JPH0255764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aperture and mirror drive device for an aperture-controlled single-lens reflex camera, and more particularly to an improvement for resetting the aperture lock after aperture control.

To explain this type of conventional device, the first
As an example, the aperture stop operation and the mirror raising operation are performed in parallel, and the aperture locking device is operated during that time to control the aperture to a predetermined value. Then, after the shutter operation is completed, an opening operation to return the aperture to the open aperture value and a mirror lowering operation are performed in parallel. After the above operations are completed, some cameras reset the aperture locking device (release the aperture lock) using a reset member that works in conjunction with the winding operation of the camera. Here, since the reset of the diaphragm locking device is performed after the diaphragm opening operation, the locked member that is locked by the diaphragm locking device and the interlocking member that is directly linked to opening and closing of the diaphragm are separated. are separated. However, since the two members are configured to operate as one unit during the diaphragm control operation, the number of parts inevitably increases and the mechanism becomes complicated.

As a second example, first perform a narrowing operation,
During this time, the diaphragm locking device is operated to control the diaphragm to a predetermined value. After that, raise the mirror. After the shutter operation is completed, the mirror lowering operation and the aperture opening operation are performed in parallel, and the aperture locking device is reset in the meantime. Compared to the first example described above, the diaphragm locking device has not been reset at the time when the diaphragm opening operation is started. Therefore, the locked member and the interlocking member need to be separated, resulting in the above drawback.

As a third example, the aperture stop operation and the mirror raising operation are performed in parallel, and the aperture locking device is operated during this time to control the aperture to a predetermined value. Then, in conjunction with the completion of the next shutter operation, the diaphragm locking device is reset by a reset member that is specifically linked to the operation of the shutter trailing blade drive mechanism. After that, there are some devices that perform the mirror lowering operation and the aperture opening operation in parallel.

This does not have the above disadvantages but has the following disadvantages. It is a shutter feather (or curtain)
Due to technological advances in reducing running energy due to weight reduction, the driving energy of the drive mechanism has also become smaller.As a result, if the reset member is interlocked at the beginning of the operation of the drive mechanism, the shutter running becomes unstable. This causes variations in shutter speed. On the other hand, if the reset member is interlocked near the end of the operation of the drive mechanism, shutter closing failures tend to occur, particularly in cold regions, and the reset of the diaphragm locking device tends to become uncertain.

SUMMARY OF THE INVENTION An object of the present invention is to solve these drawbacks and provide an aperture and mirror drive device for an aperture-controlled single-lens reflex camera that has a simple configuration and improved reliability.

In order to achieve the above object, the present invention includes a motor 1, and reciprocating members 5-8, 29-33 that receive driving force from the motor and move forward at the time of release and move back at the completion of exposure. a mirror drive member 36 that is interlocked with the reciprocating member and raises the mirror by forward movement of the reciprocating member and lowers the mirror by backward movement; In the aperture and mirror drive device for a single-lens reflex camera, the aperture and mirror drive device for a single-lens reflex camera is equipped with a aperture member 10 that moves the aperture of the photographic lens in the narrowing direction by a movement and moves the aperture in the aperture direction by a backward movement. Rotating members 12 to 16, each having a ratchet wheel, which always rotates integrally with the narrowing member, and a retracted position where the rotary member is retracted from the claw portion of the rotating member, and an engagement that engages with the claw portion of the rotating member. a locking member 19 that is movable to a predetermined aperture value and that locks the aperture member when displaced to the engagement position; electromagnetic devices 22 to 24 that release the absorption of the locking member to displace the locking member to the engagement position and lock the narrowing member during the narrowing operation, and the reciprocating member. , only when the reciprocating member moves back, it acts on the locking member to restore the locking member from the engaged position to the retracted position, and the return movement of the reciprocating member causes the squeezing member to stop. The release member 41 is provided before being driven in the opening direction.

Examples will be described below based on the drawings.

In FIG. 1, a known slip mechanism 2 operates so that when an abnormal load is applied to the motor 1, the slip mechanism slips at this portion so as not to place any burden on the motor 1.

The rotational force of the motor 1 is transmitted to the rotation shaft 3 of the motor via the slip mechanism 2. A worm 4 fixed to the shaft 3 is constantly engaged with a worm wheel 5, and performs a deceleration effect. When the shaft 3 rotates counterclockwise (in the direction of the arrow) in the figure, the worm wheel 5 rotates clockwise (in the direction of the arrow).

