JPH09113955A - Focal-plane shutter base plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, light and inexpensive shutter by compensating mechanical strength. SOLUTION: Two sets of blade groups provided between a shutter base plate 1 and a cover plate 2 are provided on the side of a shutter opening 1a. The blade group is driven by a driving member M provided near the shutter opening 1a. The supporting shaft of the driving member and at least a part of a mirror box set at the peripheral part of the shutter opening are formed of plastic material integrally with the shutter base plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a shutter substrate of a focal plane shutter for a camera, and more specifically, a set of two blades made of a plurality of light-shielding thin plates is provided on the side of the shutter opening of the shutter substrate. It relates to the structure of a shutter substrate of a working type focal plane shutter.

[0002]

2. Description of the Related Art Conventionally, a shutter substrate of this type has been formed by punching a metal material such as brass or aluminum alloy by press working, forming a supporting shaft, a spacer, a column, etc. of one of the operating members by turning and then caulking it. The shutter substrate is formed by being combined with the substrate.

[0003]

On the other hand, as recent cameras are required to be smaller and lighter and to be further reduced in price, it has been proposed to use a plastic material. However, although the plastic material has a sufficient adaptability for the above purpose, it lacks mechanical strength. For this reason, as disclosed in Japanese Utility Model Laid-Open No. 58-16625, a metal reinforcing plate is required, and it is not enough to adopt a plastic material alone. Further, in the unitized focal plane shutter, harmful light is likely to enter the opening from the portion close to the mirror box. Therefore, if the distance is made as close as possible, but excessively close, the traveling performance of the shutter is deteriorated. Cause

[0004]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a shutter substrate that complements the mechanical strength and meets the above demands. In particular, it is an object of the present invention to improve a portion of the opening of the focal plane shutter, which has been difficult to be reinforced by being attached to the camera body, to improve the light shielding property. That is, according to the present invention, in order to achieve such an object, at least a part of the support shaft of the drive member that operates the blade group and the mirror box are integrally formed on the shutter substrate.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Two sets of blades composed of a plurality of light-shielding thin plates are provided on a side of a shutter opening on a shutter substrate.
A focal plane shutter in which the blade group is covered with a cover plate is characterized in that a support shaft of a driving member for operating the blade group and at least a part of a mirror box are integrally molded with a shutter substrate by a plastic material. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a shutter opening 1a is formed in a shutter substrate 1, and a peripheral portion of the opening 1a forms a part of a mirror box of a single-lens reflex camera, and a frame portion 1b for mounting the mirror box. And the support shaft 1 of the drive member for operating the blade group of the shutter blade control mechanism M.
A support shaft 1d for c and other operating members, a blade post 1e for mounting the cover plate 2 covering the blade group, a shutter mounting hole 1f, etc. are integrally formed of a plastic material.

FIG. 2 shows a single unit of the shutter substrate 1, in which the support shafts 1c and 1d are integrally formed with the mounting post 1e, the mounting hole 1f, etc., and the state shown in FIG. However, the operation is not described in detail. FIG.
2A is a cross-sectional view taken along line AA of FIG. 1A, in which the arm 4 supporting the blade group 3 is configured on the shutter substrate 1 side, the right end of the blade group 3 is prevented from vibrating during operation, and In the stationary state, a rod-shaped projection 1g that receives the blades in a direction in which they are in close contact with each other is integrally formed on the substrate 1.

A bar-shaped projection 1h having a height slightly lower than that of the bar-shaped projection 1g is formed on the base side of the arm 4, and both ends of the other two sides excluding the side on which the projections 1g and 1h are formed. Also, the same rod-shaped protrusion 1h is formed. Further, in order to prevent the light that has entered through the gap of the camera body from passing through the side of the shutter and adversely affecting the film leaking to the cover plate 2 side, a thin shield portion 1i is integrally formed, and the same shield is provided. The portion 1i is also formed in the space L between the two mounting holes 1f that enter from the finder portion above the camera.

Although the frame portion 1b forming a part of the mirror box is integrally molded in the above embodiment, the entire mirror box may be molded. In that case, the mirror box mounting hole 1k is unnecessary. The shielding portion 1i may be provided on the entire green portion of the substrate 1 as necessary.
Further, in the above description, the frame 1b has been described as constituting a mirror box of a single-lens reflex camera or a part thereof, but when applied to a rangefinder camera or the like that does not have a mirror box, a frame is used as a shielding frame. Can be configured.

[0010]

As apparent from the above description, since the frame portion forming a part of the mirror box is integrally formed on the focal plane shutter substrate, the flat substrate 1
The reinforcing beam standing upright on the plane can also be used as a part of the essential parts, and the surrounding area of the opening, which was difficult to reinforce in the past, meets the mechanical strength without requiring a special space. Since the support shaft etc. are also integrally molded,
It is possible to provide a shutter that can reduce the cost of processing each axis and the like and the cost of coupling, block harmful light, and reduce the size and weight as well as the cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a completed shutter product showing an embodiment of the present invention.

FIG. 2 is a perspective view of the shutter substrate of FIG.

FIG. 3 is a sectional view of a main part of FIG.

[Explanation of symbols]

 1 Shutter Substrate 1c Support Shaft 2 Cover Plate 3 Blade Group 4 Arm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Nakagawa 934-13 Shikato, Yotsukaido-shi, Chiba Seiko Optical Co., Ltd.

Claims (1)

[Claims] 1. A focal plane shutter in which two sets of blades composed of a plurality of light-shielding thin plates are provided on a shutter substrate on a side of a shutter opening, and the blades are covered with a cover plate to operate the blades. A focal plane shutter substrate for a camera, characterized in that at least a part of a support shaft of a driving member and a mirror box around the opening is integrally molded with a shutter substrate by a plastic material.