JPH08286237A - Visual field switching device - Google Patents

Abstract

PURPOSE: To provide a visual field switching device capable of arranging a driving member in a part around a visual field switching member and increasing the stability of the driving member to improve operating feeling. CONSTITUTION: In a visual field switching device provided with a visual field switching member 4 inserted into the optical path of an optical system, a driving member 6 rotated around a rotation center line (the center line of a rotary shaft 6c) in parallel with the optical axis of the optical system in a condition that this driving member is engaged with the visual field switching member 4 and guiding mechanisms 2b, 2c, 4b and 4c for moving the visual field switching member 4 among a plurality of positions corresponding to a plurality of visual fields linked with the rotation of the driving member 6, the rotation center line of the driving member 6 is set other than visual fields F1 to F3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for switching the field of view of a finder of a camera.

[0002]

2. Description of the Related Art As a viewfinder of a camera capable of setting a plurality of fields of view, Japanese Patent Laid-Open No. 6-82882 discloses a finder of FIG.
Are disclosed. In the illustrated apparatus, two L-shaped visual field frames 10 symmetrical with respect to the finder optical axis are provided on a visual field mask 100 that defines a rectangular first visual field F1.
1, 102 and the driving wheel 103 are sequentially superposed in the finder optical axis direction (direction orthogonal to the paper surface). Driving wheel 1
Reference numeral 03 denotes the pins 101a and 102a of the field frames 101 and 102.
And the long holes 101 of the field frames 101 and 102, respectively.
b and 102b are fitted with the pins 100a of the field mask 100. When the driving wheel 103 is rotated, the field frames 101 and 102
Moves in the longitudinal direction of the long holes 101b and 102b, and the first visual field F1 is narrowed by the visual field frames 101 and 102. Figure 5
5A shows a state in which the first visual field F1 is narrowed in the short side direction and the second visual field F2 is defined, and FIG. 5C shows a state in which the first visual field F1 is narrowed in the long side direction and the third visual field F3 is The specified states are shown respectively. In addition, FIG.
Both 1 and 102 are in a state of being retracted out of the first visual field F1.

[0003]

In the above visual field switching device, the center of rotation of the moving wheel 103 is set within the first visual field F1. Therefore, a large moving wheel 103 that surrounds the first field of view F1 from all sides is required, and the device becomes large. Since the driving wheel 103 cannot be supported at the center of rotation, the driving wheel 10
There is a possibility that the stability of 3 is poor and smooth operation cannot be guaranteed.

An object of the present invention is to provide a visual field switching device in which a driving member can be compactly arranged around a part of the visual field switching member, the stability of the driving member can be enhanced, and the operation feeling can be improved.

[0005]

1 to 4 showing an embodiment, the invention of claim 1 relates to a visual field switching member 4 inserted into the optical path of an optical system and a visual field switching. The drive member 6 that is rotated around a rotation center line (center line of the rotation shaft 6c) parallel to the optical axis direction of the optical system while being engaged with the member 4, and in association with the rotation of the drive member 6, Guide mechanisms 2b, 2c, 4b, 4c for moving the visual field switching member 4 among a plurality of positions respectively corresponding to the plurality of visual fields F1 to F3.
And the rotation center line of the driving member 6 is the visual fields F1 to F.
The above-mentioned object is achieved by the visual field switching device set to the outside. The invention of claim 2 is applied to the visual field switching device of claim 1, and the click mechanism 6d for constraining the driving member 6 at a plurality of positions corresponding to a plurality of visual fields F1 to F3,
7d, 7f, 7g, 7h are provided. The invention of claim 3 is applied to the visual field switching device of claim 2, and click mechanisms 6d, 7d, 7f, 7g, 7h are provided between the member 7 for rotatably supporting the drive member 6 and the drive member 6. ing.

