JPH06308578A - Focal plane shutter for camera - Google Patents

Abstract

PURPOSE:To prevent the forming end of a rear slit forming blade from coming into contact with the aperture edge of an image frame forming member and running into the aperture edge so that it may not be broken, and also to prevent the generation of scratches due to the contact with the rear blade pressing plate. CONSTITUTION:As to the covering plate 6, the aperture edge 6b on the side where the rear blade group 3 of the aperture 6a travels and reaches is formed in an inclined shape, and as to the rear blade pressing plate 9, an extending part 9a having a control part 9b provided with a part whose inclined shape agrees with that of the aperture edge 6b of the covering plate 6 is formed on the side where the rear blade group 3 travels and reaches, and the focal plane shutter is formed so that the hardness of the extending part 9a may be lower than that of the rear slit forming blade 3a. Or, the shutter is formed so that the strength of the extending part 9a may be lower than that of the rear slit forming blade 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade-collision preventing mechanism for a focal-plane shutter for a camera, and more specifically, it prevents a forming end of a rear slit forming blade from colliding with an opening edge of an image frame forming member. Regarding the mechanism.

[0002]

2. Description of the Related Art A conventional example will be described with reference to the drawings. Figure 3
It is an exploded perspective view showing the general composition of the focal plane shutter for cameras used conventionally. A front blade group 11 including a plurality of blades is pivotally attached to a plurality of front arms (not shown) that are rotatably supported by a main plate 12. The base plate 12 is formed with an opening 12a that serves as an optical path during photographing. Blades 13a, 13b, 13c, 13d,
A rear blade group 13 composed of 13e is pivotally attached to rear arms 14 and 15 that are rotatably supported by the main plate 12. In the rear blade group 13, particularly, 13a is a rear slit forming blade that forms an exposure slit during photographing. The front blade group 11 and the rear blade group 13 are sandwiched between the main plate 12 and
A cover plate 16 is arranged on the side opposite to the base plate 12. The opening 16a formed in the cover plate 16 serves as an optical path during photographing.
Between the front blade group 11 and the rear blade group 13, a partition plate 17 having an opening 17a serving as an optical path at the time of photographing is arranged to form an operating space for each blade group.

The leading blade pressing plate 18 arranged between the main plate 12 and the leading blade group 11 is for alleviating and preventing the swaying and bouncing phenomenon of the blades, and is attached to the tip of each blade, that is, the leading arm. The blade end opposite to the supported side is held down. Similarly, the trailing blade holding plate 19 disposed between the cover plate 16 and the trailing blade group 13 has a tip of each blade, that is, the trailing arm 1.
The end opposite to the side supported by 4, 15 is pressed.

By the way, in recent years, thin and lighter blade materials have been demanded in response to the demand for higher shutter speeds, and not only conventional materials such as aluminum and resin materials but also fiber reinforced resin materials such as carbon are used. It became so. However, when the speed is increased by using such a material, the impact of the impact of the blades when the traveling of the blade is stopped becomes unprecedented, which is a problem.

In particular, the problem was serious with respect to the rear slit forming blade 13a of the rear blade group 13. Cover plate 16
The positional relationship between the rear blade holding plate 19 and the rear blade pressing plate 19 is as shown in FIG. 4, FIG. 4 (A) is a plan view, and FIG. 4 (B) is a side view. The rear slit forming blade 13a is the rear blade pressing plate 1.
However, due to a bounce phenomenon near the end of traveling, there is a situation in which the edge 16b of the opening 16a of the cover plate 16 comes into contact with and collides with the rear blade pressing plate 19 due to a bounce phenomenon near the end of traveling. Occurs, and the cover plate 16 has greater hardness or strength than the rear slit forming blade 13a, resulting in damage to the rear slit forming blade 13a.
It was inconvenient for speeding up. Further, even when the trailing blade pressing plate 19 suppresses / restricts the bounce phenomenon of the trailing slit forming blade 13a, the trailing slit forming blade 13a
Since the hardness and strength of the rear blade pressing plate 19 and the rear blade pressing plate 19 are substantially the same, there is also a problem that the rear slit forming blade 13a comes into contact with the rear blade pressing plate 19 to cause scratches on the rear slit forming blade 13a. It was inconvenient.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to solve the above-mentioned problems of contact and collision, scratches and damages. To do.

[0007]

In order to achieve the above object, a focal plane shutter for a camera of the present invention comprises a front blade group and a rear blade group which are composed of a plurality of blades and are pivotally attached to an arm, and an optical path at the time of photographing. A partition plate that divides the front blade group and the rear blade group with an opening that forms an opening, and a cover plate that sandwiches the rear blade group with the partition plate that has an opening that forms an optical path during shooting. In a focal plane shutter for a camera provided with a cover plate and a rear blade holding plate arranged between the rear blade group, the cover plate is formed with an inclined opening edge on the side where the rear blade group travels. The trailing blade holding plate is provided with an extension portion provided with a restriction portion having a portion matching the inclined shape of the opening edge of the cover plate, on the side where the trailing blade group travels, and the extension portion Hardness is less than that of the rear slit forming blade Those were. Further, the strength of the extension portion is made smaller than that of the rear slit forming blade.

