JPH09265119A - Focal-plane shutter unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a shutter unit whose rigidity is made high without changing the efficiency of a shutter by providing a 2nd plate separated from a camera body. SOLUTION: A shutter base plate (1st plate) 10 is provided with an aperture 10a and equipped with a shutter mechanism 20 set on the base plate 10. A shutter cover plate (2nd plate) 30 having an aperture 30a is arranged to be opposed to the base plate 10, and forms a shutter blade chamber between the base plate 10 and the plate 30. Blade groups 40 and 50 formed of plural light shielding thin plates are housed in the shutter blade chamber, and the blade groups 40 and 50 are driven by the mechanism 20 so as to perform the opening/ closing operation of the aperture 30a. Furthermore, the plate 30 is provided with two in-film rails 30c set to be lower than the surface 30b and a film passing path is formed in space between a film tunnel back plate (3rd plate) 100 and the rails 30c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focal plane shutter unit for a camera.

[0002]

2. Description of the Related Art The structure of a conventional camera body and a focal plane shutter unit is shown in FIG. Reference numeral 1 denotes a shutter substrate 1 having an aperture 1a. Reference numeral 2 is a shutter mechanism section. A cover plate 3 has an aperture 3a. A front curtain group 4 and a rear curtain group 5 are arranged between the shutter substrate 1 and the cover plate 3. The shutter substrate 1,
The shutter mechanism unit 2, the cover plate 3, the front curtain group 4, and the rear curtain group 5 constitute a shutter unit. A camera body 6 has an aperture 6a that defines a shooting screen. At the time of shooting, the film is defined by the two film outer rails 6b provided on the camera body 6 with respect to the position with respect to the aperture 6a in the up-and-down direction of the camera which is a direction orthogonal to the film advancing direction. Further, the film includes a rail 6c inside the film and a rail 6b outside the film.
The position in the optical axis direction is defined by being housed in the tunnel formed by the step of the. Further, 6d is a film cartridge chamber, and 6e is a spool chamber for winding the film.

FIG. 8 is a vertical sectional view of a conventional interchangeable lens type single-lens reflex camera. Reference numeral 7 is a mirror box that houses a mirror for the finder optical system, and includes screws 9a and 9a.
It is fixed to the body 6 by b. Reference numeral 8 denotes a bayonet having a mounting reference surface 8a for an interchangeable lens, and a screw 9
It is fixed to the mirror box 7 by c. The blade chamber formed by the shutter substrate 1 and the shutter cover plate 3 is arranged between the mirror box 7 and the camera body 6 and fixed to the mirror box 7 or the camera body 6.

[0004]

In the above structure, the shutter is the aperture 6a provided in the camera body 6.
However, it is preferable that the distance between the film surface and the shutter blade is short in consideration of the shutter efficiency. Therefore, the thickness of the cover plate 3 has to be reduced. Therefore, the cover plate 3 cannot be desired to have rigidity, and when the shutter charging force is large in a high-speed shutter or when the shutter substrate 1 is formed of a plastic mold and has insufficient rigidity, the shutter substrate 1 and Due to the deformation of the cover plate 3, the blade traveling space is narrowed, which adversely affects the shutter speed.

Therefore, an object of the present invention is to increase the strength of the substrate forming the shutter blade chamber and to realize a highly accurate shutter time without deteriorating the shutter efficiency.

[0006]

In order to achieve the above object, the present invention is a focal plane shutter unit having two sets of blade groups made of a plurality of light-shielding thin plates, the first plate having a first aperture. A second plate that has a second aperture and that is arranged opposite to the first plate and that has a part of a film passage on the surface opposite to the surface on which the first plate is arranged; A configuration is provided that includes a blade storage portion that stores the two sets of blade groups arranged between the plate and the second plate.

[0007]

With the above construction, a shutter unit having significantly improved rigidity can be realized without changing the shutter efficiency as compared with the conventional one.

[0008]

1 and 2 are perspective views showing the configuration of a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a shutter substrate (first plate), which has an aperture 10a.
Is provided. Reference numeral 20 denotes a shutter mechanism section installed on the shutter substrate 10. Reference numeral 30 denotes a shutter cover plate (second plate) having an aperture 30a, which is arranged so as to face the shutter substrate 10 and forms a shutter blade chamber with the shutter substrate 10. The aperture 30a is set smaller in the aperture 10a and the aperture 30a, and the photographing screen is defined by the aperture 30a. The shutter blade chamber accommodates a blade group 40, 50 composed of a plurality of light-shielding thin plates, and the blade group 40, 50 is driven by the shutter mechanism section 20 to open and close the aperture 30a. The shutter substrate 10 and the shutter cover plate 30 are fastened to each other at a position avoiding the movable range of the blade groups 40 and 50. Shutter cover plate 3
A film tunnel rear plate 100 is arranged at a position facing the surface of the shutter cover plate opposite to the blade chamber 0, and is attached in close contact with the surface 30b of the shutter cover plate. The shutter cover plate 30 is provided with two film inner rails 30c set to a height lower than the surface 30b, and a space between the film tunnel rear plate (third plate) 100 and the film inner rails 30c. A film passage path is formed in the film. The fastening between the shutter cover plate 30 and the film tunnel rear plate 100 is performed on the surface 30b, which is a position avoiding the film passage path. A camera body 60 is provided with a film cartridge chamber 60d and a film winding chamber 60e.

