JPH08286236A - Visual field switching device - Google Patents

Abstract

PURPOSE: To provide a visual field switching device capable of reducing an installation space in a particular direction more than conventional one. CONSTITUTION: This visual field switching device is provided with a visual field switching member 4 inserted into the optical path of an optical system and guiding mechanisms 2b, 2c, 4b and 4c guiding the visual field switching member 4 among a first position corresponding to a first rectangular visual field, a second position corresponding to a second visual field formed by narrowing the first visual field in the short side direction and a third position corresponding to a third visual field formed by narrowing the first visual field in the long side direction. When the visual field switching member 4 is moved among the first, second and third positions, the guiding sequence of the guiding mechanisms 2b, 2c, 4b and 4c are set so as to obtain the first position in a sequence other than the second.

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 in which a standard visual field is narrowed in the long side direction and the short side direction and three types of visual fields can be set, Japanese Patent Laid-Open No. 6-82882 discloses a viewfinder shown in FIG. It is disclosed. In the illustrated apparatus, two L-shaped visual field frames 101 symmetrical with respect to the finder optical axis are provided on a visual field mask 100 that defines a rectangular first visual field F1.
102 and the moving wheel 103 are sequentially superposed in the finder optical axis direction (direction orthogonal to the paper surface). Driving wheel 103
Are engaged with the pins 101a and 102a of the field frames 101 and 102, respectively, and the long holes 101b and 101b of the field frames 101 and 102,
102b fits with the pin 100a of the field mask 100. When the driving wheel 103 is rotated, the visual field frames 101 and 102 move 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 6 (a)
6C 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 in FIG. 6C, the first visual field F1 is narrowed in the long side direction and the third visual field F3 is defined. Each state is shown. Further, FIG. 6B shows the field frames 101, 10
2 shows the state of being retracted outside the first field of view F1.

[0003]

In the apparatus shown in FIG. 6, when the field frames 101 and 102 are moved between the three positions corresponding to the three fields F1 to F3, respectively, the pin 100a is moved.
And the field frames 101 and 10 formed by the long holes 101b and 102b
The first field of view F1 is obtained at the second (center) of the guide order of No. 2. Therefore, when switching between the second visual field F2 and the third visual field F3, the visual field frames 101 and 102 must be the first visual field F.
Via the position corresponding to 1. When switching between the second visual field F2 and the third visual field F3, the visual field frames 101 and 102 are set to the first visual field.
While it is necessary to retract toward the outside of either the long side or the short side of the field of view F1 and to advance toward the inside of the other of the long side or the short side, the above setting makes it possible to change the first side during switching. At the stage where the one visual field F1 is obtained (the stage of FIG. 6B), the visual field frames 101 and 102 are already withdrawn sufficiently and sufficiently,
By the retracting operation thereafter, the field frames 101 and 102 are separated from the first field F1 more than necessary. Therefore, the installation space of the visual field switching device unnecessarily expands in the vertical and horizontal directions of the visual fields F1 to F3.

An object of the present invention is to provide a visual field switching device capable of reducing the installation space in a specific direction as compared with the conventional one.

