JPH11282043A - Diaphragm controller of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a bound caused on a step-up gear train side for increasing action amount at the time of charging a diaphragm system in advance by restricting the action of a diaphragm interlocking means as soon as the diaphragm interlocking means is restored to an initial state. SOLUTION: Since the engagement of a diaphragm stopping lever 29 with a ratchet wheel 23 is released before starting diaphragm opening action, the ratchet wheel 23, a gear 22 and a secuta gear 20 perform restoring action by the counterclockwise rotational force of a spring 17 with the counterclockwise rotation of a diaphragm interlocking lever 15 so that it may follow the lever 15. At a final stage for restoring the gear train, that is, just before a pin 20a on the gear 20 collides with the arm part 15f of the lever 15 at an abutting part, a bound preventing switch SW4 is turned on. Energizing a solenoid MG2 is cut off according to the on-signal of the SW4 again, and the lever 29 is rotated counterclockwise by the counterclockwise rotational force of a spring 30, and the engaging part 29c of the lever 29 is engaged with the circumference part of the ratchet wheel 23, so that the action (rotation) of the ratchet wheel 23 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture control device used for a camera or the like.

[0002]

2. Description of the Related Art Conventionally, with respect to an aperture control device used for a camera or the like, the operation linked to the aperture of a lens has been expanded,
The technology of reading and controlling it by detecting means such as a photocoupler is widely known. To explain the conventional device in detail, an interlocking member interlocking with the lens-side aperture is provided inside the camera, the operation of the interlocking member is expanded via a speed increasing gear train, and the expanded operation amount is photocoupler. It is configured to obtain a desired aperture value by detecting the aperture operation detection mechanism such as to drive a magnet that stops the gear train when a predetermined aperture value is reached, and stopping the gear train and the associated aperture. I have.

After the end of the photographing operation, these diaphragm systems (a diaphragm interlocking member system composed of a plurality of members including a diaphragm and a speed increasing gear train) are charged by a motor to return to a state before photographing. .

[0004]

Since the above-mentioned apparatus is provided with a speed increasing gear train for the purpose of expanding the operation amount, the apparatus necessarily has a large inertia when viewed from the interlocking member system of the aperture. It becomes a mechanism. Therefore, if the throttle system is charged while the speed increasing gear train is engaged in the throttle interlocking member system, the load on the motor increases, which is disadvantageous in terms of current consumption and motor durability. In addition, the strength of the mechanical parts such as gears and levers must be improved, which is disadvantageous in terms of cost and internal space.

Therefore, in general, when charging the diaphragm system as in the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 5-297435 filed by the present applicant, inertia is established in the diaphragm interlocking member system. The large speed increasing gear train and the throttle interlocking member other than the gear train are separated. Then, after charging only the throttle interlocking member other than the gear train, a structure is adopted in which the speed increasing gear train is returned relatively slowly by a spring or the like.

However, when such a structure is adopted, when the aperture returns to the open side after the photographing is completed, a part of the gear train is connected to one end of the aperture interlocking member other than the gear train (a function of restricting the aperture open side). When the vehicle collides with a part of the interlocking member, the bounce generated on the side of the gear train due to repulsion at the time of collision between the two (a throttle interlocking member other than the gear train is engaged by a locking member so that its operation is restricted). (There is no bouncing on the interlocking member side because it is stopped), but it does not readily converge. If the bounce does not converge, it is not possible to shift to the next photographing operation, so that the frame speed (the number of frames that can be photographed per unit time) cannot be increased.

In order to solve this problem, it is conceivable to provide a braking member for applying a braking force to the speed increasing gear train as disclosed in Japanese Patent Application Laid-Open No. 9-133953, which has already been filed by the present applicant. The number of parts increases, which makes it difficult to reduce the cost.

[0008]

In order to solve the above-mentioned problems, according to the present invention, an aperture control device for a camera is provided with a lens aperture (46) capable of changing the aperture from an initial value to a desired set value.
Aperture interlocking means (18, 15, 20, 22, 23) for changing from an initial state to a set state in conjunction with a change of the lens aperture from the initial value to the set value; Aperture stop means (MG2, MG2) for stopping the lens aperture at the set value by stopping the operation of
29, CPU 1) and aperture return means (M, 43, 44, 45, CPU) for returning the lens aperture to the initial value by returning the aperture interlocking means to the initial state.
1) and limiting means (SW4, MG2, 29, CPU1) for limiting the operation of the aperture interlocking device almost simultaneously with the return of the aperture interlocking device to the initial state.

