JP2002296640A - Focal plane shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent slit forming blades from abutting on and biting divider plates, eliminate light leakage, and attain cost reduction. SOLUTION: A focal plane shutter has a group of opening blades 8 and a group of closing blades 12 for opening and closing a shutter aperture 1a, and the divider plates 10, 11 disposed between both blade groups. When both blade groups run so as to cover the shutter aperture, a pair of edges which belongs to edges of shutter apertures 10a, 11a provided in the divider plates 10, 11 and is approximately orthogonal to the running direction of both blade groups, forms edges on an approaching side of slit forming blades 8a, 12a of both blade groups as tilting edges 10c, 11c and other edges as straight edges 10b, 11b. The straight edges 10b, 11b for one blade group are positioned closer to the center of the shutter apertures 10a, 11a than corners 11c1 , 10c1 of the shutter aperture formed by the tilting edges 11c, 10c for another blade group.

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.

[0002]

2. Description of the Related Art As a conventional focal plane shutter, as shown in FIG. 3, an open blade group A and a closed blade group are respectively supported by a plurality of arms constituting a parallel link and divided into a plurality of divided arms. There is a type in which two sets of shutter blades B are operated to open and close the shutter opening 1a of the substrate 1. In the case of this configuration, a partition plate C is provided between the two blade groups in order to avoid a direct collision between the blade group that is folded when the shutter is operated and the blade group that is deployed.

The partition plate C has a pair of edges substantially perpendicular to the traveling direction of the two blade groups formed by a slanted edge C1 and a straight edge C2, which spread in a substantially V-shape. The partition plate C prevents collision between the two blade groups, and the inclined edge C1 prevents the slit-forming blades of the closed blade group B from hitting and biting into the partition plate C. The reason why the straight edge C2 that the slit forming blades of the open blade group A easily collide with is linear when the shutter is in the reset state when the slit forming blades of the open blade group A approach the straight edge C2. This is because the movement of the blade is relatively slow, and there is a low possibility that the blade will collide with and bite the straight edge C2 without inclining the edge.

As another example, see, for example, Japanese Utility Model Laid-Open No. 5-456.
Japanese Patent Application Publication No. 59-59139 discloses a configuration in which a pair of edges substantially perpendicular to the running direction of a blade group are each extended and inclined substantially in a V-shape, and a groove is formed in one of the V-shaped vertices as an intermediate partition member. Are shown.

[0005]

SUMMARY OF THE INVENTION FIG.
Although it is preferable to make the V-shaped notch deeper and make the edge angle with respect to the slit forming blade in order to prevent the slit forming blade from hitting the partition plate C and biting, If the cut is deep, there is a problem of light leakage. In the second conventional example, since a groove is formed at one of the V-shaped vertices, there is a problem that another member must be provided so as not to cause light leakage. The focal plane shutter of the present invention is configured by changing the configuration of the partition plate.
It is possible to prevent the slit forming blades from hitting the partition plate and biting, to eliminate light leakage, and to reduce the cost.

[0006]

SUMMARY OF THE INVENTION A focal plane shutter according to the present invention is a focal plane shutter having an opening blade group and a closing blade group for opening and closing a shutter opening, and a partition plate disposed between the two blade groups. Of the edges of the shutter openings provided in the partition plate, a pair of edges substantially perpendicular to the traveling direction of the two blade groups are slits of the two blade groups when the two blade groups travel to cover the shutter opening. The edge on the side where the forming blade approaches is an inclined edge, the other edge is a linear edge, and the linear edge for one blade group is a corner of a shutter opening formed by the inclined edge for the other blade group. It is characterized in that it is located closer to the center of the shutter opening.
By forming the edge on the side where the slit forming blade approaches as the inclined edge in this way, it is possible to prevent the blade from hitting and biting into the partition plate, so that the straight edge is closer to the corner of the shutter opening formed by the inclined edge. The light leakage can also be eliminated by positioning the shutter near the center of the shutter opening.

[0007] The partition plate is composed of two sheets, one of which has an inclined edge and a straight edge for an open blade group, and the other has an inclined edge and a straight edge for a closed blade group. Preferably, the two partition plates are overlapped such that the straight edge of one partition plate is located closer to the center of the shutter opening than the corner of the shutter opening formed by the inclined edge of the other partition plate.

