JP2000002931A - Mirror locking mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mirror locking mechanism which is for making a locking operation for a mirror sure and can be constituted with simple structure and control the timing of the locking operation for the mirror. SOLUTION: A main mirror 120 is attached to a mirror box 110 with a pivotal shaft and rocked between a first position where the main mirror 120 is arranged at an angle of 45 deg. with an image pickup path therein and a second position where the main mirror 120 is arranged in parallel with the image pickup path. A first pad 144 is guided in a direction parallel with an axis line. The side part of the mirror 120 is provided with a second pad 148. When the supply of power to a solenoid 146A is stopped, a plunger 146B is moved in a projection direction, so that the first pad 144 comes into press-contact with the second pad 148, to lock the mirror 120. When the power is supplied to a solenoid 146, the plunger 146B is pulled in the solenoid 146A and the first pad 144 is separated from the second pad 148, to release the locking of the mirror 120.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mirror locking mechanism for a single-lens reflex camera.

[0002]

2. Description of the Related Art In a single-lens reflex camera, an optical path of light incident from a photographing lens is switched by swinging a mirror provided in a camera body so as to be swingable, so that the light can be selectively applied to a film surface or a viewfinder. I try to guide. In other words, this camera has an imaging optical path from a photographic lens attached to the front of the camera body to a film surface arranged near the back of the camera body. In addition, by arranging a mirror in the imaging optical path at an angle of 45 degrees with respect to the optical axis of the imaging lens, the imaging optical path is blocked, and the incident light from the imaging lens is reflected by the mirror at 90 degrees. Has a finder optical path leading to a finder prism mounted above.

The mirror is swingably supported via a pivot in a mirror box defined in the camera body, is controlled to swing by a mirror driving mechanism, and is arranged in the imaging optical path in parallel with the imaging optical path. The rocking displacement is performed to the set position. That is, when the subject is viewed through the finder, the mirror is arranged at an angle of 45 degrees in the imaging optical path, and the incident light from the photographing lens is guided to the finder side while the imaging optical path is blocked. In addition, at the time of imaging, the mirror driving mechanism operates according to the shutter operation,
The mirror is momentarily retracted from the imaging optical path, the imaging optical path is communicated, and the film surface is exposed by incident light from the photographing lens. The mirror is locked at a position where the mirror is retracted from the imaging optical path only during a period required for the exposure operation on the film. The mirror is locked by locking a locking claw provided on the mirror box side to a locked portion provided on the mirror side by a mirror locking mechanism.

[0004]

In such a mirror locking mechanism for locking the locking claw provided on the mirror box side to the locked portion on the mirror side, the mirror cannot be sufficiently swung for some reason. If the locked portion of the mirror does not reach the position of the locking claw, the locking of the mirror may be uncertain. Also, such a mirror locking mechanism tends to be complicated. Also, with such a mirror locking mechanism, it has been difficult to control the timing of locking the mirror. The present invention has been devised in view of the above circumstances, and an object of the present invention is to ensure that the mirror locking operation can be performed with a simple structure, and that the timing of the mirror locking operation can be improved. To provide a mirror locking mechanism capable of controlling the mirror locking mechanism.

[0005]