The limiting means (SW4, MG2, 29, C
PU1) to stop stop means (MG2, 29, CPU1)
(MG2, 29) is used (shared).

[0010]

According to the present invention, since the above-described configuration is employed, the speed increasing gear for expanding the operation amount at the time of charging the throttle system (a throttle interlocking member system comprising a plurality of members including a speed increasing gear train). Bounce that occurs on the row side can be prevented beforehand. Therefore, the next release operation can be started quickly, and the frame speed can be greatly improved.

[0011]

FIG. 1 is a block diagram showing an embodiment of an aperture driving mechanism of a single-lens reflex camera to which the present invention is applied. In a microcomputer 1 (hereinafter, referred to as a CPU) that controls the electric system in each unit in the camera, a program described later with reference to FIG. 3 is written. CPU1
Controls the driving of each part of the camera according to this program. The CPU 1 includes a timer described below.

Known focal plane shutter mechanism 2
Is to give a predetermined exposure time by controlling the running state of the shutter front curtain and the shutter rear curtain, respectively. The focal-plane shutter mechanism 2 is connected to a rear-curtain switch SW3 that is turned on before photographing and turned off in association with rear-curtain travel. By turning off the rear curtain switch SW3, an end signal of the photographing operation is obtained.

The release magnet drive circuit 3 includes a CPU
The release magnet MG1 is driven according to the instruction of No. 1. The aperture control circuit 4 corrects the waveform of the signal from the photocoupler 27 that detects the movement of the aperture driving mechanism, and then adjusts the CP.
Transmit to U1. The aperture control circuit 4 drives and controls the solenoid MG2 according to a command from the CPU 1.

The motor drive control circuit 5 controls the drive and stop of the motor M in accordance with a command from the CPU 1. The motor M uses a one-way (clockwise) rotation type motor as described later with reference to FIG. Release switch SW
Reference numeral 1 denotes a switch which is connected to the CPU 1 and activates the camera when the camera 1 is turned on. The switch SW1 is turned on when a release operation is performed on a release button (not shown).

The completion switch SW2 is connected to the CPU 1 and is a cam 45 which rotates according to the rotation of the motor M.
It is opened and closed (OFF / ON) in accordance with the operation (described later). The bounce prevention switch SW4 is connected to the CPU 1, and the iris control gear train (gear 22 described later) is opened at an open position corresponding to the iris open state (initial state, state before photographing, charge completed state, state in FIG. 2). ON only when returning to. FIG. 2 is a schematic perspective view showing a specific configuration of the aperture driving mechanism of the camera. The figure shows a state before the start of photographing (initial state, charge completed state). Hereinafter, the detailed configuration of the aperture driving mechanism according to the present invention will be described with reference to FIG.

The aperture interlocking lever 15 is rotatably supported about a shaft 15a, and is provided with a right turning force from a spring 19. Pin 15b provided at one end of lever 15
Is locked to one end 31b of a start lever 31 described later. For this reason, the aperture interlocking lever 15 is held at the position shown in FIG. 2 (initial state, charge completed state) before photographing. The other end of the lever 15 is provided with a roller 15d serving as a cam follower for a cam 45 described later. The lever 15 has pins 15c and 15 described later.
e, and an arm 15f are also provided. Also, pin 15
c, the aperture lever 18 rotatably supported by the
2 and is held at a position where one end 18a thereof comes into contact with the pin 15e.

The lens-side aperture interlocking lever 46 is engaged with the distal end portion 18b of the aperture lever 18 and urged in the aperture-down direction by a spring 47. For this reason, the aperture lever 18 is given a right turning force. This right turning force (the right turning force applied to the lever 18 by the spring 47 via the lever 46) is weaker than the left turning force applied to the lever 18 from the spring 16; Lever 18 and 46).