The shaft 6 is fixed to the wall wheel 5, and a first gear 7 is fixed to the center thereof, and a narrowing cam 8 is fixed to the tip thereof. A pin 9 is in contact with the narrowing cam 8. The narrowing lever 10 is rotatable about a shaft 11, and the pin 9 is fixed in the middle thereof. Therefore, the lever 10 swings in response to the lift of the cam 8.

A sector gear 12 is fixed coaxially and integrally with the lever 10. The pinion 13 is integrated with the gear 14 and constantly meshes with the sector gear 12. The gear 14 is always engaged with a pinion 15, and the pinion 15 is integrated with the ratchet wheel 16 and the shaft 7.

Therefore, the swinging motion of the lever 10 is amplified and transmitted to the ratchet wheel 16.

Although not shown, a known aperture mechanism is included inside the lens 17. When the aperture interlocking lever 18 is in the position shown, the aperture is open, and when it moves downward in the figure due to the biasing force of a spring (not shown), the aperture is narrowed down according to the amount of movement. It's summery. In other words, since the lever 18 is engaged with the tip 10a of the lever 10, as the lift of the cam 8 becomes smaller, the lever 10 rotates clockwise, and the lever 18 also moves downward in the figure. Therefore, the aperture is narrowed down.

The lever 19 is rotatably supported by a shaft 20 and biased counterclockwise by a spring 25. The lever 19 has a claw portion 19a, and this claw portion 19
When a engages with the ratchet wheel 16, rotation of the lever 10 is stopped. Since the armature 21 attached to the lever 19 is attracted to the yoke 22 (normal state), the lever 19 cannot rotate counterclockwise. This attraction force is due to the magnetic force of the permanent magnet 23, but when the coil 24 is energized, the attraction force of the permanent magnet 23 is reduced, so that the armature 21 separates from the yoke 22. As a result, the lever 19 is rotated counterclockwise by the biasing force of the spring 25, and the claw portion 19a and the ratchet wheel 16 are engaged. Note that a leaf spring 2 is attached to the tip of the lever 19.
6 is attached, and when the leaf spring 26 is pushed upward, the lever 19 rotates clockwise and the armature 21 is attracted again.

Next, the second gear 2, which is always engaged with the first gear 7,
7 has three holes 27a, 27b and 27 for light transmission.
c is drilled. 28a is a light emitting body such as an LED,
28b is a photo sensor.

It is detected that the sensor 28b and any one of the holes 27a, 27b, or 27c are directly facing each other, and this is used for sequence control.

A shaft 29 is fixed to the second gear 27, with a reset lever 30 in the middle and a crank 3 at the tip.
1 are attached to each. When the worm 4 rotates counterclockwise (in the direction of the arrow), the shaft 29 also rotates in the counterclockwise direction (in the direction of the arrow). A pin 32 is fixed to the tip of the crank 31,
One end of a rod 33 is rotatably supported by the pin 32.

The other end of the rod 33 is rotatably supported by a pin 34. This pin 34 is fixed to the tip of a lever 36. A lever 36 integrated with the shaft 35 is rotatable about the shaft 35.
The shaft 29, crank 31, pin 32, rod 33, pin 34, lever 36, and shaft 35 constitute a lever crank mechanism. Therefore, when the shaft 29 is rotated in the direction of the arrow in the figure, the rod 3
3 moves upward and the lever 36 rotates counterclockwise.

The pin 37 is fixed to a mirror holding frame 38, and this frame 38 is rotatably supported by the shaft 35. A reflex mirror (not shown) is attached to the holding frame 38, and reflects the light that has passed through the lens 17 to a finder optical system (not shown). A predetermined gap A is formed between the side surface 36a of the lever 36 and the pin 37.

A tension spring 39 is applied between the pins 37 and 34, so that the mirror holding frame 38 is biased clockwise (mirror downward direction). However, the lowering of the frame 38 is limited to a position where its tip 38a is locked by the cradle 50. When the lever 36 is rotated counterclockwise by the rotation of the shaft 29 in the direction of the arrow, the side surface 36a and the pin 37 come into contact after the gap A is lost, and as a result, the lever 36 and the mirror holding frame 38 are integrated. It will rotate counterclockwise. Therefore, the mirror holding frame 38 can be retracted from the photographing optical path.

