JP3347207B2 - Focal plane shutter for camera - Google Patents

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 for a camera having two sets of blades composed of a plurality of sheets.

[0002]

2. Description of the Related Art This type of focal plane shutter is
Each blade group is pivotally supported by two arms that are pivotally attached to the sides of the exposure opening, and the rotation of those arms causes each blade group to spread or fold like a fan. It has been done. In addition, each blade group is separated from the traveling path by an intermediate plate disposed between two substrates, and the leading ends thereof slide between the respective blade holding plates and the intermediate plate. ing. Each blade group is provided with a slit forming blade, and the film is exposed by the slit formed by the slit forming blades. In addition, in order to prevent a so-called bouncing phenomenon from occurring at the end of traveling of each blade group, a brake is applied from before the end of traveling by a braking device, but the traveling speed of each blade group is about an average hourly speed. Since it is 40 km, in this case, the impact when contacting the braking device much earlier and the impact when contacting the stopper are extremely large.

At the end of such an exposure operation, the leading blade group is folded outside the exposure opening in the traveling direction, but at this time, the impact is bent so as to undulate in the direction perpendicular to the traveling direction. Symptoms occur. On the other hand, since the above-mentioned intermediate plate is usually made of a thin metal plate or a sheet of synthetic resin, the intermediate plate is deformed by the bending phenomenon of the front blade group and is pushed out into the working passage of the slit forming blade of the rear blade group. Therefore, the leading edge of the slit forming blade of the rear blade group that has traveled to follow the slit forming blade of the front blade group collides with the opening end of the intermediate plate,
It causes a fatal accident of damage. Conventionally, in order to prevent such an accident, a protrusion is planted by caulking or the like on the substrate on the rear blade group side, and the front end portion is applied to the intermediate plate, so that the bending phenomenon of the front blade group is performed. The intermediate plate was supported so as not to be deformed even if pressed.

[0004]

As described above, each blade group travels by the rotation of the arm. Therefore, the blades travel while the posture of the blades is kept horizontal. Draw. Therefore, the shape of the above-mentioned rear blade holding plate is partially extended outside the exposure opening forming edge in the exposure traveling direction so as to correspond to the tip of the slit forming blade having the largest momentum in the rear blade group. It is formed so that it comes out. Therefore, the above-mentioned protruding portion cannot be provided at that position because the overhanging portion is in the way, and is provided only at a position corresponding to the root portion from substantially the center of the blade group. However, since the amount of deflection of the front blade group is greater at the tip end portion than at the root portion of the blade group, merely providing the projections as described above completely prevents the slit forming blades of the rear blade group from colliding with the intermediate plate. It was difficult to prevent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an intermediate plate provided on a substrate in order to prevent the intermediate plate from being deformed by the bending phenomenon of the front blade group. An object of the present invention is to provide a focal plane shutter for a camera in which an intermediate plate can be supported at a position corresponding to a tip end of a group of front blades by a projection provided.

[0006]

In order to achieve the above object, a focal plane shutter for a camera according to the present invention is pivotally supported by a leading blade drive arm and arranged between a first substrate and an intermediate plate. A front blade group, a rear blade group pivotally supported by a rear blade drive arm and disposed between the intermediate plate and the second substrate, and a front end portion of the rear blade group at one side of an exposure opening. A rear blade holding plate disposed so as to be sandwiched between the second substrate and the rear surface of the second substrate on the side of the one side portion outside the exposure opening in the exposure traveling direction of the rear blade group. A protrusion is provided toward the plate, and a relief portion through which the protrusion penetrates is provided on the rear blade holding plate so that a tip end of the protrusion contacts the intermediate plate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing a charged state of a shutter, and FIGS. 2A to 2F are main component parts diagrams of the embodiment shown in FIG. 1 excluding a blade group and the like. FIG. 3 is a main part front view showing the position of the front blade group immediately before the end of the exposure travel, and FIG. 4 is a bottom view of FIG.

