JPH0713256A - Picture size controlling device - Google Patents

Abstract

PURPOSE:To obtain an exposure picture size as aimed size regardless of a variable zooming position by arranging the tip part of a mask member nearby a film face. CONSTITUTION:A picture size controlling device is constituted of the mask members 4a and 4b that are bent so as to arrange the end parts 4c and 4d near to the surface of the film 1, and to prevent the light beam 30 from a zoom lens system regulated by the end parts 4c and 4d from intruding inside the end parts 4c and 4d. Corresponding to changeover of the exposure screen size, the both mask member 4a and 4b mutually come near or get away each other, however, in either case of being set at the respective size position or moved between the respective size position, each position in the optical axis direction of the film facing side 4e and 4f of the end part 4c and 4d is fixed, and approximately at the same position as the inner rail 22 of the aperture forming member 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera screen size control device for controlling the size of an exposure screen on a film, and more specifically, it can be switched to each screen size such as a Leica size, a panorama size or a high definition size for zooming. The present invention relates to a screen size control device mounted on an operable camera.

[0002]

2. Description of the Related Art The size of an exposed area on a film (hereinafter, referred to as an exposure screen size) is generally determined by the size of the aperture of an aperture forming member arranged in the vicinity of the film.

The size of the exposure screen is specified by the JIS standard. For example, in the case of a full size of 35 mm film (Leica size), the vertical size is 24.0 to 24.8 mm and the horizontal size is 36.0 to 36.8 mm. JIS like this
The aperture is formed in a size that meets the standard. That is, the light rays that have passed through the lens system are regulated by the aperture edge portions of the aperture forming member, and the light rays that have passed the vicinity of the opening edge portions form the outer edge portion of the exposure screen size on the film.

On the other hand, in recent years, it has been demanded that various cameras be provided with a zoom function, and for example, a small compact camera or the like has been widened or has a high magnification.

In such a zoom lens system of a camera with a zoom function, the position of the exit pupil of the zoom lens system changes back and forth with zooming. Due to this change in the position of the exit pupil, a light beam passing near the edge of the aperture. Even if the angle with the optical axis of the is changed, the distance between the aperture forming member and the film surface is as small as 0.5 mm or less, so the change in the exposure screen size due to zooming is about 2 times the standard zoom. If so, it doesn't matter much.

[0006]

By the way, in recent years, there has been known a type in which an exposure screen size is switched over a plurality of stages with one camera, for example, a Leica size, a panorama size, and a high-definition size.

The standard size of 35 mm film of each of the above sizes is 24.0 mm x 36.0 mm for Leica, 13.3 mm x 36.0 mm for panoramic size, and 21.0 mm for high-definition size.
The size is 36.0 mm, and each exposure screen size changes only in the vertical direction. The exposure screen size is switched by moving the aperture by moving a predetermined amount in a direction in which a pair of upper and lower mask members arranged on the lens side of the aperture forming member approaches each other or in a direction away from each other in accordance with a photographer's instruction. This is done by changing the masking amount. For example, in the case of the size described above, in the case of the Leica size, the mask member does not reach the aperture,
In the high-definition size, the mask member slightly masks the aperture, and in the panoramic size, the mask member masks about half of the aperture so that the vertical width of the aperture can be substantially changed.

However, when the aperture is masked by the mask member in this way, that is, in the case of the above-mentioned size, in the panorama size and the high-definition size, the light beam from the zoom lens system is restricted by the edges of the upper and lower mask members. The Rukoto. Since the mask member is arranged on the lens side of the aperture forming member as described above, it is normally separated from the film surface by about 1.5 mm, which is considerably larger than the distance between the aperture forming member and the film surface. When the position of the exit pupil changes in the front-back direction due to zooming, an error occurs in the size of the exposure screen actually formed.

That is, in the case of the panoramic size and the high-definition size because the mask member is separated from the film surface, the size of the exposure screen formed at both the telephoto end and the wide-angle end changes greatly. Will end up.

