JPH10213839A - Operation device for visual field frame switching mechanism of finder, and operation device for turning operation member having neutral position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation device capable of being easily assembled and hardly causing the operational lag of a light shielding member by holding the light shielding member at a high-vision position by using a torsion spring and elastically moving it by using the end parts of a pair of springs fitted to a dial member to a classic position and a panoramic position. SOLUTION: When a photographic picture frame switching dial 33 is set at the high-vision position, a switching lever 96 is held at a neutral turning position by a neutral position holding spring 111 so as to form a visual field for high-vision. When the dial 33 is turned to the classic position or the panoramic position from this state, the lever 96 is normally and reversely turned to a position where a visual field for classic or panoramic is formed by a visual field frame switching mechanism by the end par of a lever driving spring 114 being stronger than the spring 111. Then, the visual field frame switching mechanism is integrated in a camera main body. Thereafter, the lever 96 and the neutral position holding mechanism being the spring 111 are coupled. Besides, the operation device on the dial 33 side is separately assembled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation device for a view frame switching mechanism of a finder and an operation device for a rotary operation member having a neutral position.

[0002]

2. Description of the Related Art A new system using a self-propelled film cartridge (Advanced Photo System)
In the camera of (2), the shooting screen size is set to the horizontal standard field of view (high-definition, aspect ratio: about 9:16) and the narrow field of view (classical, aspect ratio: about 2: 3) in which the left and right parts of the standard field of view are shielded. Some can be switched to a landscape view (panorama, aspect ratio of about 1: 3) in which the upper and lower parts of the standard view are shielded from light. In this camera, an image at the time of shooting is imprinted on a film in a high-definition size, and the selected screen size information is magnetically or optically recorded for each frame. The processing for each photographing screen size is performed at a stage after development based on the magnetic recording. When the left and right sides of the HDTV size are cut, a classic screen is obtained, and when the upper and lower sides are cut, a panoramic screen is obtained. Therefore, a light-blocking mechanism for changing the aspect ratio of the screen size is not required on the photographing optical path in the camera, but the photographer needs to indicate the selected screen size in the viewfinder in order to determine the composition. Therefore, a field frame switching mechanism is provided in the finder optical system.

When such a field frame switching mechanism is mechanically constructed, a movable light shielding member is provided in the vertical and horizontal directions of the field frame, and the light shielding member is driven using an operation device which can be operated from the outside. If the operation device is directly connected to the light-shielding member, an assembly error directly results in an operation deviation of the light-shielding member. Therefore, the assembly accuracy must be strictly controlled, which is not practical. Therefore, at the time of assembling the operating device and the light shielding member, a play is provided between them. From the viewpoint of assemblability, it is desirable to provide a large amount of play because the smaller the camera is, the smaller the parts are. However, providing a play between the operating device and the light blocking member causes the following problems.

Since the light-shielding member is driven to each of the classical and panoramic visual-field forming positions centering on the high-vision visual-field forming position (neutral position), a holding means for fixing at least the light-shielding member to the high-vision visual-field forming position is required. It is not preferable to provide the neutral position holding means on the side of the movable light shielding member because the structure becomes complicated and assemblability is poor. Therefore, the neutral position holding means is generally installed on the operation device side. For example, a configuration is possible in which a click stop mechanism is provided on a dial member that can be rotated from the outside, and a light shielding member forms a field frame of a predetermined size corresponding to a plurality of click positions of the dial member. However, there is a play between the operating device and the light shielding member, and there is no mechanism for holding the light shielding member itself at the neutral position, so that the position of the light shielding member may be shifted. If the position of the light-blocking member is shifted, an accurate field frame cannot be obtained not only in the high-vision position but also in the classic and panoramic positions. Further, if the neutral position holding means is constituted only by a mechanical device such as a click stop, if there is an error in the holding means itself, the position of the light shielding member also shifts. Further, in order to reliably move the light shielding member to the classical and panoramic visual field forming positions, an assembly error between the operating device and the light shielding member must be taken into consideration.

[0005] These problems are not limited to the view frame switching mechanism of the finder. For example, when there is a rotation operation member having a neutral rotation position and a rotation position in the forward / reverse direction from the neutral rotation position, when the rotation operation member and the operation device are combined with play, the rotation operation member It is difficult to reliably set the rotation position opposite to the neutral position.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an operating device for a viewfinder frame switching mechanism of a finder which is easy to assemble and does not have a possibility of an operation shift of a light shielding member. . The present invention is also easy to assemble,
It is another object of the present invention to provide an operation device for a rotation operation member having a neutral position, which can reliably obtain a neutral position and a forward / reverse rotation position.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided an operating device for a view frame switching mechanism of a finder, a seesaw member having a rotation axis and swinging in a plane parallel to the view frame surface, and receiving the swing of the seesaw member. A movable light-blocking member that switches the size of the field frame between a horizontal standard field of view, a narrow field of view in which the left and right parts of the standard field of view are shielded, and a horizontal field of view in which the upper and lower parts of the standard field of view are shielded. A shaft member having a central shaft portion for rotating the seesaw member about its rotation axis, and a radial arm portion from the central shaft portion; A neutral rotation position about the center shaft portion as a rotation center,
It has a forward / backward rotation position from this neutral rotation position, and the field frame switching mechanism forms a standard visual field via the seesaw member at the neutral rotation position, and a narrow visual field at the forward / reverse rotation position. A spring means for holding the shaft member at a neutral rotation position at all times, and for applying a return force to the neutral rotation position when the shaft member rotates forward and backward from the neutral position. ; Characterized by having; The neutral position holding means of the field frame switching mechanism is provided outside the switching mechanism, so that it is easy to assemble, and the neutral position of the light blocking member does not shift if it is coupled with the switching mechanism without play. For example, the spring means is a first torsion spring, and the torsion spring is engaged with the projection member fixed to the camera body and the radial arm of the shaft member, so that the shaft member is in the neutral rotation position. Can be held. That is, a neutral position holding mechanism is constituted by the fixed projection member, the radial arm portion of the shaft member, and the first torsion spring.

It is desirable that the operating device of the view frame switching mechanism of the finder further includes a dial member which has a pair of spring ends sandwiching a radial arm of the shaft member and is rotatably operated from the outside. When the dial member is rotated, the pair of spring ends rotates the shaft member about the central shaft portion via the radial arm portion against the first torsion spring. And have elasticity that can deform itself.

This configuration has the following advantages. First, since the first torsion spring holds the neutral position of the field frame switching mechanism, a certain amount of play can be provided between the shaft member and the dial member coupled to the field frame switching mechanism. The light shielding member is located at the standard visual field forming position (neutral position).
When the shaft member moves from the neutral position, the pair of spring ends provided on the dial member resiliently move to the narrow visual field forming position and the horizontal visual field forming position. Also, there is no operation shift of the light shielding member.

