JPH10339913A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently suppress the generation of an impact and noise at the time of actuating a mirror driving mechanism for a camera. SOLUTION: The camera is constituted to provide a mirror member 5 being movable between the inside and outside positions of a photographing optical path. In such a case, energizing force switching means 1 and 2 are provided to exert energizing force on the mirror member 5 to push it toward the outside position, when the mirror member 5 is placed in the inside position and a middle position and toward the inside position, when the mirror member 5 is placed between the outside and middle positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a mirror member for guiding photographing light to a finder optical system or a film surface.

[0002]

2. Description of the Related Art Hitherto, it has been considered that a camera, particularly a single-lens reflex camera, has a drawback of loud noise, and various noise reductions have been made. For example, by using a belt or making the material of the gear soft in the film feeding mechanism, the film feeding mechanism can be made quieter, and the film feeding sound is hardly heard in the case of using the belt. The noise is reduced to the level.

Further, as a shutter mechanism, there has been proposed an impact absorbing mechanism using a balancer which runs in the direction opposite to the running direction in conjunction with the running of the shutter blades. Is considerably reduced.

[0004]

However, with respect to a mirror mechanism which generates a loud operating sound or an impulsive sound as compared with a film feeding mechanism or a shutter mechanism, an impact is absorbed by using a counter balance interlocked with the movement of the mirror. Although some things have been proposed, sufficient noise reduction has not yet been achieved.

For example, in the above counterbalance method, a mirror moves from a position outside the photographing light path (a position where the photographing light is guided to the film surface without being disturbed by the mirror) to a position inside the photographing light path (the photographing light is reflected by the mirror). When the mirror moves to the viewfinder optical system), it can absorb the shock when the mirror reaches the inner position, but does not exhibit the shock absorbing effect when the mirror moves to the outer position. Loud noise and shock still remain.

Accordingly, the present invention provides a relatively simple configuration,
It is an object of the present invention to provide a camera capable of suppressing the generation of impact and sound both when the mirror member moves from the inside position to the outside position and when the mirror member moves from the outside position to the inside position.

Another object of the present invention is to provide, in addition to the above-mentioned object, a camera capable of reducing the running time of a mirror to at least the same time as a conventional one.

[0008]

In order to achieve the above object, the present invention provides a camera having a mirror member movable between an inner position and an outer position in a photographing optical path, wherein the mirror member is located at the inner position. When it is located between the intermediate position, it applies a biasing force to the mirror member in the direction of the outer position, and when it is located between the outer position and the intermediate position, it applies a biasing force to the mirror member in the direction of the inner position. There is provided an urging force switching means for causing the urging force to change.

More specifically, a first contact portion for selectively contacting the biasing force switching means with the mirror member to push the mirror member toward the outside position and a second contact portion for pushing the mirror member toward the inside position. A first urging portion and a second urging portion for generating an urging force, engaging the abutting member, and urging the abutting member in a direction in which the first abutting portion abuts on the mirror member. An urging force generating member provided with a second urging portion for urging the abutting portion in a direction in which the abutting member comes into contact with the mirror member, and when the mirror member is located between the inner position and the intermediate position, The first urging portion is engaged with the contact member, and the second urging portion is separated from the contact member. When the mirror member is located between the outer position and the intermediate position, the second urging portion is The first urging portion is disengaged from the contact member while engaging with the contact member.

That is, according to the present invention, a contact member is provided which comes into contact with the mirror member both when the mirror member moves from the inside position to the outside position and when the mirror member moves from the outside position to the inside position. The member is provided with one spring or the like that applies a force (biasing force) that resists the movement of the mirror member when the mirror member moves from the intermediate position to the outer position and when the mirror member moves from the intermediate position to the inner position. With a simple configuration in which the power generation member is provided, the movement speed of the mirror member when the mirror member reaches the destination position is sufficiently reduced, and the generation of impact and noise is greatly reduced.

