JP4593709B2 - Mirror quick return mechanism for SLR cameras - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mirror box mechanism of a single-lens reflex camera, and more particularly to a mirror quick return mechanism.
[0002]
[Prior art]
The mirror box mechanism of a single-lens reflex camera with a built-in motor requires not only the raising and lowering of the mirror, but also the shutter starting operation and the shutter charging operation. However, there is a problem with the complexity of the mechanism and the price, and as a solution to this, there is a method of driving each by forward / reverse rotation of one motor. Proposed. In the past, the method of raising the mirror by forward rotation of the direct motor proposed by the present inventor and lowering the mirror at the initial stage of reverse rotation (Japanese Patent Publication No. 60-26203) or charging the mirror up spring by reverse rotation and flipping the mirror up and down There is a method of lowering the mirror by rolling (Japanese Patent Publication No. 62-38439).
[0003]
[Problems to be solved by the invention]
In the case of the method shown in Japanese Patent Publication No. 60-262203, the mirror is lifted directly by decelerating motor rotation, so that the raising speed of the mirror is slow and the dependency on the rotation speed of the motor is strong. In the case of the method disclosed in Japanese Patent Publication No. 62-38439, a spring is used to increase the mirror ascending speed. However, since a time for charging by a motor is required at the start, the shutter operation is performed in continuous shooting. There was a problem in the speed of the quick return of the mirror including it, and a mechanism that guarantees an accurate and high-speed shutter and the sequence operation of the mirror was desired.
[0004]
[Means for Solving the Problems]
In order to solve such a problem, the present invention divides the rotation operation of the motor into a slight rotation in one direction and a large number of rotations in the other direction, and releases the charge of the mirror and the shutter by a slight rotation in one direction, and the mirror lifting operation The solution was achieved by enabling the shutter operation, lowering the mirror at the initial stage of rotation in the other direction, and charging the mirror and shutter while reducing the load on the motor by continuing multiple rotations thereafter.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The motor rotation is divided into two operations: mirror and shutter charge by forward rotation, and release of charge by reverse rotation. A charge cam and a latch disk that rotate through a speed reduction mechanism connected to the motor output shaft are installed, and the charge cam slides. The charging lever and the latching lever that slides on the latch disk keep the shutter and mirror fully charged and keep the tensioned state. The mirror is flipped up, and the mirror is flipped up and kept in tension by the mirror holding lever and the latch disk. We propose a quick return mechanism for mirrors that is configured to release the latch and lower the mirror at the beginning of the next forward rotation, and to charge the mirror and shutter by continuous rotation.
[0006]
【Example】
Hereinafter, the best embodiment of the present invention will be described with reference to the drawings.
[0007]
FIG. 1 is a configuration plan view of a mirror quick return mechanism of the present invention, and FIG. FIG. 3 is an operation circuit block diagram of the mirror quick return mechanism of the present invention, and FIG. 4 shows an operation timing chart of the motor, mirror and shutter mechanism. FIG. 1 shows the finder observation position where the mirror 1 is lowered, and the shutter set lever pin 18 (not shown) is at the uppermost charging position, and the spring 22 for raising the mirror is charged before the start of photographing. Shows the state.
[0008]
The finder mirror 1 is received by a mirror receiver 2 and can swing about 45 ° up and down about a hinge shaft 3 and is always urged downward by a spring (not shown). The roller 5 of the drive shaft 4 fixed to the mirror receiver 2 is in contact with the left end portion 6a of the return lever A6, and the return lever A6 is a downward biasing spring with the return lever shaft 7 as a center. If the mirror 1 is rotated rightward, the mirror 1 rises in an arc around the hinge shaft 3.
[0009]
The return lever shaft 7 of the return lever A6 is coaxial, there is a return lever B8, and an R spring 11 stronger than the return spring of the mirror 1 (not shown) is applied to the return lever A6 on the pins A9 and B10. The notch 8a of B8 is urged with the pin A9 as a stopper.