It is desirable that the dial member and the shaft member be connected in the following manner. The pair of spring ends are provided at both ends of a second torsion spring supporting the coil portion on the shaft portion of the dial member, and are provided with torsional characteristics in directions approaching each other. The dial member is provided with a stopper for holding the interval between the pair of spring ends larger than the diameter of the radial arm of the shaft member in a free state. As a result, at the neutral position, the pair of spring ends are separated from the radial arm of the shaft member, and a large play at the time of assembly can be obtained.

Further, between the dial member and the camera body, the dial member itself is held at a neutral position and at a forward / reverse rotation position against the elastic force of the first torsion spring and the second torsion spring. Click mechanism that performs the click operation. This makes it possible to hold the light blocking member at the narrow visual field forming position or the horizontally long visual field forming position.

However, if the amount of rotation of the dial member and the amount of movement of the light-blocking member match, if there is an assembly error between the shaft member and the dial member, the light-blocking member may be placed in the narrow field-of-view forming position or the horizontally long field of view. It will not move accurately to the forming position. In addition, if the light blocking member can be moved ahead of the narrow visual field forming position or the horizontally long visual field forming position, the visual field frame is not determined even if the dial is locked. Therefore, it is desirable to configure as follows so that the light shielding member can be reliably moved to the narrow visual field forming position and the horizontally long visual field forming position even if there is some assembly error. That is, the movement of the light shielding member is restricted at the narrow visual field forming position and the horizontally long visual field forming position around the standard visual field forming position. On the other hand, the forward / reverse click position from the neutral rotation position of the dial member is set to a position at which the light blocking member is further moved in the regulating direction from the movement regulating position. That is, the amount of rotation of the dial member is made larger. in this case,
Since the dial member rotates even when the light shielding member is brought into contact with the restriction position, the pair of spring ends of the second torsion spring is elastically deformed, and the restoring force holds the light shielding member at the movement restriction positions at both ends. . Even if there is a slight assembling error, the light-shielding member is reliably driven to the narrow visual field forming position or the horizontally long visual field forming position.

The radial arm portion of the shaft member has a connecting portion extending in the radial direction of the shaft member, and an eccentric shaft portion extending from an end of the connecting portion in parallel with the axis of the central shaft portion of the shaft member. The second torsion spring has a crank shape, and a pair of spring end portions of the second torsion spring can be configured to sandwich the eccentric shaft portion.

In the operating device for the field frame switching mechanism described above, it is preferable from the viewpoint of assemblability that the dial member is incorporated into the finder body after the field frame switching mechanism and the shaft member are assembled into the finder body. At this time, the viewing frame switching mechanism including the seesaw member and the shaft member are separated from each other, and the viewing frame switching mechanism including the seesaw member is assembled in a unit state. In the assembled state, the axis of the central shaft portion of the shaft member and the rotation axis of the dial member can be installed in any state of being orthogonal or parallel.

The present invention also relates to a general operation device for a rotary operation member having a neutral position, other than an operation device for a view frame switching mechanism of a finder. An operating device for a rotary operating member having a neutral position according to the present invention is a shaft member having a central shaft portion serving as a rotating shaft and a radial arm portion from the central shaft portion; A moving position and a forward / reverse turning position from the neutral turning position; when the shaft member is always held at the neutral turning position and the shaft member is turned forward / reverse from the neutral position. First torsion spring means for applying a returning force to a neutral rotation position; a dial member which is rotatably operated from outside; a coil portion supported by a shaft portion of the dial member; and a radial arm portion of the shaft member A second torsion coil spring stronger than the first torsion coil spring, and a pair of spring ends of the second torsion coil spring. In the free state, the distance between the Characterized in that comprises; large holding than the diameter of the part, the stopper portion provided in the dial member. Thereby, the neutral position and the forward / reverse rotation position of the rotation operation member can be obtained without impairing the assemblability.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 to 5 show an embodiment of a camera using a self-propelled film cartridge to which an operation device of a view frame switching mechanism of a finder according to the present invention is applied. The camera of this embodiment has a zoom lens barrel 21 at the front center of the camera body 11. The zoom lens barrel 21 includes first and second lens barrels 22 and 23.
It is movable between a storage position on the rear side in the optical axis direction and a photographable position (zoom range) in the front, and is a retractable type stored in the camera body 11 at the storage position. The zoom lens barrel 21 is driven in the optical axis direction by a zoom motor provided inside the camera body 11. The camera body 11 includes a fixed cover 13, a storage cover 14, and a slide cover 15 for protecting the stored zoom lens barrel 21 on the front. The fixed cover 13 is fixed to the camera body 11, and the slide cover 15
The camera body 11 is supported so as to be able to advance and retreat along the slide rail 16 in the longitudinal direction of the camera body 11. In addition, storage cover 14
Is linked with the slide cover 15, and the slide cover 15
Is in the closed state in which the fixed cover 1 contacts the fixed cover 13.
3 and the slide cover 15 is closed (see FIG. 1), and the slide cover 1 is opened when the slide cover 15 is separated from the fixed cover 13.
5 and completely move to the back surface of the slide cover 15 to expose the zoom lens barrel 21 (see FIG. 2).

The camera is provided with a main switch that operates just before the slide cover 15 reaches the fully opened position from the closed position and when the slide cover 15 is slightly moved from the fully opened position to the closed position. The main switch is turned on immediately before the slide cover 15 reaches the fully open position from the closed position, and is turned off when the slide cover 15 is slightly moved from the fully open position to the closed position. When the main switch is turned on, the zoom motor starts in the extending direction, and the lens barrels 22 and 23 are driven to the photographable positions. On the other hand, when the main switch is turned off, the zoom motor starts in the storage direction, and the lens barrels 22 and 23 are retracted to the storage position.

A cylindrical grip portion 12 is formed on the front left side of the camera body 11.
A large mode dial 17 and a release button 19 on the shaft of the mode dial 17 are provided on the upper end face of the camera. The mode dial 17 is a click stop type rotary dial. Depending on the click stop position, an automatic exposure mode, a pre-flash mode for automatic exposure and red-eye reduction, a slow shutter mode, a bulb and forced strobe flash mode, a bulb mode, and a flash A forced light emission mode and a strobe light emission stop mode can be selected alternatively. The release button 19 is a two-stage switch. When the shutter release button 19 is half-pressed, the photometry switch is turned on to perform photometry and distance measurement. When the release button 19 is fully pressed, the release switch is turned on to execute focusing, exposure processing, film winding processing, and the like.

A cover 1 is further provided on the front of the camera body.
Exposure window 27, AF with exposure 4, 15 open
A window 29 and a finder window 30 are provided.

On the upper surface of the camera body 11, a pop-up strobe 25 is provided. The pop-up strobe 25 is interlocked with the opening and closing of the slide cover 15, pops up by an open movement, and is stored by a closed movement.