In order to achieve the above-mentioned object, the present invention is directed to an image pickup optical path from a photographing lens to a photographing film, wherein a mirror is pivotably mounted between a first position and a second position. The first position is a position where the mirror intervenes in the imaging optical path to reflect incident light from the imaging lens and guides the light to a finder; and the second position is where the mirror retreats from the imaging optical path. In a single-lens reflex camera in which the mirror is swung between the first position and the second position in response to the operation of a shutter by a mirror driving mechanism, wherein the mirror is moved between the first position and the second position. A locking mechanism that locks the mirror at each position, the locking mechanism includes a first pad that can be pressed against a side of the mirror, and a mirror that locks the first pad by pressing the first pad against a side of the mirror. Drive hand Characterized in that it comprises and.
Further, the present invention is characterized in that the mirror is swingably supported in a mirror box via a pivot.
Further, according to the present invention, a guide pin extending in a direction parallel to the pivot is provided on a side portion of the mirror box, and the first pad has a guide hole inserted through the guide pin, The pressing movement of the first pad against the mirror and the separation movement of the first pad from the mirror are guided by the guide pins. Further, the invention is characterized in that the first pad is formed to extend in an arc shape centering on the pivot. Further, the present invention is characterized in that a second pad is provided on a side portion of the mirror, and the first pad is pressed against the second pad when the first pad is pressed against the side portion of the mirror. I do. Further, the present invention provides the second aspect,
The pad is characterized by having a circular shape. Further, according to the present invention, the driving means is a solenoid plunger-type actuator having a solenoid and a plunger, and the solenoid plunger-type actuator is disposed such that an axis of the plunger extends in a direction parallel to the pivot. The first pad is attached to a tip of the plunger. Further, in the present invention, the solenoid plunger type actuator incorporates an urging member for urging the first pad connected to the plunger in a direction of pressing the first pad against a side portion of the mirror. The pad is moved in a direction away from a side of the mirror against the urging force of the urging member by the plunger displaced by energizing the solenoid, and the energizing member is turned off when the energization of the solenoid is cut off. The plunger which is displaced by the urging force is configured to be pressed against the first pad.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a single-lens reflex camera will be described below. FIG. 1 is a schematic left side view showing an internal structure of a camera provided with a mirror locking mechanism of the present invention, FIG. 2 is a schematic front view showing an assembled state of a mirror box of the camera shown in FIG. 1, and FIG. It is a principal part side view which shows the structure of. The schematic configuration of the single-lens reflex camera will be described with reference to FIG. 1, a lens mount 102 is provided on the front surface of a camera body 100 of the single-lens reflex camera.
Is mounted with a photographing lens 200. Further, a finder 210 is provided at an upper portion of the camera body 100, and a finder prism, an eyepiece, and the like (not shown) are arranged in the finder 210. Also,
A mirror box 110 is provided inside the camera body 100.
Are arranged, and the mirror 12 is placed in the mirror box 110.
0 is provided. Then, by controlling the position of the mirror 120, the optical path of the incident light from the photographing lens 200 is switched, and the incident light is transmitted to the camera body 100.
Is selectively guided to the film surface 104 or the finder 210 described above.

That is, in this camera, the taking lens 2
00 through the mirror box 110 to the film surface 10
4 (a first image forming unit) has an imaging optical path (indicated by an arrow α in FIG. 1). Also, a mirror 120 is provided in the imaging optical path.
Is arranged at an angle of 45 degrees with respect to the optical axis of the imaging optical path, thereby shielding the imaging optical path, and reflecting the incident light from the photographing lens 200 by 90 degrees by the mirror 120, so that the camera body 100 The optical path is guided to a finder screen (second imaging unit) (not shown) provided above, and this optical path is connected to the finder optical path (in FIG.
). The light incident on the finder screen is further refracted through the finder prism and guided to the eyepiece lens system.

[0008] A pivot 116 having an axis in a direction orthogonal to the imaging optical path and the finder optical path is provided in an upper portion of the mirror box 110 near the rear surface, and the mirror 120 is mirrored via the pivot 116. Box 11
0 and is swingably supported. And
The mirror 120 is pivoted by the mirror driving mechanism described later.
The swing control is performed so as to rotate about the center 16, and from the first position (indicated by the phantom line in FIG. 1) which is disposed at an angle of 45 degrees with the imaging optical path in the imaging optical path, retreats from the imaging optical path, A second position (solid line 120 in FIG. 1) arranged parallel to the imaging optical path
(shown by a).

Therefore, the first position is a position where the mirror 120 intervenes in the image pickup optical path and reflects the incident light from the image pickup lens 200 to guide it to the finder 210, while the second position is a position where the mirror 120 Is the position when the robot is retracted from the imaging optical path.

That is, when the subject is viewed through the finder 210, the mirror 120 is arranged at an angle of 45 degrees in the imaging optical path, and the incident light from the photographing lens 200 is guided to the finder side while the imaging optical path is blocked. To
Further, at the time of imaging, the mirror driving mechanism operates in response to the shutter operation, the mirror 120 is momentarily retracted from the imaging optical path, the imaging optical path is communicated, and the film surface 104 is exposed by the incident light from the imaging lens 200. The mirror box 110 includes a left frame 120A and a right frame 120B of the mirror 120 extending in a direction orthogonal to the pivot 116.
A pair of receiving pins 114 for receiving the first position from below is provided.

