JPH06250281A - Picture frame size switching camera - Google Patents

Abstract

PURPOSE:To provide a picture frame size switching camera having a finder visual field frame switching mechanism capable of being disposed in a small space, absorbing fluctuations caused by connection with a photographic picture frame size switching mechanism and preventing the play of a finder visual frame by adroitly using a linear elastic member. CONSTITUTION:The picture frame size switching camera is equipped with finder visual field frame regulating means 9 and 10 arranged in the image forming surface of a finder optical system and having cam groove holes 9f and 10f for changing over the picture frame size of the finder visual field frame, the linear elastic member 14 disposed in the vicinities of the finder visual field frame regulating means 9 and 10 and passing through the cam groove holes 9f and 10f in an optical axial direction and an elastic member driving means 13 moving the elastic member 14 so as to displace came groove holes 9f and 15f linking with a photographic picture frame size switching operation, as a characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen size switching camera, and more specifically to a finder field frame for switching a finder field frame to a finder field frame corresponding to the switched shooting screen size. It relates to a switching mechanism.

[0002]

2. Description of the Related Art Various conventional view frame switching mechanisms for a viewfinder in a screen size switching camera have been provided, but a representative one is disclosed in Japanese Patent Laid-Open No. 4-53.
There is a viewfinder frame switching mechanism disclosed in Japanese Patent No. 939. This mechanism is composed of two relatively movable movable field frames that form a finder field frame, and a large-diameter ring cam that changes the aspect ratio of the finder field frame that is composed of these two movable field frames. That is, the ring cam is rotated in conjunction with the switching operation of the shooting screen size, and the movable field frame is moved so that the viewfinder field corresponds to the switched shooting screen size.

[0003]

However, since the conventional finder visual field frame switching mechanism uses a large-diameter ring cam, it requires a large space for arrangement and requires a high degree of precision in parts. There are points,
In addition, there are the following difficult problems in interlocking with the shooting screen size switching mechanism.

That is, the viewfinder frame switching mechanism is
The viewfinder field frame must be moved in the viewfinder optical system to correspond to the changed shooting screen size in conjunction with the shooting screen size switching operation, but there is variation in the connection system with the shooting screen size switching mechanism. Occurs, it is difficult to accurately move the viewfinder field frame to a predetermined switching position, and the viewfinder field frame is rattled.

An object of the present invention is to use a linear elastic member skillfully so that it can be arranged in a small space. Absorption of variations due to connection with a photographing screen size switching mechanism and a viewfinder field frame. (EN) A screen size switching camera having a viewfinder frame switching mechanism capable of preventing rattling.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a finder optical system in a screen size switching camera for switching a finder field frame to a screen size corresponding to a switched photographic screen size in association with a photographic screen size switching operation. Of the finder visual field frame defining means having a cam groove hole for switching the screen size of the visual field frame and disposed near the finder visual field frame defining means, and the cam groove hole A linear elastic member penetrating in the axial direction and elastic member driving means for moving the elastic member so as to displace the cam groove hole in association with the switching operation of the photographing screen size are provided. .

[0007]

In operation, the elastic member driving means moves the elastic member in conjunction with the switching operation of the photographing screen size to displace the cam groove hole, thereby operating the finder visual field frame defining means and corresponding to the switched photographing screen size. Screen size,
Switch the viewfinder field frame.

[0008]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is an exploded perspective view of a viewfinder field frame switching mechanism in a screen size switching camera showing an embodiment of the present invention. The present embodiment will be described by taking as an example a camera that uses a roll film having a width of 35 mm and can switch the photographing screen size between a full size (standard size) and a horizontally long panoramic size smaller than this. However, the screen size switching mechanism is not shown because it is not directly related.

As shown in FIG. 1, the finder optical system of this camera is a real image type finder optical system including finder objective lenses 1 to 4, first and second prisms 5 and 6, and an eyepiece 7. Has been done. First above
The prism 5 and the second prism 6 are each formed of a right-angled prism, and both prisms are arranged so as to be coupled to each other such that the emission surface and the incidence surface thereof face each other and transmitted through the objective lenses 1 to 4. The subject light enters the first prism 5, is reflected by the first reflecting surface 5a toward the second reflecting surface 5b below, and is reflected forward by the second reflecting surface 5b and is reflected by the second prism 6. Incident. Then, after being reflected laterally (to the right in FIG. 1) by the first reflecting surface 6a of the prism 6, it is emitted rearward by the second reflecting surface 6b and reaches the eyepiece lens 7.