The start lever 31 is rotatably supported by a shaft 31a, and is provided with leftward rotation by a spring 32. As described above, one end 31b of the lever 31 prevents the aperture interlocking lever 15 from turning right. One end 31c of the start lever 31 is arranged so as to be in contact with an end surface 33b of a release lever 33 described later. The release magnet reset lever 36 is rotatably supported on a shaft 36a. The lever 36 receives the right-handed turning force from the spring 37 and is held at a position limited by a standing bent portion 38c of the reset lever 38 described later. The tip 36b of the lever 36 is connected to a release lever 33 (described later).
Extends to a position where it can abut on one end 33c.

The lever 36 is in a state shown in FIG. 2 (a state before photographing).
In order to prevent the operation of the release lever 33 from being obstructed (that is, to prevent the operation of the one end 33c of the lever 33 downward in FIG. 2), the distance between the tip 36b of the lever 36 and the one end 33c is set. Is provided). The reset lever 38 is rotatably supported by the shaft 36a described above, and is provided with a left turning force by a spring 40. In the state of FIG. 2 (the state before photographing), the arm 38 b of the lever 38 is connected to a pin 45 on a cam 45 described later.
a, and its operation is restricted.

The motor M is a one-way rotary motor that is driven to rotate only in one direction (clockwise in FIG. 2). A pinion gear 43 is fixed to the motor M. The engagement of the gear 43 with the gear 44 having a shaft 44b and functioning as an interlocking means for the motor M causes the shaft 4
The cam 45 integral with 4b is rotatable. The radius of the cam 45 is formed so as to gradually increase as the diameter shifts from r1 in the clockwise direction (as r1 → r2 → r3) (that is, it has a relationship of r1 <r2 <r3). ).

A pin 44a implanted on the gear 44
Abuts on one contact of the completion switch SW2, and the switch SW2
Can be opened and closed (OFF / ON). The completion switch SW2 detects whether or not the gear 44 interlocked with the motor M is at a predetermined position (that is, an initial state, a state before photographing, an aperture open state, or a state of FIG. 2 showing a fully charged state). It becomes a detecting means.

That is, when the motor M starts rotating from the state shown in FIG. 2, the gear 44 starts to rotate leftward, so that the engagement between the pin 44a and the contact piece of SW2 is released, and the completion switch SW is turned off (closed). To the ON (open) state. After that, when the gear 44 makes exactly one rotation and returns to the position shown in FIG. 2, SW2 is turned off from ON. This SW2
(ON → OFF), the rotation of the motor M is stopped. That is, the motor M is controlled so as to make one rotation per one photographing operation.

The cam 45 is provided with a pin 45a. The pin 45a is connected to the reset lever 38 as described above.
Are arranged so as to be able to abut on the arm 38b. In the state of FIG. 2 (the state before the start of the photographing operation), the cam 45
It has escaped from the operation range of the roller 15d, and is in a state in which the operation of the aperture interlocking lever 15 acting as a follower is not restricted.

The release lever 33 is rotatably supported by a shaft 33a and is provided with a left turning force by a spring 35. An armature 34 attracted to the release magnet MG1 is fixed to one end of the release lever 33. Before the photographing operation, it is held at the position shown in FIG. The end surface 33b of the release lever 33 is connected to the start lever 3 as described above.
1 can be in contact with one end 31c. The release magnet MG1 is configured to adsorb the armature 34 when not energized, and release the adsorption when energized.

The aperture stop lever 29 is rotatably supported by a shaft 29a, and is provided with a left turning force by a spring 30. Due to this left-handed turning force, the engaging portion 29c causes the ratchet wheel 2
3 and is prevented from rotating. The solenoid MG2 has a shaft MG2a which is pushed downward in FIG. 2 (in a direction protruding from the solenoid MG2) with a predetermined amount of power when energized, and is in a free state when not energized. Since the current is not supplied before photographing, the engagement between the engagement portion 29c and the ratchet wheel 23 due to the left rotation of the aperture stop lever 29 is not prevented. The upright bent portion 29b can be provided on a shaft MG2a protruding from the solenoid MG2 when energized. The right turning force applied to the lever 29 from the axis MG2a is
The force is set to be sufficient to release the engagement between the engagement portion 29c and the ratchet wheel 23 by the spring 30.