[0008]

With the above structure, even if the rear blade group bounces and the rear slit forming blade is bent, the extension of the rear blade pressing plate restricts the rear slit forming blade to prevent the rear slit forming blade from moving. It prevents the opening edge of the cover plate from coming into contact with or colliding with the cover plate and prevents the damage. In addition, since the hardness or strength of the trailing blade pressing plate is smaller than the hardness or strength of the trailing slit forming blade, the trailing blade forming plate can prevent the bending of the trailing slit forming blade from contacting both members when the trailing blade forming plate regulates the deflection of the trailing slit forming blade. Prevent scratches.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing the structure of a focal plane shutter for a camera according to the present invention. The front blade group 1 is composed of a plurality of blades, and is pivotally attached to a plurality of front arms (not shown) that are rotatably supported by the main plate 2. The base plate 2 is formed with an opening 2a which serves as an optical path during photographing. The rear blade group 3 includes the blades 3a, 3b, 3c, 3
d, 3e, and is pivotally attached to rear arms 4, 5 which are rotatably supported by the main plate 2. Of the rear blade group 3, particularly 3a is a rear slit forming blade that forms an exposure slit during photographing. A cover plate 6 is arranged on the side opposite to the main plate 2 so as to sandwich the front blade group 1 and the rear blade group 3 with the main plate 2. Opening 6a formed in cover plate 6
Becomes the optical path when shooting. The opening edge 6b on the side where the rear blade group 3 of the opening 6a reaches and travels is formed in an inclined shape, and the tip end side of the blade is inclined so that the opening becomes smaller. Between the front blade group 1 and the rear blade group 3, a partition plate 7 having an opening 7a serving as an optical path at the time of photographing is arranged to form an operating space for each blade group. In addition, an inclined shape 7b is formed.

The front blade pressing plate 8 arranged between the main plate 2 and the front blade group 1 is for alleviating / preventing the swaying or bouncing phenomenon of the blades, and the tip of each blade, that is, the front arm. The blade end opposite to the supported side is held down. Rear blade holding plate 9 arranged between cover plate 6 and rear blade group 3
Holds the tip of each blade, that is, the end opposite to the side supported by the rear arms 4 and 5.

Further, as shown in FIG. 2A, the rear blade pressing plate 9 is provided with an extension portion 9a having a regulating portion 9b which is inclined in the same shape as the opening edge 6b of the cover plate 6. Further, the hardness of the extension portion 9a is formed to be smaller than the hardness of the rear slit forming blade 3a. This hardness can be adjusted by each material and the like. Or
The extension portion 9a is formed so that its strength is smaller than that of the rear slit forming blade 3a. This strength can be adjusted by the thickness of each plate.

When a shutter made of a fiber reinforced resin material or the like is made to travel at a high speed with such a structure, as shown in FIG. Contact with the regulating portion 9b of the rear blade holding plate 9
Since it collides, it does not contact or collide with the cover plate 6. And
The hardness / strength of the extension portion 9a forming the regulation portion 9b is
Since the rear slit forming blade 3a is formed so as to have a hardness and strength smaller than that of the rear slit forming blade 3a, even if the rear slit forming blade 3a comes into contact with or collides with the restriction portion 9b of the rear blade pressing plate 9, no scratches are generated. .

[0013]

As described above, in the present invention, the restricting portion 9b provided on the extension portion 9a of the trailing blade pressing plate 9 is formed so as to match the inclined shape of the opening edge 6b of the cover plate 6. In addition, since the hardness or strength of the extension portion 9a forming the regulation portion 9b is smaller than the hardness or strength of the rear slit forming blade 3a, the bound phenomenon of the rear slit forming blade 3a. It is possible to prevent contact and collision with the opening edge 6b of the cover plate 6 due to, and to prevent scratches even if the rear slit forming blade 3a contacts and collides with the restriction portion 9b of the rear blade pressing plate 9. You can

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a focal-plane shutter for a camera according to the present invention.

2A and 2B are a plan view and a side view showing a main part of a focal-plane shutter for a camera according to the present invention.

FIG. 3 is an exploded perspective view showing a configuration of a conventional focal-plane shutter for a camera.

FIG. 4 is a plan view and a side view showing a main part of a conventional focal plane shutter for a camera.

[Explanation of symbols]

 1 Front Blade Group 2 Base Plate 3 Rear Blade Group 4, 5 Rear Arm 6 Cover Plate 7 Separation Plate 8 Leading Blade Holding Plate 9 Rear Blade Holding Plate

Claims (2)

[Claims] 1. A front blade group and a rear blade group which are composed of a plurality of blades and are pivotally attached to an arm, and a partition plate which divides the front blade group and the rear blade group by forming an opening which serves as an optical path during photographing.
A cover plate having an opening that serves as an optical path at the time of shooting and arranged so as to sandwich the rear blade group with the partition plate, and a rear blade pressing plate disposed between the cover plate and the rear blade group are provided. In a camera focal plane shutter, the cover plate is formed with an inclined opening edge on the side where the rear blade group travels, and the rear blade pressing plate has a portion that matches the inclined shape of the opening edge of the cover plate. A focal plane shutter for a camera characterized in that an extension portion provided with a restriction portion is formed on a side where the rear blade group reaches and travels, and the hardness of the extension portion is smaller than that of the rear slit forming blade. . 2. The focal plane shutter for a camera according to claim 1, wherein the strength of the extension portion is made smaller than the strength of the rear slit forming blade.