[0010]
Further, a pin C12 is planted at the tip of the return lever B8, and is held by the fork 13a of the return lever C13 with the return lever C shaft 14 as a rotation axis. At the other end of the return lever C13, a mirror holding lever 15 having the M holding lever shaft 17 as a rotation axis is installed. The projection 13B of the return lever C13 is always used as a stopper, and a circle of a latch disk 33 to be described later is always used. It is urged by the M spring 16 so as to contact the peripheral side surface. As a result, the return lever C13 rotates in conjunction with the movements of the return levers A6 and B8, and the mirror holding lever 15 moves in contact with the circumferential side surface of the latch disk 33 in response to this.
[0011]
A kick lever 29 is installed at the tip of the right arm portion 20c of the charge lever 20 in the vicinity of the protruding portion 8b below the return lever B8, and the branch portion 29b is urged by the K spring 31 with the CH pin B32 as a stopper. ing. This is because when the charge lever 20 rotates leftward about the charge lever shaft 21, the tip end portion 29a of the kick lever 29 hits the protruding portion 8b of the return lever B8, the return lever B8, and the return lever A6 corresponding thereto. The mirror 1 is kicked up by the rightward rotation of.
[0012]
The charge pin 19 implanted at the tip of the left arm portion 20a of the charge lever 20 acts on a shutter set lever pin 18 (not shown), and the charge lever 20 rotates to charge or release the shutter set lever. You can also. A sliding lever 20d of the lower arm portion 20b of the charge lever 20 slides on a surface of a charge cam 34, which will be described later, and is a latch lever that can rotate about the S latch lever shaft 26 so as to overlap the lower arm portion 20b. 25 is installed and is energized by the S spring 28 hooked on the S spring pin 28 with the CH pin A24 as a stopper, and the tip projection 25a is a circle of the latch disk 33 superimposed on the charge cam 34. It comes in contact with the circumferential side. The charge lever 20 is always urged to rotate counterclockwise by a stationary spring hook pin 23 around the charge lever shaft 21 and a strong spring 22 hung on the edge of the lower arm portion 20b.
[0013]
As a charge mechanism, a speed reduction mechanism is constituted by a spur gear 38 meshing with a motor pinion 39 fixed to an output shaft of the motor 40, a small gear 37 meshing with the spur gear 37, and a charge gear 35 having a charge gear shaft 36 as a rotation axis. The charge cam 34 fixed to the charge gear 35 is rotated so that charging can be performed in one rotation cycle. A latch disk 33 is fixed to the charge gear 35 so as to overlap the charge cam 34, and a locking groove A33a and a locking groove B33b are formed on the side surface. The mirror holding lever 15 and the latch lever 25 are given a habit of constantly contacting the latch disk 33 at a substantially opposite position on the side surface of the latch disk 33, and are slidable.
[0014]
In the machine configuration shown in FIG. 1, a block diagram of an electronic circuit necessary for causing the operation intended by the present invention is shown in FIG. 3, and a time sequence of each main mechanism is shown in FIG. The operation of the invention will be described in accordance with the operation explanatory diagram of FIG. 2 with reference to these two diagrams. FIG. 2 (I) shows the mirror receiver before the start which can be photographed as in FIG. 1 showing the configuration of the present invention. The spring 22 hung on the center of the charge lever 20 is illustrated by the charge pin 19 at the tip of the left arm portion 20a in the charged state with the drive shaft 4 of 2 being in the finder observation position where the lowest mirror 1 is lowered. The set lever pin 18 of the non-shutter is at the uppermost position. This charge state is maintained because the tip 25a of the latch lever 25 on the lower arm portion 20b is immersed in the locking groove A33a of the latch disk 33 and prevents the charge lever 20 from being restored. Since the mirror 1 is in the lowered state, the edge of the mirror holding lever 15 at the position opposite to the latch lever 25 is in contact with the side surface of the latch disk 33 that is out of the locking groove B33b. As shown in FIG. 2, a slide substrate 50 for detecting a rotation angle is provided with the charge gear shaft 36 as a coaxial, and the SW1 of the switch 42 and the SW2 of the switch 43 are constituted by the slider 49 and the slide pattern. .
