JP2001125172A - Light passing area variable device and finder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce space by elastically energizing plural field frame size setting member in the optical axis direction of a finder at least after finishing the setting of field frame size in a finder device provided with a means for securing the specified space of plural movable mask members 2, 3 in the optical axis direction in the midst of light passing area varying operation and reducing the space after finishing the light passing area varying operation, and switching plural field frame size by moving plural field frame size setting members in a direction orthogonal to the optical axis of the finder in the specified space in the optical axis direction. SOLUTION: The deviation of diopter on the respective sides of one field range constituted of plural movable mask members is reduced. Then, actuation load is decreased, the actuation force of a movable member is weakened, and easy changing operation and sure holding after change are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for changing a light passing area in an optical path, and more particularly to a finder device capable of switching a photographing range to a plurality of sizes when observing a subject of a camera. When, with a plurality of shielding members, the rattling of the space of the shielding member in the optical axis direction is regulated, for example, in a finder device, relates to a device that suppresses a diopter shift due to rattling of the plurality of shielding members. is there.

[0002]

2. Description of the Related Art In cameras for photographing, cameras capable of switching photographed photograph sizes to a plurality of sizes have appeared. For example, a camera using a 240-size film has three photographing sizes of C, H, and P. Can be selected. Since the photographer confirms the photographing size by changing the photographing size by observing the viewfinder of the camera, various means for changing the field frame size are proposed in the viewfinder field.

FIGS. 10 to 13 show an example of commonly used field frame size changing means. FIGS. 10 to 12
FIG. 10 is a schematic plan view at each shooting size, and FIG.
11 shows the H size, FIG. 11 shows the C size, and FIG. 12 shows the P size. FIG. 13 is a side view as viewed from above. FIG.
In 0 to 13, 101 indicates the H size as 4
The fixed masks 102 and 103 formed by the sides are first and second movable masks, which are respectively disposed before and after along the finder optical axis of the fixed mask 101. 104
Denotes an optical prism, and a spherical vertex 104a on the eyepiece side of the optical prism 104 is an image forming surface in an optical path of the finder optical system. Reference numeral 105 denotes a ground plate that holds the optical prism 104, and reference numeral 106 denotes a drive plate that operates the first and second movable masks 102 and 103 in conjunction with an external operation member (not shown). Reference numeral 107 denotes a fixed plate that holds the fixed mask 101, the first movable mask 102, the second movable mask 103, and the driving plate 106 on the base plate 105 along the finder optical axis, and then holds the fixed mask 101 in an operable state. . In addition, an objective lens group 108 arranged on the object side of the optical prism, an eyepiece prism 109 arranged on the photographer's eyepiece side of the fixed plate 107, and an eyepiece 11
0 constitutes a finder optical system. 111
Is the finder optical axis.

In these components, the operation of the photographing field frame changing means will be described in order. FIG. 10 shows a state in which the field frame is formed of only the fixed mask 101 when the photographer observes the viewfinder in the H size state, and the first and second movable masks 102 and 103 are fixed masks 10 as indicated by broken lines.
1 is retracted outside the opening. From this state, the photographer operates the operation knob (not shown), and the driving plate 1
06 in conjunction with the first and second movable masks 102 and 10
Move 3 For example, the operation knob is changed from the H size position to the C size. Then, the driving plate 106 rotates counterclockwise (hereinafter, referred to as CCW rotation) about the finder optical axis 111. The driving plate 106 includes
Since the driving shaft 106a has two positions and is engaged with the interlocking hole 102a of the first movable mask 102 and the interlocking hole 103a of the second movable mask 102, respectively, the first and second movable masks 102, 103 are provided. Also try to rotate CCW. However, two guide slots 102b and 103b provided in the first and second movable masks 102 and 103, respectively.
Are guided by the two guide shafts 105a of the base plate 105, and the first and second movable masks 102 and 103 can move only in the longitudinal direction of the guide elongated hole. Is moved in the B direction, and the second movable mask 103 is moved in the A direction. Interlocking holes 102a, 103a of first and second movable mask plates 102, 103
Is the finder optical axis 1 of the drive shaft 106a of the drive plate 106.
11, guide elongated holes 102 b and 103 b of the first and second movable masks 102 and 103.
The hole is elongated to absorb the difference in the moving direction of the parallel movement in the longitudinal direction. First and second movable masks 10
2 and 103 move in the respective directions, and the guide slot 10
When the first and second movable masks 102 and 103 stop when they come into contact with the ends of 2b and 103b, the change of the field frame to the C size in FIG. 10 is completed. At this time, the upper and lower sides of the C size field frame are constituted by the upper and lower sides of the fixed mask 101, and the left and right sides are respectively the first movable mask 102 on the left side and the second movable mask 103 on the right side. It is configured. Then, when the operation reverse to the above operation, that is, when the operation knob (not shown) is operated in the reverse direction, the size returns from the C size to the H size.

