JPH0513292B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvement of an aperture drive control device used in single-lens reflex cameras and the like.

[Conventional technology]

In conventional aperture drive control devices, the aperture is kept fully open during focusing operations, the aperture ring rotates in conjunction with the shutter release, and when the aperture has been stopped down to a predetermined aperture, the electromagnet is activated and held by the electromagnet. The locking pawl is released and locked to the ratchet of the aperture ring, the rotation of the aperture ring is stopped, and a predetermined aperture is maintained during opening and closing of the shutter. Furthermore, when returning the aperture to full opening, it is common to simply rotate the aperture ring in the opposite direction.

[Problem that the invention seeks to solve]

In the conventional aperture drive control device as described above, when the aperture is returned to full opening, the ratchet of the aperture ring rotates while contacting the locking pawl, so the ratchet and the locking pawl are easily worn out, resulting in poor durability. There was also an unpleasant operating sound.

[Means for solving problems]

The present invention provides an aperture ring that sets an aperture diameter based on the amount of rotation from an initial position, and an aperture ring that is rotated from the initial position in a first direction to set a predetermined aperture aperture diameter, and then rotated in a second direction. a planetary gear mechanism comprising a sun gear that rotates following the aperture ring and a planetary gear that rotates around the sun gear; A ratchet that rotates integrally with the planetary gear, a locking pawl that locks the ratchet, and an electromagnet that attracts and holds the locking pawl are provided, and the aperture ring is rotated in the first direction. When a predetermined diaphragm opening diameter is reached, the electromagnet releases the locking pawl, locks the pawl rotated by the planetary gear mechanism, and moves the aperture ring to the second aperture ring. When rotating in the direction, the planetary gear mechanism rotates the ratchet wheel while retracting it, and then the aperture ring causes the electromagnet to restore the locking pawl to a position where it can be held by suction.

〔Example〕

FIG. 1 is a front view of the main parts of the aperture drive control device of the present invention, showing a front field charge state in which a photographing operation is performed;
FIG. 2 is a perspective view of the engagement portion where the aperture setting mechanism stops the movement of the aperture interlocking mechanism; FIG. 3 is a front view of the main parts of the aperture drive control device of the present invention showing a state in which the aperture setting has been performed; and FIG. FIG. 5 is a perspective view of an engaged portion of the aperture interlocking mechanism and the aperture restoring mechanism, showing a state in which movement for aperture setting is performed and a state in which restoration is performed.

In the figure, reference numeral 1 denotes an aperture lever for driving an aperture provided on the photographing lens side, and is biased clockwise so as to follow the aperture ring 2. The aperture ring 2 is also biased clockwise, and when it is released from the lock by the charge locking pawl 3, it rotates in the direction of the arrow from the position shown in FIG. A movement for setting the aperture is thereby carried out. The reason why the aperture lever 1 and the aperture ring 2 are not integrated is that the aperture can be manually preset. The aperture ring 2 is provided with a gear portion 2a, and a swing pinion 7 meshes with the gear portion 2a via a carrier gear 4 and speed-increasing carrier gears 5, 6.
A ratchet wheel 8 is integrally provided on the swing pinion 7. The swing pinion 7 and the ratchet wheel 8 are rotatable about the axes of the speed-increasing gears 5 and 6 from the position shown in the first figure, where they are stopped by stoppers (not shown), to the position shown in the third figure. It is provided on the swing lever 9. Further, a restoring gear 10 meshes with the carrier gear 4, and a restoring missing gear 11 is rotatably fitted onto the shaft of the restoring gear 10. This restoring missing gear 11 is biased clockwise by a spring 11a, and its rotation due to the bias is stopped at the fourth illustrated position by a stopper (not shown). Furthermore, although not shown, the speed increasing carrier gear 5 is provided with rotation angle detection means for providing aperture information. The rotation angle detection means includes a disc having light transmitting parts at equal pitches on the circumference, a light emitting part and a light receiving part, and detects light passing through the light transmitting part of the disc and generates a pulse. It consists of a combination with a photocoupler, and a combination of a disk having a conductive part instead of a light transmitting part, and a rubbing element that generates a pulse signal by sliding on the circumference on which the conductive part is arranged. thing,
Alternatively, any arbitrary type, such as a variable capacitor or a variable resistance type, can be used.

The above series of mechanisms is an interlocking mechanism in which the aperture is interlocked.

12 is rotated clockwise by the bias of the spring 13, and the engaging claw portion 12a engages with the ratchet wheel 8 of the aperture interlocking mechanism, thereby stopping the movement for setting the aperture of the aperture interlocking mechanism. The aperture setting member 14 is a holding member whose iron piece 14a is attracted to an electromagnet 15, and whose holding arm 14b prevents the aperture setting member 12 from rotating clockwise. The bent portion 12b is the holding member 14
This is done by hooking onto the holding arm 14b of. 1
A spring 6 biases the holding member 14 to rotate counterclockwise, and its bias is weaker than the bias applied by the spring 13 to rotate the aperture setting member 12 clockwise.