That is, in the real image type finder optical system, the exit surface 5c of the first prism 5 facing the second reflection surface 5b is an image forming surface, and the image formed on the exit surface 5c is in the eyepiece. It is designed to look through the lens 7.

The exit surface 5c of the first prism 5 is
And a light-entering surface 6c of the second prism 6, a finder visual field frame defining means is disposed, and the visual field frame defining means is operated by an elastic member driven by an elastic member driving means. , The field frame can be switched. That is, the finder visual field frame defining means, the elastic member, and the elastic member driving means constitute a finder visual field frame switching mechanism.

The finder visual field frame defining means comprises a visual field mask 8, a first moving mask 9 and a second moving mask 10. The visual field mask 8 is formed of a plate member and is fixed to a stationary member, and a laterally long opening 8a for forming a normal full-sized visual field frame is formed in an upper half portion of the visual field mask 8 and a lower half portion thereof. A horizontally elongated narrow horizontal guide hole 8d is formed in which a later-described elastic member 14 is inserted.
The one side edge (the left side edge in FIG. 1) is provided with screw holes 8b and 8c for attaching the moving mask at the upper and lower positions thereof.

The first moving mask 9 is arranged so that the front surface of the field mask 8 overlaps with the crocodile mask and is vertically slidable. The first moving mask 9 is formed in an L-shape with a thin plate member, and the horizontal portion thereof is formed on a driving plate portion 9b having a shape substantially matching the shape of the lower half portion of the field mask 8. The upper portion of the driving plate portion 9b covers the lower portion of the opening 8a when switching the visual field frame, and the upper edge thereof forms the frame portion 9a at the lower side of the visual field frame. The drive plate portion 9b is provided with a cam groove hole 9f that is inclined obliquely downward to the right. The vertical portion is an extension arm portion 9c having a narrow width corresponding to the portion of the visual field mask 8 where the mounting screw holes 8b and 8c are provided. The extension arm portion 9c includes:
Vertical guide elongated holes 9 corresponding to the screw holes 8b and 8c.
d and 9e are provided. The lower guide elongated hole 9e of the guide elongated holes 9d and 9e serves to regulate the position of the moving mask 9 when moving upward and downward.

On the other hand, the second moving mask 10 is arranged so that the front surface of the first moving mask 9 overlaps with the crocodile mask and is slidable in the vertical direction. The second moving mask 10 is also a thin plate member formed in an inverted U-shape, and the horizontal portion below the second moving mask 10 is a driving plate portion 9 of the first moving mask 9.
The driving plate portion 10b is formed on the driving plate portion 10b that is slightly narrower in vertical width than the driving plate portion 9b.
A cam groove hole 10f, which is inclined in a direction opposite to the cam groove hole 9f of the first moving mask 9 and a part of which overlaps with the cam groove hole 9f, is formed in b. Further, the upper horizontal portion is formed on a relatively narrow covering arm portion 10g, and its lower edge portion forms the frame portion 10a of the upper side of the field frame when switching the field frame. A vertical portion connecting the upper horizontal portion and the lower horizontal portion is formed by a connecting arm portion 10c that overlaps the extending arm portion 9c of the first moving mask 9, and this connecting arm portion 10c includes Vertical guide slots 10d and 10e corresponding to the guide slots 9d and 9e are formed. The lower guide elongated hole 10e of the guide elongated holes 10d and 10e serves to regulate the position of the moving mask 10 when moving upward and downward.

As shown in FIG. 2, the first moving mask 9 and the second moving mask 10 have mounting screws 11,
It is attached to the field mask 8 by 12 so as to be vertically movable. The mounting screws 11 and 12 are each formed of a stepped screw. That is, the mounting screws 11 and 12
Are provided with small-diameter threaded portions 11c and 12c at their tip portions, and short shaft portions 11b and 12b through which the above-mentioned elongated guide holes 9d, 9e, 10d and 10e are inserted are formed in the middle thereof, and a short shaft portion at their rear end portions. Dish-shaped head portion 11 having a larger diameter than the portions 11b, 12b
a, 12a are provided, and the short shaft portion 11 is provided.
b and 12b, the elongated guide holes 9d and 9e of the first moving mask 9 and the elongated guide holes 10d and 10e of the second moving mask 10 are respectively inserted, and the small-diameter screw portions 11c and 12c are attached to the mounting screws of the field mask 8. The first moving mask 9 and the second moving mask 10 are screwed into the holes 8b and 8c, respectively,
The front surface of the field mask 8 is attached to the crocodile so as to be vertically movable. In addition, the field mask 8, the first moving mask 9, and the second moving mask 10 arranged between the exit surface 5c of the first prism 5 and the entrance surface 6c of the second prism 6 in this manner are located at their lower portions. Guide hole 8d and cam groove holes 9f, 10 formed in
f is arranged so as to project downward from the lower ends of the prisms 5 and 6, and one linear spring, which is a linear elastic member 14, is provided in the guide hole 8d and the cam groove holes 9f and 10f from the rear side. It is arranged so as to penetrate in the axial direction.