Next, the function of the reset lever 30 fixed to the middle of the shaft 29 will be described. A reset pin 40 is fixed to the tip 30a of the lever 30,
It is in a positional relationship that allows it to engage with the first arm 41a of the reset intermediate lever 41. Reset intermediate lever 41
A spring 42 is applied to the second arm 41b of the lever 41, and is biased so that the lever 41 returns to its initial position (the state shown in the figure) no matter which direction it rotates. Further, the lever 41 is provided with a third arm 41c, which creates a predetermined gap B between it and the leaf spring 26 in the illustrated state. And lever 4
When the lever 1 is rotated counterclockwise, the leaf spring 26 and the third arm 41c first come into contact with each other, and then the lever 19 is rotated clockwise.

The other end 30b of the reset lever 30 is for restricting the rotation of the shaft 29 in the direction of the arrow, and this is achieved by the contact between the end 30b and the restriction 43.

Next, its operation will be explained.

FIG. 1 shows the camera in a state where it is ready to take a picture after winding the film and charging the shutter. Here, when release switch SW ₁ is turned ON in conjunction with pressing the release button, the motor control circuit
Motor 1 starts rotating counterclockwise due to the action of C ₁ . Then, the shaft 6 begins to rotate clockwise via the worm 4 and worm wheel 5. As a result, the cam 8 integrated with the shaft 6 also rotates in the same direction, and the cam surface 8a of the cam 8 gradually reduces the lift relative to the pin 9. Also lever 18
is urged downward in the figure, so it rotates clockwise.

The cam surface 8a is inclined until a minimum lift that is slightly smaller than the lift that gives the lens 17 the minimum aperture diameter is obtained, and is set so that the minimum lift continues in subsequent rotations. This is called the minimum lift region. The light that has passed through the lens 17 generates a photoelectric output in the light receiving element PD ₁ according to the aperture. And the light receiving element
When the output of PD ₁ corresponds to a predetermined aperture value determined by film sensitivity and shutter speed, control circuit C ₂ energizes coil 24 . Therefore, the adhesion between the yoke 22 and the armature 21 is released, and the claw portion 1
9a meshes with the ratchet wheel 16, and as a result the pinion 1
5, gear 14, pinion 13, sector gear 12
The lever 10 is locked via. Therefore, a predetermined aperture value is set for the lens 17.

During this aperture value setting operation, the first gear 7
The second gear 27 that meshes with the second gear continues to rotate counterclockwise. Therefore, since the crank 31 also rotates in the same direction, the lever 36 starts rotating counterclockwise. However, in the lever crank mechanism at the bottom dead center, the rotation angle of the lever 36 is significantly smaller than the rotation angle of the crank 31. Here, it is assumed that the gap A is determined so that the mirror holding frame 38 is not moved during the above-described aperture determination operation. Therefore, since the mirror lifting operation is not performed during the aperture determining operation, the amount of light entering the light receiving element _PD1 is not adversely affected.

The reason why this aperture determination operation takes the longest is that if the aperture is not narrowed down to the minimum aperture diameter in the lens 17 or other interchangeable lens groups, the coil 24
This is a case where power is not applied to the In the operation up to this point, the load on the motor is extremely small, so
The shaft 6 rotates rapidly. However, in order to accurately determine the aperture value, it is necessary to rotate the lever 10 clockwise slowly to some extent. This is because the claw portion 19a and the ratchet wheel 16 need to be engaged with each other at a sufficiently stable timing to compensate for the response delay of the light receiving element PD ₁ and the control circuit C ₂ and the delay in the operation of the coil 24. For this reason, gears 12 to 16
The enlarged gear train in between is provided with a sufficiently large inertia. Therefore, even if the cam 8 rotates rapidly, the lever 10 rotates at a moderate speed with a delay. Therefore, when the cam 8 reaches the starting end of the minimum lift region, the motor 1 stops rotating and waits until the aperture value determining operation is completed.

The rotation stop signal Sig-1 is generated by detecting that the hole 27b provided in the second gear 27 and the sensor 28b are directly facing each other. For example, from when the hole 27a and the sensor 28b are directly facing each other (at the start of the aperture determining operation) until the hole 27b and the sensor 28b are directly facing each other, two pulse-like photoelectric outputs can be obtained from the sensor 28b. All you have to do is count.
When the hole 27b directly faces the sensor 28b, a rotation stop signal Sig-1 is sent to the circuit C1, and as a result, the electric brake is applied to the motor ₁ , and the shaft 6 and shaft 29
Both will stop. However, as described above, the mirror holding frame 38 still does not move due to the gap A. The above is the operation from release to aperture value determination.