Further, when the operation knob is operated to change the H size to the P size, the drive plate 106 interlocks and rotates clockwise (hereinafter referred to as CW rotation) around the finder optical axis 111. The two drive shafts 106a of the drive plate 106 are, as in the case of changing to the C size, respectively.
Since the interlocking hole 102a of the first movable mask 102 and the interlocking hole 103a of the second movable mask 103 are engaged,
The first and second movable masks 102, 103 also try to rotate CW by the two drive shafts 106a of the drive plate 106, but similarly, the first and second movable masks 102, 1 are also rotated.
03 two guide slots 102b
And 103b are two guide shafts 105 of the main plate 105.
The first movable mask is moved in the A direction and the second movable mask is moved in the B direction. The first and second movable masks 102 and 103 move in the respective directions, and the other ends of the two guide elongated holes 102b and 103b are
When the first and second movable masks 102 and 103 are stopped at the two guide shafts 105a, the field frame is completely changed to the P size in FIG. At this time, the left and right sides of the P size field frame are formed by the left and right sides of the fixed mask 101, and the upper and lower sides are respectively formed by the upper side of the second movable mask 103 and the lower side by the first movable mask 102. Have been. When the reverse operation of the above operation is performed, that is, when the operation knob (not shown) is operated in the direction in which the size is changed from H size to C size, the size returns from P size to H size.

Prior to the above-mentioned field frame changing means, as a conventional example having a different purpose but similar, a camera for switching an aspect ratio of a photographic screen into two types, full size photography and panorama size photography, has been proposed. Kaihei 4-32024
No. 3 and Japanese Utility Model Application Laid-Open No. 3-122435 switch a photographing screen by moving two screen regulating members rotatably supported on the film surface side of a photographing lens to a main body aperture portion for determining a photographing range. The structure is such that the two screen regulating members are biased by a spring member to one side of the full size side, or both sides of the full size side and the panorama size side.

[0007]

However, in the configuration of changing the size of the visual field frame as in the above-described conventional example, the H size defines the photographing range of the upper, lower, left, and right sides by one fixed mask 101. Therefore, the four edges of the fixed mask 101 (upper, lower, left, and right) have a diopter shift due to an optical requirement due to a difference in distance from the upper, lower, left, and right viewfinder optical centers. , Almost the same diopter. However, the left and right 2
Since the first movable mask and the second movable mask form one side each of the side and the upper and lower sides in the P size, one side formed by the first movable mask 102 is formed. On the other hand, the other side of the second movable mask 103 having the same field frame size is the fixed mask 102 and the second side.
The thickness of the movable mask 103, plus, between these masks, and between the mask and the driving plate 106, the gap between the masks and the driving plate 106 so as not to cause a load at the time of operation. Distance is shifted. As a result, the right and left two sides and the two upper and lower sides in the case of the C size, and the upper and lower two sides and the two left and right sides in the case of the P size are shifted in diopter,
The photographer would feel uncomfortable when observing the subject while looking through the viewfinder, and would find it difficult to see the entire viewfinder.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light-passing area changing device having a photographing field frame changing means for solving the above-mentioned conventional drawbacks and making it difficult to view the viewfinder.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of movable mask members are moved in a direction orthogonal to an optical axis to transmit light in a plurality of light passing areas. In the variable light passage area device that switches the amount, a predetermined space in the optical axis direction of the plurality of movable mask members is secured during the light passage area variable operation, and the space is reduced after the light passage area variable operation is completed. This is a light passage area variable device having a hand throw.