The sector gear 20 is rotatably supported coaxially and independently of a rotation shaft 15a of the aperture interlocking lever 15. The arm 15 of the aperture interlocking lever 15 is provided on the sector gear 20.
A pin 20a that comes into contact with f is implanted, and a left turning force is applied by a spring 17. Therefore, when the stop stop lever 29 (engagement portion 29c) is not engaged with the ratchet wheel 23 as described later, the shutter rotates integrally with the stop interlocking lever 15.

The gear 22 has a small gear portion 22a meshed with the sector gear 20 and a large gear portion 22c meshed with a small gear portion 23a of the ratchet wheel 23. The pin 22b implanted in the gear 22 turns on the bounce prevention switch SW4 at the aperture opening position shown in FIG.
(Closed). This bounce prevention switch S
Since the left turning force given to the gear 22 by the W4 is smaller than the right turning force given to the gear 22 by the spring 17 via the sector gear 20, the gear 22 is moved to the position shown in FIG. (Charge completed state) is maintained.

A ratchet wheel 23 having a small gear portion 23a meshing with a large gear portion 22c of the gear 22 is provided with a small hole group 23b.
Is provided. The known photocoupler 27 outputs one predetermined pulse when one of the small hole groups 23b passes through the ratchet wheel 23 as the ratchet wheel 23 rotates, and outputs the rotation angle of the ratchet wheel 23. It is configured to measure by counting the number of pulses. Further, as described above, the ratchet wheel 23 is configured to forcibly stop rotation by engaging the circumferential portion thereof with the engaging portion 29c of the stop stop lever 29. The operation of this device is controlled by the CPU 1. The flowchart of FIG. 3 shows the operation control by the CPU 1. Hereinafter, the operation of the present apparatus will be described with reference to FIG.

A known main power switch (not shown) or a known half-press switch (not shown) linked to the release button (not shown) is turned on to turn on the camera power.
Then, this flow starts. Step S101
Then, initialization for setting a later-described counter, timer, and the like to initial values is performed.

In step S102, the release switch S
The state of W1 is determined. If SW1 is ON (that is, if the release button (not shown) is fully pressed), the process proceeds to step S103. If SW1 is OFF, the flow returns (the subroutine ends). Step S10
At 3, the timer is started and the process proceeds to step S104. Here, the timer is built in the CPU 1 and measures a predetermined time in order to secure a time required for aperture control (setting). The predetermined time is a time sufficient for completing the aperture setting operation if the aperture system is operating normally.

In step S104, the solenoid MG2 is energized (ON). This energization causes the shaft MG2a to press the upright bent portion 29b downward in FIG. 2, so that the engagement between the ratchet wheel 23 and the aperture stop lever 29 is released, and the aperture setting (from the aperture open state to the desired aperture setting value). ). In step S105, the release magnet MG1 is energized (ON). This energization causes the magnet MG1 to release the attraction of the armature 34. In response to the release of the suction, the aperture operation and the raising operation of the mirror (not shown) are started. The power supply to the MG 1 is performed for a certain period of time, and the power supply is automatically turned off after the predetermined period of time. A detailed description of the operation of each mechanism (lever and the like) accompanying the energization of MG1 will be described later.

In step S106, the count value of the output pulse of the photocoupler 27 is set to a predetermined value N described later.
Determine if it is greater than. More specifically, the rotation angle of the ratchet wheel 23 (which corresponds to the stop position set by the lever 46) of the ratchet wheel 23, which has started rotating following the release of the suction of the armature 43 performed in step S105, is detected. Therefore, the output pulse of the photocoupler 27 is counted. And this count value is a desired value N
(Here, the desired value N is a value corresponding to a desired aperture value determined by an exposure control circuit, not shown, and is a value determined before the aperture control operation.) Is determined. If the pulse count value reaches N, the process proceeds to step S107; otherwise, the counting is continued until it reaches N.

