JP2589063Y2 - Focal plane shutter - Google Patents

Description

[Detailed description of the invention]

[0001]

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

[Prior art]

FIG. 3 shows a general structure of a focal plane shutter of a camera. In FIG. 3, a front blade group 3 and a rear blade group 4 are separated by an intermediate plate 1, so that each blade group Working space is secured. However, the rigidity and strength of the blades are insufficient and the blade holding plates 7a and 7b
The blades may bend during traveling or the like due to the relationship between the blades and the support arms 5 and 6. In such a case, during the operation of the blade, the blade bulges in the optical axis direction due to the deflection of the blade and furthermore, the vibration causes the blade to move toward the aperture 2 of the intermediate plate 1.
Sometimes hit the edge. Conventionally, as a means for preventing the blade from colliding with the edge of the aperture 2, for example, the following collision prevention structure has been proposed.

That is, as shown in FIG. 4, an upper edge 2a and a lower edge 2b of the aperture 2 of the intermediate plate 1 in a direction substantially perpendicular to the blade running direction are V-shaped such that the apex is located at the center. It is spread out and formed. Thereby, when the blade bends in the optical path direction during blade travel, when the bent portion comes into contact with the V-shaped upper edge 2a or the lower edge 2b, the bent portion comes into contact with two inclined edges having the same inclination angle at two points, Flexure and V
The rubbing of the edges with each other causes the blades to travel while the deflection is pushed and suppressed, and the collision with the edges is reduced by passing through the V-shaped apex.

As shown in FIGS. 5A and 5B, a front blade group 3 and a rear blade group 4 are pivotally mounted on support arms 5 and 6 rotatably supported by a shutter substrate 8, respectively. By rotating the support arms 5 and 6 by driving means (not shown), the leading blade group 3 and the trailing blade group 4 are respectively moved in the vertical direction in the drawing, and open / close operation with respect to the aperture 2. It has become. In addition, each of the blade groups 3 and 4 is provided with a blade holding plate 7 in order to prevent undesired running.
The traveling space between the intermediate plate 1 and the intermediate plate 1 is limited by the a and 7b.

[0005]

[Problem to be solved by the invention] However, FIG.
As shown in (A), the front blade group 3 is pivotally connected at its base by a support arm 5 and its free end is regulated by a blade holding plate 7a, so that the entire blade is intermediate from the base toward the free end. It is inclined in the direction of the plate 1 and flexure occurs in the vicinity of the free end during deployment travel. The deflection of the front blade group 3 abuts on the inclined edge of the upper edge 2a during the unfolding travel, and in order to travel further in this state, the deflection moves while waving toward the V-shaped vertex while being pressed by the upper edge 2a. , And two abutting edges near the V-shaped apex at two points, resulting in a large impact.
Further, since the rear blade group 4 operates at a stretch by the elasticity of the spring at the time of the deployment operation, as shown in FIGS. 5B and 6B,
Deflection occurs near the pivotal connection to the support arm 6. The deflection of the rear blade group 4 also comes into contact with and presses against one of the inclined edges of the lower edge 2b. To touch
The impact is large. As described above, the conventional structure cannot sufficiently prevent the collision of the blades, hinders smooth running of the blades, and has a disadvantage that the blades may be damaged at the time of collision.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a focal plane shutter capable of mitigating a collision with an edge of an aperture due to deflection of a blade during traveling of the blade and preventing damage to the blade. I do.

[0007]

A focal plane shutter for a camera according to the present invention comprises a plurality of blades.
Their bases are pivotally connected to a plurality of support arms sequentially.
The front blade group deployed in one of the round trips
Consisting of a number of blades whose bases are
To the front blade
After being deployed by running in the direction opposite to the deployment direction of the group
Partitions the running space for the wing group and the front and rear wing groups.
An aperture is formed in the photographing optical path,
A pair of edges substantially orthogonal to the running direction of each of the blade groups of the tea
Each is formed in a substantially V-shaped and inclined shape.
The intermediate plate and the free end of the blade group are moved between the intermediate plate and the intermediate plate.
And a pair of rims.
The edge of the leading blade group in the deployment traveling direction is substantially V-shaped.
Is formed closer to the free end of the front blade group than the center of the edge
The edge of the rear wing group in the running direction is substantially V-shaped.
The vertex of the shape is formed closer to the base of the rear blade group than the center of the edge .

[0008]

[Function] Near the free end of the leading blade group and near the base of the trailing blade group
If there is a bend next to the blade , the bent blades
While traveling while abutting on one of the two inclined edges formed in the aperture , the deflection moves while waving in the direction of the V-shaped vertex while being suppressed, but only near one vertex near the vertex. Because it touches, there is only one point of contact,
The scissors run as if they intersect with each other without a strong impact between the edge and the stop position.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of an intermediate plate according to the present embodiment, and FIG. 2 (A) is a diagram showing a relationship between an upper edge of the intermediate plate and a deflection position of a leading blade.
(B) is a diagram showing the relationship between the lower edge of the intermediate plate and the deflection position of the rear blade.