Next, begin the process of raising the mirror. The hole 27b and the sensor 28b are directly facing each other, and a rotation stop signal is sent to the control circuit _C1 .
When Sig-1 is sent, timer circuit _C3 starts and restarts after delaying for the longest time required to determine the minimum aperture diameter of all interchangeable lenses. Generates signal Sig-2.
When signal Sig-2 is applied, circuit _C1 energizes motor 1. Therefore, the motor 1 starts rotating again in the direction of the arrow, and the shafts 6 and 29 also start rotating as before.

As the crank 31 rotates counterclockwise, the lever 3
6 continues to rotate counterclockwise. Finally, the gap A becomes zero, the pin 37 and the side surface 36a of the lever 36 come into contact, and as a result, the mirror holding frame 38 is pushed up and retreated from the photographing optical path. When the arm of the crank 31 is substantially upward in the figure, the arm 30b of the reset lever 30 hits the limit 43, and the rotation of the shaft 29 is limited.

At this time, the hole 27c provided in the second gear 27
and the sensor 28b directly faces. When this is detected, a restart signal Sig-3 is sent to the circuit _C1 , and the power to the motor 1 is cut off. During restart of motor 1 cam 8
rotates, but since it is in the minimum lift region, the lever 10 does not rotate. Then, when the motor 1 stops, it reaches the end of the minimum lift region. In this process, the reset pin 40 contacts the first arm 41a of the reset intermediate lever 41 and rotates it clockwise.
When the arm 41a passes through, the intermediate lever 41 returns to the illustrated position by the biasing force of the spring 42. In this way, the aperture is first narrowed down, and then the mirror is raised.

After this, a shutter (not shown) starts operating. This start signal may be a restart signal Sig-3 generated by the hole 27c of the second gear 27 and the sensor 28b, or may be a mechanical signal related to the movement of the mirror holding frame 38 or lever 36.

When the shutter has been closed, the circuit _C1 is actuated in a known manner, for example, by an ON signal of the switch _SW2 associated with the shutter trailing blade drive mechanism, to rotate the motor 1 in the direction opposite to the arrow in the figure. After that, the mirror is lowered and the aperture is opened.

At this time, a film feed system may be attached to the shaft 3 of the motor 1 via a one-way clutch, and the film may be wound one frame at the same time as the mirror and aperture are returned. Or worm 4 on axis 3
It is also possible to provide a clutch that can selectively switch between power transmission to and from the film feed system, and wind the film after the mirror is restored and the aperture is opened.

Now, when the shaft 3 of the motor 1 starts rotating clockwise, the shaft 6 starts rotating counterclockwise via the worm 4 and worm wheel 5. Therefore, the cam 8 also starts rotating counterclockwise from the end of the minimum lift area, but since the cam surface 8a is at the minimum lift, the pin 9, that is, the lever 10
There will be no immediate action taken. On the other hand, since the first gear 7 also starts rotating together with the shaft 6, the second gear 27 also rotates clockwise. Therefore, the mirror is lowered by the reverse rotation of the crank 31, lever 36, and mirror holding frame 38.

On the way, the reset pin 40 provided on the reset lever 30 engages with the first arm 41a of the intermediate reset lever 41, causing the lever 41 to rotate counterclockwise. Therefore, the third arm 41c of the lever 41 pushes the leaf spring 26 upward, and as a result,
The lever 19 rotates clockwise, and the armatures 21 are pressed against the yoke 22 and attracted to each other by the magnetic force of the permanent magnets 23. Therefore, the pawl 19a and the pawl wheel 1
6 is released, and the enlarged gear train of gears 12 to 16 and the lever 10 can move freely.

On the other hand, when the reverse rotation of the crank 31 progresses and the tip 38a of the mirror holding frame 38 comes into contact with the cradle 50, the frame 38 cannot rotate any further. Therefore, the lever 36 continues to rotate clockwise while pulling the spring 39, so that the gap A is created again.
At this time, the cam 8 passes the starting end of the minimum lift region and the lift gradually begins to increase, causing the lever 18 to be displaced upward in the figure via the lever 10. Therefore, the aperture of the lens 17 tends to open up. When the motor 1 continues to rotate further, one end 30a of the reset lever 30 hits the limit 43, and the rotation of the shafts 29 and 6 stops.

Now, in the case of a configuration in which the film is fed during the above operation, it is detected that the hole 27a of the second gear 27 faces the sensor 28b again, and the motor 1
to stop. If the film is to be fed after the above operations, it is sufficient to detect the return of the shaft 6 to its original phase and switch the aforementioned clutch to the film feeding side.