In step S107, the solenoid MG2 is turned off. As a result, the ratchet wheel 23 and the aperture stop lever 29 are engaged again, and the aperture drive is stopped. In step S108, it is determined whether or not the timer that has started measuring time in step S103 has completed measuring the predetermined time. If the timer has completed the time measurement for the predetermined time, the process proceeds to step S109, otherwise, the time measurement is continued until the time measurement for the predetermined time is completed.

In step S109, an exposure operation is performed by performing known shutter control, that is, running control of a shutter first curtain and a shutter rear curtain. In step S110, the state of the shutter rear curtain switch SW3 is determined. S
If W3 is ON, wait until SW3 is OFF, that is, the shutter is closed. If SW3 is OFF, the process proceeds to step S111.

In step S111, the solenoid MG2 is energized again (ON), and the engagement between the aperture stop lever 29 and the ratchet wheel 23 is released. In step S112, the motor M is energized. With energization (that is, rotation) of the motor M, the aperture system moves toward the aperture open side to charge the mechanism. The details of the operation of each mechanism (lever and the like) accompanying the energization of the motor M will be described later.

In step S113, the bounce prevention switch SW4 is turned on, that is, whether the aperture control gear train (particularly the gear 22) has returned to the open position (initial state, state before photographing, charge completed state, ie, the state of FIG. 2). It is determined whether or not. If SW4 is ON, the process proceeds to step S114,
In the case of FF, the flow branches to step S117. Step S
At 114, the solenoid MG2 is de-energized (OFF). As a result, the aperture stop lever 29 and the ratchet wheel 23
Is engaged again, and the drive of the aperture stops.

In step S115, it is determined whether the completion switch SW2 is OFF. If SW2 is OFF, the process proceeds to step S116. If SW2 is ON, the process waits until it is turned OFF. In step S116, driving of the motor M is stopped (energization of the motor M is stopped), and the flow returns (the subroutine ends).

On the other hand, in step S117, it is determined whether or not the completion switch SW2 is OFF. SW2 is O
If it is FF, the process proceeds to step S118, and if it is ON, it waits until it is turned OFF. In step S118, driving of the motor M is stopped (power supply to the motor M is stopped), and the process proceeds to step S119.

In step S119, the state of the bounce prevention switch SW4 is determined. If SW4 is ON, that is, if the aperture control gear train has returned to the open position (initial state, state in FIG. 2), the process proceeds to step S120. Otherwise, it waits until it is turned ON. In step S120, the solenoid MG2 is de-energized (OFF). As a result, the stop stop lever 29 and the ratchet wheel 23 are engaged again, and the drive of the stop is stopped. Then, the flow returns. Next, a detailed description of the actual operation of each mechanism unit (lever and the like) at the time of the photographing operation will be described with reference to FIG.
This is performed according to the flowchart of FIG.

When a release signal (ON of the release switch SW1) is input by operating a release button (not shown), power is supplied to the solenoid MG2, the shaft MG2a projects downward in FIG. Part 2
By pushing 9b, the lever 29 is turned clockwise against the left turning force of the spring 30. By the clockwise rotation of the lever 29, the engagement between the engaging portion 29c and the ratchet wheel 23 is released, and the ratchet wheel 23 becomes rotatable.

Thereafter, when the release magnet MG1 is energized and the attraction force of the MG1 is released, the spring 3 is released.
The armature 34 is separated from the MG1 by the left turning force of 5, and the release lever 33 starts left turning. With the leftward rotation of the lever 33, one end 33b of the lever 33 becomes one end 31 of the aperture start lever 31 constituting a mirror driving mechanism.
c is kicked off and is turned clockwise against the spring 32.

With the clockwise rotation of the aperture start lever 31, the aperture interlocking lever 15 moves the lever 31 with the pin 15b.
Is released, the right-handed turning force of the spring 19 and the right-handed turning force of the spring 47 on the photographic lens system side transmitted via the aperture lever 18 turn right. Along with the clockwise rotation of the aperture interlocking lever 15, the aperture operation by the aperture lever 18 is started.