[0010] With this configuration, it is possible to minimize the diopter shift of a plurality of fixed and movable mask plates constituting one visual field range, and to realize a light transmissive area variable device in which the visual field frame is easy to see. be able to.

According to a second aspect of the present invention, a plurality of field frame size setting members are moved in a direction perpendicular to the optical axis within a predetermined space in the direction of the viewfinder optical axis to achieve a plurality of field frame sizes. A finder device for switching, wherein the finder device has means for reducing the space at least after the setting of the field frame size is completed, and further, in the invention according to claim 3, the finder device according to claim 2. In the means for reducing the space,
The finder device according to claim 2, wherein the space is reduced by elastically urging a plurality of field frame size setting members in the optical axis direction.

By having these configurations, it is possible to minimize the diopter shift of a plurality of fixed and movable mask plates constituting one view range, and to realize a finder device in which the view frame is easy to see. it can.

According to a fourth aspect of the present invention, a plurality of movable mask members are moved in a direction orthogonal to the optical axis with respect to the fixed mask member in a predetermined space in the direction of the viewfinder optical axis. A viewfinder device for switching to the field frame size, wherein at least after the field frame size setting is completed, means for reducing the space in the optical axis direction of the plurality of movable masks with respect to the fixed mask member is provided. In the finder device according to the fifth aspect, in the finder device according to the fourth aspect, the means for reducing the space is provided with a plurality of movable masks with respect to the fixed mask member at least after completion of the setting of the field frame size. The finder device according to claim 4, wherein the space is reduced by elastically urging the member in the optical axis direction.

With these structures, the working load is reduced by increasing the working space during the change of the movable visual field frame, and when the change is completed, the working space is reduced and the working load is increased. By preventing the member from moving, the operating force of the movable member is reduced, and the holding force after the change is increased, so that the changing operation can be easily performed and the changed state can be reliably held.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 9
1 is a view showing a first embodiment of the present invention, FIG. 1 is an exploded perspective view showing the arrangement of components when the present invention is applied to a camera, and FIGS. FIG. 2 is a plan view seen from the axial direction, FIG. 2 shows a state of H size, FIG. 3 shows a state of C size, and FIG. 4 shows a state of P size in a field frame portion of a finder device for observing a subject image. is there. 1 is H
Fixed mask consisting of four sides, up, down, left and right, 2 and 3
Are first and second movable masks, which are respectively disposed before and after along the finder optical axis of the fixed mask 1.
Reference numeral 4 denotes an optical prism, and a spherical vertex 4a on the eyepiece side of the optical prism 4 is an image forming surface in an optical path of the finder optical system. Reference numeral 5 denotes a base plate that holds the optical prism 4, first and second movable masks 2 and 3, and two guide shafts 5 a on the base plate 5 side between the base plate 5 and the first and second movable masks. On the mask 2 and 3 sides, two guide slots 2b and 3
b is provided so that the first and second movable masks 2 and 3 can be moved only in a predetermined direction. Reference numeral 6 denotes a drive plate that operates the first and second movable masks 2 and 3 in conjunction with an external operation member (not shown). Two drive shafts 6 a of the drive plate 6 are engaged with the interlocking holes 2 a of the first movable mask 2 and the interlocking holes 3 a of the second movable mask 3, respectively. The tip of the drive shaft 6a has a spherical shape and abuts against the main plate 5. And
As shown in FIG. 5, concave portions 5 b, 5 c, 5 d and concave portions 5 abutting upon setting the respective sizes of C, H, and P on the surface of the base plate 5.
b and 5c, and between 5b and 5d, convex portions 5e and 5
f. The concave portion and the convex portion are provided at two rotationally symmetric positions about the optical axis 11. Reference numeral 7 denotes a fixed plate that holds the fixed mask 1, the first movable mask 2, the second movable mask 3, and the driving plate 6 on the base plate 5 along the finder optical axis and then keeps them in an operable state. is there. This fixing plate 7 has two elastic arm portions 7a,
The fixed plate 1, the first movable mask 2, and the second movable mask 3 are biased by elastically urging the driving plate 6 toward the ground plate 5 in the optical axis direction. In addition, the objective lens 8 arranged on the object side of the optical prism, the eyepiece prism 9 arranged on the eyepiece side of the photographer of the fixed plate 7, and the eyepiece 1
With 0, it is arranged on the axis of the finder optical axis 11 and forms a finder optical system.