In addition, the partition plate is composed of one sheet, the plate thickness of a pair of edges of the shutter opening of the partition plate is divided into two, and an inclined edge and a straight edge for the open blade group are formed on one surface side. An inclined edge and a straight edge for the closing blade group are respectively formed on the other surface side, and it is preferable that the one inclined edge and the other straight edge constitute one edge. A straight line may be used. For example, a V-shape or the like may be formed by a plurality of straight portions having a smaller inclination angle than the inclined edge.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a shutter opening 1a is formed in a substrate 1 disposed opposite to a photographic lens of a camera (not shown). On the substrate 1, shafts 2, 3, and 4 are erected, and a set lever (not shown) is provided on each shaft.
An opening lever and a closing lever are pivotally supported.
The substrate 1 is formed with arc-shaped guide holes 5 and 6 centered on the shafts 3 and 4, and drive pins projecting from the opening lever and the closing lever respectively penetrate the guide holes 5 and 6. It is movable.

A drive spring (not shown) is hooked to the open lever and the close lever, and the soft magnetic plate of each lever is attracted to each electromagnet device when the setting is completed. At the time of exposure, the release lever is released from the suction and the driving spring retracts the opening blade from the shutter opening to enter an exposure state. After a predetermined time, the closing lever is released from the suction and the driving spring spreads the closing blade to open the shutter opening. Close and end shooting for one frame. Further, by the reset operation, the open blades are expanded to close the shutter opening and return to the set completion state.

On the back side of the substrate 1, a sliding plate 7 is fixed, and a group of open blades 8 is provided. Open feather group 8
Are a slit forming blade 8a and a plurality of covering blades 8b to 8e.
And a plurality of arms 9 constituting a parallel link mechanism.
It is supported rotatably. On the back side of the open blade group 8, partition plates 10 and 11, which will be described in detail later, are provided. As in the case of the substrate 1, shutter openings 10a and 11a are formed in the partition plates 10 and 11.

On the rear side of the partition plate 11, a group of closing blades 12 is provided. The closing blade group 12 includes a slit forming blade 12.
a and a plurality of cover blades 12b to 12d, which are rotatably supported by a plurality of arms 13 constituting a parallel link mechanism. A sliding plate 14 is provided on the back side of the closing blade group 12, and the sliding plate 14 is fixed to a receiving plate 15 provided on the back side. A shutter opening 15a is formed in the receiving plate 15 similarly to the substrate 1, and guide holes 16 and 17 are opened at positions facing the guide holes 5 and 6 provided in the substrate 1. A film (not shown) is provided behind the shutter opening 15a.

The partition plates 10 and 11 will be described. The conventional configuration described with reference to FIG.
A pair of edges substantially orthogonal to the traveling direction of the two blade groups are formed as a slanted edge C1 and a straight edge C2 that spread substantially in a V-shape, and the cut cannot be made deep so as not to cause light leakage. This caused the problem. Therefore, in the present invention, two partition plates 10 and 11 are used, one edge on the opposite side is formed as a V-shaped inclined edge, and the other edge facing the inclined edge is formed as a straight edge. It is to be formed.

That is, in the partition plate 10, when the open blade group 8 is retracted from the shutter opening 10a, the cover blade 8e, which is the lowest in the open blade group 8 and is always in contact with the partition plate 10, is moved. The contacting edge is a straight edge 10b,
The edge on the side where the slit forming blade 8a approaches when the open blade group 8 travels so as to cover the shutter opening 10a is a V-shaped inclined edge 10c.

In the partition plate 11, when the closed blade group 12 is retracted from the shutter opening 11a, the top cover blade 12d which is always in contact with the partition plate 11 in the closed blade group 12 is moved. Straight edge 11b
The edge on the side where the slit forming blade 12a approaches when the closing blade group 12 travels so as to cover the shutter opening 11a is a V-shaped inclined edge 11c.

When the partition plates 10 and 11 are overlapped, the straight edge 10b and the inclined edge 11c overlap, and the inclined edge 10c and the straight edge 11b overlap. The straight edges 10b, 11b for one blade group correspond to corners 11c1 corresponding to the V-shaped vertices of the edge of the shutter opening formed by the V-shaped inclined edges 11c, 10c for the other blade group. , 10c1 are located closer to the center of the shutter openings 10a, 11a. Therefore, in a state where the partition plates 10 and 11 are overlapped, both corners 10c1 and 11c1
And 10b, respectively, so that light leakage from this portion does not occur.