With the clockwise rotation of the aperture interlocking lever 15, the sector gear 20 also rotates clockwise integrally, and the ratchet wheel 23 starts clockwise rotation via the gear system (22, 23). A pulse is output from the photocoupler 27 by the rotational movement (passing) of the small hole group 23b accompanying the rotation of the ratchet wheel 23. The pulse output and the rotation angle of the aperture interlocking lever 15, that is, the amount of aperture reduction are uniquely determined. Therefore, when the count value of the pulse number reaches the pulse number N corresponding to the aperture control value (desired aperture setting value) determined by a known exposure calculation device (not shown), the solenoid M
When the energization of G2 is stopped (a stop stop signal), the stop stop lever 29 rotates left by the left turning force of the spring 30, and the engaging portion 29
c and the circumference of the ratchet wheel 23 are engaged. By this engagement, the rotation of the ratchet wheel 23 is stopped, so that the desired aperture value is controlled.

After the completion of the above-described aperture control operation, when a signal indicating that a predetermined time has elapsed is output from the timer that has been counting from immediately after the release signal is generated (S103),
A shutter mechanism (not shown) performs a leading shutter curtain movement and a trailing shutter curtain movement, thereby completing the exposure operation.
Further, when a signal accompanying the travel of the rear curtain of the shutter, that is, an OFF signal (rear curtain signal) of the rear curtain switch SW3 is output, the solenoid MG2 is energized, so that the shaft MG2 is turned on.
a projects downward and turns the stop lever 29 clockwise.
However, the engagement between the engaging portion 29c and the ratchet wheel 23 is released again, and the ratchet wheel 23 becomes rotatable. Thereafter, in order to return (charge) the aperture system (aperture interlocking member system including the aperture and the gear train) to the initial position (initial state, pre-shooting state, charge completed state) in FIG. Start operation. First, reset of the release magnet MG1 will be described. When the motor M starts rotating clockwise in FIG.
The cam 45 rotates counterclockwise in FIG.
Accordingly, the pin 45a causes the reset lever 38 to rotate clockwise, and the release magnet reset lever 36 also rotates clockwise integrally via the spring 37. With the rightward rotation of the lever 36, the tip 36b of the lever 36 pushes up one end 33c, so that the armature 34 releases the release magnet M
The release lever 33 is turned clockwise until it is attracted to G1.
In addition, the tip 3 of the release magnet reset lever 36
The amount of force of the spring 37 applied to the contact portion 6 b and the one end 33 c of the release lever 33 is configured to be larger than the amount of force by the spring 35. After the armature 34 and the release magnet MG1 are attracted, the overcharge is absorbed by the flexure of the spring 37.

The reset operation of the release magnet MG1 (return to the position before the photographing) is completed by the series of operations of the reset lever 38 described above. As described above, when the cam 45 rotates counterclockwise, the diameter of the cam 45 gradually increases (r1 → r2 → r3), so that the roller 15d, which is a cam follower, is pushed up as the cam 45 rotates (counterclockwise). By pushing up the roller 15d, the aperture interlocking lever 15 is gradually turned left counter to the right turning force of the springs 19 and 47. The left rotation of the lever 15 causes the pin 15
b is engaged with the engaging portion 31b of the start lever 31, and the operation of returning the lens aperture to the open state is completed.

Prior to the start of the aperture opening operation, the engagement between the aperture stop lever 29 and the ratchet wheel 23 is released, so that the left rotation of the aperture interlocking lever 15 causes the left turning force of the spring 17 to rotate the ratchet wheel 23 and the gear. 22, and sector gear 2
0 performs a return operation (return operation from the set state to the initial state) in a form following the aperture interlocking lever 15. Immediately before the final stage of the return of the gear train, that is, immediately before the collision at the contact portion between the pin 20a on the sector gear 20 and the arm 15f of the aperture interlocking lever 15 (this arm 15f performs the function of restricting the aperture opening side). The bounce prevention switch SW4 is turned on. The energization of the solenoid MG2 is stopped again by the ON signal of the switch SW4, the leftward turning force of the spring 30 causes the aperture stop lever 29 to turn leftward, and the engagement portion 29c of the ratchet wheel 23
, The operation (rotation) of the ratchet wheel 23 is stopped.