In addition, the urging force of the urging force generating member is
While the mirror member moves from the inner position to the intermediate position and from the outer position to the intermediate position, it acts as a force to assist the movement of the mirror member, so that the initial movement speed of the mirror member can be increased, As described above, even if the final movement speed becomes slow, the movement can be finally completed in the same movement time as the movement time of the conventional mirror member.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) First, FIG. 9 shows the overall configuration of a camera according to a first embodiment of the present invention. In this figure, reference numeral 55 denotes a camera body. Inside the camera body 55, a mirror box 51 having a mirror driving mechanism and a mirror member 5 and a focus plate for forming an image focused by a photographing lens 56 are formed. 52 and a pentaprism 53 for forming an image formed on the focus plate 52 toward the eyes of the photographer
And the lens 54 are excreted.

Next, the configuration of the mirror driving mechanism is shown in FIG.
This will be described in detail with reference to FIG.

FIG. 1 schematically shows an urging force switching mechanism in the mirror driving mechanism, and FIG. 2 shows a side of the mirror driving mechanism opposite to the side where the urging force switching mechanism is provided. Is shown.

In these figures, reference numeral 1 denotes a contact member, in which a rectangular hole having a first contact surface 1e and a second contact surface 1d is formed inside. This contact member 1 is a shaft 1
A swinging movement is possible around a, and the contact shaft 5b of the mirror member 5 is inserted into the rectangular hole.

Reference numeral 2 denotes a torsion coil spring (biasing force generating member) for applying a biasing force to the contact member 1.
The first and second urging arms 2a and 2b of the torsion coil spring 2 are formed with first and second engaging portions 1b and 1c, respectively. The first and second urging arms 2a and 2d of the torsion coil spring 2 are provided on the camera body.
Each of the urging arms 2b is a body engaging portion that can be disengaged.

Numeral 5 is inclined at an inner position (hereinafter referred to as an observing position) of a photographing optical path during finder observation, and reflects a photographing light beam in a finder direction. The mirror member is capable of swinging about a shaft 5e. Reference numeral 6 denotes a stopper that is provided on the camera body and contacts the mirror member 5 at the observation position to position the mirror member 5.

Reference numeral 10 denotes a mirror driving member that drives the mirror member 5 from the observation position to the retracted position, and can swing about a shaft 12. Reference numeral 11 denotes a torsion coil spring attached around the shaft 12, and one arm portion is connected to the mirror driving member 10
By engaging the other arm with the engaging shaft 13 provided on the camera body, the mirror driving member 10 is moved counterclockwise in FIG. 2 (the mirror member 5 is retracted). (The direction to drive to the position).

Reference numeral 14 denotes a first tensioning member which can be engaged with and disengaged from the mirror driving member 10 at the leading end locking portion 14a, and can swing about a shaft 16. Reference numeral 15 denotes a torsion coil spring attached around a shaft 16, which engages one arm with an engagement shaft 14b of the first tightening member 14 and engages the other arm 15a with an engagement shaft provided on the camera body. The first tensioning member 14 is urged in a counterclockwise direction in FIG. 2 (a direction in which the locking portion 14a is engaged with the mirror driving member 10) by engaging with the first tensioning member 14.

Reference numeral 17 denotes a first tension release member which pushes the first tension member 14 in a clockwise direction to release the engagement between the first tension member 14 and the mirror driving member 10; Is moved in the left-right direction in the figure by a drive mechanism (not shown) attached to the camera.

Reference numeral 19 denotes a charging member which pushes the mirror driving member 10 in a clockwise direction to charge the mirror driving member 10 at a position shown in FIG. 2, and moves in the left-right direction in the figure by a driving mechanism (not shown) attached to the camera body. I do.

Reference numeral 20 denotes a torsion coil spring provided around the shaft 22 provided on the camera body. One arm is engaged with the engaging portion 5c of the mirror member 5, and the other arm is provided on the camera body. The mirror member 5 is urged in the counterclockwise direction in FIG. 2 (the direction in which the mirror member 5 is moved to the observation position) by being engaged with the engaged engagement shaft 21.

Reference numeral 23 denotes a second tensioning member which engages with the mirror member 5 located at the retracted position and holds the mirror member 5 at this position, and is capable of swinging about a shaft 25. Numeral 24 denotes a torsion coil spring attached around a shaft 25. One of the arms is engaged with the engagement shaft of the second tightening member 23, and the other arm is engaged with the engagement shaft 27 provided on the camera body. By engaging, the second tensioning member 23 is urged in a counterclockwise direction in FIG. 2 (a direction in which the second tensioning member 23 is engaged with the mirror member 5).