In these components, the operation of the photographing field frame changing means will be described in order. FIG. 2 shows that, when the photographer views the viewfinder in the H size state, the field frame is composed of only the fixed mask 1, and the first and second movable masks 2 and 3 are fixed masks as shown by broken lines. 1 is retracted outside the opening. In this state, when the photographer operates an operation knob (not shown), the drive plate 6 moves the first and second movable masks 2 and 3 in conjunction with each other. For example, an operation of changing the operation knob from the position of the H size in FIG. 2 to the C size in FIG. 3 is performed. Then, the driving plate 6 rotates CCW about the finder optical axis 11 in conjunction with the driving plate 6. The two drive shafts 6a of the driving plate 6 are engaged with the interlocking holes 2a of the first movable mask 2 and the interlocking holes 3a of the second movable mask 3, respectively. Accordingly, the first and second movable masks 2 and 3 also try to rotate CCW. However, two guide slots 2b and 3b provided in the first and second movable masks 2 and 3, respectively.
Is guided by the two guide shafts 5a of the base plate 5 and can move only in the longitudinal direction of the guide elongated hole, so that the first movable mask 2 is in the B direction and the second movable mask 3 is
Moves in the A direction. First and second movable mask plates 2 and 3
Are provided with two drive shafts 6 a of the drive plate 6.
The difference in the moving direction of the parallel movement in the longitudinal direction due to the two guide elongated holes 2b and 3b of the first and second movable masks 2 and 3 is absorbed by the rotational movement about the finder optical axis 11 as a center. In order to do so, it is a long hole. 1st, 2nd
When the movable masks 2 and 3 move in the respective directions and hit the ends of the guide slots 2b and 3b,
The second movable masks 2 and 3 are stopped, and the field frame is completely changed to the C size as shown in FIG. At this time, the upper and lower sides of the C size field frame are constituted by the upper and lower sides of the fixed mask 1, and the left and right sides are the first movable mask 2 on the left side and the second movable mask 3 on the right side, respectively. It is configured.

The two guide shafts 6a of the drive plate 6 are
At the time of the H size, as shown in FIG. 5, the arm 7a of the fixed plate 7 is urged against the concave portion 5b provided on the surface of the base plate 5, and the drive plate 6 is in this state. Time,
First, the gap 12 formed by the drive plate 6 and the ground plate 5 approaching the ground plate 5 is almost equal to the thickness of each component, and the play 13 is almost zero. This state (H size)
In the course of moving to the C size, the guide shaft 6a of the driving plate 6 is moved from the concave portion 5b on the surface of the base plate 5 to R
It moves toward the convex part 5e of the surface. At this time, the drive plate 6 rides on the R surface of the convex portion 5e and gradually moves away from the base plate 5 in the optical axis direction. When the driving plate 6 moves away from the base plate, the first and second movable masks 2, 3 and
The gap 12 increases before and after the fixed mask 1 in the optical axis direction, and a play 13 is generated. This allows the first and second movable masks 2 and 3 to move smoothly. In FIG.
The gap 12 is max when the guide shaft 6a of the drive plate 6 has reached the apex of the protrusion 5e of the base plate 5.

When the guide shaft 6a of the driving plate 6 exceeds the vertex of the convex portion 5e of the base plate 5, the guide shaft 6a moves toward the concave portion 5c.
By moving along the surface, the drive plate 6 gradually approaches the base plate 5 in the thickness direction. Then, when the change to the C size is completed, the drive plate 6 is moved in the same manner as the H size.
The gap 12 formed by the drive plate 6 and the ground plate 5 closest to the ground plate 5 is substantially equal to the thickness of each component, and the play 13 is substantially zero. During the operation of the drive plate 6, the arm 7a of the fixed plate 7 constantly urges the base plate 5 side in the optical axis direction. The arm 7a of the fixing plate 7 has two positions at rotationally symmetric positions of the finder optical axis 11, and elastically urges in a well-balanced manner.