On the back of the camera body 11, an LCD panel 31 is provided substantially at the center, an eyepiece 32 of a finder is provided almost at the center, and a photographing screen switching dial 33 and a zoom operation lever 34 are sequentially provided on the right side thereof. A cartridge cover opening / closing lever 36 for locking and releasing the cartridge cover 35 is provided below the cartridge cover 35. On the side surface of the camera body 11, an opening / closing lever 37 for opening and closing the battery compartment is provided. Note that LC in FIG.
The D panel 31 shows all display elements in a lighting state. The shooting screen switching dial 33 is a high-definition (H)
With the position neutral, the photographing screen size can be switched between the classic (C) and panoramic (P) positions by switching between the three positions. The screen size information selected by the shooting screen switching dial 33 is recorded on a film surface by a magnetic recording device (not shown).

A finder optical system is provided between the finder window 30 on the front side of the camera body 11 and the eyepiece 32 on the back side. In this viewfinder optical system, the photographer observes from the eyepiece 32 to determine the composition.
Classic (narrow) focusing on high-definition (standard) vision
A field frame switching mechanism capable of switching the size of a finder field between a field of view and a panoramic (landscape) field of view is provided. Also, a shooting screen switching dial 33 is separately provided inside the camera body 11.
An operation device that drives the field frame switching mechanism in response to the operation described above is provided.

FIGS. 6 to 11 show the view frame switching device of the finder inside the camera body 11. FIG. The configuration of the field frame switching device will be described with reference to FIG. The main plate 41 of the field frame switching device has a rectangular opening 42 near the center.
Having. Above and below the rectangular opening 42, the rectangular opening 4
A pair of sliding guide grooves 43 and 44 extending parallel to the long sides
A circular hole 45 and an arc-shaped guide hole 46 are formed in pairs above the pair of slide guide grooves 43.
A plate-like portion 47 projects from one short side of the rectangular opening 42, and a circular bearing hole 48 is formed in the plate-like portion 47.
A pair of fitting pins 49 project from both lower ends of the master plate 41 in a direction perpendicular to the plate surface.
A pair of fixing protrusions 50 protrude in the lateral direction. Also,
A hook hook 52 is formed on the upper part of the main plate 41.

A pair of guide pins 57 (see FIGS. 7 to 9) projecting from the side surface of the horizontally long wall 56 of the first L-shaped light shielding member 55 slide in the pair of slide guide grooves 43 of the master plate 41. Mating is possible. From one end of the horizontally long wall 56, a vertical light shielding wall 5 is formed at a right angle.
8 is extended, and a vertical groove 59 is formed at the other end of the horizontally long wall 56. A pair of cam engagement projections 60 are provided on the upper surface of the horizontally long wall 56 so as to project therefrom. Similarly, the pair of sliding guide grooves 44 of the main plate 41 have the horizontally long walls 62 of the second L-shaped light shielding member 61.
A pair of guide pins 63 (see FIG. 7 to FIG. 9) protruding from the side surfaces are fitted slidably. A vertical light shielding wall 64 facing the vertical light shielding wall 58 at a right angle from one end of the horizontally long wall 62.
Is extended, and one side of the vertical light shielding wall 64 is provided with the vertical groove 5.
A vertical groove 65 facing 9 is formed.

The vertical groove 59 of the first L-shaped light shielding member 55 and the second
The operation projections 81 and 82 of the seesaw member 80 are rotatably and slidably fitted into the vertical grooves 65 of the L-shaped light shielding member 61, respectively. The seesaw member 80 has a rotation shaft 83 protruding at an intermediate point between the operation protrusion 81 and the operation protrusion 82, and the rotation shaft 83 is rotatably mounted in the bearing hole 48 of the master plate 41. . A coupling hole 84 having a non-circular cross-sectional shape is formed on the surface of the seesaw member 80 opposite to the rotation shaft 83. When the seesaw member 80 swings forward and backward around the state shown in FIG. 7, the first L-shaped light shielding member 55 and the second L-shaped light shielding member 6
1 is guided by each pair of sliding guide grooves 43, 44,
The rectangular opening 42 is slid in the right and left directions by the same amount in the left and right directions. Accordingly, the vertical light-shielding wall 58 and the vertical light-shielding wall 64 perform an operation of approaching and separating from each other in the left-right direction of the rectangular opening 42. Hereinafter, the first L-shaped light shielding member 5
Regarding the fifth and second L-shaped light shielding members 61, a position where the vertical light shielding wall 58 and the vertical light shielding wall 64 approach the maximum is a narrow visual field forming position, and a position where the vertical light shielding walls 58 and 64 are maximally separated is a horizontal long visual field forming position. Call.

As described above, a pair of circular holes 45 are provided above the main plate 41. The pair of circular holes 45 are formed at equal heights from the upper side of the rectangular opening 42, and rotatably support the rotation support shafts 67a of the pair of swing cams 66. A swing guide pin 68a is fixed to each swing cam 66 on the side of the rotation support shaft 67a.
The main plate 41 is movably fitted in a pair of arc-shaped guide holes 46. Therefore, the pair of swing cams 66 are
8a swings in a range guided by the arc-shaped guide hole 46.

A cam surface 69 (see FIGS. 7 to 9) for engaging with the cam engaging projection 60 of the first L-shaped light shielding member 55 is formed on the lower surface side of the pair of swing cams 66. The cam surface 69 has a concave cam surface 69a near the rotation support shaft 67a and a flat portion 69b. In each swing cam 66,
A turning support shaft 67b protrudes in a direction opposite to the turning support shaft 67a, and a first suspension pin 68b protrudes in a direction opposite to the swing guide pin 68a. Further, a second suspension pin 70 protrudes at a position axially symmetric with respect to the first suspension pin 68b with the rotation support shaft 67b interposed therebetween. When the cam engaging projection 60 is engaged with the flat portion 69b of the cam surface 69, the swing cam 66 is held in a state where the second suspension pin 70 moves up and the first suspension pin 68b moves down ( 7 and 8), when the cam engaging projection 60 is fitted on the concave cam surface 69a of the cam surface 69, the first suspension pin 68b is raised and the second suspension pin 70 is lowered. It is rocked (see FIG. 9).

A horizontal light shielding plate 71 is arranged adjacent to the side surface of the horizontally long wall 56 of the first L-shaped light shielding member 55. This horizontal light shielding plate 7
1 has a pair of suspending arms 71a facing upward, and a pair of pin receiving holes 72 provided in the suspending arms 71a, and a pair of second suspending pins 70 of the pair of swing cams 66. Is supported through. Further, a frame-shaped light shielding plate 73 is arranged adjacent to the side surfaces of the first L-shaped light shielding member 55 and the second L-shaped light shielding member 61. From the upper side of the frame-shaped light shielding plate 73, a pair of suspension arms 7
3a is extended. The pair of suspension arms 73a have a pair of pin receiving holes 74, which are supported by a pair of first suspension pins 68b of the pair of swing cams 66, respectively. The lower frame of the frame-shaped light shielding plate 73 is a horizontal light shielding portion 75 extending in parallel with the horizontal light shielding plate 71. The inner peripheral surface of the frame-shaped light shielding plate 73 is a rectangular opening 76 having substantially the same size as the rectangular opening 42 of the master plate 41.