The base portion of the wire spring 14 is, as shown in FIGS. 1 and 2, a switching gear 13 which constitutes elastic member driving means.
Installed on. The switching gear 13 is formed of a partial gear in which a gear 13a is partially formed on a part of the peripheral surface of the disk, and the line described above is formed on the outer periphery of a short cylindrical boss portion 13b formed at the center thereof. A circular base portion 14a formed at the base end of the spring 14 is rotatably fitted. The free end portion of the collinear spring 14 penetrates the biasing convex portion 13c formed at a part of the peripheral edge of the upper surface of the switching gear 13, and the tip end portion thereof has the guide hole 8d, the cam groove holes 9f, 10f. Have been inserted into.

The biasing convex portion 13c is formed by a protrusion whose open portion faces the boss portion 13b and has an inverted U-shape in a plan view, and has a radial through hole 13f therein. The pushing projections 13d, 13e are formed on the inner surface of the through hole 13f facing each other.

The switching gear 13 is rotatably attached to an immovable member (not shown), and the gear 1
A drive gear (not shown) meshes with the third gear 13a. As shown in FIG. 9, this drive gear transmits the driving force generated by the screen size switching means 16 to the switching gear 13 to operate the field frame switching mechanism 18 configured as described above. At this time, the switching gear 13 is preset so as to further rotate slightly in the rotation direction after switching the field frame. Further, the driving force generated by the screen size switching means 16 simultaneously operates the screen size switching mechanism 17, and when the screen size is full size, the field frame also becomes the field frame corresponding thereto. When the screen size is switched to the panoramic size, the field frame is also switched to the panorama compatible field frame.

Next, the operation of the viewfinder field frame switching mechanism in the screen size switching camera of this embodiment having the above structure will be described. First, the screen size switching means 16
When is driven to switch the screen size to the full size, the switching gear 13 rotates in the direction of arrow a as shown in FIG. Then, the protrusion 13d for pushing moves the wire spring 1
4 is pushed to rotate the spring 14 in the same direction. As a result, the tip of the wire spring 14 pushes down the cam groove hole 9f of the first moving mask 9 and the cam groove hole 10f of the second moving mask 10.
Is pushed up, so that the first moving mask 9 is moved downward and the second moving mask 10 is moved upward. As shown in FIG. 3, this movement is performed below the first moving mask 9 by bringing the inner upper edge of the guide elongated hole 9e below the first moving mask 9 into contact with the short shaft portion 12b of the mounting screw 12. Of the guide slot 10e below the second moving mask 10
When the inner lower edge of the second abutment contacts the short shaft portion 12b of the mounting screw 12, the upward movement of the second moving mask 10 is stopped.

In this state, the driving plate portion 9b of the first moving mask 9 is retracted below the opening 8a, and the covering arm portion 10g of the second moving mask 10 is retracted above the opening 8a. The opening 8a is displayed as a full-size field frame in the finder field.

Thus, the viewfinder frame switching mechanism is
The finder visual field frame defining means is switched to the full size visual field frame in conjunction with the screen size switching mechanism. At the time of this switching, the drive by the screen size switching means 16 is further continued. When this driving is continued, the switching gear 13 is further moved to the arrow a as shown in FIG.
Rotate in the direction of and stop. When the switching gear 13 slightly rotates, the free end of the wire spring 14 cannot move any further, and therefore the wire spring 14 is pushed by the pushing protrusion 13d to bend. Therefore, the elastic force of the wire spring 14 due to this bending allows the first and second moving masks 9 and 10 to be stably maintained at the full-size field frame switching position (see FIG. 3).