Next, when the above operation is reversed, that is, when the operation knob (not shown) is operated in the reverse direction, the size returns from the C size to the H size. Further, when the operation knob is operated to change from the H size to the P size, the drive plate 6 interlocks and rotates CW about the finder optical axis 11. The two drive shafts 6a of the drive plate 6 are respectively connected to the interlocking holes 2a of the first movable mask 2 as in the case of the change to the C size.
And the second and third movable masks 2 and 3 also try to rotate CW by the two drive shafts 6 a of the drive plate 6 because the first and second movable masks 2 and 3 are engaged with the interlocking holes 3 a of the second movable mask 3. Similarly, the two guide slots 2b and 3b provided in the first and second movable masks 2 and 3 are respectively guided by the two guide shafts 5a of the base plate 5, and this time, the first The movable mask 2 is moved in the direction A, and the second movable mask 3 is moved in the direction B. When the first and second movable masks 2 and 3 move in the respective directions, and the other ends of the guide elongated holes 2b and 3b abut against two guide shafts 5a, the first and second movable masks 2 and 3 are moved.
The second movable masks 2 and 3 are stopped, and the field frame is completely changed to the P size as shown in FIG. At this time, the left and right sides of the P size field frame are constituted by the left and right sides of the fixed mask 1, and the upper and lower sides are respectively the upper side of the second movable mask 3 and the lower side of the first movable mask 2 It is composed of Also in this process, the guide shaft 6a of the driving plate 6 has the H size as shown in FIG.
The guide shaft 6a of the driving plate 6 moves from the concave portion 5b on the surface of the base plate 5 toward the convex portion 5f on the R surface in the same manner as in the process of moving to the C size from the state shown in FIG.
At this time, the drive plate 6 gradually moves away from the ground plate 5 in the optical axis direction. When the driving plate 6 moves away from the ground plate 5, the gap 12 increases before and after the first and second movable masks 2 and 3 and the fixed mask 1 in the optical axis direction, and a play 13 is formed. . This allows the first and second movable masks 2 and 3 to move smoothly. And the driving plate 6
When the guide shaft 6a moves beyond the top of the convex portion 5f of the main plate 5, the drive plate 6 moves along the slope toward the concave portion 5d, so that the drive plate 6 gradually approaches the main plate 5 in the optical axis direction. To go. When the change to the P size is completed, the drive plate 6 comes closest to the main plate 5 as in the case of the H and P sizes, and the gap 12 formed by the drive plate 6 and the main plate 5 is substantially equal to the thickness of each component. And the play 13 is almost zero. Even during the operation of the drive plate 6, the arm portion 7a of the fixed plate 7 is constantly elastically biased toward the base plate 5 in the optical axis direction. When the reverse operation of the above operation is performed, that is, when the operation knob (not shown) is operated in the direction in which the H size is changed from the H size to the C size, the size returns from the P size to the H size.

In the present embodiment, the first and second movable masks 2 and 3 are disposed before and after the fixed mask 1 in the configuration of the finder field frame changing device.
This is because when the first and second movable masks 2 and 3 are movable,
This is because the operation direction is different so that the operation load is not affected. Therefore, the order in which the fixed mask and the two movable masks are superimposed in the optical axis direction is not particularly limited because they are not directly related to the gist of the present invention.

Further, according to the present invention, after the movable field frame switching operation is completed, the fixed field is set at each of the C, H, and P field frame setting positions.
As a means for reducing the working space of the plurality of movable masks in the optical axis direction, they are urged by spring elasticity. The spring elasticity may be applied to the movable masks.

(Second Embodiment) As another embodiment, in a diaphragm device provided in a photographing optical system of a camera, the incident light at the time of photographing is changed by a plurality of diaphragm blades to change the diaphragm amount. The working space in the optical axis direction in which the plurality of diaphragm blades operate is reduced after the aperture amount is determined. It is also conceivable that the diaphragm blades are elastically biased against the main plate holding them.