A pair of oscillating cams 66 are pivotally supported shafts 67a.
(67b), the pair of second suspension pins 7
0 and a pair of first suspension pins 6
The frame-shaped light shielding plate 73 supported by 8b moves in the vertical direction of the rectangular opening 42 by the same amount in the vertical direction while slightly changing the position in the horizontal direction. Thereby, the horizontal light shielding plate 71 and the horizontal light shielding portion 75
Are performed in the vertical direction of the rectangular opening 42 and in the vertical direction.

A holding plate 85 is provided adjacent to the horizontal light shielding plate 71 and the frame-shaped light shielding plate 73. The holding plate 85 engages the locking holes 86 and the hooks 87 with the pair of fixing projections 50 provided at the lower ends of both ends of the master plate 41, and fits the pair of fitting pins 49 into the pair of small circular holes 88. Then, the hook 89 is engaged with the hook hook 52 of the master plate 41 to be fixed to the master plate 41. In this fixed state, the pair of second suspension pins 70 penetrating the pair of pin receiving holes 72 are slidably fitted in the pair of arcuate guide holes 90 provided in the holding plate 85, and The pair of first suspension pins 68b penetrating through the receiving holes 74 are slidably fitted into the same pair of arcuate guide holes 91. The pair of rotation support shafts 67b are rotatably supported by a pair of circular holes 92 formed between each pair of arc-shaped guide holes 90 and the arc-shaped guide holes 91.

Near the center of the holding plate 85, a rectangular opening 9 is provided.
3 are formed. The rectangular opening 93 has an aspect ratio of about 9:16, and forms a high-definition visual field frame (standard visual field). The rectangular opening 42 provided in the main plate 41 and the rectangular opening 76 of the frame-shaped light shielding plate 73 are slightly larger than the rectangular opening 93, and are provided between the holding plate 85 and the main plate 41. Even if there is an assembling error, the field frame for HDTV is secured without interference.

When the first L-shaped light-blocking member 55 and the second L-shaped light-blocking member 61 are in the narrow visual field forming position, the vertical light-blocking wall 58
The vertical light-shielding wall 64 advances to the left and right ends of the rectangular opening (high-vision field frame) 93. Therefore, the first L-shaped light shielding member 55 and the second L-shaped light shielding member 61 are
The classical light-shielding frame that shields the left and right ends of the high-definition viewing frame according to the swing of. Further, the horizontal light-shielding plate 71 and the frame-shaped light-shielding plate 73 (horizontal light-shielding portion 75) advance to the upper and lower ends of the rectangular opening (high-definition visual-field frame) 93 when the classic light-shielding frame moves to the position where the horizontally long visual field is formed. . Therefore, the horizontal light-shielding plate 71 and the frame-shaped light-shielding plate 73 constitute a panoramic light-shielding frame that shields the upper and lower ends of the high-vision field frame according to the swing of the pair of swing cams 66. Further, a pair of cam engaging projections 60 of the first L-shaped light shielding member 55
And a pair of swing cams 66 that are engaged and driven to form an interlocking movement mechanism that drives the panoramic light shielding frame by receiving the moving force of the classic light shielding frame. From the above, the view frame switching device of the finder has a unit configuration in which the classic light-blocking frame, the panorama light-blocking frame, and the interlocking moving mechanism are assembled with the master plate 41, and are pressed and held by the holding plate 85. ing.

A through hole 95 for exposing the coupling hole 84 of the seesaw member 80 is formed in the plate-like portion 94 on the side of the rectangular opening 93.
Are drilled. The coupling pin 97 of the switching lever (operation member) 96 fits into the coupling hole 84 through the through hole 95. Since the coupling hole 84 and the coupling pin 97 have a non-circular cross-sectional shape, they are coupled without relative rotation, and the rotation of the switching lever 96 is transmitted to the seesaw member 80.

The switching lever 96 has a central shaft portion 96a and a connecting portion 96b extending in the radial direction of the central shaft portion 96a.
And a spring-shaped projection (eccentric shaft portion) 98 extending eccentrically and in parallel with the central shaft portion 96a from the end of the connecting portion 96b. Since the connection portion 96b and the spring hook projection (eccentric shaft portion) 98 are located in the radial direction with respect to the central shaft portion 96a, they are collectively called a radial arm portion. The switching lever 96 can rotate the seesaw member 80 about the rotation shaft 83 through the central shaft portion 96 a by rotating the spring hook projection 98. As mentioned earlier,
The seesaw member 80 slides the first L-shaped light shielding member 55 and the second L-shaped light shielding member 61 forward and backward in the left-right direction of the high-vision field frame. Since this slide is guided by the slide guide grooves 43 and 44 provided in the master plate 41, the seesaw member 80 swings within a certain range. Accordingly, the amount of rotation of the switching lever 96 corresponds to the amount of sliding of the first L-shaped light-blocking member 55 and the second L-shaped light-blocking member 61, and each of the pair of guide pins 57, 63 makes each pair of sliding of the master plate 41. When it comes into contact with the ends of the guide grooves 43 and 44, the rotation of the switching lever 96 is locked.

FIG. 10 shows the view frame switching mechanism in the assembled state. The classic light-shielding frame, panorama light-shielding frame, and interlocking moving mechanism are sandwiched between the master plate 41 and the holding plate 85, and are configured as an integrated field frame switching unit 100. In the unit 100, a seesaw member 80 operated by the switching lever 96 is also sandwiched and supported. After the field frame switching unit 100 is assembled integrally, it is mounted on the finder optical system support portion 101 (FIG. 11) of the camera body. In the finder optical system support unit 101, an objective optical system 102, a fixed mirror 103, a fixed lens 104, a Porro prism 105, and an eyepiece 32 are arranged in this order from the object side. The viewfinder optical system is provided with a fixed mirror 1 to secure an optical path length in the camera body 11 which is thin in the front-back direction.
The optical axis is bent in a crank shape when viewed planarly by the 03 and the Porro prism 105. The image from the objective optical system 102 is reflected by a fixed mirror 103, and then the fixed lens 1
The image is formed at the position (focus plane) immediately after the fixed mirror 1
The image is converted into an erect image by a total of four reflecting surfaces of the lens 03 and the Porro prism 105, and is observed through the eyepiece 32.

A unit mounting portion 106 is formed on the finder optical system support portion 101 at a position corresponding to the focal plane. The field frame switching unit 100 is fitted into the unit mounting portion 106 with the holding plate 85 facing the fixed lens 104 and the master plate 41 facing the Porro prism 105. The seesaw member 80 is provided on the wall surface of the unit mounting portion 106.
A through-hole 108 for exposing the coupling hole 84 to the outside is formed, and the coupling pin 97 of the switching lever 96 can be coupled to the coupling hole 84. The reason why the field frame switching unit 100 and the switching lever 96 are separate is to improve the assemblability, and it is also possible to form the unit integrally and to form a unit.

