedded in the clutch lever 7 unlocks the locking lever 32, so the locking lever 32 swings by the spring 34, and the locking pawl 33 is rotated. In contact with the clutch teeth 29. However, since the locking pawl 33 and the clutch teeth 29 constitute a one-way clutch, when the focus adjustment ring 5 rotates counterclockwise following the shutter drive ring 3, that rotation is prevented. It continues without incident. Note that during this time, the disc 17 is also rotated via the gear 18, but the pin 19 does not engage with the interlocking lever 20, so the shutter blade drive mechanism 25 is not operated.

By thus rotating the focusing ring 5 counterclockwise, the lens barrel 36 is gradually extended by the cam surface 28. In parallel with this, the distance measuring device 52 (FIG. 2) performs a focusing operation. Then, when the distance measuring device 52 detects the focused position, it outputs a focusing signal to the controller 50.

That is, in the time chart shown in FIG. 3, the shutter drive ring 3 gradually rotates forward from timing T when the shutter release is performed, and a focus signal is output at timing T2. Of course, the timing T2
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 T3 upon input of the focus signal.

As a result, the shutter drive ring 3 rotates in the opposite direction, so that the protrusion 7a of the clutch lever 7
is momentarily separated from the protrusion 30. At this time, the focus adjustment ring 5 tries to return due to the bias of the spring 35, but remains held in that position by the engagement between the locking pawl 33 and the clutch teeth 29.

When the protrusion 7a of the clutch lever 7 is separated from the protrusion 30 by rotating the shutter drive ring 3 clockwise, the clutch lever 7 is pivoted by the bias of the spring 8, as shown in FIG. 6 further swings counterclockwise and enters the inside of the protrusion 30 (not shown) 7
stopped by Pa. After timing T3, the controller 50 causes the stepping motor 13 to rotate normally again via the motor drive circuit 51. However, timing T
When the shaft drive ring 3 rotates after 3, the clutch lever 7 moves to the disengaged position with respect to the focus adjustment ring 5, so that the projection 7a is rotated as shown in FIG.
passes inside the protrusion 30, and the focusing ring 5 remains stopped at the position where the photographing Y lens is extended to the in-focus position.

In the process of rotating the shutter drive ring 3, the gear 16
The disc 17 rotates via the. And timing T4
When this point is reached, the pin 19 implanted in the disc 17 rotates the interlocking lever 20.

By rotating the interlocking lever 20, the shutter drive pin 23
As the shutter blade 48 moves counterclockwise within the slot 24, the shutter blade 48 is moved through the well-known shutter blade drive mechanism 25.
is opened and exposure begins.

The controller 50 is connected to an exposure control section 54 that determines exposure based on brightness information obtained from a well-known photometry section 53 that measures subject brightness and information such as film sensitivity. 4
The timing T5 at which the 8 is to be closed is determined.

When the timing T5 determined by the exposure control section 54 is reached, the stepping motor 13 is reversed. As a result, the shutter drive ring 3 rotates clockwise, and the shutter drive pin 23 moves clockwise.

When the shutter drive pin 23 is rotated clockwise, the shutter drive mechanism 25 operates the shutter blade 48 in the closing direction. Therefore, exposure by the shutter blade 48 is performed between timings T4 and T6 as shown in FIG. Note that the timing T5, that is, the timing at which the stepping motor 13 is reversed and the shutter blade 48 is closed, is automatically adjusted by the exposure control section 54 and the controller 50. Then, as the subject brightness increases, the timing T5 is controlled to be advanced.

After the shutter blade 48 is closed at timing T6 due to the reverse rotation of the shutter drive ring 3, when the shutter drive ring 3 is further reversed, the lower edge 7 of the clutch lever 7
b comes into contact with the boss 31a of the support shaft 31, and the clutch lever 7
is swung clockwise against the spring 8. As a result, the protrusion 7a of the clutch lever 7 is connected to the slope 3 connected to the protrusion 30.
It will now be moved within the trajectory of 0a. Also, at this time, the pin 9 installed in the clutch lever 7 presses the upper edge 32a of the locking lever 32, causing it to swing clockwise.
The locking pawl 33 disengages from the clutch teeth 29. As a result, the focus adjustment ring 5 is released from the lock, and the focus adjustment ring 5 returns to rotation in the clockwise direction by the bias of the spring 35 from the timing T7.

When the focus adjustment ring 5 returns in this way, the slope 30a is aligned with the protrusion 7a of the thalassotile 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 fixed initial position when one sequence of photographing is completed. Further, in conjunction with the return of the focus adjustment ring 5 to its initial position, the lens barrel 36 is also returned to its most retracted position, and each mechanism is returned to its initial state.

In this way, if the lock lever 32 that holds the focus adjustment ring 5 at a predetermined stop position is released from the lock in conjunction with the operation of the clutch lever 7, an electromagnetic device such as a magnet can be used. Therefore, the focusing ring 5 can be returned to the initial position at the optimum timing during the mechanical sequence operation. Moreover, since the slope 30a formed on the focusing ring 5 is used to accurately restore the clutch lever 7 to its initial position, the protrusion 30 connected to the slope 30a and the clutch lever
The relative contact position of 7 with the protrusion 7a is always kept constant in the initial state, which is effective in accurately maintaining mechanical interlocking.

〔Effect of the invention〕

As explained above, according to the clutch interlocking mechanism of the present invention, the driving ring is provided with a locking member for locking the driven ring that follows the driving ring driven by the motor in a predetermined position. The engagement and disengagement operations are performed in conjunction with mechanical displacement of a clutch member that is operated for drive transmission between the ring and the driven ring. therefore,
The locking member can be actuated accurately at a fixed timing within one sequence of mechanical interlocking by the rotation of the driving ring and the driven ring, without using electromagnetic devices such as magnets and plungers as in the past. This is very effective in saving cost and space.

[Brief explanation of the drawing]

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. 1. 4 to 7 are front views of main parts showing the process of operation of the embodiment shown in FIG. 1. 1... Shutter board 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 tooth 30... Protrusion 31... Support shaft 32... Locking lever 33... Locking claw 36... Lens barrel.

Claims (2)

[Claims] (1) A drive ring rotated by a motor, a clutch member swingably provided on this drive ring, and an engagement portion with which this clutch member engages are provided, and the drive ring is provided with a drive ring rotated by a motor. a driven ring that rotates following the ring; a locking member that locks the driven ring at a predetermined position after being driven when the engagement between the clutch member and the engaging portion is released; 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 reversing the motor;
A clutch interlocking mechanism comprising: a lock release member that releases the lock of the lock member in conjunction with the return of the clutch member to the engagement position. (2) The locking member contacts clutch teeth formed on the driven ring when the driving ring is rotated by a predetermined amount by the motor, and allows the rotation when the driven ring is driven by the driving ring, and the clutch member 2. The clutch interlocking mechanism according to claim 1, wherein the clutch interlocking mechanism is a clutch tooth that prevents the driven ring from rotating in the return direction when the engagement of the driven ring is released.