JPS6120585Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a light shielding device for a movable reflector in a single-lens reflex camera, specifically, a light shielding device for a movable reflector that blocks external light that enters from the viewfinder eyepiece when the movable reflector is raised. Regarding equipment.

As is well known, in a single-lens reflex camera, the subject image formed through the photographic lens is directed upward at a right angle by a movable reflector tilted at 45 degrees to the optical axis, except when shooting. An image of the subject is formed on a focusing glass, and the object image formed on the focusing glass is observed by a viewfinder eyepiece through a pentagonal prism. When photographing, the movable reflector rotates upward by 45 degrees to take a horizontal position and retreats out of the photographing optical path, and the subject image formed by the photographic lens is focused on the film surface perpendicular to the optical axis, When a shutter curtain covering the film surface is opened, the image of the subject is exposed on the film surface and photographed.

By the way, at the time of photographing, the movable reflector is flipped up and retreated from the photographing optical path, but a viewfinder is inserted into the mirror box through the gap between the rotating base of the movable reflector and a stationary member near the base. External light enters through the eyepiece and may reach the film surface. Therefore, in conventional cameras, various light shielding devices are provided to prevent external light entering from the viewfinder eyepiece side from reaching the film surface.

Next, before explaining the present invention, an example of a conventional light shielding device of this type will be explained with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of a main part of a single-lens reflex camera equipped with the above-mentioned light shielding device, with reference numeral 1.
2 is a single-lens reflex camera body, 2 is a viewfinder pentagonal prism disposed above the camera body, 3 is a viewfinder eyepiece, and 4 is a focusing glass disposed opposite to the lower surface of the pentagonal prism. , 5 is a back cover, 6 is a film, 7 is a shutter curtain, and 8 is arranged at the rear of the camera body 1, including a film guide section 8b and a shutter curtain guide section 8.
9 is a movable reflecting mirror frame that holds a reflecting mirror 10 and has a pair of cylindrical rotating support parts 9a formed at its base; 11 is attached to a fixed member of the camera body 1; , is a shaft that is inserted into the cylindrical rotation support portion 9a of the movable reflecting mirror frame 9 and rotatably supports the frame 9. The upper end of the movable reflector 9 of the camera body 1 is fixed to the upper position facing the rotation support part 9a by adhesive, and the lower end extends so as to cover the rotation support part 9a. A light shielding member 12 is provided. The light shielding part 12 is made of a horizontally long light shielding cloth or plastic sheet, and the light shielding member 12 constitutes the main part of the light shielding device.

However, if such a light shielding member is made of cloth, the fibers may be separated due to friction with the rotating support part 9a and enter the mechanism operating member, or if it is made of a plastic sheet, the fibers cannot be reliably shielded from light. Disadvantages include the inability to obtain suitable materials, the need for painting, and the unreliable work of fixing the upper end with adhesive, which inevitably results in variations in quality. have.

In FIG. 2, instead of the light shielding member 12 made of cloth or plastic sheet shown in FIG. The movable reflective mirror frame 9 uses a light shielding plate whose portion is bent downward as a light shielding member 13.
This is another example of the conventional light shielding device, which covers the rotation support portion of the light shielding device.

If the light shielding plate is used as the light shielding member 13 in this way, the drawbacks of the light shielding member 12 shown in FIG. Since it has to extend in all directions, the rear part of the focusing glass 4 is scratched by its tip, as shown in the figure. Therefore, it is necessary to lower the light shielding member 13 and the rotation support part 9a of the movable reflecting mirror frame backward,
Accordingly, the shutter curtain 7 and the film 6 must also be placed at the rear, which has the disadvantage that the length of the camera body 1 in the front and rear direction increases, making the camera larger.

The purpose of the present invention is to form a light shielding part directly on the rotating base of the movable reflecting mirror frame, and to have a cross-sectional shape that is co-shaped so as to cover the top and bottom of the base, in order to eliminate the drawbacks of the conventional light shielding device. A single-lens reflex camera is equipped with a light-shielding plate formed in the shape of an arrow and fixed to the fixed frame member of the camera body, and these two work together to reliably block external light entering from the viewfinder eyepiece. To provide a light shielding device for a movable reflector of a Tsukusu camera.