[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 member 4 has a first position (FIG. 2) corresponding to the rectangular first visual field F1 and a second visual field F2 in which the first visual field F1 is narrowed in the short side direction.
And a third position (FIG. 4) corresponding to the third visual field F3 in which the first visual field F1 is narrowed in the long-side direction (FIG. 4). 2b,
2c, 4b, 4c, and the first visual field switching member 4
The guide order of the guide mechanisms 2b, 2c, 4b, 4c is set so that the first position can be obtained in the order other than the second position when moving between the three positions of the position, the second position and the third position. The above-described object is achieved by the visual field switching device.
According to the invention of claim 2, the visual field defining member 3 which is inserted into the optical path of the optical system to define the rectangular first visual field F1, the second visual field defining edge e21 which is parallel to the long side of the first visual field F1, The visual field switching member 4 having the third visual field defining edge e31 parallel to the short side of the first visual field F1 and the visual field switching member 4 are connected to the second visual field defining edge e21.
And the third visual field defining edge e31 is the first position (FIG. 2) retracted outside the first visual field F1, and the second visual field defining edge e21 is the first position.
The third visual field defining edge e31 is located inside the long side of the visual field F1.
Is retracted out of the first field of view F1 to a second position (FIG. 3) and a third position
The third visual field defining edge e31 is inwardly advanced from the short side of the first visual field F1 and the second visual field defining edge e21 is receding outside the first visual field F1.
A guide mechanism 2b, 2c, 4b, 4c for guiding a predetermined guide sequence to and from the position (FIG. 4), and the visual field switching member 4 is provided in three positions of a first position, a second position and a third position. When sequentially moving between the positions, the guide mechanisms 2b, 2c, 4b, 4 are arranged so that the first position is obtained in the order other than the second position.
The above-described object is achieved by the visual field switching device in which the guide order of c is set. The invention of claim 3 is applied to the visual field switching device of claim 2, wherein the visual field switching member 4 moves between the first position and the third position via the second position, and from the first position to the second position. The guide mechanisms 2b, 2c, 4b, 4c are configured so that the amount of retreat of the third visual field defining edge e31 from the short side of the first visual field F1 gradually decreases as the position approaches.

[0006]

According to the invention of claim 1, the guide mechanisms 2b, 2c, 4 are provided.
The visual field switching member 4 is moved to the first visual field F according to the guides b and 4c.
When moving between three positions corresponding respectively to the first, second field F2 and third field F3, the first field F1 is obtained at the beginning or the end of the guiding sequence, and the second field F2 and the third field F3 are obtained. When switching between and, the first field of view F1 is not passed. Therefore, in the process of switching between the second visual field F2 and the third visual field F3, the visual field switching member 4 retracts to the outside of either the long side or the short side of the first visual field F1 by a necessary amount, and the first visual field. Unnecessary expansion of the installation space can be prevented by matching the time of advancing only the necessary amount inside the other of the long side and the short side of F1. According to the invention of claim 2,
The visual field switching member 4 is moved according to the guidance of the guide mechanisms 2b, 2c, 4b, 4c from a state in which both the second visual field defining edge e21 and the third visual field defining edge e31 of the visual field switching member 4 are retracted outside the first visual field F1. First, one of the second visual field defining edge e21 and the third visual field defining edge e31 (e21) advances into the first visual field F1 to obtain the second visual field F2 or the third visual field F3, and then the second visual field defining One of the second visual field defining edge e21 and the third visual field defining edge e31 (e21) is outside the first visual field F1 while the other (e31) of the edge e21 or the third visual field defining edge e31 advances into the first visual field F1. The third field of view F3 or the second field of view F2 is obtained by retracting. At this time, when the other (e31) of the second visual field defining edge e21 or the third visual field defining edge e31 advances into the first visual field F1 by a necessary amount, and one of the second visual field defining edge e21 and the third visual field defining edge e31. It is possible to suppress the expansion of the installation space by matching the time when (e21) is retracted to the outside of the first visual field F1 by the required amount. In the invention of claim 3, when the visual field switching member 4 is moved from the first position to the second position, the second visual field defining edge e21 of the visual field switching member 4 advances into the long side of the first visual field F1 and the second visual field defining edge e21 is formed. The field of view F2 is defined, and the third field defining edge e31 gradually approaches the short side of the first field of view F1 during this switching process. When the visual field switching member 4 is moved from the second position to the third position, the third visual field defining edge e31 advances into the short side of the first visual field F1 and the second visual field defining edge e21 moves the first visual field F21.
The third field of view F3 is obtained by retracting outside the long side of 1. In this switching process, the second visual field defining edge e21 is unnecessarily increased in the first visual field F1.
Therefore, the amount of movement of the visual field switching member 4 in the short side direction (vertical direction in the drawing) of the visual fields F1 to F3 is reduced.