In this way, the mirror returns to the subject observation position and the aperture of the lens 17 returns to its open state, and the aperture locking device 1
6 to 25 also return to their original positions.

Here, a supplementary explanation will be given regarding the operation of the reset pin 40 and the reset intermediate lever 41.

FIG. 2 shows the mirror being raised and the shaft 29 rotating counterclockwise (in the direction of the arrow).
At this time, the reset pin 40 and the reset intermediate lever 4
1 makes contact, and the shaft 29 further rotates from the illustrated state, so the pin 40 passes and the reset intermediate lever 41 returns to its initial position due to the biasing force of the spring 42. At this time, due to the action of the gap B, the claw 19
The engagement between a and the ratchet wheel 16 will not be released.

FIG. 3 shows the mirror being lowered. In this case, the reset intermediate lever 41 is rotated counterclockwise by the pin 40, the third arm 41c pushes the leaf spring 26, and as a result, the armature 21 is moved from the yoke. 2
It is adsorbed by 2. After this, the shaft 29 continues to rotate counterclockwise, so the pin 40 is attached to the lever 4.
Pass through 1. Therefore, the lever 41 returns to its initial position due to the biasing force of the spring 42, and the third arm 41c
The contact between the leaf spring 26 and the leaf spring 26 is released. Thereafter, whenever the coil 24 is energized, the lever 19 will be in a counterclockwise rotating position.

To summarize the above embodiment, the aperture is started by starting the motor, the motor is temporarily stopped until the aperture is determined, the motor is restarted after a predetermined delay by the timer circuit, and the motor is restarted. This uses an optical switch to control the timer circuit.

In this example, the motor used as the drive source is the same as that used in a known quick return mirror, that is, the direction of the biasing force is changed from the first direction to the second direction. It goes without saying that a spring device can be used instead. Therefore, it is not a device exclusively for electric cameras.

As described above, in the present invention, the rotating members 12 to 16 that are locked by the locking members and the narrowing member 10 do not need to be separately configured to be operable, so the configuration is very simple. Not only does this have advantages, but it also does not have a negative effect on the shutter system.

In addition, if the mirror lowering and aperture opening operations are performed sequentially as in the embodiment, low torque and high speed control can be achieved through time series control, especially when driving the motor, and energy efficiency can also be improved. .

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention; Fig. 2 is a perspective view showing an embodiment of the invention;
FIG. 3 is a side view showing the operation of the diaphragm locking portion. [Explanation of symbols of main parts], 1... Drive source, 8
... Reciprocating member, 10 ... Squeezing member, 12 -
16... Operating member, 19-24, 26... Locking member, 29, 31-39... Mirror drive member, 2
9, 30, 40-42...Release member.

Claims (1)

[Scope of Claims] 1. A motor 1, a reciprocating member 5 to 8, 29 to 33 that receives driving force from the motor, moves forward at the time of release, and moves back when exposure is completed, and is interlocked with the reciprocating member. A mirror drive member 36 moves the mirror up by the forward movement of the reciprocating member and lowers the mirror by the backward movement; In the aperture and mirror drive device for a single-lens reflex camera, which is equipped with a aperture member 10 that moves in the aperture direction and moves the aperture in the aperture direction by a backward movement, the aperture wheel is provided with a pawl portion continuously on the circumference. and a rotary member 12 to 16 that always rotates integrally with the narrowing member, and is movable between a retracted position where it is retracted from the claw portion of the rotary member and an engagement position where it is engaged with the claw portion of the rotary member. and a locking member 19 that locks the aperture member when displaced to the engagement position, and a locking member 19 that attracts the locking member and holds it in the retracted position, and that locks the aperture when the aperture reaches a predetermined aperture value. Electromagnetic devices 22 to 24 that release the adsorption of the locking member and displace the locking member to the engagement position to lock the narrowing member during the narrowing operation; Acting on the locking member only during the backward movement, the locking member is restored from the engagement position to the retracted position, and the return movement of the reciprocating member drives the narrowing member in the direction of opening the aperture. A diaphragm and mirror drive device characterized in that it has a release member 41 that achieves the effect at the front. 2. The release member is comprised of a swinging lever 41 that is swingably supported, and the swinging lever engages with the reciprocating member when the reciprocating member moves forward and backward, respectively, to prevent the swinging. The first part that makes the entire lever swing
and a second end portion 41a positioned so as to act on the locking member only when the reciprocating member moves forward.
Claim 1 having an end portion 41c of
The diaphragm and mirror drive device described in .