Next, when the screen size switching means 16 is driven to switch the screen size to the panorama size,
The switching gear 13 rotates in the direction of arrow b, as shown in FIG. Then, the pushing projection 13e pushes the wire spring 14 to rotate the spring 14 in the same direction. As a result, the tip of the wire spring 14 pushes up the cam groove hole 9f of the first moving mask 9 and pushes down the cam groove hole 10f of the second moving mask 10. Therefore, this moves the first moving mask 9 upward and the second moving mask 10 downward. As shown in FIG. 4, this movement moves upward of the first moving mask 9 by contacting the inner lower edge of the elongate guide hole 9e below the first moving mask 9 with the short shaft portion 12b of the mounting screw 12. Of the guide slot 10e below the second moving mask 10
When the inner upper edge of the second abutment contacts the short shaft portion 12b of the mounting screw 12, the downward movement of the second moving mask 10 is stopped.

In this state, the driving plate portion 9b of the first moving mask 9 covers the lower portion of the opening 8a with its upper portion, and the covering arm portion 10g of the second moving mask 10 has the opening portion 8g.
Since the upper part of the opening 8a is covered, the opening 8a has the upper side of the frame 1
At 0a, a horizontally long panoramic field frame whose lower side is regulated by the frame 9a is formed, and this is displayed in the viewfinder field as a panoramic field frame.

In this way, the viewfinder frame switching mechanism is
The finder visual field frame defining means is switched to the panoramic size visual field frame in conjunction with the screen size switching mechanism. At the time of this switching, the driving by the screen size switching means 16 is the same as in the full size switching. A little more will continue. When this drive is continued, the switching gear 13 further rotates in the direction of the arrow b and stops, as shown in FIG. When the switching gear 13 slightly rotates, the free end of the wire spring 14 cannot move any further, and therefore the wire spring 14 is pushed by the pushing protrusion 13e to bend. Therefore, the elastic force of the wire spring 14 due to this bending allows the first and second moving masks 9 and 10 to be stably maintained at the panoramic size field frame switching position (see FIG. 4).

Since the first and second movable masks 9 and 10 forming the field frame are pressed in their respective directions by the wire spring 14 after the switching operation is completed, this prevents the field frame from rattling. To be done. Furthermore,
The elastic force due to the bending of the line spring 14 also absorbs the variation in the connection between the screen size switching means, the field frame switching mechanism, and the screen size switching mechanism. Therefore, the field frame is held at a stable position.

Although the wire spring is used as the linear elastic member in the above embodiment, it goes without saying that a mold or a pressed product may be used.

[0027]

As described above, according to the present invention, since a linear elastic member is used to switch the finder field frame in the finder field frame switching mechanism in the screen size switching camera, the finder field frame can be saved. A small finder field frame switching mechanism that does not exist can be configured, and the elastic member is slightly bent after the field frame is switched, so that the field mask can be prevented from rattling and the screen size can be switched. The remarkable effect that the variation due to the connection with the mechanism can be absorbed is obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a viewfinder field frame switching mechanism in a screen size switching camera according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the finder field frame switching mechanism of the above embodiment.

FIG. 3 is a front view showing a state in which the finder field frame switching mechanism is switched to a full size field frame.

FIG. 4 is a front view showing a state in which the viewfinder field frame switching mechanism is switched to a panoramic size field frame.

FIG. 5 is a plan view showing the operation of switching the field frame to the full size of the wire spring by the switching gear.

FIG. 6 is a plan view showing an operation in which a line spring switches a field frame to a panoramic size by a switching gear.

FIG. 7 is a plan view showing a state in which a line spring is urged following a full-size field frame switching operation.

FIG. 8 is a plan view showing a state where a line spring is urged following a panoramic size field frame switching operation.

FIG. 9 is a block diagram showing the relationship between the screen size switching means, the field frame switching mechanism, and the screen size switching mechanism.