Therefore, the collision between the pin 20a (part of the gear train) on the sector gear 20 described above and the contact portion of the arm 15f of the aperture interlocking lever 15 (part of the aperture interlocking member other than the gear train) occurs. Bounce (bounce of the gear trains 20, 22, and 23 in a direction against the left turning force of the spring 17) generated on the gear train side can be prevented. Focusing on the completion switch SW2, the completion switch SW2 is turned ON once because the pin 44a is disengaged from the contact piece of the completion switch SW2 with the counterclockwise rotation of the gear 44 integrated with the cam 45, but at this time, the stop command is issued. Is not output, and the counterclockwise rotation is further continued. When it is turned off by the re-engagement with the pin 44a, a command (signal) is sent to the motor drive circuit 5 to stop the motor drive. As a result, all the states before the photographing of FIG. 2 are restored, and the entire series of exposure operations is completed. Note that the O of the above-described bounce prevention switch SW4 is
Switching from FF to ON and O of completion switch SW2
Switching from N to OFF depends on which aperture value is to be controlled first. For this reason,
As shown in steps S113 to S120 in FIG. 3, a predetermined operation (the above-described operation associated with the above-mentioned switching of SW4 or SW2) is executed instantaneously, regardless of which switch is switched first.

After the two conditions of turning off the solenoid MG2 and stopping the rotation of the motor M are satisfied,
A series of photographing operations ends. According to the embodiment described above, the aperture system (the aperture interlocking member system including the aperture and the gear train)
At the time of charging, when a part of the speed increasing gear train for expanding the operation amount collides with a part of a throttle interlocking member other than the gear train, a bouncing operation (bound) generated on the gear train side is observable. This can be prevented. As a result, since it is not necessary to wait for the convergence of the generated bounce, it is possible to quickly start the release operation at the next photographing after photographing, and it is possible to greatly improve the frame speed in continuous photographing.

Since the stop mechanism (magnet MG2, stop lever 29) is used as the bounce prevention mechanism, the bounce prevention switch SW4 can be added at low cost without greatly increasing the number of parts. A prevention mechanism can be realized.

[0050]

According to the present invention, when a throttle system (a throttle interlocking member system including a plurality of members including a throttle and a speed increasing gear train) is charged, a bounce generated on the speed increasing gear train side for expanding an operation amount. Can be prevented beforehand. Therefore, the next release operation can be started quickly, and the frame speed can be greatly improved.

Since there is no need to provide a braking member on the side of the speed increasing gear train for eliminating the bounce generated on the speed increasing gear train side, the bound problem can be solved at a low cost without increasing the number of parts.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an aperture driving mechanism of a camera according to the present invention.

FIG. 2 is a schematic perspective view showing a specific configuration of an aperture driving mechanism of the apparatus according to the embodiment of the aperture driving mechanism of the camera according to the present invention.

FIG. 3 is an example of a flowchart showing a flow of an overall operation in the apparatus of the present invention.

[Description of Signs of Main Parts]

 1: CPU 2: shutter drive circuit 3: release magnet drive circuit 4: aperture control circuit 5: motor drive circuit 15: aperture interlock lever 18: aperture lever 20: sector gear 22: gear 23: ratchet wheel 27: photo coupler 29: Aperture stop lever 31: Start lever 33: Release lever 36: Release magnet reset lever 38: Reset lever 43: Pinion gear 44: Gear 45: Cam 46: Lens side aperture interlocking lever MG1: Release magnet MG2: Solenoid M: Motor SW1: Release Switch SW2: Complete switch SW3: Rear curtain switch SW4: Bounce prevention switch

Claims (2)

[Claims] 1. A lens diaphragm capable of changing an aperture value from an initial value to a desired setting value, and changing from an initial state to a setting state in conjunction with a change of the lens aperture from the initial value to the setting value. Aperture interlocking means, Aperture stop means for stopping the operation of the aperture interlocking means in the set state to stop the lens aperture at the set value, and by returning the aperture interlocking means to the initial state, Aperture return means for returning the lens aperture to the initial value, and limiting means for restricting the operation of the aperture interlocking means almost simultaneously with the return interlocking means returning to the initial state. Aperture control device for camera. 2. An aperture control device for a camera according to claim 1, wherein said restriction means also functions as a part of said aperture stop means.