[0015]
Next, when the release SW 41 shown in FIG. 3 is turned on ([1] in FIG. 4) and a start signal is sent to the CPU 44 in order to start shooting, first the shutter front curtain magnet (Mg1) 47 is passed through the driver (1) 45. Then, the rear curtain magnet (Mg2) 48 is energized, and even if the shutter set lever is released, both curtains are held so as not to run ([7] and [8] in FIG. 4). Then, after a little time in the CPU 44, a reverse current is sent to the motor 40 by a signal sent to the driver (2) 46 ([2] in FIG. 4). When the motor 40 starts to reverse, the spur gear 38, Reduction power is obtained from the small gear 37 to the charge gear 35, and the locking groove A33a of the latch disk 33 starts to rotate counterclockwise as shown in FIG. At a slight rotation position before the rotation advances from (1) to (2), the protruding portion tip 25a of the latch lever 25 is disengaged from the locking groove A33a of the latch disk 33, and the latch lever 25 slides on the side surface of the latch disk 33. The charge lever 20 rapidly rotates counterclockwise according to the restoring force of the spring 22, and the sliding tip 20d of the lower arm portion 20b hits the valley of the minimum swing of the charge cam 34 as shown in the drawing and stops. .
[0016]
In this operation process, the tip 29a of the kick lever 29 installed at the tip of the right arm 20c of the charge lever 20 pushes the protruding portion 8b of the return lever B8 to the left, so that the return lever A6 is returned to the return lever A6 through the R spring 11. When the roller 5 is rotated rightward about the shaft 7 and pushes up the roller 5 at the left tip 6a ([5] in FIG. 4), the charge lever 20 continues to rotate left even when the mirror 1 is fully raised. Therefore, this time, the return lever B8 is further rotated to the right against the R spring 11, and the tip 29a of the kick lever 29 sinks from the protruding portion 8b of the return lever B8 as shown in the figure and protrudes forward. And stop. Further, as the return lever B8 rotates counterclockwise, the fork 13a of the return lever C13 connected to the pin C12 also descends, so that the return lever C13 rotates counterclockwise around the return lever C shaft 14 and holds the mirror. The lever 15 touches the edge of the latch disk 33 and lifts up along the side. As the return lever C13 rotates, the mirror holding lever 15 is refracted to the protrusion 13b of the return lever C13, and when the latch disk 33 rotates from (1) to (2), the locking groove B33b is exactly the mirror. The mirror 1 is held at the raised position when it jumps in just below the tip 15a of the holding lever 15. At the position (2) of the latch disk 33 in this state, SW1 of the switch 42 is turned on, the current of the motor 40 is cut off by the determination of the CPU 44, and the rotation stops ([3] [2] in FIG. 4).
[0017]
These series of operations are performed in a very short time and completed before the SW1 of the switch 42 is turned on and the motor 40 is stopped. , The Mg1 current of the front curtain magnet 47 is cut off as shown in [7] in FIG. 4 to run the front curtain, the predetermined exposure time t is calculated, and the rear curtain magnet is shown in [8]. Shut off the Mg2 current of 48 and run the trailing curtain to complete the shutter operation. Next, the CPU 44 cuts off the Mg2 current of the rear curtain magnet 48 of the shutter and then waits for the curtain travel time to stabilize, and then sends a signal to the driver (2) 46 to pass a forward current to the motor 40. When the motor 40 is rotated forward, the charge cam 34 and the latch disk 33 start to return from the position (2) to the position (1) by rotating clockwise as shown in (II) of FIG. At the first stage of this rotation, the tip 15a of the mirror holding lever 15 is disengaged from the locking groove B33b of the latch disk 33, slides on the side of the latch disk 33, and the mirror holding lever 15 is opened as shown in the figure. Keep in contact with the sides. By this operation, the return lever C13 rapidly rotates rightward about the shaft 14, and accordingly, the return lever B8 returns to rotate leftward. At this time, the sliding tip 20d of the charge lever 20 is still at the valley of the charge cam 34, and the charge lever 20 is not moved. However, as described above, the protrusion 8b of the return lever B8 is behind the tip 29a of the kick lever 29. Therefore, the return lever B8 can return to the initial position while pressing the kick lever 29, and at the same time, the return lever A6 also returns to the start position, and the mirror 1 also returns to the initial finder observation position ([5 in FIG. 4]. ]). After the SW1 of the switch 42 is cut off by this rotation operation, the SW2 of the switch 43 is turned on at the position (1), but the forward rotation of the motor is continued ([3] [4] [2] in FIG. 4), The state moves to the state of (IV) in FIG.