Next, the mirror driving mechanism will be described.
The mirror driving mechanism is provided on the outer surface of the mirror box 110, and is driven by the linear motor
0 is driven to oscillate between the first position and the second position.

As shown in FIG.
A support member 122 having an elongated linear shape, a stator 132 fixed and supported on the support member 122,
A movable element 134 is provided on the supporting member 122 so as to be swingable in the longitudinal direction. The support member 122 has one end rotatably attached to a pivot 124 provided on the mirror box 110, thereby allowing the linear motor 130 to rotate.
Is swingably supported by the mirror box 110.
The mover 134 of the linear motor 130 has a connecting pin 128
And the support member 122 is disposed so as to extend in a direction substantially along the movement trajectory of the connecting pin 128 when the mirror 120 swings. .

The linear motor 130 is connected to the mirror 1
In order to absorb the displacement between the arc trajectory of the connecting pin 128 caused by the swinging motion of the mirror 20 and the linear trajectory of the movable element 134 with respect to the stator 132, the mirror 120 can be freely pivoted about the pivot 124 with the swinging displacement of the mirror 120. It is configured to swing and displace. Further, the support member 122 is provided with a linear slit 126 in the longitudinal direction, and one of a pair of longitudinally extending portions on both sides defining the slit 126 is fixed to the stator 132. Is configured as

The linear motor 130 of this embodiment is a so-called flat plate type linear synchronous motor.
For example, the stator 132 is configured as a secondary side, and the stator 132 is configured with a field magnetic field whose polarity alternates between an S pole and an N pole along a longitudinal direction, and the movable body 134 is configured as a primary side and an electric motor is formed. An armature coil 136 is provided, and a moving magnetic field is generated by controlling a current flowing through the armature coil 136.

It should be noted that the linear motor 130 is not limited to the above-described configuration. For example, the primary motor and the secondary motor may be replaced with each other, or the linear motor 130 is not limited to the above-described linear synchronous motor. Instead, for example, a linear induction motor or a linear pulse motor may be used, and various methods can be adopted as long as the mover 134 can move along the stator 132.

The mirror box 110 has a mirror 120
Arc-shaped slit 11 corresponding to an arc trajectory caused by rocking
2 are formed. On the other hand, the mirror 120 is provided with the above-described connecting pin 128 at a side edge thereof. The connection pin 128 is connected to the mover 134 through the slit 112 of the mirror box 110 and the slit 126 of the support member 122 of the linear motor 130. Therefore, when the mover 134 and the connecting pin 128 move along the respective slits 112 and 126, the linear mirror 130 freely swings and the main mirror 120 is smoothly swung and displaced.

Next, the configuration of the mirror locking mechanism 140 will be described with reference to FIGS. Mirror locking mechanism 14
Numeral 0 includes a guide pin 142, a first pad 144, a second pad 148, a solenoid plunger type actuator (corresponding to a driving means in the claims) 146, and the like.

The guide pins 142 are connected to the mirror box 11
0 are provided on the outer surface of the mirror 0 so as to extend in a direction parallel to the pivot 116 of the mirror 120.

The first pad 144 is formed to extend in an arc shape about the pivot 116 of the mirror 120.
That is, it is formed so as to extend along the movement locus of the second pad 148 described later. The first pad 144 is guided in a direction parallel to the axis 116 by inserting guide holes 144A formed near four corners of the first pad 144 into the guide pins 142.

At the upper end of each guide pin 142, a mounting plate 14 having substantially the same shape as the first pad 144 in plan view is provided.
7 is fixed, and a solenoid plunger type actuator 146 is fixed to the mounting plate 147.

The solenoid plunger type actuator 146 includes a solenoid 146A and the solenoid 1
46A, and a plunger 146B that moves in and out in response to the interruption of the current.
The axis of 6B is arranged to extend in a direction parallel to the pivot 116 of the mirror 120. This plunger 146B
Is connected to the first pad 144.