As described above, if the size of the formed exposure screen changes in accordance with the zooming position and does not reach the expected size, it is not preferable because the time and effort during the subsequent print printing process increase.

The present invention has been made in view of the above circumstances, and in a screen size regulating device of a type in which a mask member arranged in front of an aperture forming member is moved on the aperture to change the setting of the exposure screen size, It is an object of the present invention to provide a screen size control device that can obtain an exposure screen size according to a set size regardless of a change in a zooming position.

[0012]

In order to switch the size of an exposure screen on a film, the screen size control device of the present invention moves a mask on the aperture to cover a predetermined amount of the aperture with the aperture. In a screen size regulating device arranged between an installed aperture forming member and a zoom lens system in which an exit pupil position changes back and forth with zooming, a tip portion of the mask member located on the aperture is the It is characterized in that it is bent so as to come close to the surface of the film, and the tip portion is located on the aperture regardless of the designated size of the exposure screen.

That is, in the apparatus of the present invention, the film surface is
By using a mask member having its leading end portion brought close to each other, screen regulation is performed for all exposure screen sizes.

The screen restriction by the mask member may be limited to the vertical direction, or may be performed in the horizontal direction in addition to the vertical direction.

The above-mentioned approach means that the distance between the leading end of the mask member and the film surface is set to such an extent that an exposure screen size error caused by a change in zooming position does not substantially pose a problem. Say.

[0016]

According to the above construction, the tip of the mask member is close to the film surface, and what angle the light from the zoom lens system regulated by the tip of the mask member has with respect to the optical axis. However, even if the position of the exit pupil changes between the telephoto position T and the wide-angle position W due to zooming of the zoom lens system, the exposure on the film is performed because the light is irradiated to almost the same position on the film. The screen size hardly changes.

Further, in the case of a Leica size which is a full screen size in the past, the mask member was retreated from above the aperture, and the screen was restricted by the aperture edge portion. Even in the case of Leica size, the screen is regulated by a mask member,
Since the tip of the mask member is always arranged in the aperture, even if the tip is brought close to the film surface as much as the film facing surface (inner rail) of the aperture edge of the aperture forming member, It is possible to avoid the collision between the tip portion and the aperture edge portion due to the movement of the mask member.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing a main part of a screen size control device according to an embodiment of the present invention. An aperture forming member 3 in which a rectangular aperture 2 is bored is arranged in front of the film 1, and a pair of masks that move on the aperture 2 in front of it to change the opening area of the aperture 2. Members 4a and 4b are arranged, and the aperture 2
The optical axis 20 of the zoom lens system (not shown) passes through the center of the.

Each of the mask members 4a and 4b has a substantially L-shape, and rectangular rack holes 5a and 5b having rack teeth formed on the edges thereof are formed in each of the lateral bent portions which overlap each other. ing. A gear 6 axially supported by a camera body portion (not shown) is configured to be inserted into the rack holes 5a and 5b, and the gear 6 is provided at a position where the rack teeth of the rack holes 5a and 5b face each other. Configured to mesh with the teeth of the. A protrusion 7 that functions as a follower of the cam mechanism is provided above the mask member 4a, and the upper end of the protrusion 7 contacts the cam surface 8a of the linear cam 8. , A mask member according to the movement of the linear cam 8 in the directions of arrows A and B.
4a moves up and down, and the mask member 4b moves up and down via the gear 6 in the direction opposite to the mask member 4a. This allows the mask member 4
The a and 4b can be moved toward each other or away from each other.