[0018]
By continuing the rotation in the same direction, the sliding tip 20d of the charge lever 20 that is in contact is applied to the inclined portion of the charge cam 34, and the sliding tip 20d is pushed to the left according to the rotation, and the charge lever 20 is pushed to the charge lever shaft 21. While rotating to the right around the center, the spring 22 is charged and the set lever pin 18 is pushed up by the charge pin 19 to charge the shutter ([6] in FIG. 4). The state of the right rotation of the charge lever 20 in accordance with the rotation of the charge cam 34 and the latch disk 33 is shown in FIG. 2 (IV). The position of (a) is at the peak of the charge cam 34 (1). The position (e) is not yet in the charged state, and the latch lever 25 is in the state (a) in which the edge contacts the latch disk 33. As the charge lever 20 rotates to the right, the latch lever 25 rises and is in the state (b) at the charge completion position and does not yet enter a state where the return of the charge lever 20 is not prevented. When the lever (f) is reached, the charge lever 20 is further advanced (b) and slightly overcharged. The tip protrusion 25a of the latch lever 25 is lifted from the latch disk 33, so that the latch lever 25 As shown in (c), the light is refracted to a position where it hits the CH pin A24 of the stopper, and the tip protrusion 25a faces the charge gear shaft 36, which is the center of the latch disk 33. When the rotation of the charge cam 34 further advances and reaches the position of (g), the peak is detached from the sliding tip 20d of the charge lever 20 and tries to return by the restoring force of the spring 22, but the tip protrusion 25a of the latch lever 25 It hits the side surface of the latch disk 33 and is blocked. In this state, while the tip protrusion 25a of the latch lever 25 slides on the side surface of the latch disk 33, the charge cam 34 and the latch disk 33 continue to rotate past the position (2) and rotate once (3). At the position (the same position as (1)), it jumps into the locking groove A 33a of the latch disk 33, the rotation is prevented and the switch 43 is turned on at the same time, and the CPU 44 returns to the initial position by the signal. And the motor current is cut off ([2] in FIG. 4).
[0019]
The forward rotation of the charge cam 34 and the latch disk 33 obtained by the rotation of the motor 40 starts from (2), passes (1) and returns to (2) as shown in (II) and (IV) of FIG. In order to pass more than (3), that is, more than one rotation until (1), SW1 of the switch 42 and SW2 of the switch 43 of the sliding board 50 correspond to normal rotation as shown in [2] of FIG. 3] and [4], but the motor 40 can be accurately stopped at position {circle around (3)} (position {circle around (1)}) by the logical judgment of the CPU 44. The left arm 20a charges the shutter by the right rotation of the charge lever 20 obtained by the forward rotation, while the right arm 20c has the kick lever 29 of the return lever B8 that has been returned as shown in FIG. When the charging lever 20 approaches the charging completion position, the tip 29a of the kick lever 29 is disengaged from the protruding portion 8b, and the K spring 31 is restored. Lift the head with force and return to the initial state. In this way, the charge lever 20 returns to the fully charged state, and the charge cam 34 and the latch disk 33 where the rotation of the motor 40 stops return to the position (3), that is, the position (1). Return to and complete one operation.
[0020]
【The invention's effect】
As described above, according to the present invention, a quick return mechanism for a desired mirror that reduces the dependency on the rotational speed and responsiveness of the motor by applying the forward and reverse actions of a single motor with a simple mechanism. The practical effects that can be provided are great.
[Brief description of the drawings]
FIG. 1 is a configuration plan view of a mirror quick return mechanism of the present invention.