According to the above construction, the thickness of the shutter cover plate can be increased without changing the shutter efficiency as compared with the conventional one, so that the rigidity of the shutter blade chamber is increased and the shutter substrate 10 is molded with plastic or the high speed shutter is used. Even when the amount of shutter charge is large, the deformation of the blade chamber is reduced as compared with the conventional case, and accurate shutter time can be realized. Further, if the film tunnel rear plate 100 is fixed to the shutter cover plate 30, the rigidity of the shutter cover plate 30 can be further increased. In this case, the thickness of the shutter cover plate 30 can be reduced, the distance between the film surface and the shutter blades can be made shorter than before, and the shutter efficiency can be increased. Also, the shutter cover plate 30
If is made of plastic, the wall that shields the periphery of the blade chamber and the drive shaft that supports the shutter blade group can be integrally formed, and the cost can be reduced.

In FIG. 2, the shutter cover plate 30 is fixed to the shutter substrate 10 with screws 90a, and the tunnel rear plate 100 is fixed to the shutter cover plate 30 with screws 90b to form a shutter unit including a film tunnel. Reference numeral 70 denotes a mirror box for storing a mirror for a finder optical system. Mirror box 70
Is a bayonet mounting seat 70a having an interchangeable lens mounting reference surface, a mounting seat 70b of the film tunnel rear plate 100, a prism box mounting seat 70c equipped with a screen for photographic image observation and a pentaprism, and a mirror for a finder optical system. The rotary shaft mounting hole 70d is provided. The film tunnel rear plate 100 includes a mounting seat 100a for mounting the mirror box 70, and is fixed to the mirror box 70 with screws 90c. That is, the film tunnel is configured as a unit in a mirror box. The mirror box 70 has screws 90d and 90
It is fixed to the camera body 60 by e.

FIG. 3 is a vertical sectional view showing the structure of the first embodiment of the present invention. 80 is an interchangeable lens mounting reference surface 8
It is a bayonet having 0a and is fixed to the mirror box 70 by screws 90f. Reference numeral 110 denotes a prism box which includes a screen 111 for observing a captured image and a pentaprism 112, and is fixed to a mounting seat 70c provided on the mirror box 70. Reference numeral 120 denotes a finder optical system mirror, which is rotatable around a hole 120a, and the hole 120a is a hole 7 provided in the mirror box.
It is supported by the mirror box 70 so as to be coaxial with 0d. The photographic film includes a rail 30c inside the film provided on the shutter cover plate 30 and a rear plate 1 of the film tunnel.
It is housed in a tunnel portion formed between the optical disc and the optical disc, and its position in the optical axis direction is defined. In the configuration of this embodiment,
The rail-back dimension, which is the distance from the lens mounting reference surface to the rail in the film, is the dimension from the lens mounting surface 80a of the bayonet 80 to the mounting surface of the mirror box 70, and the bayonet mounting surface 70a of the mirror box 70 to the rear of the film tunnel. Dimensions up to the plate mounting surface 70b and the film tunnel rear plate 10
0 from the mirror box mounting surface 100a to the rail 30c in the film, that is, the shutter cover plate 3
It is configured by accumulating dimensions from the film tunnel rear plate mounting surface 100 to the film inner rail 30c at 0.

According to the above construction, there is no concern that the film rail surface will be deformed by the attachment of other parts such as the exterior cover. If the dimension control of the bayonet 80, the mirror box 70 and the shutter cover plate 30 is performed with high accuracy, the secondary processing is performed. The railback dimensions can be ensured without. Further, even if a large external force is applied to the camera body 60 from the grip, tripod mount, suspension ring, etc., the film surface near the shooting screen is separated from the camera body 60, and the railback dimension does not change. Not only that, the rigidity of the camera body 60 may be lower than that of the conventional one. For improving the strength, the camera body formed of the metal insert may be formed of only plastic or the body thickness may be reduced. It is also possible to reduce the size and weight of the body.