A spring member which engages with the foot 23b of the member 23 and applies a biasing force to the mirror device tightening member. Reference numeral 26 denotes a second tension release member that pushes the second tension member 23 to release the engagement between the second tension member 23 and the mirror member 5, and a drive mechanism (not shown) attached to the camera body. Moves right and left in the figure.

Next, the operation of the mirror driving mechanism thus configured will be described with reference to FIGS. 1 and 2 show a state in which the mirror member 5 is located at the observation position. In this state, as shown in FIG. 1, the second biasing arm 2 b of the torsion coil spring 2 engages with the main body engaging portion 4 (disengages from the second engaging portion 1 c of the contact member 1) and the first Since the urging arm 2a is engaged with the first engaging portion 1b of the contact member 1, a biasing force in the counterclockwise direction in FIG. For this reason, the contact shaft 5b of the mirror member 5 contacts the first contact surface 1e of the contact member 1, and is urged in the counterclockwise direction in FIG.

On the other hand, in this state, as shown in FIG.
The mirror driving member 10 is engaged with the first tensioning member 14, and is held at the position shown in FIG. 2 against the urging force of the torsion coil spring 11 in the counterclockwise direction in FIG. The mirror member 5 is
The torsion coil spring 20 is urged in the counterclockwise direction in FIG. 2 by the urging force. Here, the urging force of the torsion coil spring 20 acting on the mirror member 5 is set to be larger than the urging force of the torsion coil spring 2 (the urging force acting on the mirror member 5 via the contact member 1). The member 5 is held at the observation position.

When a release signal is input to the camera by the photographer, as shown in FIG. 3, the first tension release member 17 moves to the left in the figure, and the first tension release member 17 is moved clockwise. To push. Thereby, the engagement between the mirror driving member 10 and the first tension member 14 is released, and the mirror driving member 1 is released.
0 starts to rotate counterclockwise in FIG. 3 by the urging force of the torsion coil spring 11. When the mirror driving member 10 starts rotating, the arm portion 10c of the mirror driving member 10 pushes the engagement shaft 5c of the mirror member 5, and pushes up the mirror member 5 toward the retreat position against the urging force of the torsion coil spring 20. .

Here, not only the driving force from the mirror driving member 10 generated by the urging force of the torsion coil spring 11 but also the urging force of the torsion coil spring 2 applies to the mirror member 5 as a force for pushing the mirror member 5 in the retracted position direction. The generated driving force from the contact member 1 acts. Therefore, the mirror member 5 can be moved in the direction of the retreat position at a higher speed than when the mirror member 5 is moved only by the driving force from the mirror driving member 10.

When the mirror member 5 starts to move from the observation position to the retreat position in this way, the contact member 1 follows the mirror member 5 by the urging force of the torsion coil spring 2 and rotates counterclockwise in FIG. To start.

Then, as shown in FIG.
Reaches the intermediate position, the first biasing arm 2a of the torsion coil spring 2, which has been engaged only with the first engagement portion 1b of the contact member 1 until then, also engages with the main body engagement portion 3, and Until then, the second of the torsion coil spring 2 engaged only with the main body engaging portion 4
The urging arm 2b also engages with the second engaging portion 1c of the contact member 1. Therefore, the contact member 1 generated by the torsion coil spring 2
And the force transmitted to the mirror member 5 via the contact member becomes zero, and the contact member 1 temporarily stops at this position.

However, the mirror driving member 1 is attached to the mirror member 5.
Since a driving force from 0 (a driving force larger than the urging force of the torsion coil spring 20) is acting, the movement of the mirror member 5 in the retreat position direction is continued. For this reason, the contact shaft 5b of the mirror member 5 separates from the first contact surface 1e of the contact member 1, and the mirror member 5 once stops receiving the driving force from the contact member 1.

