JPH0594832U - Focal plane shutter - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a compact and simple focal plane shutter that effectively absorbs the impact when the deflection of the blade collides with the opening. [Composition] Image frames on the upper and lower sides of the opening of the cover plate
The blade is formed so as to be inclined with respect to the traveling direction of the blade, and the edge of the image frame is bent and projected toward the film surface. The flexure is pressed along the inclination of the image frame of the opening, and the impact when the flexure collides is dispersed on the slope of the image frame. Therefore, the bent portion of the image frame can be made smaller than the amount of entry of the flexure, and the thickness of the cover plate can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a blade collision mitigation mechanism of a focal plane shutter for a camera.

[0002]

[Prior Art]

 FIG. 4 shows an example of the structure of a conventional focal-plane shutter of this kind. In the figure, 1 is a shutter base plate having a photographing opening 2 formed therein, and 3 and 4 are openings for opening and closing the opening 2. A group of blades and a group of rear blades, 5 and 6 are rotatably supported on the shutter base plate 1, and are supporting members for moving the group of front blades 3 and the group of rear blades 4, 7 is a group of front blades 3 and the rear blades. An intermediate plate partitioning the group 4 is provided, 8a and 8b are blade pressing plates, and 9 is a cover plate having an opening 10 having the same shape as the photographing opening 2.

FIG. 5A is a plan view of the cover plate 9 and FIG. 5B is a sectional view taken along the line BB of FIG. 5A, in which the opening 10 of the cover plate 9 is shown. In order to absorb the impact when the rear blade group 4 is deflected during traveling and collides, the surrounding image frame is formed by bending so as to project to the film surface side (see FIG. 2B). ).

[0004]

[Problems to be solved by the device]

 By the way, when a mechanism for switching the image frame range is attached to the shutter having the above-described structure, it is preferable that the image frame switching be performed at a position close to the film surface. However, in this case, since the image frame of the opening 10 projects to the film surface side as described above, there is a problem that the shutter becomes large.

Further, when the bending of the image frame of the opening 10 is reduced to reduce the width of protrusion (indicated by reference numeral d ′ in FIG. 5B), the rear blade group 4 is bent and the opening is reduced. There was a problem in that the impact of the collision with No. 10 was not alleviated, the smooth running of the blade was hindered, and the blade was easily damaged.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to reduce the size of the blade and cause the blade to bend and to collide with the edge of the opening. An object of the present invention is to provide a focal plane shutter that can effectively mitigate the impact when it strikes.

[0007]

[Means for Solving the Problems]

 A focal plane shutter according to the present invention has a shutter base plate having an opening for photographing, a blade member that runs on the opening and opens and closes the opening, and one end thereof is rotatably supported by the shutter base plate. And a focal plane having a blade actuating member having the other end pivotally supporting the blade member, and a cover plate having an opening formed by bending the peripheral wall toward the film surface in order to mitigate the collision of the blade member. In the shutter, the image frames on the upper and lower sides of the opening of the cover plate are formed so as to be inclined with respect to the traveling direction of the blade member.

[0008]

[Action]

 When the blade bends in the optical path direction while the blade is running, the deflected portion contacts the concave side of the bent portion of the image frame when contacting the upper side or the lower side of the opening, and the deflected portion becomes the V-shaped side. By rubbing each other with the concave portions, the blades travel while suppressing and suppressing the deflection, and the impact when the deflection collides is dispersed. Further, it is not necessary to make the bent portion of the image frame larger than the amount of the bend entering the bent portion, and the thickness of the cover plate can be reduced.

[0009]

【Example】

 The present invention will be described in detail with reference to the illustrated embodiment, but the same members as those in the above-described conventional art are designated by the same reference numerals and the description thereof will be omitted. FIG. 1A is a front view of the cover plate according to this embodiment, and FIG. 1B is a sectional view taken along the line AA of FIG. In the figure, the arrow H indicates the traveling direction of the front blade group 3 and the rear blade group 4 (not shown).

The opening 20 formed in the cover plate 19 of this embodiment has a V-shape so that the image frames of the upper side 20a and the lower side 20b of the opening 20 are located at the center between the left side 20c and the right side 20d. It is formed so as to be expanded in a V shape, and the image frames on the respective sides are inclined at a certain angle without being orthogonal to the blade traveling direction H. A bent portion protruding toward the film surface is formed at the edge of the image frame on each side. Reference numeral 20e is a notch for entering the blade dowel.