The cam surface 8a of the linear cam 8 is a mask member.
It has a three-step shape so that 4a and 4b can be set at three positions of a Leica size position (L), a high definition size position (H) and a panorama size position (P). In FIG. 1, the protrusion 7 is in contact with the Leica size position (L) of the cam surface 8a, and at this time, the masking amount of the aperture 2 by the mask members 4a and 4b is minimized. After this,
When the exposure screen size is set to the high-definition size by the photographer, the linear cam 8 moves in the direction of arrow A, whereby the protrusion 7 comes into contact with the high-definition size position (H) of the cam surface 8a, and the protrusion 7 is slightly pushed downward, the mask member 4a is moved downward, and the mask member 4b is moved slightly upward. As a result, the masking amount of the aperture 2 is slightly increased. Similarly, when the exposure screen size is set to the panorama size, the direct-acting cam 8 moves in the direction of arrow B, whereby the protruding portion 7 comes into contact with the panorama size position (P) of the cam surface 8a, and protrudes. The part 7 is pressed downward significantly,
The mask member 4a largely moves downward and the mask member 4b largely moves upward. This significantly increases the masking amount of the aperture 2.

The rack holes 5a of the mask members 4a, 4b,
Slots 9a, 9b, 10a, and 10b are formed on the upper and lower sides of 5b, respectively, and of the two positioning pins 11a and 11b implanted in the rear camera body portion (not shown). The pin 11a is fitted in the oblong holes 9a and 10a, and the pin 11b is fitted in the oblong holes 9b and 10b, whereby the mask members 4a and 4b are inserted.
Is guided by the pins 11a and 11b so that it can move stably in the vertical direction.

Further, the mask member 4a is provided with a spring 12 so that the upper end of the protruding portion 7 of the mask member 4a always contacts the cam surface 8a.
Is urged upward by.

FIG. 2 is a sectional view taken along line XX of FIG. As shown in FIG. 2, a pair of outer rails 21 and inner rails 22 are formed on the rear surface of the aperture forming member 3, respectively. The outer rail 21 is a pressure plate 23 attached to the camera back cover.
The inner rail 22 and the film 1
It contacts with the curled upper and lower ends of the surface (sensitive material surface). The distance between the outer rail 21 and the inner rail 22 in the optical axis 20 direction is 0.2 to
The film 1 is set to about 0.5 mm, and the film 1 moves while being guided by the pressure plates 23 and the inner rails 22 in the tunnel-like space formed by both the rails 21, 22, that is, the pressure plate 23 and the inner rails 22.

Further, as shown in FIG. 2, a pair of mask members 4a and 4b are arranged on the lens side of the aperture forming member 3, and the aperture 2 is moved by moving the mask members 4a and 4b in the directions of arrow C and arrow D, respectively. It will be narrowed in the vertical direction.

For example, when the exposure screen size is set to be switchable to each of the Leica size, the high-definition size and the panorama size, the mask is provided near the inside of the vertical edge of the aperture 2 of the aperture forming member 3 in the Leica size. The size of the aperture 2 is set with the tips of the members 4a and 4b positioned, and in high-definition size and panoramic size, the mask members 4a and 4b are moved from the position of the Leica size by a predetermined amount in the directions C and D, respectively. Try to narrow aperture 2. In other words, with the standard size of 35 mm film, the Leica size is 2
4.0mm x 36.0mm, HDTV size is 21.0mm x 3
The size is 6.0 mm and the panorama size is 13.3 mm x 36.0 mm. Therefore, the mask members 4a and 4b at the Leica size position as shown in FIG.
Close to each other, and 10 in panoramic size
They are moved so as to approach each other by about mm.

By the way, since the conventional mask members 4a and 4b are located closer to the lens than the aperture forming member 3, the pressure plate
The distance from 23 is larger than that in the case of the aperture forming member 3, and for example, the distance is about 1.5 mm to 2.0 mm. Therefore, for example, the light from the zoom lens system regulated by the tip of the mask member 4a 'in FIG.
It will wrap around inward more than the tip of.

However, since the position of the exit pupil changes to the telephoto position T, the intermediate position M, and the wide-angle position W with zooming of the zoom lens system, a real screen area is formed which is restricted by the tip of the mask member 4a. The lines are P _T , P _M , P _W
If the intersections of these lines and the surface (sensitive material surface) of the film 1 are Q _T , Q _M , and Q _W , respectively, the positions of Q _T and Q _W will deviate greatly from each other. That is, since the mask member 4a 'is separated from the film 1, the exposure screen size is significantly changed between the case where the telephoto position T is set and the case where the wide angle position W is set.