[0006]

According to the first aspect of the present invention, since the rotation center line of the driving member 6 engaging with the visual field switching member 4 is set outside the visual fields F1 to F3, the driving member 6 is surrounded so as to surround the visual fields F1 to F3 from four directions. Therefore, the drive member 6 can be compactly arranged on one side of the visual field switching member 4. The drive member 6 can be supported on the rotation center side. In the invention of claim 2, when the visual field switching member 4 is moved to the position corresponding to any of the plural visual fields F1 to F3 by the driving member 6, the driving member 6 is moved to the click mechanisms 6d, 7d, 7f, 7g, 7h. Be restrained. Thereby, the visual field switching member 4 can be reliably stopped at the designed position. Since the driving member 6 itself can be made small, click mechanisms 6d, 7d, 7f, 7g, 7h
The distance from the restraining position of the driving member 6 to the supporting position (for example, the rotation center position) of the driving member 6 can be set small,
As a result, the click mechanism 6d, 7d, 7f, 7g, 7h
It is possible to suppress twisting and bending when the drive member 6 is rotated against the restraining force of. In the invention of claim 3, from the restraining position of the drive member 6 by the click mechanism 6d, 7d, 7f, 7g, 7h to the support position of the drive member 6 (for example, the rotation center position).
Member 7 for supporting the driving member 6 due to the small distance to
Click mechanism 6d, 7d, 7
f, 7g, 7h can be added.

Incidentally, in the section of means and action for solving the above problems for explaining the constitution of the present invention, the drawings of the embodiments are used for making the present invention easy to understand. It is not limited to.

[0008]

1 to 4 show an embodiment in which the present invention is applied to a visual field switching device of a real image type viewfinder of a camera, and FIG. 1 is an exploded perspective view of the visual field switching device and its surroundings, and FIGS.
[Fig. 3] is a diagram showing a state in which visual fields are switched. In FIG. 1, 1 is a focusing screen for forming a subject image, and 2 is a focusing screen 1.
Is a holder having a rectangular hole 2a into which is fitted. The holder 2 includes a fixed mask 3 and a first movable mask 4
And the second movable mask 5 is sequentially overlapped in the direction of the optical axis X. The masks 3 to 5 are made of a light-shielding material, and holes 3a, 4a, and 5a for defining a rectangular field of view are formed inside the focusing screen 1 at the center thereof.
In the fixed mask 3, the positioning holes 3b and 3c are in the holder 2
It is fitted to the pins 2b and 2c and is restrained at a fixed position on the holder 2. The fitting portions of the movable masks 4 and 5 with the pins 2b and 2c are elongated holes 4b, 4c, 5b and 5c. Therefore, the movable masks 4 and 5 are elongated holes 4b and 4 with respect to the fixed mask 3.
It is movable in the longitudinal direction of c, 5b, 5c.

A mask driving member 6 is arranged on the side of the masks 3 to 5 superposed on the holder 2 (on the left side in FIG. 1). A pair of shafts 6a and 6b are formed in the mask driving member 6, and the shaft 6a includes a long hole 4d of the first movable mask 4, a long hole 3d of the fixed mask 3 and a long hole 2d of the holder 2, and a shaft 6b.
Fit with the long holes 5d of the second movable mask 5, respectively. On the outside of the mask driving member 6 and the second movable mask 5, a mask holding plate 7 having a hole 7a having substantially the same shape and size as the hole 2a of the holder 2 is superposed. At this time, the central axis 6c (see FIGS. 2 to 4) of the mask driving member 6 fits into the fitting hole 7c formed in the bearing portion 7b of the mask holding plate 7 and is rotatable about the central axis 6c. Supported by. The central axis 6c is outside the first visual field F1 (FIG. 2) described later. The operation lever 6d on the outer periphery of the mask driving member 6 projects to the outside of the mask holding plate 7 via the groove 7e between the bearing portion 7b and the arm 7d. When the mask holding plate 7 is attached, the pins 2b and 2c protruding from the long holes 5b and 5c of the second movable mask 5 are attached.
Is pressed into a fitting hole (not shown) of the mask holding plate 7. Therefore, the focusing screen 1, the holder 2, the masks 3 to 5, the mask driving plate 6 and the mask pressing plate 7 are assembled as an integral part. The assembled components are installed in the camera with the focusing screen 1 aligned with the image plane (real image plane) of the objective lens of the finder.

As shown in FIGS. 2 to 4, three recesses 7f, 7g and 7h are formed on the inner circumference of the arm 7d.
When the operating lever 6d is disengaged from the recesses 7f to 7h, the arm 7d is displaced laterally about the base end portion 7i as an axis as shown by the two-dot chain line in FIGS. When any of the above is engaged, the arm 7d returns to the original position (solid line position) and the mask drive member 6 is restrained. 2 to 4 show the through hole 3a of the fixed mask 3.
And the movable masks 4, 5, the mask drive member 6, and the arm 7d of the mask holding plate 7 are shown in the state of being viewed from the direction of arrow A in FIG.