The example of use is different from that of the first embodiment, but the working space in the optical axis direction in which a plurality of diaphragm blades work is
By reducing the working space in the optical axis direction after the aperture amount is determined, the rattling of the diaphragm blades in the optical axis direction is reduced, and unnecessary light from the rattled portions of the plurality of diaphragm blades is prevented from entering. Can be. Also, at the time of setting the throttle amount, the operation space is widened, the operation is performed smoothly, the operation space is reduced after the setting, and furthermore, it is elastically urged and loosely held, so that it is securely held at the set position. be able to.

[0024]

As described above, according to the invention described in each claim of the present application, the fixed and plural movable mask members of the movable visual field frame variable device are moved in the direction orthogonal to the optical axis,
In the finder for switching to a plurality of field frame sizes, at least after the end of the movable field frame switching operation, the working space is reduced by fixedly operating the plurality of movable mask members in the optical axis direction and elastically biasing the working space. Is reduced, it is possible to reduce the diopter shift of each side of one field of view formed by a plurality of movable mask members.

Also, while changing the movable visual field frame, the working load is reduced by increasing the working space, and when the change is completed, the working space is reduced to increase the working load so that the movable member is not accidentally moved. By reducing the operating force of the movable member and increasing the holding force after the change,
Easy change operation and reliable holding after the change are also possible.

[Brief description of the drawings]

FIG. 1 is a perspective view in which parts of a finder field frame changing device of the present invention are developed.

FIG. 2 is a front view showing the H size state of the present invention.

FIG. 3 is a front view showing a C size state of the present invention.

FIG. 4 is a front view showing a P size state of the present invention.

FIG. 5 is a cross-sectional view of a main part showing an operation space in the H size state of the present invention.

FIG. 6 is a cross-sectional view of a main part showing an operation space in the middle of a change from H size to C size according to the present invention.

FIG. 7 is a cross-sectional view of a main part showing an operation space in a C size state according to the present invention.

FIG. 8 is a cross-sectional view of a main part showing an operation space in a P size state according to the present invention.

FIG. 9 is a top view of the finder field frame changing device of the present invention in a state where components are assembled.

FIG. 10 is a front view showing a conventional H size state.

FIG. 11 is a front view showing a conventional C size state.

FIG. 12 is a front view showing a conventional P size state.

FIG. 13 is a top view of a state where components of a conventional finder field frame changing device are assembled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mask 2 1st movable mask 3 2nd movable mask 4 Optical prism 5 Ground plate 6 Drive plate 7 Fixed plate 8 Objective lens 9 Eyepiece prism 10 Eyepiece 11 Finder optical axis

Claims (5)

[Claims] 1. A light-passing area variable device that moves a plurality of movable mask members in a direction orthogonal to an optical axis to switch the amount of light passing through the plurality of light-passing areas. A light-passing area changing device, wherein a predetermined space in the optical axis direction of a plurality of movable mask members is secured, and after the light-passing area changing operation is completed, means for reducing the space is provided. 2. A finder device for switching a plurality of view frame sizes by moving a plurality of view frame size setting members in a direction orthogonal to the optical axis within a predetermined space in a viewfinder optical axis direction. A finder device comprising means for reducing the space after setting of a field frame size. 3. The finder device according to claim 2, wherein
3. The finder device according to claim 2, wherein the means for reducing the space reduces the space by elastically urging a plurality of field frame size setting members in the optical axis direction. 4. A plurality of view frame sizes are switched by moving a plurality of movable mask members relative to a fixed mask member in a direction perpendicular to the optical axis within a predetermined space in the direction of the viewfinder optical axis. A viewfinder device, comprising: means for reducing the space in the optical axis direction of a plurality of movable masks with respect to a fixed mask member at least after setting of a field frame size. 5. The finder device according to claim 4, wherein
The means for reducing the space reduces the space by elastically urging the plurality of movable mask members in the optical axis direction with respect to the fixed mask member at least after setting the field frame size. Item 5. The finder device according to Item 4.