Therefore, in the apparatus of the present embodiment, as shown in FIG. 2, the tip portions 4c, 4d of the mask members 4a, 4b are bent so as to be close to the surface of the film 1, and are regulated by the tip portions 4c, 4d. The light 30 from the zoom lens system is the tip 4c, 4d
I try not to wrap around inside. The tip portions 4c and 4d are arranged over the entire left and right width of the aperture 2.

Both mask members 4a and 4b are moved closer to or separated from each other in accordance with the switching of the exposure screen size. Even when moving between them, the positions of the film facing surfaces 4e and 4f of the tip portions 4c and 4d in the optical axis direction are constant, and are substantially the same as the inner rail 22 of each mask member 3.

However, if the film facing surfaces 4e and 4f are set to be closer to the zoom lens system side than the inner rail 22 by about 0.1 to 0.3 mm, when the film 1 is moved and the mask members 4a and 4b are moved. These mask members 4a and 4b are preferable because they do not slide on the surface of the film 1 and can prevent the sensitive surface of the film 1 from being damaged.

The mask members 4a and 4b are configured such that the tip portions 4c and 4d thereof are located inside the aperture 2 regardless of the exposure screen size. Although the screen size is regulated in the vertical direction by the screens 4c and 4d, as described above, since the tip portions 4c and 4d are arranged close to the surface of the film 1, which exposure screen is displayed. Even when the size is set, as shown in FIG. 4, each line P _T , P _M , P _W forming the actual screen area in the case of each of the telephoto T, the middle M, and the wide angle _W is one point on the film 1. Q
Will be converged on.

As a result, it is possible to form a constant size of the actual exposure screen regardless of the zooming position for each designated exposure screen size.

The screen size control device of the present invention is not limited to the one having the above-mentioned structure, but can be modified in various modes.

For example, the shape of the tip portion of the mask member is not limited to that of the above-mentioned embodiment, and the film facing surface of this tip portion can be arranged in the vicinity of the film, and the light from the zoom lens system can be accurately arranged. Any shape may be used as long as it can be regulated.

Various types of means can be applied as means for moving the mask members 4a and 4b according to the designated exposure screen size. For example, the gear 6 in FIG.
It is also possible to drive the rotation by using a motor controlled by.

Further, in the above embodiment, the designated exposure screen size and zooming position are each of three types.
These types are not limited to these numbers, but can be set to numbers appropriate for the appropriateness of the camera, and the mask movement amount can be changed accordingly.

The device of the present invention can be applied to the case where the zoom lens is a multifocal switching lens.

[0039]

As described above, according to the screen size control device of the present invention, the mask member disposed close to the film surface can be used regardless of the exposure screen size set. Since the exposure screen is regulated by the tip,
It is possible to prevent the light from the zoom lens system from going inward from the tip, and it is possible to form an exposure screen on the film in a constant size regardless of the zooming position. As a result, the labor required for size adjustment and the like during the subsequent print printing process can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a main part of a screen size control device of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a diagram for explaining a problem caused by a conventional screen size control device.

FIG. 4 is a view for explaining the operation of the screen size control device shown in FIG.

[Explanation of symbols] 1 film 2 aperture 3 aperture forming member 4a, 4b, 4a 'mask member 4c, 4d tip 4e, 4f film facing surface 5a, 5b rack hole 6 gear 7 protrusion 8 direct cam 8a cam surface 12 Spring 20 Optical axis 21 Outer rail 22 Inner rail 23 Pressure plate

Claims (1)

[Claims] 1. A mask member that moves on an aperture to cover a predetermined amount of the aperture for switching a size of an exposure screen on a film, and an aperture forming member having the aperture, and an exit pupil according to zooming. In a screen size regulating device arranged between zoom lens systems whose positions change back and forth, the tip of the mask member located on the aperture is bent so as to be close to the surface of the film, and the exposure is performed. A screen size regulating device, characterized in that the tip portion is configured to be positioned on the aperture regardless of a designated size of the screen.