In the above apparatus, when the operation lever 6d is moved along the groove 7e, the mask driving member 6 rotates about the central axis 6c and engages with the shaft 6a of the mask driving member 6 in the first movable mask. 4 in the longitudinal direction of the long holes 4b and 4c,
The second movable mask 5 that engages with the shaft 6b of the mask driving member 6.
Move in the longitudinal direction of the long holes 5b and 5c, respectively. Along with this, the positions of the holes 4a, 5a of the movable masks 4, 5 with respect to the holes 3a of the fixed mask 3 change, and the fields of view of the finder are as shown in FIGS. Switch between F2 and third field of view F3. Note that FIG.
In FIG. 4, the fields of view F1 to F3 are shown by hatching areas.
The relationship between the visual fields F1 to F3 and the stop position of the mask driving member 6 is as follows: the holes 4a, 5a and the long holes 4b, 4c, 5b, 5
It may be appropriately set according to the shape of c, the engagement position between the shafts 6a and 6b and the masks 4 and 5, and the like.

As described above, in this embodiment, the position of the rotary shaft 6c of the mask driving member 6 is set outside the first field of view F1. Therefore, the mask driving member 6 and the mechanism for restraining the mask driving member 6 at a predetermined position are provided in the mask 3 It can be compactly assembled on one side of ~ 5. Especially when compared with the conventional example of FIG.
The mask driving member 6 is removed from above and below the fields 1 to F3, and the field switching device is downsized in the short side direction of the fields F1 to F3. According to such a layout, the prism (not shown) of the real image finder is used for the field of view F with respect to the focusing screen 1.
1 to F3 can be arranged close to each other in the short side direction.

In this embodiment, both the first movable mask 4 and the second movable mask 5 serve as visual field switching members and the pins 2b, 2 are used.
c and the elongated holes 4b, 4c, 5b, 5c serve as a guide mechanism, the mask driving member 6 serves as a driving member, the operation lever 6d of the mask driving member 6, the arm 7d of the mask holding plate 7 and the recess 7f.
.About.7h constitute a click mechanism, and the mask holding plate 7 constitutes a member that rotatably supports the drive member. In addition,
The present invention is not limited to the viewfinder of a camera and can be used for switching various fields of view.

[0014]

As described above, in the present invention, the rotation center line of the drive member that engages with and drives the visual field switching member is set outside the visual field, so that the drive member is placed around the visual field switching member. It can be placed compactly in the section. It is also easy to support the driving member on the rotation center side to ensure stability and enhance the operational feeling of the driving member. Particularly, in the invention of claim 2, the visual field according to the design value can be obtained by surely stopping the visual field switching member at the designed position by the click mechanism. Moreover, since the click mechanism can be arranged in the vicinity of the supporting position of the drive member, the positioning accuracy of the visual field switching member can be ensured, and the twisting and bending when rotating the drive member against the restraining force of the click mechanism can be suppressed. It is possible to enhance the sense of rigidity when operating the drive member. In the invention of claim 3, the click mechanism can be added by slightly enlarging the member supporting the drive member,
It is possible to suppress an increase in the number of parts and assembling work.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a visual field switching device and its surroundings according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a first visual field is defined by the apparatus of the embodiment.

FIG. 3 is a diagram showing a state in which a second visual field is defined by the device of the embodiment.

FIG. 4 is a diagram showing a state in which a third visual field is defined by the device of the embodiment.

FIG. 5 is a diagram showing a conventional example.

[Explanation of symbols] 2b, 2c Pin 3 Fixed mask 4 First movable mask 4b, 4c Long hole 5 Second movable mask 5b, 5c Long hole 6 Mask driving member 7 Mask holding plate F1 First field of view F2 Second field of view F3 Second 3 fields of view

Claims (3)

[Claims] 1. A visual field switching member inserted into an optical path of an optical system, and a drive which is rotationally operated around a rotation center line parallel to the optical axis direction of the optical system in a state of being engaged with the visual field switching member. A guide mechanism for moving the visual field switching member between a plurality of positions corresponding to a plurality of visual fields in association with rotation of the driving member, wherein the rotation center line of the driving member is The visual field switching device is set outside the visual field. 2. The visual field switching device according to claim 1, further comprising a click mechanism that constrains the drive member at the plurality of positions corresponding to the plurality of visual fields, respectively. 3. The visual field switching device according to claim 2, wherein the click mechanism is provided between a member that rotatably supports the drive member and the drive member.