FIG. 2 is an explanatory diagram of the operation.
FIG. 3 is an operational circuit block diagram of the mirror quick return mechanism of the present invention.
FIG. 4 is an operation timing chart of a motor, a mirror, and a shutter mechanism.
[Explanation of symbols]
1 Mirror 2 Mirror Receiver 5 Roller 6 Return Lever A
8 Return lever B
11 R spring 13 Return lever C
15 Mirror holding lever 16 M spring 20 Charge lever 25 Latch lever 29 Kick lever 31 K spring 33 Latch disk 34 Charge cam 40 Motor 44 CPU
45 Drivers (1)
46 Drivers (2)
47 Front curtain magnet 48 Rear curtain magnet

Claims (1)

Motor, motor pinion, spur gear, small gear, latch lever, latch lever shaft, latch disk, charge cam, charge gear, charge gear shaft, mirror holding lever, first return lever, first return lever shaft, mirror holding Lever shaft, second return lever, second return lever shaft, third return lever, kick lever, mirror, mirror receiver, hinge shaft, drive shaft, charge lever, charge lever shaft, charge pin, set lever pin, A mirror quick return mechanism of a single-lens reflex camera having a spring and a kick lever shaft,
The motor is connected to the charge gear via the motor pinion, the spur gear and the small gear,
The charge cam and the latch disk are fixed to the charge gear,
The charge gear, the charge cam, and the latch disk are supported by the charge gear shaft,
A locking groove is provided around the side surface of the latch disk,
The mirror holding lever and the latch lever are arranged so that they are always in contact with each other at substantially opposite positions via the locking groove of the latch disk or the circumferential side surface of the latch disk, and are slidable.
The second return lever has a protrusion and a pin,
The first return lever has a hawk part,
The first return lever and the second return lever engage with each other when the fork portion holds the pin,
The first return lever is pivotally supported on the first return lever shaft;
The first return lever and the mirror holding lever are pivotally supported by the mirror holding lever shaft,
The said third return lever and said second return lever is pivotally supported by the second return lever shaft,
The mirror is pivotally supported on the mirror receiver by the hinge shaft,
The drive shaft is fixed to the mirror receiver, and the third return lever is engaged with the drive shaft,
The charge pin is disposed on the charge lever so as to be engageable with the set lever pin,
The charge lever is pivotally supported by the charge lever shaft,
The charge lever and the latch lever are pivotally supported by the latch lever shaft,
The charge lever and the kick lever are supported by the kick lever shaft,
When the motor starts reverse rotation, deceleration power is obtained from the motor pinion to the spur gear and from the small gear to the charge gear, the locking groove of the latch disk starts to rotate counterclockwise, and the latch disk rotates slightly. Then, the latch lever is released from the latching groove of the latch disk, the latch lever slides on the side surface of the latch disk, and the charge lever moves to the left with the charge lever shaft as the rotation axis according to the restoring force of the spring. And the kick lever hits the protrusion of the second return lever, and the second return lever and the right turn of the third return lever aligned with the second return lever cause the mirror to rotate. And the charge lever stops against the charge cam,
When the motor is rotated forward, the charge cam and the latch disk rotate clockwise, and the mirror holding lever is released from the locking groove of the latch disk at the first rotation of the charge cam and the latch disk to the right. Sliding the side of the latch disk,
The mirror holding lever is kept in contact with the side surface of the latch disk, the first return lever rotates clockwise around the first return lever axis, and interlocks with the rotation of the first return lever. The second return lever returns to the left,
Since the charge lever does not move because the charge lever is in the valley of the charge cam, the protrusion of the second return lever is behind the kick lever, so the second return lever is While pressing the kick lever, it returns to the initial position, at the same time the third return lever also returns to the start position, the mirror also returns to the initial position,
By continuing the forward rotation of the motor, the charge lever that is in contact with the charge cam rotates right about the charge lever shaft in response to the right rotation of the charge cam, along with the charge of the spring, and the charge A mirror quick return mechanism of a single-lens reflex camera, wherein the set lever pin is pushed up by a pin to perform charging .

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