A fixing protrusion 110 is provided on a side surface of the upper cover 107 fixed to the finder optical system support portion 101 from above.
Is protruding. When the upper cover 107 is attached, the fixing protrusion 110 is located near the center shaft portion 96 a of the switching lever 96 and the spring hook protrusion 98.

When the coupling pin 97 is attached to the coupling hole 84, the switching lever 96 (spring hook 98)
Of the camera body 11 extends in the left-right direction.
On the other hand, the shooting screen switching dial 33 is
Pivots in a plane parallel to the rear plate of. That is, the rotation axis of the central shaft portion 96a of the switching lever 96 is orthogonal to the rotation axis of the shooting screen switching dial 33. An operation device for transmitting the operation of the photographing screen switching dial 33 to the field frame switching unit 100 will be described with reference to FIGS.

As shown in FIG. 15, the switching lever 9
A coil portion of a neutral position holding spring (torsion spring) 111 is wound around the central shaft portion 96a of the motor shaft 6. The neutral position holding spring 111 intersects with a pair of fixed protrusion holding portions 11 that sandwich and hold the fixed protrusion 110 of the upper cover 107.
2, the ends of the fixed projection holding portion 112 are engaged with the spring hook projection 98 as a pair of lever holding ends 113 bent at substantially right angles. The neutral position holding spring 111 is
Since the fixed portion (fixed projection 110) of the camera body and the rotating operation portion (spring hook 98) of the switching lever 96 are engaged, the switching lever 96 is elastically moved to a fixed position (FIG. 12) by the spring force. Is held At this time, the seesaw member 80 coupled to the switching lever 96 includes the vertical groove 59 of the first L-shaped light shielding member 55 and the vertical groove 6 of the second L-shaped light shielding member 61.
5 is in a neutral position (FIG. 7), which is positioned on a straight line. Since the switching lever 96 and the seesaw member 80 rotate integrally,
The position in FIG. 12 is referred to as a neutral rotation position of the switching lever 96.
That is, the radial arm of the switching lever 96 and the upper cover 1
07 and the neutral position holding spring 111 constitute a neutral position holding mechanism for urging the switching lever 96 to the neutral rotation position.

The photographing screen switching dial 33 has three rotation positions shown in FIG. 4 between the camera body and the camera body, ie, clicks for locking at high definition (H), classic (C), and panorama (P). It has a mechanism 120. The photographing screen switching dial 33 further includes a brush 124 that rotates integrally. The brush 124 detects the three click stop positions, and detects the three click stop positions.
An electric signal indicating the screen size is transmitted to U. The camera is provided with a magnetic recording device (not shown) near the film surface, and information on the screen size detected by the brush 124 is magnetically recorded on the film surface. Based on this magnetic information, the left and right sides of the photographing screen are cut off for the one shot in the classic size, and the top and bottom of the shooting screen are cut off for the one shot in the panoramic size.

A stopper 109 is provided on the back side of the photographing screen switching dial 33 at a position eccentric from the center of the rotating shaft 33a. A coil portion 114 of a lever drive spring (torsion coil spring) 114 is provided on the rotating shaft 33a.
a from the coil portion 114a, a pair of projection holding portions 115 and 116
Extending in the radial direction. The lever drive spring 114 is
The projection holding portions 115 and 116 are provided with a twisting characteristic in a direction of approaching each other, and the stopper 109 is inserted between the projection holding portions 115 and 116 to slightly increase the interval between the projection holding portions 115 and 116. It is held in a state where it is held. When the shooting screen switching dial 33 is turned, the lever driving spring 114 is turned integrally. The ends of the projection holding portions 115 and 116 further include a pair of bent ends 11 bent in a direction substantially parallel to the axis of the rotation shaft 33a.
7, 118 are formed. The bent ends 117 and 118 are located at positions eccentric from the axis of the rotation shaft 33a, and when the photographing screen switching dial 33 is attached to the camera body 11,
The bent ends 117 and 118 face each other with the spring hook 98 of the switching lever 96 interposed therebetween. The protrusion holding portions 115 and 11
The distance between the bent ends 117 and 118 is kept larger than the diameter of the spring hooking projection 98 by the stopper 109 sandwiched between the springs 6 (see FIGS. 13 and 14).

When the photographing screen switching dial 33 is click-stopped at the high vision position (H), the bent ends 117 and 118 are separated from the spring hook projection 98 (FIG. 12). At this time, the neutral position holding spring 111 holds the switching lever 96 at the neutral rotation position. When the shooting screen switching dial 33 is turned to the classic position (C), the lever driving spring 114 turns in a direction in which the bent end portion 118 engages with the spring hooking projection 98 (FIG. 16), and the shooting screen switching dial When 33 is rotated to the panoramic position (P), the lever drive spring 114 rotates in a direction in which the bent end 117 engages with the spring hook projection 98 (FIG. 1).
7). When the bent end 117 or the bent end 118 engages with the spring hook projection 98, the neutral position holding force of the neutral position holding spring 111 and the rotation urging force of the lever drive spring 114 simultaneously act on the switching lever 96. Is the lever drive spring 1
The restoring force 14 is set stronger than the restoring force of the neutral position holding spring 111. Therefore, when the shooting screen switching dial 33 is turned to the classic position (C) or the panorama position (P), the bent end 117 or the bent end 11
8 rotates the switching lever 96 in the forward and reverse directions via the spring hooking projection 98 against the neutral position holding spring 111.

As described above, the forward and reverse rotation of the switching lever 96 is controlled by the first L-shaped light shielding member 55 and the second L-shaped light shielding member 61.
Can be performed until the left-right sliding is restricted. On the other hand, the shooting screen switching dial 33 is click-stopped at the classic position (C) and the panorama position (P) centering on the high vision position (H), so that the forward and reverse rotation amounts are similarly determined. In the present embodiment,
The shooting screen switching dial 33 is moved from the high definition position (H) to the classic position (C) or the high definition position (H).
From the neutral position to the click position at which the first L-shaped light-blocking member 55 and the second L-shaped light-blocking member 61 move from the neutral position to the click position at the panorama position (P). The slide amount is set to be larger than the forward and reverse slide amount before being regulated by the end. Therefore, before the photographing screen switching dial 33 is locked at the classic position (C) or the panoramic position (P), the first L-shaped light shielding member 55 and the second L-shaped light shielding member 61 are each provided with a pair of guide pins 57 and 63. Engage with the ends of the pair of sliding guide grooves 43 and 44 of the master plate 41. Since the photographing screen switching dial 33 can be further rotated, when the dial is rotated to the click position, the bent end 117 or the bent end 118 of the lever drive spring 114 is deformed by its own elasticity, and the switching lever 96 is moved. Energized, 1st L
The character light shielding member 55 and the second L-shaped light shielding member 61 are pressed to the slide restriction position. From the above, the lever drive spring 1
Reference numeral 14 denotes a state in which the field frame switching mechanism is not driven when the shooting screen switching dial 33 is at the high vision position (H), and when the shooting screen switching dial 33 is turned to the classic position (C) and the panorama position (P). Then, the field frame switching mechanism is driven with an overdriving driving force.