The series of mechanisms described above is an aperture setting mechanism.

Reference numeral 17 indicates a charge defect which is rotated clockwise by one rotation by a drive means such as a motor (not shown), and when rotated, meshes with the restoration defect gear 11 of the aperture interlocking mechanism to provide a restoring movement to the aperture interlocking mechanism. Charge missing gear 1 from a drive means such as a motor
The series of mechanisms up to 7 is the aperture restoring mechanism.

In the aperture drive control device of the present invention, further:
An engagement/disengagement mechanism is provided between the aperture interlocking mechanism and the aperture setting mechanism for restoring the aperture setting mechanism by the restoring movement of the aperture interlocking mechanism. The engagement and disengagement mechanism includes a restoring operation pin 2b installed in the aperture ring 2 of the aperture interlocking mechanism, a restoring driven pin 12c installed in the aperture setting member 12 of the aperture setting mechanism, and a restoring operation pin 2b of the aperture ring 2. It consists of a restoring lever 18 having a driven arm 18a that receives an action and an operating arm 18b that gives a restoring action to the restoring driven bin 12c of the aperture setting member 12.

The operation of the aperture drive control device of the present invention having the above-mentioned configuration will be explained next.

In the charged state shown in the first figure, the restoring operation pin 2b installed in the aperture ring 2
8 is maintained in a clockwise rotated position, whereby the restoring lever 18 holds the aperture setting member 12 in the illustrated position against the bias of the spring 13.

When a release operation is performed in this charged state, a release switch (not shown) is turned on, and the electromagnet 15 is activated to attract the iron piece 14a of the holding member 14, and the electromagnet (not shown) is activated to engage the charge locking claw. 3 in a counterclockwise direction against the bias of the spring 3a to release it from the aperture ring 2. Therefore, the aperture ring 2 is biased to rotate clockwise, and the aperture lever 1 is also driven to perform a movement for setting the aperture. When the aperture ring 2 rotates clockwise, the restoring operation pin 2b releases the pushing of the restoring lever 18 against the driven arm 18a. As a result, the aperture setting member 12 attempts to rotate clockwise due to the bias of the spring 13, but this clockwise rotation is blocked by the holding member 14, which has the iron piece 14a attracted to the electromagnet 15. . Further, the rotation of the aperture ring 2 rotates the carrier gear 4, the speed-increasing carrier gears 5 and 6, the swing pinion 7, the ratchet wheel 8, and the restoring gear 10, respectively, in the direction of the arrow in FIG. And the speed increasing carrier gear 5,
The rotation 6 rotates the swing lever 9 in the direction of the arrow and brings it to the position shown in the third figure. The amount of rotation of the speed-increasing carrier gear 5 is detected moment by moment by the rotation angle detection means described above, and when the amount of rotation reaches a value that provides a desired aperture value, the electromagnet 15
Release the adsorption of a. At that time, the holding member 14 loses its force to stop the aperture setting member 12, and the aperture setting member 12 is biased by the spring 13 to
At the same time, the locking claw portion 12 is rotated clockwise to engage the ratchet wheel 8, the aperture interlocking mechanism is stopped, and the aperture is set to a desired aperture value. The rotation of the restoring gear 10 until this aperture is set is such that the driven pin 10a installed in the restoring gear 10 rotates in the direction of the arrow from the position shown in the fourth figure to drive the restoring gear 11 installed in the missing restoring gear 11. This is the range up to just before it hits the pin 11b. Therefore, the restoring gear 10 does not interfere with the movement for setting the aperture.

Once the aperture is set as described above, a shutter operation is then performed and exposure is performed. For example, the central processing unit CPU in the camera releases the attraction by the electromagnet 15 based on the information from the rotation angle detection means of the speed-increasing gear 5, and then causes the leading shutter curtain and then the trailing shutter curtain to run. It is carried out with

When the exposure is completed, restoration is carried out by rotating the charge defective gear 17 once in the direction shown by the arrow in FIG. The rotation of this charge defective gear 17 is controlled by, for example, the CPU when driven by a motor.
This is performed by driving a charge motor (not shown) for a predetermined time after a predetermined period of time after the shutter trailing curtain travel signal is output and the travel of the trailing curtain is completely completed.