Referring to FIG. 1, an aperture 10 formed on an intermediate plate 9 for passing photographing light has a V-shape in a direction in which an upper edge 10a and a lower edge 10b in a direction substantially perpendicular to the blade traveling direction face each other. It is spread out and formed. The upper edge 10a with which the deflection (see FIG. 6 (A)) of the leading blade group 3 which is deployed and abuts, has a V-shaped vertex from the center to the free end of the leading blade group 3 (right side in FIG. 1) It is formed closer. Moreover, the inclined edge portion 10a-1 forming the V-shaped upper edge 10a.
The inclined edge 10a-2 has a different inclination angle from the inclined edge 10a-2. The inclined edge 10a-1 having a shorter side length has a larger inclination angle and extends from the vertex to the right end (in the drawing). On the other hand, the bent portion of the rear blade group 4 that is deployed (see FIG. 6B)
Has a V-shaped apex formed near the base of the rear blade group 4 (left side in FIG. 1) from the center.
In addition, the inclined edge portion 10b forming the V-shaped lower edge 10b-
1 and the inclined edge portion 10b-2 have different inclination angles, and the inclined edge portion 10b-1 having a shorter side length has a larger inclination angle and extends from the vertex to the left end (see FIG. 1).

Since the present embodiment is configured as described above, when the front blade group 3 is deployed and moved in the direction of the upper edge 10a from the superimposed position during blade travel, as shown in FIG. In addition, the deflection 3a may occur on the free end side of the blade. In this case, the bending 3a of the blade 3 abuts on the short edge 10a-1 of the short side of the upper edge 10a at one point (see FIG. 2A). Further, since the leading blade group 3 further travels, the deflection 3a is suppressed by the inclined edge portion 10a-1 abutting at one point, and the deflection portion undulates toward the V-shaped vertex of the upper edge 10a. Move with. Moreover, since the inclination angle of the short side inclined edge portion 10a-1 is larger than that of the long side inclined edge portion 10a-2, the inclined edge portion 10a-1 passes through the vertex portion of the upper edge 10a without abutting at two points, and is like a scissors blade The aperture 10 intersects the upper edge 10a smoothly as if
To the deployed stop position.

When the rear blade group 4 travels from the superimposed position in the direction of the lower edge 10b, a deflection 4a may be generated near the base as shown in FIG. 6B.
Is an inclined edge portion 10b of a short side having a large inclination angle of the lower edge 10b.
-1 at one point. Then, as the rear blade group 4 travels, the deflection 4a is pressed by the inclined edge portion 10b-1 and V
It moves in the direction of the character vertex, but passes near the vertex without contact at two points, smoothly intersects the lower edge 10b as if the scissor blades pass each other, covers the aperture 10, and stops at the deployed position I do.

As described above, this embodiment has a simple structure.
Even if the blade bends, the collision with the upper edge 10a or the lower edge 10b of the aperture 10 during traveling can be suppressed more effectively than the conventional one, suppressing the deflection and realizing the smooth traveling of the blade. In addition, damage to the blade due to collision between the intermediate plate 9 and the blade due to bending can be reliably prevented.

The position where the blade bends and the position where the deflection abuts on the edge of the aperture are slightly different depending on the type of the shutter device and the shutter speed.
The positions of the V-shaped vertices 0a and 10b may be appropriately selected within the range of the area deviated from the center of each edge. The upper and lower edges 10
The angles of the two inclined edges forming the V-shaped vertices a and 10b can be appropriately selected under the condition that the angles are different from each other.

[0015]

As described above, in the focal plane shutter according to the present invention , of the pair of substantially V-shaped edges of the aperture of the intermediate plate, the edge in the deployment traveling direction of the front blade group is provided.
Indicates that the substantially V-shaped apex of the front blade group is
It is formed near the free end and is in the running direction of the rear blade group.
The edge has a substantially V-shaped vertex of the rear blade group from the center of the edge.
Because it is formed closer to the base, it is important in practical use that it can effectively suppress the deflection that can occur when the blade travels, run smoothly, and reliably prevent collision between the blade and the intermediate plate. Has many advantages.

[Brief description of the drawings]

FIG. 1 is a front view of an intermediate plate according to an embodiment of the present invention.

FIGS. 2A and 2B show a position where the blade contacts the intermediate plate of FIG. 1; FIG. 2A shows a state where the leading blade contacts the upper edge;
7A and 7B are diagrams each showing a state in which the rear blade comes into contact with a lower edge.

FIG. 3 is an exploded perspective view showing a general configuration of a focal plane shutter.

FIG. 4 is a front view of a conventional intermediate plate.

5 (A) and 5 (B) are views similar to FIGS. 2 (A) and 2 (B), showing a state in which a blade comes into contact with a conventional intermediate plate.

6A and 6B show positions where deflection of the blade occurs in relation to the edge of the aperture, wherein FIG. 6A shows the deflection position of the leading blade with respect to the upper edge, and FIG. 6B shows the deflection position of the trailing blade with respect to the lower edge. FIG.

[Explanation of symbols]

 3 Front blade group 4 Rear blade group 9 Intermediate plate 10 Aperture 10a Upper edge 10b Lower edge

Claims (1)

(57) [Scope of request for utility model registration] Claims: 1. A plurality of blades, the bases of which are
One of the reciprocating traveling, which is pivotally attached to a plurality of support arms sequentially
Consists of a group of blades deployed on the road and multiple blades
And their bases are sequentially pivoted to multiple support arms
The reciprocating traveling is possible and the deployment traveling direction of the front blade group
Rear wing group deployed by traveling in the opposite direction to the front wing
It separates the traveling space between the group and the rear wing group, and
An aperture is formed and each of the blades of the aperture is formed
A pair of edges substantially perpendicular to the running direction of the group are each broadened in a substantially V shape.
An intermediate plate formed into a slanted shape and a leading blade
The free end of the group is run between said intermediate plate and
A blade holding plate, and the front blade of the pair of edges
The substantially V-shaped apex of the edge of the group in the deployment traveling direction is
It is formed near the free end of the front blade group from the center of the edge, and the rear blade
The edge of the root group in the deployment traveling direction has a substantially V-shaped vertex
A focal plane shutter formed near the base of the rear blade group from the center of the edge .