A left frame 120A provided on the left side of the mirror 120 is provided with a shaft 148A having an axis parallel to the pivot 116 so as to pass through a not-shown notch provided on the side wall of the mirror box 110. The second pad 148 is provided at a position facing the first pad 144 at the tip of the shaft portion 148A. This second
The surface of the pad 148 facing the first pad 144 has a circular shape. The notch (not shown) provided on the side wall of the mirror box 110 is formed so that the shaft portion 148A can move as the mirror 120 swings. A right frame 120B is provided on the right side of the mirror 120.

A plunger 146B is provided on the solenoid plunger type actuator 146.
By incorporating an unillustrated urging member that applies an urging force in a direction protruding from 6A, the plunger 146 is formed.
The first pad 144 coupled to B is urged in the direction of pressing against the left side of the mirror 120, that is, in the direction of pressing against the second pad 148.

Therefore, when the power supply to the solenoid 146A is cut off (when no power is supplied), the plunger 146B moves in the projecting direction by the urging force of the urging member, and the first pad 144 moves. The mirror 120 is locked by being pressed against the second pad 148.
The pressing movement of the first pad 144 against the second pad 148 is guided by the guide pin 142. On the other hand, when power is supplied to the solenoid 146 (when power is supplied)
First, the first pad 144 is separated from the second pad 148 by the movement of the plunger 146B in the direction of being pulled into the solenoid 146A against the urging force of the urging member, and the lock of the mirror 120 is released. It has become so. The separation of the first pad 144 from the second pad 148 is guided by the guide pin 142.

Next, the operation of the mirror locking mechanism configured as described above will be described. In the initial state, the mirror 120 is locked by the mirror locking mechanism 140 at the second position. That is, the power to the solenoid 146A is cut off, and the first pad 144 is pressed against the second pad 148 by the urging force of the urging means, so that the mirror 120 is locked.

Here, when the shutter operation of the camera is performed, the solenoid 146A is energized, the first pad 144 is separated from the second pad 148, and the mirror 1 is turned on.
20 is released. Then, with the release of the lock of the mirror 120, the armature coil 13 of the linear motor 130 is released.
6 is supplied with a drive signal, and the mover 134
By moving upward along the mirror 120, the mirror 120
Rocked from the position to the first position.

When the mirror 120 reaches the first position, the power supply to the solenoid 146A is cut off, and the first pad 144 is pressed against the second pad 148, so that the mirror 1
20 is locked in the first position. At this time, the supply of the drive signal to the armature coil 136 of the linear motor 130 is stopped.

Then, when the exposure operation for the film is completed, the solenoid 146A is energized.
The first pad 144 is separated from the second pad 148, and the locking of the mirror 120 is released. And the mirror 120
When the lock is released, a drive signal is supplied to the armature coil 136 of the linear motor 130, and the mover 134 moves downward along the stator 132, so that the mirror 120
Is swung from the first position to the second position.

When the mirror 120 reaches the second position, the power supply to the solenoid 146A is cut off, and the first pad 144 is pressed against the second pad 148, so that the mirror 1
20 is locked at the second position to prepare for the next shutter operation. At this time, the armature coil 13 of the linear motor 130
The supply of the drive signal to 6 is stopped.

According to the above configuration, the mirror is locked at the first position and the second position by pressing the first pad against the second pad. Even if the movement is not sufficient, the mirror 120
Can be securely locked. Further, as described above, the mirror locking mechanism can be composed of a small number of components such as the first pad, the second pad, the guide pin, and the solenoid plunger type actuator, and thus has a simple structure. Further, unlike the related art, the timing at which the mirror 120 is locked can be controlled by switching between energization of the solenoid 146A of the solenoid plunger type actuator 146 and interruption of energization.

In the above-described embodiment, the first pad 144 is pressed against the second pad 148 to lock the mirror 120 when the power supply to the solenoid plunger type actuator 146 is cut off. 120
While the camera is locked at the second position, that is, while the camera is not performing a shutter operation, there is no need to energize the solenoid 146A, and thus there is an advantage that power consumption can be reduced.