According to the present invention, the structure is extremely simple, there is no operational uncertainty, there is no need to increase the size of the camera body, and it is extremely effective in reliably blocking light without contacting the movable reflector frame, etc. A light shielding device can be provided.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

FIG. 3 is a sectional view of a main part of a light shielding device showing an embodiment of the present invention. The components of the single-lens reflex camera to which the light shielding device of the present invention is installed are as follows:
Except for the related members of the light shielding device, the structure is substantially the same as that of the single-lens reflex camera shown in FIG.

The light shielding device 14 of the present invention includes a light shielding portion 16 formed at the base of a movable reflective mirror frame 15, and a light shielding portion 16 formed at the base of a movable reflecting mirror frame 15.
In order not to hinder the rotation of the shutter curtain guide section 8a, the main part thereof is constituted by a light shielding plate 18 having a U-shaped cross section and fixed to the front surface of the shutter curtain guide section 8a.

As shown in enlarged views in Figs. 4 to 6, the light shielding portion 16 is formed such that the cylindrical portion at the upper end edge, which is the base for the rotation of the movable reflecting mirror frame 15, is supported by the support shaft 1 on both the left and right sides.
The light shielding portion 16 is formed in a semi-cylindrical shape, and the bearing portion 16a on the central axis of the light shielding portion 16 is provided with a left side wall and an upper wall, and the lower portion of the light shielding portion 16 is hollowed out.
A bearing hole 16b into which the short support shaft 11 is fitted is drilled from both sides.

The light shielding plate 18 has the light shielding portion 16 connected to the support shaft 1.
When rotating 45 degrees around 1, move the light shielding part 16 close to the light shielding part 16 within a range that does not impede the rotation.
It is a plate having a U-shaped cross section and is formed to cover the top and bottom of the shutter curtain guide portion 8a, and its rear side surface is integrally fixed to the front surface of the shutter curtain guide portion 8a.
The lower part 18a extending forward is located below the light shielding part 16 and is located at the movable reflecting mirror frame 15.
It is designed to fit into the hollowed-out portion 17 of the rotating base.

In the light shielding device of the present invention constructed in this way, when the movable reflecting mirror frame 15 is raised to a horizontal state, as shown in FIG.
When exposed, the triple light shielding structure of the light shielding part 16 and the upper part 18b and lower part 18a of the light shielding part 18 located directly above the light shielding part 16 allows light to be seen from the viewfinder eyepiece part 3 (see FIG. 3). The incident external light is completely blocked and does not reach the photosensitive surface of the film 6. Moreover, the movable reflecting mirror frame 15 is
As shown in the figure, even when rotating from the non-photographing state position tilted at 45 degrees to the photographing state position shown in FIG.
Since it rotates without contacting the light shielding plate 18, there is no change in its relative position with respect to the light shielding plate 18, and since there is no contact, there is no wear and tear.

As explained above, according to the present invention, there is provided a light-shielding part with a simple structure in which the rotating base of the movable reflector frame is simply cut out, and a core with a cross-section sufficient to cover the top and bottom of this light-shielding part. By simply providing a square-shaped light-shielding plate, there is no need for the unreliable operation of the conventional light-shielding devices of this type mentioned above, and there is no need to increase the size of the camera body. It is possible to provide a light shielding device that further improves quality and cost.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of the main parts of conventional light shielding devices for single-lens reflex cameras, and Figures 3 and 3 are
The figure is a cross-sectional view of a main part of a light shielding device showing an embodiment of the present invention, FIGS. 4 and 5 are enlarged cross-sectional views of main parts showing the operating mode of the light shielding device of FIG. FIG. 4 is an enlarged perspective view of a movable reflecting mirror of the light shielding device shown in FIG. 3 above. 9, 15...Movable reflecting mirror frame (movable reflecting mirror) 14
... Light shielding device, 16 ... Light shielding section, 18 ... Light shielding plate.

Claims (1)

[Scope of Claim for Utility Model Registration] A light-shielding portion substantially parallel to the center axis of rotation of the reflector, which is provided at the upper end of the center axis of rotation of the base that rotatably supports the movable reflector, and a camera. is fixed to an immovable member of the main body and is disposed at a position facing the light shielding part of the movable reflecting mirror,
A light-shielding plate extending above and below the light-shielding part and substantially parallel to the light-shielding part is provided so as not to impede the rotation of the movable reflecting mirror, and when the movable reflecting mirror is raised, the light-shielding plate extends above and below the light-shielding part. A movable reflex camera in a single-lens reflex camera, characterized in that the light-shielding plate enters between an upper extension part and a lower extension part to block external light incident from the viewfinder eyepiece part. Mirror shading device.