JPH1124163A - Mirror brake for mirror driving mechanism and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a buffer mechanism for efficiently absorbing/relaxing a shock caused by the raising and lowering of the mirror of a camera, with reduction in size and number of parts. SOLUTION: A camera is equipped with a mirror unit provided with a mirror 2 for changing the direction of a ray of light, on a mirror receiving plate 3 held to be movable between first and second stopping positions, and for driving the mirror unit in such a manner that its driving lever 4 drives a mirror driven- pin 3a provided on the mirror receiving plate. Further, this camera is equipped with a mirror brake mechanism for regulating the drive of the mirror driven-pin 3a from the midst of the movement of the mirror unit, to block this movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror brake device for a mirror driving mechanism and a camera, and more particularly to a brake device for absorbing and reducing a shock generated when a mirror of a camera is moved up and down.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 9 and 10, a quick return mechanism of a main mirror of a single-lens reflex camera has a 45.degree.
It is pressed against and held by the adjusting dowel 7 by the mirror biasing spring 6. At the time of exposure, the mirror driving lever 4 is operated by a spring, a motor, or the like, and by this operation, the mirror driven pin 3a attached to the mirror receiving plate 3 is pushed up, and the mirror unit is turned up and flipped up. It is evacuated from the optical path by pressing. Then, the mirror driving lever 4 is returned to the original position, the mirror driven pin 3a is pressed down, and the mirror driven pin 3a is pressed against the 45 ° adjustment dowel 7, thereby enabling the subject observation.

[0003] As described above, when the mirror is moved up and down, the mirror unit collides with another member to stop the mirror unit. In order to alleviate this, conventionally, when the mirror is raised, a cushioning member is attached to the top of the front plate where the mirror unit hits,
When the mirror is down, Japanese Patent Laid-Open No. 6-75296 shown in FIG.
The mirror unit is urged by the SH return spring 21 just before the mirror unit hits the 45 ° adjusting dowel 7 as in the publication, and once hits the guide lever 20 having the buffer member 20a on the contact surface. Thereafter, the mirror unit is slowly lowered to the 45 ° adjusting dowel by pushing up the slide lever 19 to avoid a sudden collision.

[0004]

However, in the above-mentioned conventional example, the shock cannot be sufficiently absorbed even if the cushioning member is attached.
When a movable lever is used, the amount of movement is large, and the movable part is relatively large, which hinders miniaturization.

An object of a first invention according to the present application is to realize a shock absorbing mechanism capable of efficiently absorbing an impact caused by a mirror up / down of a camera with a small number of parts and a small number of parts.
An object of the present invention is to provide a mirror brake device of a mirror driving mechanism that can reduce impact noise and vibration when the mirror stops.

A second object of the present invention is to reduce the speed at which the mirror unit comes into contact with a mirror driven pin, which is a regulating member, and to reduce the impact due to the up and down movement of the mirror in a small and small component. It is an object of the present invention to provide a mirror brake device of a mirror driving mechanism that can realize a buffer mechanism that can efficiently absorb the number of points.

An object of a third invention according to the present application is to provide a mirror driving mechanism capable of smoothly performing a switching operation of a main mirror between a subject observation position and a photographing position of a camera without any trouble. It is to provide a brake device.

A fourth object of the present invention is to provide a camera which achieves the first to third objects.

[0009]

According to a first aspect of the present invention, there is provided a mirror receiving plate movably held between a first stop position and a second stop position. A mirror driving mechanism for driving the mirror unit by driving a mirror driven pin provided on the mirror receiving plate, wherein the mirror driving mechanism has a mirror unit provided with a mirror for changing the direction of the light beam; It has a brake means for restricting the driving of the mirror driven pin during the movement to prevent the movement of the mirror unit.

According to this configuration, it is possible to realize a shock absorbing mechanism capable of efficiently absorbing the shock due to the up / down movement of the mirror of the camera with a simple structure, and to reduce the impact noise and vibration when the mirror stops.

[0011] According to a second aspect of the present invention, in the above-mentioned configuration, the mirror brake mechanism is configured such that the mirror unit moves the mirror unit from a first stop position to a second stop position or a second stop position. From the position near the stop position from the position to the first stop position, the brake member is spring-biased so as to contact the mirror driven pin and prevent the movement of the mirror unit.

According to this configuration, the brake is spring-biased so as to abut on the mirror driven pin provided on the mirror receiving plate used for moving the mirror unit from near the stop position of the mirror unit and hinder the movement. Buffer mechanism that can reduce the speed at which the mirror unit contacts the mirror driven pin, which is a regulating member, and can efficiently absorb the impact of mirror up / down with a small number of parts and a small number of parts. Can be realized.