The field frame switching mechanism and the operating device having the above-described structure operate as follows. A frame shown by a two-dot chain line in FIGS. 7 to 9 is a rectangular opening 93 forming a fixed high vision field frame.

FIG. 12 shows the operation device of the field frame switching mechanism when the shooting screen switching dial 33 is at the high vision position (H). Bent end 11 of lever drive spring 114
7 and 118 are separated from the spring hook projection 98,
The switching lever 96 is maintained at the neutral rotation position by the spring force of the neutral position holding spring 111. That is, the seesaw member 80 coupled to the switching lever 96 is held at the neutral position.

FIG. 7 shows the field frame switching mechanism at this time.
Since the seesaw member 80 is in the neutral position, the vertical light-shielding wall 58 of the first L-shaped light-shielding member 55 and the vertical light-shielding wall 64 of the second L-shaped light-shielding member 61 are out of the angle of view of the rectangular opening (high-definition viewing frame) 93. is there. At this time, the first L-shaped light shielding member 55 is at a position where the pair of cam engaging projections 60 push up the flat portion 69 b of the cam surface 69 below the pair of swing cams 66. As a result, the pair of oscillating cams 66 in which the second suspension pin 70 rises and the first suspension pin 68b is lowered, raises the horizontal light shielding plate 71 out of the angle of view of the rectangular opening 93, and The frame-shaped light-shielding plate 73 is held at a position where 76 substantially matches the rectangular opening 42 of the master plate 41. That is, the shooting screen switching dial 33
Is in the high-definition (H) position, the rectangular opening 93 provided in the holding plate 85 serves as a view frame of the finder.

FIG. 16 shows an operating device of the field frame switching mechanism when the photographing screen switching dial 33 is operated from the high vision position (H) to the classic position (C). Since the shooting screen switching dial 33 is rotated clockwise in the figure, the lever drive spring 114 is integrally rotated clockwise. Then, the bent end portion 118 engages with the spring hooking projection 98, and a force acts to rotate the spring hooking projection 98 upward in the drawing. Due to the difference in spring force between the lever drive spring 114 and the neutral position holding spring 111, The switching lever 96 is rotated in the direction of arrow A in FIG. Thereby, the seesaw member 80 rotates counterclockwise in FIG. 7 from the neutral position.

FIG. 8 shows the field frame switching mechanism at this time.
The rotation of the seesaw member 80 causes the operation projection 81 to push the vertical groove 59 leftward in the figure, so that the first L-shaped light shielding member 55 is guided by the pair of sliding guide grooves 43 and moves leftward in FIG. Slided. At the same time, the operation protrusion 82 pushes the vertical groove 65 rightward in the drawing, so that the second L-shaped light shielding member 61 is guided by the pair of sliding guide grooves 44 and slides rightward in FIG. With this slide, the vertical light shielding wall 58 and the vertical light shielding wall 6
4 advance to the left and right ends of the rectangular opening 93. Since the left and right sides of the field frame are shielded from light by the vertical light-blocking walls 58 and the vertical light-blocking walls 64, the field frame becomes narrower in the horizontal direction. On the other hand, when the first L-shaped light shielding member 55 is slid to the left, the cam surface 69 of the swing cam 66 has a planar shape in the moving direction of the cam engaging projection 60. Face 69
7 does not change, and the pair of swing cams 66
Is not rotated from the position. Therefore, the horizontal light-shielding plate 71 and the frame-shaped light-shielding plate 73 (horizontal light-shielding portion 75) are held without being driven from a position outside the angle of view of the rectangular opening 93. That is, the vertical visual field is determined by the rectangular opening 93. In this state, the aspect ratio of the field frame is about 2: 3, and the field frame is a classic field frame.

The amount of rotation of the shooting screen switching dial 33 from the high vision position (H) to the click stop at the classic position (C) is the first L-shape from the high vision field forming position (neutral position) to the narrow field forming position. It is larger than the movement amount of the light shielding member 55 and the second L-shaped light shielding member 61.
Therefore, in FIG. 16, the spring hook projection 9 of the switching lever 96 interlocked with the light shielding members 55 and 61 via the seesaw member 80.
Reference numeral 8 indicates that rotation upward from the illustrated position is restricted, and the lever drive spring 114 is slightly bent to press the spring hook projection 98 in the restriction direction.

FIG. 17 shows an operation device of the field frame switching mechanism when the photographing screen switching dial 33 is operated from the high vision position (H) to the panorama position (P). Since the photographing screen switching dial 33 is rotated counterclockwise in the figure, the lever drive spring 114 is integrally rotated counterclockwise. Then, the bent end portion 117 engages with the spring hooking projection 98 and a force acts to rotate the spring hooking projection 98 downward in the drawing, and the difference between the spring force of the lever drive spring 114 and the spring force of the neutral position holding spring 111 causes The switching lever 96 is turned in the direction of arrow B in FIG. Thereby, the seesaw member 80 rotates clockwise in FIG. 7 from the neutral position.

FIG. 9 shows the field frame switching mechanism at this time.
The rotation of the seesaw member 80 causes the operation protrusion 82 to push the vertical groove 65 leftward in FIG.
Is slid leftward in FIG. 7 under the guidance of the pair of sliding guide grooves 44. At the same time, the operation projection 81 is
Is pushed rightward in FIG. 7, so that the first L-shaped light shielding member 5
5 is slid rightward in FIG. 7 under the guidance of the pair of sliding guide grooves 43. In this slide, the vertical shading wall 5
8 and the vertical light-shielding wall 64 are moved in a direction away from the rectangular openings 42, 93, so that the first L-shaped light-shielding member 55 and the second L-shaped light-shielding member 61 are not related to the size of the field frame, and The field of view is determined by the rectangular opening 93. When the first L-shaped light shielding member 55 slides rightward, the pair of cam engagement protrusions 60 of the first L-shaped light shielding member 55 are
Is fitted to the concave cam surface 69a formed in the above. Then, the pair of swing cams 66 swing counterclockwise in FIG. 7, the pair of second suspension pins 70 move down, and the pair of first suspension pins 68b move up. As a result, the horizontal light-shielding plate 71 is moved substantially parallel downward in the figure, the frame-shaped light-shielding plate 73 is moved substantially parallel upward in the figure, and the horizontal light-shielding portion 75 of the frame light-shielding plate 73 is rectangular. The opening 93 extends to the upper and lower ends. Since the upper and lower portions of the rectangular opening 93 are shielded by the light shielding plate 71 and the horizontal light shielding portion 75,
The field frame becomes narrower in the vertical direction. In this state, the aspect ratio of the field frame becomes approximately 1: 3, and the field frame becomes a panoramic field frame.