Since the present embodiment is configured as described above, when the trailing blade group 4 is deflected in the optical path direction while the blade is traveling, when the deflected portion contacts the V-shaped upper side 20a or the lower side 20b, By contacting the concave side of the bent part and the bent part rubs against the concave part along the V-shaped side, the blade runs while the bending is suppressed and suppressed, and further passes through the apex of the V-shape. By doing so, the impact when the deflection collides with the image frame of the opening 20 is dispersed.

In this case, by adopting a configuration in which the upper side 20a and the lower side 20b are inclined at a constant angle with respect to the blade traveling direction H, the impact when the flexure collides is effectively softened, so that the image frame It is not necessary to make the bending portion of the cover larger than the amount by which the bending enters the bending portion. Therefore, the width of the protrusion to the film surface side (indicated by symbol d in FIG. 1 (b)) can be reduced, and the cover plate. The thickness of 19 can be reduced.

FIG. 2 is a view showing a state in which a shutter 21 is constructed by attaching an image frame range switching mechanism 21 to the cover plate 19 of this embodiment. The image frame switching mechanism 21 switches the image frames by sliding the masks blades 22, 23 over the openings while abutting the edges of the image frames on each side of the opening 20.

Further, FIG. 3 is a view showing a state in which the deflection of the blade generated during traveling of the blade collides with the opening 20 of the cover plate 19 in the shutter using the cover plate of the present embodiment. (A) shows a state in which the rear blade group 4 is unfolding and running in the direction of the upper side 20a from the position where it is superposed, and (b) in the figure shows a state in which the shutter is charged. Deflection occurs from the vicinity of the pivot portion of the support member 5 of the trailing blade group 4 in the unfolding traveling state, and from the vicinity of the free end portion of the leading blade group 3 in the state of being shutter charged. In this case, since the impact is mitigated by the tilted shape of the upper side 20a or the lower side 20b as described above, the blades running on the opening 20 smoothly move as if the blades of the scissors pass each other. And, it intersects with each side of the lower side 20b and stops at the expanded position or the overlapping position.

The inclined shapes of the upper side 20a and the lower side 20b of the opening 20 are not limited to those in the above embodiment, and an appropriate inclined angle / shape may be selected depending on the shutter configuration and the desired shutter speed. Further, in the above-mentioned embodiment, the case where the invention is applied to the trailing blade group, which is more effective, is described, but of course, it may be applied to the leading blade group side.

[0016]

[Effect of the device]

 As described above, according to the present invention, the impact caused when the blade is deflected and collides with the edge of the opening is effectively mitigated by the simple structure, and the blade can be smoothly moved. Effective for improving reliability and durability. Further, since the shutter can be thinned, it is effective for downsizing the camera.

[Brief description of drawings]

1A and 1B are views showing a shape of a cover plate of an embodiment used for a shutter of the present invention, in which FIG. 1A is a front view and FIG. 1B is a sectional view taken along line AA of FIG. .

FIG. 2 is a view showing a state in which a shutter is configured by attaching an image frame range switching mechanism to the cover plate of FIG.

FIG. 3 is a diagram showing a state in which a blade deflection generated during traveling of a blade collides with the cover plate in the shutter using the cover plate of FIG. 1, and FIG. (B) shows the states in which the shutter is charged.

FIG. 4 is an exploded perspective view showing a general configuration of a focal plane shutter.

FIG. 5 is a view showing a shape of a conventional cover plate, (a)
Is a plan view and (b) is a cross-sectional view taken along the line BB of (a).

[Explanation of symbols]

 3 Front blade group 4 Rear blade group 9,19 Cover plate 10, 20 Opening 20a Upper side 20b Lower side 21 Image frame switching mechanism

Claims (1)

[Scope of utility model registration request] 1. A shutter base plate having a photographing opening,
A blade member that travels on the opening and opens and closes the opening; and a blade operating member that has one end rotatably supported by the shutter base plate and the other end that pivotally supports the blade member. A focal plane shutter comprising: a cover plate having an opening in which a peripheral wall is bent and projected toward a film surface side to mitigate the collision of the blade member; Is formed so as to be inclined with respect to the traveling direction of the blade member.