According to a third aspect of the present invention, in the above-described configuration, the mirror unit is configured so that the first stop position is a subject observation position and the second stop position is a shooting position. It is a main mirror of a camera mounted to rotate between positions.

According to this configuration, the switching operation of the main mirror between the subject observation position and the photographing position of the camera can be smoothly performed without any trouble.

A camera for realizing the object of the fourth invention according to the present application has a mirror brake device having any one of the above structures.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1 and 4 show a first embodiment of the present invention. FIG. 1 shows a mirror down state, and FIG. 4 shows a mirror up state. In these figures, 1 is a front plate, 2 is a mirror for guiding light rays from a subject to a finder, 3
Is a mirror receiving plate that is rotatably attached to the front plate 1 and holds a mirror.

Reference numeral 3a denotes mirror driven pins provided on the mirror receiving plate 3 for raising and lowering the mirror unit.
Is a mirror drive lever for contacting the mirror driven pin 3a to move up and down the mirror unit, and 5 is a mirror up spring which is hooked on the mirror drive lever 4 in the direction to raise the mirror unit.

Reference numeral 6 denotes a mirror driven pin provided on the mirror driving lever 4 so that the mirror driven pin 3a is sandwiched between the mirror driving lever 4 and the mirror driven pin 3a when the mirror driving lever 4 is rotated in a direction to lower the mirror unit. This is a mirror biasing spring that pushes down 3a.

Reference numeral 7 denotes a 45 ° adjusting dowel for abutting the mirror receiving plate 3 to maintain the mirror unit in a 45 ° attitude.
A sub-mirror 9 for guiding the light beam to the F sensor, a sub-mirror plate 9 rotatably mounted on the mirror receiving plate 3 and a sub-mirror receiving plate for holding the sub-mirror 8, and a sub-mirror 10 for contacting the sub-mirror receiving plate 9 to open and close the sub mirror. Submirror drive pin.

Reference numeral 11 denotes an up brake which is rotatably biased by the front plate 1 and comes into contact with the mirror driven pin 3a during the stroke when the mirror unit is raised.

Reference numeral 12 denotes a down brake which is rotatably biased by the front plate 1 and comes into contact with the mirror driven pin 3a from the middle of the stroke when the mirror unit goes down.

Reference numeral 13 denotes a brake spring for applying a braking force to the up brake 11 and the down brake 12,
4 is a brake supporting member for supporting the up brake 11 and the down brake 12, and 15 is a mirror driving lever 4.
This is a charge lever for charging the battery.

Reference numeral 16 denotes a cam gear having a cam portion for rotating the charge lever 15 and a transmission gear, 17 a motor, and 18 a gear train for transmitting the driving force from the motor 17.

The operation of this embodiment will be described below with reference to FIGS.

The mirror driving lever 4 has a mirror biasing spring 6
Is hung on a mirror driven pin 3 a provided on the mirror receiving plate 3, and presses the mirror driven pin 3 a of the mirror receiving plate 3 in the mirror down direction with the rotation of the mirror driving lever 4. . The mirror-up spring 5 is urged in the mirror-up direction. As shown in FIG. 3, the gear train 18 transmits the rotational driving force from the motor 17 to rotate the cam gear 16 so that the cam drives the mirror driven pin 3a. By pushing out, the charge lever 15 is rotated. As a result, the mirror up spring 5 is overcharged when the subject is observed, and the mirror urging spring 6 pushes down the mirror driven pin 3a to bring the mirror into contact with the 45 ° adjusting dowel 7 to stop.

The up brake 11, the down brake 12, and the brake spring 13 are coaxially arranged on a shaft 14a provided on the brake support member 14, and the brake position restricting portion 14b is sandwiched between the up brake 11 and the down brake 12. The brake spring 13 is hung in the form.

When the switch SW2 of the release switch is turned on and the camera enters a mirror-up operation, the motor 17 rotates the cam gear 16 as shown in FIG. When the cam receiving pin 15b provided on the charge lever 15 reaches the concave portion of the cam surface, the tension of the mirror-up spring 5 is released, and the mirror drive lever 4 rotates to rotate the charge lever 15 in the direction B. At the same time, the mirror driven pin 3a is pushed up to raise the mirror unit.

At this time, the mirror driven pin 3a abuts on the up brake 11 biased by the brake spring 13 in the clockwise direction in FIG. We push up 11. That is, the up brake 11
As a result, the mirror unit moves up while gradually reducing the speed of the mirror unit.

Then, as shown in FIG. 4, when the tip of the mirror unit comes into contact with the buffer member provided on the upper part of the wall of the mirror box, the mirror unit stops and the mirror up is completed, and the film is exposed.

Further, as shown in FIG. 6, when the motor 17 continues to rotate and the cam pushes out the cam receiving pin 15b provided on the charge lever 15, the charge lever 15 rotates in the direction A, and the mirror driving lever 4 is moved. Rotate in the counterclockwise direction in FIG. Then the mirror biasing spring 6
Pushes down the mirror driven pin 3a to start the mirror down.