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 5 show an embodiment in which the present invention is applied to a visual field switching device of a real image type finder of a camera, and FIG. 1 is an exploded perspective view of the visual field switching device and its surroundings, and FIGS.
FIG. 5 is a diagram showing a state in which the fields of view are switched, and FIG. 5 is a diagram comparing with the conventional example. In FIG. 1, reference numeral 1 is a focusing screen for forming a subject image, and 2 is a holder having a rectangular hole 2a into which the focusing screen 1 is fitted. The fixed mask 3, the first movable mask 4, and the second movable mask 5 are sequentially stacked on the holder 2 in the direction of the optical axis X. The masks 3 to 5 are made of a light-shielding material, and the central portions of the masks 3 to 5 have punched holes 3a and 4 for defining a rectangular visual field inside the focusing screen 1.
a and 5a are formed. The fixed mask 3 has its positioning holes 3b, 3c fitted with the pins 2b, 2c of the holder 2 and is restrained at a fixed position on the holder 2. Movable mask 4,
The fitting portions of the pin 5 with the pins 2b and 2c are long holes 4b, 4c and 5
Therefore, the movable masks 4 and 5 are movable in the longitudinal direction of the elongated holes 4b, 4c, 5b and 5c with respect to the fixed mask 3.

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 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 press-fitted into fitting holes (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 can be appropriately set according to the shape of c, the engagement positions of the shafts 6a and 6b and the masks 4 and 5, and the like, but particularly in the present embodiment, it is set as follows.

First, when the operating lever 6d engages with the upper recess 7f, an edge e of the movable masks 4 and 5 which will be described later will be described.
All of 21, e22, e31, and e32 retreat to the outside of the punched hole 3a of the fixed mask 3, and the punched hole 3a defines the first visual field F1. When the operation lever 6d is moved from the state shown in FIG. 2 to the central concave portion 7g, the first movable mask 4 is moved to the long hole 4g.
The second movable mask 5 moves diagonally downward to the left according to b and 4c, and moves diagonally upward to the right according to the long holes 5b and 5c. As a result, as shown in FIG. 3, the edge e21 at the upper end of the punched hole 4a and the edge e22 at the lower end of the punched hole 5a are in the first visual field F1.
The second visual field F2 is defined by penetrating inside. Next, when the operation lever 6d is moved from the state of FIG. 3 to the lower concave portion 7h, the first movable mask 4 moves diagonally upward to the left along the long holes 4b and 4c, and the second movable mask 5 moves to the long hole. Move diagonally downward right according to 5b and 5c. As a result, as shown in FIG. 4, the edges e21, e22 of the holes 4a and 5a are removed.
While retreating to the outside of the first visual field F1, the right edge e31 of the punched hole 4a and the left edge e32 of the punched hole 5a enter the first visual field F1 to define the third visual field F3.

As described above, in this embodiment, the movable masks 4 and 5 are held at the position corresponding to the first visual field F1 when the operation lever 6d of the mask driving member 6 and the recess 7f are engaged, and from this position. When the mask driving member 6 is moved in one direction, the masks 4 and 5 are sequentially moved to positions corresponding to the second visual field F2 and the third visual field F3, so that the long holes 4b, 4c, 5b and 5 are formed.
Since c is set, the edges e21 and e of the movable masks 4 and 5 are
22 is not retracted from the hole 3a in the short side direction of the visual fields F1 to F3 (vertical direction in the drawing) more than necessary, and the moving amount of the movable masks 4 and 5 is smaller in the short side direction of the visual fields F1 to F3 than in the conventional case. Become. By the way, comparing the portion V of FIG. 2 with the conventional example, as shown in FIG. 5, conventionally, as shown in FIG. 5, a long hole 4b ′ is provided symmetrically with respect to the position where the first field of view F1 is obtained, and the hole 4a is formed.
Since the third visual field F3 is obtained at the left edge e'of, the first movable mask 4 needs to be moved further above the position at which the first visual field F1 is obtained by δ in the figure. It should be noted that if the elongated hole 4b 'is provided horizontally in the region on the left side of the pin 2b in FIG. 5, δ = 0, but in that case, the third visual field F
The play of the mask 4 in the direction of the long side of the pin
Since it cannot be regulated at the fitting portion with ′ ′, the fluctuation of the edge e ′ in the third visual field F3 becomes large. In order to prevent this, the oblong hole 4b 'must be inclined with respect to the long side direction of the third field of view F3, and therefore δ inevitably occurs. In this embodiment, the play of the masks 4 and 5 is not restricted in the long side direction (horizontal direction) in the state of FIG.
Since 5 is receded from the short side of the second visual field F2, there is no problem.