In the above embodiment, the mirror drive mechanism is constituted by a linear motor which is a linear actuator. However, the configuration of the mirror drive mechanism is not particularly limited. , A well-known mechanism realized by a combination of a gear mechanism, a link mechanism, and a spring mechanism. Further, in the above-described embodiment, the second pad is provided on the side of the mirror, and the first pad presses the second pad to lock the mirror. However, the second pad is not provided, and the second pad is provided. One pad may be pressed against the side of the mirror to lock the mirror.

[0033]

As is clear from the above description, the present invention
A mirror is swingably mounted between a first position and a second position in an imaging optical path from an imaging lens to an imaging film, and the first position is provided when the mirror intervenes in the imaging optical path and performs the imaging. The second position is a position where the light reflected from the lens is guided to the finder, and the second position is a position where the mirror is retracted from the imaging optical path. In a single-lens reflex camera that swings between a first position and the second position, a locking mechanism that locks the mirror at the first position and the second position is provided, and the locking mechanism includes: A configuration is provided that includes a first pad that can be pressed against the side of the mirror, and a driving unit that presses the first pad against the side of the mirror to lock the mirror. For this reason, the mirror is locked at the first position and the second position by pressing the first pad against the side portion of the mirror by the driving means. Even if this is not done, the mirror can be securely locked. Further, a mirror locking mechanism can be constituted by the first pad and the driving means, and a simple structure is sufficient.
Further, the timing for locking the mirror can be controlled by the operation of the driving means.

[Brief description of the drawings]

FIG. 1 is a schematic left side view showing an internal structure of a camera provided with a mirror locking mechanism of the present invention.

FIG. 2 is a schematic front view showing an assembled state of a mirror box of the camera shown in FIG.

FIG. 3 is a side view of a main part showing a structure of a mirror driving mechanism of the camera shown in FIG. 1;

[Explanation of symbols]

120 Mirror 110 Mirror box 140 Mirror locking mechanism 144 First pad 146 Solenoid plunger type actuator (drive means) 146A Solenoid 146B Plunger 148 Second pad

Claims (8)

[Claims] 1. A mirror is mounted to be swingable between a first position and a second position in an imaging optical path from an imaging lens to an imaging film, wherein the first position is such that the mirror is located in the imaging optical path. The second position is a position where the incident light from the photographing lens intervenes and is guided to the finder by intervening, and the second position is a position where the mirror is retracted from the imaging optical path, and is responsive to a shutter operation by a mirror driving mechanism. A single-lens reflex camera for swinging the mirror between the first position and the second position, wherein a locking mechanism for locking the mirror at the first position and the second position is provided; The locking mechanism comprises: a first pad that can be pressed against the side of the mirror; and a driving unit that presses the first pad against the side of the mirror to lock the mirror. mechanism 2. The mirror locking mechanism according to claim 1, wherein said mirror is swingably supported in a mirror box via a pivot. 3. A side surface of the mirror box is provided with a guide pin extending in a direction parallel to the pivot, and the first pad has a guide hole inserted through the guide pin. 3. The mirror locking mechanism according to claim 2, wherein a pressing movement of one pad to said mirror and a separation movement of said one pad from said mirror are guided by said guide pins. 4. The mirror locking mechanism according to claim 3, wherein said first pad is formed to extend in an arc shape centered on said pivot. 5. A second pad is provided on a side of the mirror, and when the first pad is pressed against the side of the mirror, the first pad is pressed against the second pad. The mirror locking mechanism according to claim 1. 6. The mirror locking mechanism according to claim 5, wherein said second pad has a circular shape. 7. The driving means is a solenoid plunger type actuator having a solenoid and a plunger. The solenoid plunger type actuator is disposed so that an axis of the plunger extends in a direction parallel to the pivot. The mirror locking mechanism according to any one of claims 2 to 5, wherein one pad is attached to a tip of the plunger. 8. The solenoid plunger-type actuator includes an urging member for urging the first pad connected to the plunger in a direction of pressing the first pad against a side portion of the mirror. Is moved in a direction away from the side of the mirror against the urging force of the urging member by the plunger displaced by energizing the solenoid, and when the energization to the solenoid is cut off, the urging member The mirror locking mechanism according to claim 7, wherein the plunger displaced by the urging force is configured to be pressed against the first pad.