At this time, the up-brake 11 comes off the mirror driven pin 3a at the same time as the up-brake 11 comes into contact with the brake position restricting portion 14b in the middle of the mirror-down, and then is applied by the brake spring 13 counterclockwise in FIG. The force comes into contact with the down brake 12 arranged coaxially with the up brake 11, and the mirror down is continued while charging the brake spring 13 as in the case of the mirror up. As a result, the speed gradually decreases, and the mirror unit goes down. Then, the mirror receiving plate 3 is adjusted by the 45 ° adjusting dowel 7.
The mirror unit stops and returns to the subject observation state.

In this manner, as shown in FIG. 7, when there is no mirror brake mechanism, the mirror unit collides with the member at the maximum speed, whereas when the mirror brake mechanism is used, the speed at the time of collision is increased. Can be reduced.

[0033]

According to the first and fourth aspects of the present invention, it is possible to realize a shock absorbing mechanism that can efficiently absorb the shock due to the up / down movement of the mirror of the camera with a simple configuration, and can provide the impact sound when the mirror stops and the impact sound. Vibration can be reduced.

According to the second and fourth aspects of the present invention, in the first aspect, a mirror driven pin provided on a mirror receiving plate used for moving the mirror unit is contacted from a position near the stop position of the mirror unit. By providing a brake member that is spring-biased so as to contact and hinder movement, the speed at which the mirror unit contacts the mirror driven pin, which is a regulating member, can be reduced, and the impact due to the mirror up / down movement can be reduced. Can be efficiently realized with a small number of components and a small number of components.

According to the third and fourth aspects of the present invention, in the first or second aspect, the switching operation of the main mirror between the subject observation position and the photographing position of the camera can be smoothly performed without any trouble. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state where a mirror is down according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a state where a mirror is down according to the first embodiment of the present invention;

FIG. 3 is a diagram showing a state of a cam gear and a charge lever when the mirror is down according to the first embodiment of the present invention;

FIG. 4 is a perspective view showing a state in which a mirror is raised according to the first embodiment of the present invention;

FIG. 5 is a diagram illustrating a state in which a mirror is raised according to the first embodiment of the present invention;

FIG. 6 is a diagram showing a state of a cam gear and a charge lever at the time of mirror up according to the first embodiment of the present invention;

FIG. 7 is a stroke-velocity graph of a mirror tip portion in the first embodiment of the present invention.

FIG. 8 is a diagram showing a conventional shock absorbing mechanism.

FIG. 9 is a diagram showing the operation of a conventional quick return mirror (mirror down state).

FIG. 10 is a diagram showing the operation of a conventional quick return mirror (mirror up state).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Front plate 2 ... Mirror 3 ... Mirror receiving plate 3a ... Mirror driven pin 3b ... Mirror buffer member 4 ... Mirror drive lever 5 ... Mirror up spring 6 ... Mirror biasing spring 7 ... 45 degree adjustment dowel 8 ... Sub mirror 9 ... Sub-mirror receiving plate 10 ... Sub-mirror drive pin 11 ... Up brake 12 ... Down brake 13 ... Brake spring 14 ... Brake support member 14a ... Shaft 14b ... Brake position restricting part 15 ... Charge lever 15a ... Lever drive pin 15b ... Cam receiving pin 16 ... Cam gear 17: Motor 18: Gear train 19: Slide lever 20: Guide lever 20a: Guide lever buffer 21: SH return spring

Claims (4)

[Claims] 1. A mirror unit having a mirror for changing a direction of a light beam provided on a mirror receiving plate movably held between a first stop position and a second stop position, wherein a drive lever is provided. In a mirror driving mechanism for driving a mirror unit by driving a mirror driven pin provided on the mirror receiving plate, the driving of the mirror driven pin is restricted during the movement of the mirror unit so that the movement of the mirror unit is restricted. A mirror brake device for a mirror drive mechanism, comprising a brake means for preventing the mirror drive. 2. The mirror brake device according to claim 1, wherein the mirror unit is connected to the mirror driven pin from near a stop position of the mirror unit from a first stop position to a second stop position or from a second stop position to the first stop position. 2. The mirror brake device for a mirror drive mechanism according to claim 1, further comprising a brake member that is spring-biased so as to abut against the movement of the mirror unit. 3. The camera according to claim 1, wherein the mirror unit is a main mirror of a camera mounted to rotate between a stop position having a first stop position as a subject observation position and a second stop position as a shooting position. A mirror brake device for a mirror driving mechanism according to claim 1 or 2, wherein: 4. A camera comprising: the mirror brake device for mirror driving section light according to claim 1, 2 or 3.