In the above embodiment, the fixed mask 3 serves as a visual field defining member, both the first movable mask 4 and the second movable mask 5 serve as visual field switching members, and the pins 2b and 2c and the long holes 4b and 4 are provided.
c, 5b and 5c are the guide mechanism, the edge e21 of the first movable mask 4 and the edge e22 of the second movable mask 5 are the second visual field defining edges, and the edge e31 of the first movable mask 4 and the second movable mask 5 are The edges e32 form the third visual field defining edges, respectively. Although the frame-shaped masks 4 and 5 having the holes 4a and 5a are used in the embodiment, the above-mentioned edges e21 and e2 are used.
As long as it has 2, e31 and e32, it may be transformed into an L-shape or the like. Further, in the embodiment, the movement amount of the mask in the short side direction of the visual field is suppressed, but the movement amount in the long side direction may be suppressed. In this case, the first field of view is passed through the third field of view F3.
The field of view F1 and the second field of view F2 may be switched. The present invention is not limited to the viewfinder of a camera and can be used for switching various fields of view.

[0015]

As described above, according to the present invention, when the visual field switching member is moved between the three positions corresponding to the first visual field, the second visual field and the third visual field in accordance with the guidance of the guiding mechanism, the guidance is provided. Since the first visual field is obtained at the beginning or the end of the sequence, the installation space of the visual field switching device can be reduced as compared with the conventional case in the long side direction or the short side direction of the view frame. In particular, according to the invention of claim 3, the installation space can be reduced in the direction of the short side of the rectangular field of view. Therefore, when it is used as a field switching device of a real image type finder of a camera, it is arranged in the optical path of the finder optical system. The finder can be miniaturized by bringing the prism and the visual field switching device close to each other in the direction of the short side of the visual field.

[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 view showing a V portion of FIG. 2 in comparison with a conventional example.

FIG. 6 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 e21, e22, e31, e32 Edge defining the field of view F1 First field of view F2 Second field of view F3 Third Field of view

Claims (3)

[Claims] 1. A visual field switching member inserted into an optical path of an optical system, the visual field switching member at a first position corresponding to a rectangular first visual field, and the first visual field narrowed in a short side direction. A second position corresponding to the second field of view and a guide mechanism for guiding the first field of view between a third position corresponding to the third field of view narrowing the first field of view in a predetermined guiding order, When the visual field switching member is moved between the three positions of the first position, the second position and the third position, the guide mechanism is provided so that the first position is obtained in an order other than the second order. A visual field switching device characterized in that a guidance order is set. 2. A visual field defining member that is inserted into an optical path of an optical system to define a rectangular first visual field, a second visual field defining edge that is parallel to a long side of the first visual field, and a first visual field of the first visual field. A field-of-view switching member having a third field-of-view defining edge parallel to a short side, and the field-of-view switching member in which both the second field-of-view defining edge and the third field-of-view defining edge are retracted out of the first field of view. 1 position, a second position in which the second visual field defining edge advances inward from a long side of the first visual field and the third visual field defining edge recedes out of the first visual field, and the third visual field defining edge A guide mechanism for guiding in a predetermined guiding order between the third position in which the second visual field defining edge has moved inward from the short side of the first visual field and the second visual field defining edge has retracted out of the first visual field. , The visual field switching member is sequentially moved between the three positions of the first position, the second position and the third position. When moving
The visual field switching device, wherein the guide order of the guide mechanism is set so that the first position is obtained in an order other than the second order. 3. The visual field switching device according to claim 2, wherein in the guide mechanism, the visual field switching member moves between the first position and the third position via the second position, and The visual field switching device is configured such that a receding amount of the third visual field defining edge from the short side of the first visual field gradually decreases as the first position approaches the second position.