As the mirror member 5 further moves toward the retreat position by the driving force from the mirror driving member 10, as shown in FIG.
b comes into contact with the second contact surface 1d of the contact member 1 and rotates the contact member 1 counterclockwise from the state of FIG.
Thereby, the first biasing arm 2a of the torsion coil spring 2 is engaged with the main body engaging portion 3 and is separated from the first engaging portion 1b of the contact member 1, while the second biasing arm 2b is engaged with the main body engaging portion. Part 4
5 and engages with the second engaging portion 1c of the contact member 1, the urging force in the clockwise direction in FIG.

For this reason, the contact member 1 is attached to the mirror member 5.
, The biasing force of the torsion coil spring 2 acts as a force in the direction of moving the mirror member 5 to the observation position (a force that resists the movement to the retreat position). Therefore, the mirror member 5 that was initially moving at a high speed toward the retracted position
Is suddenly decelerated. Therefore, when the mirror member 5 reaches the retreat position as shown in FIG. 4, the mirror member 5 is sufficiently decelerated, and the generation of impact and sound when stopping at the retreat position is sufficiently suppressed.

Immediately before the mirror member 5 reaches the retracted position, the mirror member 5 moves while pushing away the tensioning claw 23a of the second tensioning member 23 at the distal end, and when the mirror member 5 reaches the retracted position, it is tightened. It engages with the pawl 23a and is held at this position.

On the other hand, at this time, the charging member 19 moves leftward in FIG. 4, and pushes the mirror driving member 10 to rotate clockwise to return to the position shown in FIG. at the same time,
The first tension release member 17 moves rightward in FIG.
4 is rotated counterclockwise by the urging force of the torsion coil spring 15. Thereby, even if the mirror driving member 10 and the first tensioning member 14 are re-engaged and the charging member 19 moves rightward, the mirror driving member 10 is kept in the torsion coil spring 1.
1 is held in the position shown in FIG.

With the mirror member 5 held in the retracted position in this way, the shutter is operated to take a picture. When the photographing is completed, the second tension release member 26 is moved to the position shown in FIG.
Then, the second tensioning member 23 is rotated clockwise by the urging force of the torsion coil spring 24, and the engagement between the second tensioning member 23 and the mirror member 5 is released. Thus, the mirror member 5 starts moving in the direction from the retracted position to the observation position.

At this time, the urging force of the torsion coil spring 20 and the urging force of the torsion coil spring 2 in the state shown in FIG. 6 act on the mirror member 5 as a force for driving the mirror member 5 in the observation position direction. So, torsion coil spring 2
The mirror member 5 can be moved in the direction of the observation position at a higher speed than when the mirror member 5 is moved only by the urging force of zero.

Then, the mirror member 5 is moved to the state shown in FIG.
Moves, the mirror member 5 moves in the observation position direction only by the urging force of the torsion coil spring 20. Therefore, the second member of the torsion coil spring 2 that has been engaged only with the second engagement portion 1c of the contact member 1 until then. The first urging arm 2a of the torsion coil spring 2 which has been engaged only with the main body engaging portion 3 and the first urging arm 2a of the torsion coil spring 2 has been engaged with the main body engaging portion 4 as well. It also engages with the joint 1b. For this reason, the torsion coil spring 2
And the force transmitted to the mirror member 5 via the contact member 1 becomes zero, and the contact member 1 temporarily stops at this position.

However, since the urging force of the torsion coil spring 20 is acting on the mirror member 5, the movement of the mirror member 5 in the direction of the observation position is continued. For this reason, the contact shaft 5b of the mirror member 5 is separated from the second contact surface 1d of the contact member 1, and the mirror member 5 once stops receiving the driving force from the contact member 1.

When the mirror member 5 further moves in the direction of the observation position due to the urging force of the torsion coil spring 20, the contact shaft 5b of the mirror member 5 comes into contact with the first contact surface 1e of the contact member 1 this time. Then, the contact member 1 is rotated clockwise from the state shown in FIG. Thereby, as shown in FIG. 1, the second urging arm 2 b of the torsion coil spring 2 engages with the main body engaging portion 4 and separates from the second engaging portion 1 c of the contact member 1, while the first attaching arm 2 b moves. Since the forearm 2a is disengaged from the main body engaging portion 3 and engages with the first engaging portion 1b of the abutting member 1, an urging force in the counterclockwise direction in FIG. Become like For this reason, the urging force of the torsion coil spring 2 acts on the mirror member 5 via the contact member 1 as a force in a direction for moving the mirror member 5 to the retreat position (a force that resists the movement to the observation position). I do. Therefore,
The mirror member 5, which has been moving at a high speed toward the observation position at first, is suddenly decelerated.