[Explanation of symbols]

8 ……………… field mask (field frame) 9 ……………… first moving mask (finder field frame defining means) 10 ………… second mask (finder field frame defining means) 9f ... ………… Cam groove hole 10f ………… Cam groove hole 13 ……………… Switching gear (elastic member switching means) 14 ……………… Line spring (elastic member)

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[Procedure amendment]

[Submission date] May 26, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

An object of the present invention is to use an elastic member skillfully so that the elastic member can be arranged in a small space, and the connection with a photographing screen size switching mechanism absorbs variations and prevents the viewfinder frame from rattling. An object of the present invention is to provide a screen size switching camera having a viewfinder frame switching mechanism capable of performing the above.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

SUMMARY OF THE INVENTION The present invention provides a screen size switching camera for switching a finder field frame to a finder field frame corresponding to a switched shooting screen size in association with a shooting screen size switching operation. disposed on the imaging plane of the system, the finder field frame defining means having a cam slot for switching the field frame support <br/> size of the view frame, is disposed in the vicinity of the finder field frame defining means An elastic member penetrating the cam groove hole in the optical axis direction, and an elastic member driving means for moving the elastic member so as to displace the cam groove hole in conjunction with a switching operation of a photographing screen size. Is characterized by.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In operation, the elastic member driving means moves the elastic member in conjunction with the switching operation of the photographing screen size to displace the cam groove hole, thereby operating the finder visual field frame defining means and corresponding to the switched photographing screen size. Viewfinder
Switch to the frame .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

As shown in FIG. 2, the first moving mask 9 and the second moving mask 10 have mounting screws 11,
It is attached to the field mask 8 by 12 so as to be vertically movable. The mounting screws 11 and 12 are each formed of a stepped screw. That is, the mounting screws 11 and 12
Small-diameter screw portion 11c, 12c is provided at the distal end portion, the guide slots 9d in the middle, 9e, 10d, minor portion 11b 10e is inserted, 12b is formed, the minor axis portions on the rear end portion Dish-shaped head 11 for preventing slippage, which has a larger diameter than 11b and 12b
a, 12a are provided, and the short shaft portion 11 is provided.
b and 12b, the elongated guide holes 9d and 9e of the first moving mask 9 and the elongated guide holes 10d and 10e of the second moving mask 10 are respectively inserted, and the small-diameter screw portions 11c and 12c are attached to the mounting screws of the field mask 8. The first moving mask 9 and the second moving mask 10 are screwed into the holes 8b and 8c, respectively,
The front surface of the field mask 8 is attached to the crocodile so as to be vertically movable. In addition, the field mask 8, the first moving mask 9, and the second moving mask 10 arranged between the exit surface 5c of the first prism 5 and the entrance surface 6c of the second prism 6 in this manner are located at their lower portions. Guide hole 8d and cam groove holes 9f, 10 formed in
f is arranged so as to project downward from the lower ends of the prisms 5 and 6, and one linear spring, which is a linear elastic member 14, is provided in the guide hole 8d and the cam groove holes 9f and 10f from the rear side. It is arranged so as to penetrate in the axial direction.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The base portion of the wire spring 14 is, as shown in FIGS. 1 and 2, a switching gear 13 which constitutes elastic member driving means.
Installed on. The switching gear 13 is formed of a partial gear in which a gear 13a is partially formed on a part of the peripheral surface of the disk, and the line described above is formed on the outer periphery of a short cylindrical boss portion 13b formed at the center thereof. A circular base portion 14a formed at the base end of the spring 14 is rotatably fitted. The free end portion of the collinear spring 14 penetrates the biasing convex portion 13c formed at a part of the peripheral edge of the upper surface of the switching gear 13, and the tip end portion thereof has the guide hole 8d, the cam groove holes 9f, 10f. To
It has been inserted .

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

The switching gear 13 is rotatably attached to an immovable member (not shown), and the gear 1
A drive gear (not shown) meshes with the third gear 13a. As shown in FIG. 9, this drive gear transmits the driving force generated by the screen size switching means 16 to the switching gear 13 to operate the field frame switching mechanism 18 configured as described above. At this time, the switching gear 13 is preset so as to further rotate slightly in the rotation direction after switching the field frame. Further, the driving force generated by the screen size switching means 16 also operates the screen size switching mechanism 17 at the same time, and when the screen size is full size, the field frame also becomes the field frame corresponding thereto, When the size is switched to the panorama size, the field frame is also switched to the panorama field frame.

Claims (1)

[Claims] 1. A screen size switching camera that switches a viewfinder field frame to a screen size corresponding to a switched shooting screen size in association with a shooting screen size switching operation, and is arranged in an image forming plane of a viewfinder optical system. A finder visual field frame defining means having a cam groove hole for switching the screen size of the visual field frame, and a linear shape which is arranged in the vicinity of the finder visual field frame defining means and which penetrates the cam groove hole in the optical axis direction. A screen size switching camera comprising: an elastic member; and an elastic member driving unit that moves the elastic member so that the cam groove hole is displaced in association with a switching operation of a photographing screen size.