The amount of rotation of the shooting screen switching dial 33 from the high vision position (H) to the click stop at the panorama position (P) is the first L-shaped light shielding from the high vision field forming position (neutral position) to the horizontally long field forming position. Member 5
The distance is larger than the movement amount of the fifth and second L-shaped light shielding members 61. Therefore, in FIG. 17, the light shielding member 5 is
The downward movement of the spring hooking projection 98 of the switching lever 96 connected to 5 and 61 from the illustrated position is restricted.
The lever drive spring 114 is slightly bent and presses the spring hook projection 98 in the regulating direction.

When the photographing screen switching dial 33 is turned from the classic position (C) or the panorama position (P) to the high vision position (H), the pushing force of the lever driving spring 114 is released, and the switching lever 96 is moved to the neutral position holding spring. 111 returns to the neutral rotation position. As a result, the field frame switching mechanism returns to the field frame for high vision.

To briefly summarize the above operation, when the shooting screen switching dial 33 is at the high vision position (H), the neutral position holding spring 111 holds the switching lever 96 at the neutral rotation position, and the field frame switching mechanism. Forms a field of view for HDTV. From this state, the shooting screen switching dial 33
Is rotated to the classic position (C) or the panorama position (P), the end of the lever drive spring 114 stronger than the neutral position holding spring 111 causes the field frame switching mechanism to form a field frame for the classic or panorama. The switching lever 96 is rotated forward and backward to the position.

In this operating device for the field frame switching mechanism, the field frame switching mechanism is assembled in the camera body as a unit 100.
The switching lever 96 for driving this and the neutral position holding spring 11
1 and a neutral position holding mechanism, which is connected later, and an operating device on the photographing screen switching dial 33 side is separately assembled. Since the neutral position holding mechanism is attached from the outside of the unit 100, it is easy to assemble, and is coupled with the unit 100 without play, so that the neutral position can be held without causing a shift in the light blocking member. Further, since the bent ends 117 and 118 of the lever drive spring 114 are separated from the spring hook projection 98 in the neutral state, the play for adjusting the assembly error of the operating device can be increased. Therefore, the assemblability of the entire finder device is good. Further, since the lever drive spring 114 is slightly rotated, even if there is a certain assembly error, the light shielding member can be moved to the classic visual field forming position or the panoramic visual field forming position and held there. .

Although the neutral position holding spring 111 and the lever driving spring 114 are both torsion springs having coil portions, different forms are possible. For example, a pair of spring members corresponding to the bent ends 117 and 118 of the lever drive spring 114 may be directly fixed to the back side of the shooting screen switching dial 33. Further, a spring member having portions corresponding to the protrusion holding portion 112 and the lever holding end portion 113 of the neutral position holding spring 111 may be made to protrude from the upper cover 107.

In the above-described embodiment, the narrow-width light-shielding frame (classical light-shielding frame) that moves in the horizontal direction of the horizontally long standard field-of-view frame (high-vision field-of-view frame) is centered on the high-vision field-of-view formation position (neutral position). A horizontally long light-blocking frame (panoramic light-blocking frame) that is driven in the opposite direction to the narrow field-of-view frame position (classic field-of-view forming position) and the horizontal long field-of-view frame position (panoramic field-of-view forming position) moves vertically in the standard field frame. This is linked to the movement from the neutral position of the light blocking frame for narrow visual field to the position of the horizontally long visual field frame. By inverting the aspect ratio of the above-described embodiment and each field frame component member, a mode in which the master-slave relationship of this operation is reversed is also possible. In this embodiment, the light shielding frame for the horizontally long field of view (the light shielding frame for the panorama) moves forward and backward from the neutral position,
The narrow-field light-shielding frame (classical light-shielding frame) is driven only when the horizontal long-field light-blocking frame moves from the neutral position to the narrow field-of-view frame position (classical field-of-view forming position).

The above description relates to the operating device of the view frame switching mechanism of the finder. However, the technical idea of the present application can be applied to all operating devices of the rotary operating member having the same neutral position. . For example, there is a video deck of a type in which a fast-forward and rewind operation of a tape is performed by forward and reverse rotation of a dial switch. The form in which the present invention is applied to this video deck is as follows.

A rotation switch lever having a center shaft serving as a rotation shaft and a radial pin from the center shaft is disposed inside the video deck. This rotation switch lever
It has a neutral rotation position and a forward / reverse rotation position from the neutral rotation position. The neutral rotation position is an off position, and when moved to the forward / reverse rotation position, fast-forward or rewind. A switch mechanism that turns on the switch is configured. The rotation switch lever is provided with a first torsion spring that is normally held at the neutral rotation position, and applies a return force to the neutral rotation position when the rotation switch is rotated forward or backward from the neutral position. On the other hand, a shaft portion of a dial member provided outside the video deck supports a coil portion of a second torsion coil spring, and a pair of spring ends of the second torsion coil spring is connected to the rotation switch. It is located at the position where the radial pin of the lever is sandwiched. The pair of spring ends are urged in directions approaching each other,
The dial-shaped operation member further includes a stopper portion for holding the interval between the pair of spring ends larger than the diameter of the radial pin of the rotary switch lever in a free state. And the second
Is set stronger than the first torsion coil spring. When the dial-type operation switch is configured in this manner, the rotation switch lever is normally held at the neutral position, and the operation device in which the tape is fast-forwarded or rewound when the dial member is rotated in the normal or reverse direction is incorrectly operated. It can be easily assembled without fear of operation.

[0060]

As described above, according to the present invention, it is possible to provide an operation device for a view frame switching mechanism of a finder which is easy to assemble and does not cause a shift in operation of a light shielding member. In addition, it is possible to obtain an operating device of a rotating operation member having a neutral position, which is easy to assemble and can reliably obtain a neutral position and a forward and reverse rotating position.

[Brief description of the drawings]

FIG. 1 is a front view of a camera to which an operation device of a view frame switching mechanism of a finder according to the present invention is applied, in a state where a photographing lens is stored.

FIG. 2 is a front view of the camera in a photographable state.

FIG. 3 is a plan view of the camera in a photographable state.

FIG. 4 is a rear view of the camera.

FIG. 5 is a side view of the camera in a photographable state.

FIG. 6 is an exploded perspective view showing an embodiment of a view frame switching mechanism of a finder.

FIG. 7 is a diagram showing a viewfinder field frame switching mechanism when a high-definition (standard) field frame is formed, as viewed from the direction of arrow α in FIG. 6;

8 is a diagram showing a state in which the field frame switching mechanism of FIG. 7 forms a classic (narrow) field of view.

9 is a diagram showing a state in which the field frame switching mechanism of FIG. 7 forms a panoramic (horizontally long) field of view.