Therefore, when the mirror member 5 reaches the observation position as shown in FIG. 2, the mirror member 5 is sufficiently decelerated, and the impact or sound generated when the mirror member 5 comes into contact with the stopper 6 and stops at the observation position. Is sufficiently suppressed. Also,
Since the bounce of the mirror member 5 in contact with the stopper 6 is reduced, the blur of the finder image can be reduced.

Here, the relationship between the forces acting on the mirror member 5 in the mirror driving mechanism described above will be described with reference to the graph of FIG. In this graph, the horizontal axis indicates the position of the mirror member 5, and the vertical axis indicates the magnitude of the driving force acting on the mirror member 5. Further, a graph indicated by a chain line in FIG. 7 shows a relationship between forces acting on the conventional mirror driving mechanism.

In FIG. 7, point A indicates the observation position of the mirror member 5, and at this time, the mirror member 5
Observation of the driving force in the retreat position direction, which is composed of the driving force acting from the torsion coil spring 11 via the mirror driving member 11 and the driving force acting from the torsion coil spring 2 via the contact member 1, and the biasing force of the torsion coil spring 20 The driving resistance force in the position direction acts. For this reason, the driving force in the retracted position direction is the same as in the conventional case (the torsion coil spring 11).
), And the initial movement speed of the mirror member 5 increases accordingly. This relationship is maintained during the interval I.

Next, when the mirror member 5 moves from the observation position A and the first contact surface 1e of the contact member 1 comes out of contact with the mirror member 5 (intermediate position B point), the mirror member 5 moves. Continue to move toward the retreat position only by the driving force of the torsion coil spring 11. This state continues during the J section.

Further, when the mirror member 5 moves toward the retracted position and the second contact surface 1d of the contact member 1 comes into contact with the mirror member 5 (point C at the intermediate position), the driving force of the torsion coil spring 2 is reduced. The direction is reversed, and the mirror member 5 has a driving force from the torsion coil spring 11 via the mirror driving member 11 toward the retreat position, and a driving force and a torsion acting from the torsion coil spring 2 via the contact member 1. A driving resistance in the direction of the observation position, which is a driving force due to the urging force of the coil spring 20, acts. For this reason, the driving resistance in the direction of the observation position is larger than in the conventional case (in which only the driving resistance by the torsion coil spring 20 acts), and the final deceleration rate of the mirror member 5 is correspondingly increased, thereby increasing the mirror resistance. The member 5 is braked at once. This relationship is
Following the section K, the mirror member 5 reaches the retreat position at point D.

Here, as can be seen from the graph of FIG. 8 showing the relationship between the time from the start of the movement of the mirror member 5 and the amount of movement, the mirror member 5 of the present embodiment is more movable than the conventional mirror member. The initial speed is fast and the end speed is slow. For this reason, the final moving time is almost equal to the conventional one. Therefore, according to the present embodiment, it is possible to substantially suppress the occurrence of impact and sound when the mirror member 5 arrives at the retreat position while making the movement time of the mirror member 5 from the observation position to the retreat position substantially equal to that of the related art. .

On the other hand, after the mirror member 5 reaches the retreat position (point D) and the mirror driving member 10 is charged, the mirror member 5 is actuated from the torsion coil spring 2 via the contact member 1. A driving force in the direction of the observation position, which is a driving force due to the force and the urging force of the torsion coil spring 20, acts. For this reason, the driving force in the observation position direction is larger than in the conventional case (when only the driving force by the torsion coil spring 20 acts), and the initial movement speed of the mirror member 5 is correspondingly increased. This relationship is maintained during the L section.

Next, the mirror member 5 moves from the retracted position (point D), and the second contact surface 1d of the contact member 1 and the mirror member 5 move.
(The point E at the intermediate position), the mirror member 5 continues to move toward the observation position only by the driving force of the torsion coil spring 20. This state continues for the M section.