When the charge missing gear 17 rotates in the direction of the arrow, it comes to mesh with the restoring missing gear 11.
Thereby, the restoration missing gear 11 is fixed to the spring 11a.
It rotates in the direction of the arrow in FIG. 5 against the urging force. When the missing restoring gear 11 rotates in the direction of the arrow, the driving pin 11b of the restoring gear 11 rotates in the driven pin 10 of the restoring gear 10.
a to rotate the restoring gear 10 counterclockwise, and accordingly, the series of aperture interlocking mechanisms are restored and rotated in the direction opposite to the direction of the arrow shown in FIG. At this time, the aperture setting member 12 of the aperture setting mechanism is engaged with the ratchet wheel 8 of the aperture interlocking mechanism. is carried out in the relationship shown in the second diagram, the ratchet wheel 8 can rotate clockwise without any hindrance, and as the speed increasing gears 5 and 6 rotate counterclockwise, the swing lever 9 also rotates counterclockwise. Therefore, the aperture setting member 12 is immediately disengaged, and the ratchet wheel 8 rotates easily in the clockwise direction. That is, the rotational displacement of the aperture setting member 12 in the clockwise direction is limited to a certain range by a stopper (not shown).

As described above, the restoring rotation of the aperture interlocking mechanism is carried out without any trouble, and the aperture ring 2 rotates counterclockwise together with the aperture lever 1, returning from the position shown in Fig. 3 to the position shown in Fig. 1. , the restoring actuating pin 2b pushes the restoring lever 18 and rotates it clockwise, so that the restoring lever 18 resists the bias of the spring 13 and restores the aperture setting member 12 to the position shown in FIG. At that stage, the charge locking pawl 3 is connected to the spring 3a.
is engaged with the notch of the aperture ring 2 due to the bias of
1, the aperture interlocking mechanism and the aperture setting mechanism are restored to approximately the state shown in FIG. Missing gear 11 for restoration
When the charge defective gear 17 completes one rotation and its defective part comes to face the restoring defective gear 11, it returns to the position shown in FIG. 4 or 5 by the bias of the spring 11a. As a result, the push of the driving pin 11b against the driven pin 10a of the restoring gear 10 is released, and the aperture interlocking mechanism and the aperture setting mechanism are completely restored to the state shown in FIG. Since the charge deficient gear 17 stops after one rotation, the entire device completely returns to the initial charge state.

〔Effect of the invention〕

According to the present invention, when returning the aperture ring to its initial position, the planetary gear mechanism driven by the aperture ring rotates the pawl wheel away from the locking pawl, so there is no wear on the pawl wheel and the pawl. Excellent effects such as good durability and no unpleasant operating noise can be obtained.

The present invention is not limited to the illustrated example; for example, the setting member 12 and the holding member 14 may be integrated. Note that the restoration missing gear 11 does not necessarily have to be a missing gear. Further, for example, when the aperture restoration mechanism is capable of rotating with little resistance to the rotation of the aperture interlocking mechanism in the aperture setting direction, when the missing restoration gear 11 of the aperture interlocking mechanism is in a charged state, the defective part will restore the aperture. The charge gear is a missing gear if it is made to face the charge gear of the mechanism, and meshing between the restoration missing gear 11 and the charge gear is performed by performing an aperture setting movement. This is no longer necessary, and the rotation of the charge gear for restoration does not have to be one rotation.

Further, in the present invention, the restoration charge is not limited to being performed by a motor, but may be performed manually.

[Brief explanation of the drawing]

FIG. 1 is a front view of the main parts of the aperture drive control device of the present invention showing a charge state before a photographing operation is performed;
FIG. 2 is a perspective view of an engaging portion where the aperture setting mechanism stops the movement of the aperture interlocking mechanism, and FIG. FIGS. 4 and 5 are perspective views of the engaged portion of the diaphragm interlocking mechanism and the diaphragm restoring mechanism, showing a state in which movement for setting the diaphragm is performed and a state in which restoration is performed. 1... Aperture lever, 2... Aperture ring, 3...
Charge locking pawl, 4...Carrier gear, 5, 6...
...speed-increasing carrier gear, 7...swing pinion,
8... Pawl, 9... Swing lever, 10... Restoration gear, 11... Missing restoration gear, 12... Aperture setting member, 13... Spring, 14... Holding member,
15... Electromagnet, 16... Spring, 17... Charge missing gear, 18... Restoration lever.

Claims (1)

[Claims] 1. An aperture ring that sets an aperture aperture diameter based on the amount of rotation from an initial position, the aperture ring being rotated from the initial position in a first direction to set a predetermined aperture aperture diameter, and then rotated in a second direction to set the aperture aperture diameter. A camera aperture drive control device comprising a transmission means for returning the aperture ring to an initial position, the planetary gear mechanism comprising a sun gear that rotates following the aperture ring and a planetary gear that rotates around the sun gear; A ratchet that rotates integrally with the gear, a locking pawl that locks the ratchet, and an electromagnet that attracts and holds the locking pawl are provided, and the aperture ring is rotated in the first direction to achieve a predetermined position. When the aperture aperture diameter is reached, the electromagnet releases the locking pawl, locks the ratchet wheel rotated by the planetary gear mechanism with the locking pawl, and moves the aperture ring in the second direction. The aperture drive for a camera is characterized in that when the pawl is rotated by the planetary gear mechanism, the pawl is retracted while being rotated, and then the aperture ring restores the locking pawl to a position where the electromagnet can attract and hold the pawl. Control device.