FIG. 10 is a perspective view of an assembled state of a finder field frame switching mechanism.

FIG. 11 is a perspective view showing a mounting position of a field frame switching mechanism on a finder optical system.

FIG. 12 shows a high-definition (H) shooting screen switching dial
FIG. 4 is a diagram showing the operation device of the view frame switching mechanism of the finder according to the present invention when viewed from the rear side of the camera when the camera is in the position.

FIG. 13 is a plan view illustrating a main part of an operation device of a field frame switching mechanism of the finder.

14 is a front view of the operation device of the view frame switching mechanism of the finder, as viewed from the direction of arrow XIV in FIG. 13;

FIG. 15 is a side view showing the engagement state of the switching lever and the neutral position holding spring as viewed from the direction of arrow XV in FIG. 13;

FIG. 16 is a rear view showing the operation device of the view frame switching mechanism of the finder when the shooting screen switching dial is at the classic (C) position.

FIG. 17 is a rear view showing the operation device of the view frame switching mechanism of the finder when the shooting screen switching dial is at the panorama (P) position.

[Explanation of symbols]

 Reference Signs List 11 camera body 33 shooting screen switching dial 41 master plate 93 rectangular opening (view frame for high definition) 55 first L-shaped light shielding member 61 second L-shaped light shielding member 66 swing cam 71 horizontal light shielding plate 73 frame-shaped light shielding plate 80 seesaw member 85 Holding plate 96 Switching lever 96a Central shaft portion 96b Connection portion 98 Spring-hung protrusion (eccentric shaft portion) 100 View frame switching unit (view frame switching mechanism) 101 Viewfinder optical system support portion 109 Stopper portion 110 Fixed protrusion 111 Neutral position holding spring 114 Lever drive spring 120 Click mechanism

Claims (12)

[Claims] A seesaw member having a rotation axis and swinging in a plane parallel to a field frame surface;
A horizontally long standard field of view, a narrow field of view that shields left and right parts of the standard field of view, and a movable light blocking member that switches the size of the field frame between a horizontal field of view that blocks upper and lower parts of the standard field of view. A finder field frame switching mechanism provided with: a shaft member provided with a center shaft portion for rotating the seesaw member about its rotation axis, and a radial arm portion from the center shaft portion; It has a neutral rotation position about the center shaft portion as a rotation center, and a rotation position in the forward / reverse direction from the neutral rotation position. To form a narrow field of view and a horizontally long field of view respectively at the forward and reverse rotation positions; the shaft member is always held at the neutral rotation position, and the shaft member rotates forward and backward from the neutral position. Spring means for exerting a return force to a neutral rotation position when released. Operating system of the finder field frame switching mechanism. 2. The operating device for a field frame switching mechanism according to claim 1, wherein said spring means is a first torsion spring, and is associated with a projection member fixed to a camera body and a radial arm of said shaft member. An operation device for a view frame switching mechanism of a finder that holds a shaft member at a neutral rotation position by being combined. 3. The operating device for a field frame switching mechanism according to claim 1, further comprising a pair of spring ends sandwiching a radial arm portion of said shaft member, the dial member being operated to rotate from the outside. When the dial member is rotated, the pair of spring ends is opposed to the first torsion spring, and the shaft member is centered on the center shaft portion via the radial arm portion. An operation device for a view frame switching mechanism of a finder, characterized in that the finder can be rotated and the device itself has deformable elasticity. 4. The operating device for a field frame switching mechanism according to claim 3, wherein the pair of spring ends are provided at both ends of a second torsion spring having a coil portion supported on a shaft portion of a dial member. A torsion characteristic in a direction approaching each other is provided, and the dial member is provided with a stopper portion for holding the interval between the pair of spring ends larger than the diameter of the radial arm portion of the shaft member in a free state. Operation device for the viewfinder frame switching mechanism of the provided finder. 5. The operating device for a field frame switching mechanism according to claim 3, wherein the dial member itself is located at a neutral position between the dial member and the camera body, and the first torsion spring and the second torsion spring. An operation device for a view frame switching mechanism of a finder provided with a click mechanism for holding a reversing position in a forward / reverse rotation position against an elastic force of a torsion spring. 6. The operation device for a field frame switching mechanism according to claim 5, wherein the light blocking member of the field frame switching mechanism moves between a narrow field forming position and a horizontally long field forming position centering on the standard field forming position. The operation device of the view frame switching mechanism of the finder, wherein the click position opposite to the neutral rotation position from the neutral rotation position of the dial member is set to a position where the light shielding member is further moved in the restriction direction from the movement restriction position. . 7. The operating device for a field frame switching mechanism according to claim 6, wherein a pair of spring ends of the second torsion spring is elastically deformed by a difference between a rotation amount of the dial member and a movement amount of the light blocking member. An operation device for a view frame switching mechanism of a finder in which a light shielding member is held at a movement restricting position by a returning force. 8. The operation device for a field frame switching mechanism according to claim 3, wherein the dial member is provided after the field frame switching mechanism and the shaft member are assembled in the camera body.
Operation device for the view frame switching mechanism of the viewfinder incorporated in the camera body. 9. The operation device for a field frame switching mechanism according to claim 1, wherein the seesaw member and the shaft member are separate members, and cannot be relatively rotated after the field frame switching mechanism is assembled. Operation device for the view frame switching mechanism of the finder to be connected to the camera. 10. The operation device for a field frame switching mechanism according to claim 3, wherein the radial arm portion of the shaft member has a connecting portion extending in a radial direction of the shaft member and a connecting portion of the connecting portion extending in the radial direction of the shaft member. The crankshaft has an eccentric shaft portion extending from the end portion in parallel with the axis of the central shaft portion of the shaft member. A pair of spring ends of the second torsion spring sandwich the eccentric shaft portion. Operation device for the view frame switching mechanism of the viewfinder. 11. The field frame switching mechanism operating device according to claim 3, wherein the axis of the central axis of the shaft member and the rotation axis of the dial member are orthogonal to each other. Operating device for switching mechanism. 12. A shaft member provided with a central shaft portion serving as a rotation shaft and a radial arm portion from the central shaft portion;
Having a neutral rotation position and a rotation position in the forward / reverse direction from the neutral rotation position; the shaft member is always held at the neutral rotation position, and the shaft member is rotated forward / reverse from the neutral position. First torsion spring means for applying a return force to a neutral rotation position when the dial member is rotated; a dial member which is rotated from the outside; a coil portion supported by a shaft portion of the dial member; and a radial direction of the shaft member. A second torsion coil spring that is stronger than the first torsion coil spring and has a pair of spring ends biased in directions approaching each other with the arm portion interposed therebetween; and a pair of the second torsion coil springs A pivoting operation having a neutral position, comprising: a stopper provided on a dial member for holding a distance between spring ends in a free state larger than a diameter of a radial arm of a shaft member. Operating device for members.