FIG. 4 is a horizontal sectional view showing the structure of the first embodiment of the present invention. Reference numeral 61 denotes a cartridge chamber cover member that covers the rear side of the film cartridge chamber 60d provided in the camera body 60 in the optical axis direction, and includes a portion 60b provided in the camera body 60 and a portion 61a provided in the cartridge chamber cover member. Thus, a film entrance / exit is formed at a position facing the film tunnel. 130 is a film cartridge. 62 is a camera body 60
Is a winding chamber cover member that covers the rear side in the optical axis direction of the film winding chamber 60e provided in the camera body 60, and includes a 60c portion provided in the camera body 60 and a 62a portion provided in the winding chamber cover member 62. A film entrance / exit is formed at a position facing the film tunnel. The film take-up spool 60 is provided in the film take-up chamber 60e.
0, film rollers 141 and 142 are installed. The film sent from the film cartridge 130 passes through the film entrance and exit formed by 60b and 61a, passes through the film tunnel formed by the shutter cover plate 30 and the film tunnel rear plate 100, and
0c, through the film entrance and exit formed by 62a,
The film enters the film take-up chamber 60e and is taken up by the film take-up spool 140, and the operation of loading the film into the camera is completed. That is, the film is held by the camera body unit in the cartridge chamber 60d and the winding chamber 60e, and is held in the mirror box unit near the exposure screen.

5 and 6 are perspective views showing a second embodiment of the present invention. In the embodiment shown in FIG. 5, the shutter cover plate 30 is provided with a camera mounting surface 30d. Even with this configuration, the shutter blade chamber can obtain high rigidity and can be expected to improve the accuracy in seconds. Further, by controlling the dimension from the mounting surface 30d to the rail surface 30c in the film with high accuracy, the railback dimension can be secured without secondary processing, and there is no concern that the rail surface will be deformed by an external force.

In the embodiment shown in FIG. 6, the shutter substrate 1
0 is provided with a camera mounting surface 10b. Even with this configuration, the shutter blade chamber can obtain high rigidity and can be expected to improve the accuracy in seconds. Also, there is no concern about deformation of the rail surface due to external force. As described above, since the film rail plate is separated from the camera body and the shutter cover plate is unitized in the shutter, it is possible to greatly increase the rigidity of the shutter cover plate without changing the shutter efficiency as compared with the conventional one, and it is possible to achieve high accuracy. The shutter speed can be realized. Further, even if a large external force is applied to the camera body, the shutter is separated from the camera body, so there is no concern that the accuracy of the second time will be deteriorated due to the deformation of the shutter cover plate.

Further, in the case of a camera using a film cartridge having a film feeding function, a shutter back plate which also serves as a film rail plate is provided with a tunnel back plate for covering the rear side in the optical axis direction of the photographic film, and the shutter up to the film tunnel. It is possible to construct the unit as a unit, which allows the rigidity of the shutter cover plate to be further increased.

[0017]

According to the present invention, since the second plate separated from the camera body is provided, it is possible to realize a shutter unit having a significantly increased rigidity without changing the shutter efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment of the present invention.

FIG. 2 is a perspective view showing the configuration of the first embodiment of the present invention.

FIG. 3 is a vertical sectional view showing the configuration of the first embodiment of the present invention.

FIG. 4 is a horizontal sectional view showing the configuration of the first embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a second embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a second exemplary embodiment of the present invention.

FIG. 7 is a perspective view showing a conventional example.

FIG. 8 is a vertical sectional view showing a conventional example.

[Explanation of symbols]

 10 Shutter Substrate 30 Shutter Cover Plate 60 Camera Body 70 Mirror Box 80 Bayonet Mount 100 Film Tunnel Rear Plate

Claims (6)

[Claims] 1. A focal-plane shutter unit having two sets of blades composed of a plurality of light-shielding thin plates, the first plate having a first aperture, and the second plate having a second aperture, and facing the first plate. And a second plate having a part of a film passage on the surface opposite to the surface on which the first plate is arranged, and the second plate arranged between the first plate and the second plate. A focal-plane shutter unit having a blade housing portion for housing a group of blades. 2. Arranged opposite to the second plate,
The focal plane shutter unit according to claim 1, further comprising a third plate that forms a film passage path between the second plate and the second plate. 3. The focal plane shutter unit according to claim 2, wherein the second plate or the third plate has a mounting seat for a camera. 4. The focal plane shutter unit according to claim 1, wherein the first plate or the second plate further has a wall portion that shields at least a part of the periphery of the blade housing portion from light. 5. A focal plane shutter unit having two sets of blades composed of a plurality of light-shielding thin plates, comprising a first plate having a first aperture, a second aperture and a mounting seat for a camera. , A blade housing portion that is arranged opposite to the first plate and that houses the two sets of blade groups is formed between the first plate and the first plate, and a film passage path of a film passing path is formed on a surface opposite to the blade housing portion. A focal-plane shutter unit comprising a second plate having a part. 6. The focal plane shutter unit according to claim 5, wherein the second plate further has a wall portion that shields at least a part of the periphery of the blade housing portion from light.