Further, when the mirror member 5 moves toward the observation position and the first contact surface 1e of the contact member 1 comes into contact with the mirror member 5 (intermediate position F), the driving force of the torsion coil spring 2 is reduced. The direction is reversed, and the mirror member 5 has a driving force in the observation position direction due to the urging force of the torsion coil spring 20 and a driving resistance force in the retreat position direction acting from the torsion coil spring 2 via the contact member 1. Works. For this reason, the driving resistance force in the retracted position direction is larger than in the conventional case (when there is no driving resistance force due to the torsion coil spring 2), and the final deceleration rate of the mirror member 5 is correspondingly increased. Brakes at once. This relationship continues for the N section, and the mirror member 5 returns to the observation position at the point A.

Here, the relationship between the time from the start of movement of the mirror member 5 and the amount of movement when returning from the retracted position to the observation position is the same as in FIG. For this reason, according to the present embodiment,
While making the movement time of the mirror member 5 from the retracted position to the observation position almost equal to the conventional one, it is possible to significantly suppress the generation of impact and sound when reaching the observation position.

[0051]

As described above, according to the present invention,
When the mirror member moves from the inside position to the outside position and when the mirror member moves from the outside position to the inside position, a contact member is provided to contact the mirror member, and the mirror member is moved from the intermediate position to the contact member. Since there is provided a biasing force generating member such as a spring that applies a force (biasing force) that resists the movement of the mirror member when moving to the outside position and when moving from the intermediate position to the inside position. With a simple configuration, it is possible to sufficiently reduce the moving speed of the mirror member when the mirror member reaches the destination position, and to significantly reduce the generation of impact and noise.

Moreover, the urging force of the urging force generating member is
While the mirror member moves from the inner position to the intermediate position and from the outer position to the intermediate position, the mirror member acts as a force to assist the movement of the mirror member, and the initial movement speed of the mirror member can be increased. Even if the final movement speed is slow, the movement can be finally completed in the same movement time as the movement time of the conventional mirror member.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a mirror driving mechanism of a single-lens reflex camera according to a first embodiment of the present invention.

FIG. 2 is a side view (viewed from a side opposite to FIG. 1) of the mirror driving mechanism.

FIG. 3 is an operation explanatory view of the mirror driving mechanism.

FIG. 4 is a diagram illustrating the operation of the mirror driving mechanism.

FIG. 5 is an operation explanatory view of a main part of the mirror driving mechanism.

FIG. 6 is an operation explanatory view of a main part of the mirror driving mechanism.

FIG. 7 is a graph showing a relationship between a position of a mirror member and a spring force acting on the mirror member in the mirror driving mechanism.

FIG. 8 is a graph showing a relationship between an operation time and a movement amount of a mirror member in the mirror driving mechanism.

FIG. 9 is a schematic configuration diagram of the camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact member 1b, 1c Engagement part 1d, 1e Contact surface 2 Torsion coil spring 3, 4 Body engagement part 5 Mirror member 6 Stopper 10 Mirror drive member 11 Torsion coil spring 14, 23 Tightening member 15 Torsion coil spring 17, 26 Tension release member 19 Charge member 20 Torsion coil spring 24 Torsion coil spring

Claims (2)

[Claims] 1. A camera having a mirror member movable between an inside position and an outside position of a photographing optical path, wherein when the mirror member is located at the middle position between the inside position and the outside position, the mirror member is positioned at the outside position. And a biasing force switching means for applying a biasing force in the direction of the inner position to the mirror member when the mirror member is located between the outer position and the intermediate position. Camera. 2. The urging force switching means includes a first contact portion that selectively contacts the mirror member and pushes the mirror member in the direction of the outside position, and a second contact portion that pushes the mirror member in the direction of the inside position. A contact member having a portion and a first bias for generating a biasing force and engaging with the contact member to bias the contact member in a direction in which the first contact portion contacts the mirror member; And a biasing force generating member provided with a second biasing portion that biases the portion in a direction in which the second contact portion abuts on the mirror member. When located between the intermediate position, the first urging portion is engaged with the contact member, the second urging portion is separated from the contact member, and the mirror member is moved to the outer position. When located between the intermediate positions, the second urging portion engages with the contact member. The camera of claim 1, wherein the first biasing portion to be characterized in that the disengaged from said abutment member.