With such a structure, the closed blade group 1
When the vehicle 2 travels to cover the shutter opening 11a again, the slit forming blades 12a run smoothly without hitting the partition plate 11 due to the presence of the inclined edge 11c. Similarly, the opening blade group 8 retreats from the shutter opening 10a to the outside of the upper left edge to be in an exposed state, and after the shutter blade opening 12 covers the shutter opening 10a to end the exposure operation, the shutter opening group 8 is again opened. When returning to the setting completion state covering the 10a, the slit forming blade 8a runs smoothly without hitting the partition plate 10 due to the presence of the inclined edge 10c.

FIG. 2 shows a partition plate 20 as another embodiment of the present invention. The partition plate 20 is formed of a plastic material and has the same shutter opening 2 as the substrate 1.
0a is provided, and a pair of edges substantially perpendicular to the running direction of the open blade group and the closed blade group are respectively 2 in the thickness direction.
It is divided into a straight edge 20b and an inclined edge 20c on the upper surface side,
An inclined edge 20d and a straight edge 20e are formed on the lower surface side. Therefore, one edge on the upper left of the drawing is a straight edge 20b.
And the inclined edge 20d constitute one edge, and the corner 2 of the inclined edge
0d1 is closed by the straight edge 20b. In addition, the other edge at the lower right of the drawing includes one edge 20c and a straight edge 20e.
Corner 20c1 of the inclined edge is a straight edge 20e.
Is blocked by The open blade group 8 in FIG. 1 is arranged above the partition plate 20, and the closed blade group 12 in FIG. 1 is arranged below the partition plate 20. The operation is the same as described above. The straight edge may be a substantially straight line. For example, the straight edge may be formed in a V-shape by a plurality of straight portions having a smaller inclination angle than the inclined edge.

[0019]

According to the focal plane shutter of the present invention, the inclined edge is provided at the edge of the shutter opening of the partition plate, so that both the slit forming blades of the open blade group and the closed blade group hit the partition plate and bite. Without
Since the edge of the inclined edge is closed by the straight edge, light leakage does not occur even if the opening is widened by the inclined edge. By dividing the edge of the opening of one partition plate into two in the thickness direction and forming one edge with the inclined edge and the straight edge, in addition to the same effect as described above, the manufacturing can be simplified and the cost can be reduced. Can be achieved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing another embodiment of the partition plate.

FIG. 3 is a conventional exploded perspective view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a, 10a, 11a, 20a Shutter opening 8 Open blade group 10, 11, 20 Partition plate 10b, 11b, 20b, 20e Straight edge 10c, 11c, 20c, 20d Inclined edge 10c1, 11c1 Corner 20c1, 20d1 Corner 12 Closed feather group

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2H081 AA21

Claims (3)

[Claims] 1. A focal plane shutter comprising: a group of open blades and a group of closed blades for opening and closing a shutter opening; and a partition plate disposed between the two blade groups. Of the edges, a pair of edges substantially orthogonal to the traveling direction of the two blade groups is used when the two blade groups travel to cover the shutter opening.
The edge on the side where the slit forming blades of the two blade groups approach each other is formed as an inclined edge, and the other edge is formed as a linear edge.The linear edge for the one blade group is formed by the inclined edge for the other blade group. A focal plane shutter, which is located closer to the center of the shutter opening than a corner of the shutter opening to be formed. 2. The slope according to claim 1, wherein the partition plate is composed of two sheets, one of which has an inclined edge and a straight edge for the open blade group, and the other has an inclined edge for the closed blade group. An edge and a straight edge, respectively, and the two partitions are positioned such that the linear edge of one partition is located closer to the center of the shutter opening than the corner of the shutter opening formed by the inclined edge of the other partition. A focal plane shutter, wherein the plates are overlapped. 3. The partition plate according to claim 1, wherein the partition plate is formed of one sheet, and the thickness of a pair of edges of the shutter opening of the partition plate is divided into two, and one of the partition plates is provided with the opening blade group. The inclined edge and the straight edge of the closed blade group are formed on the other surface side, and the inclined edge and the straight edge for the closing blade group are respectively formed on the other surface side, and the one inclined edge and the other straight edge constitute one edge. A focal plane shutter.