First, the configuration will be described. The substrate 1 has an exposure opening 1a and arc-shaped holes 1b and 1c.
d, 1e, 1f, 1g, 1h, 1i are implanted, and a projection 1j is formed. The leading blade driving arms 2 and 3 are pivotally mounted on shafts 1f and 1g, respectively, and pivotally support a group of five leading blades including a slit forming blade 4 as is well known. The rear blade drive arms 5 and 6 are pivotally attached to the shafts 1d and 1e, respectively, and pivotally support a group of five rear blades. In FIG. 1, the rear blade group shows only the slit forming blade 7. , Other feathers are omitted. Holes 3 in drive arms 3 and 5 respectively
a and 5a are formed so that pins of the leading blade driving member and the trailing blade driving member (not shown) are fitted through the arc-shaped holes 1b and 1c.

On the shafts 1h and 1i of the substrate 1, the leading blade holding plate 8, the auxiliary holding plate 9, the intermediate plate 10,
A rear blade holding plate 11 and an auxiliary substrate 12 are attached.
Among them, the front blade holding plate 8, the auxiliary holding plate 9, the intermediate plate 10,
The rear blade holding plate 11 is mounted movably in the axial direction. Although not clearly shown on the shafts 1e, 1f, 1h, and 1i, a stepped portion is formed, and the auxiliary substrate 12 is fitted into the shafts 1h and 1i and then slid to the left in FIG. 12f and 12g engage with the shafts 1e and 1f,
Retained securely. And the forked parts 12a and 12b
The drive arms 3, 5 are prevented from moving axially on the shafts 1d, 1g during operation. The portion of the leading blade holding plate 8 projecting below the exposure opening 1a comes into contact with the projection 1j and is held in an attitude with respect to the substrate 1, and the trailing blade holding plate 8 holds the projection 1
The posture with respect to the auxiliary substrate 12 is maintained in contact with 2h and 12i.

The rear blade holding plate 11 has a hole 1 in the overhang portion 11a.
1b is formed. The auxiliary substrate 12 is formed with protrusions 12c, 12d, and 12e each having a small hole in a plane portion at the tip. The protrusion 12c passes through the hole 11b so as not to touch the rear blade holding plate 11. I have. Auxiliary board 1
In the case where 2 is made of metal, it is preferable that the protruding portion is formed by protrusion using a press machine. The auxiliary holding plate 9 has an overhang portion 9a.
The purpose thereof is described in Japanese Utility Model Laid-Open No. 5-45659, and the description thereof is omitted. The leading blade group has its leading end portion slidably held between the leading blade holding plate 8 and the auxiliary holding plate 9, and the trailing blade group has its leading end formed by the intermediate plate 10 and the trailing blade holding plate 11. It is slidably sandwiched between them. The overhanging portion 11a of the rear blade holding plate 11 projects downward under the lower edge of the exposure opening 1a. When the exposure travel is completed, the slit forming blades 7 of the rear blade group bounce due to impact. The slit forming blades 7 are arranged on the rear blade holding plate 11 side of other blades, though not explicitly shown in the drawing, so that the slit forming blades 7 Floating in the direction of the auxiliary substrate 12 to prevent light leakage from between the rear blades.

Next, the operation will be described. FIG. 1 shows a state where the shutter is charged. When the shutter is released in this state, the pin of the leading blade driving member (not shown) fitted in the hole 3a of the driving arm 3 is moved to the arcuate hole 1
Operate along c. As a result, the driving arm 3 has a shaft of 1 g.
Turn right with Accordingly, the arm 2 connected through the front blade group also turns clockwise. The right-handed rotation of the arms 2 and 3 causes the leading blade group to start moving downward so as to be folded, and the slit forming blade 4 opens the exposure opening 1a.
When the slit forming blades 4 of the front blade group reach the position shown in FIG. 3 immediately before completing the travel of the exposure opening 1a, the running of the front blade group is braked. In recent years, this braking device has been less likely to directly brake the blades as the shutter speed has increased, and it has become common to brake the arm driving member.

As described above, the front blade group is braked by the braking device immediately before the end of the exposure travel. At this stage, the traveling speed of the front blade group is extremely high, and the front blade group is affected by the braking, and the front blade group is affected by the braking. When it stops, it bends in a wavy manner. FIG. 4 shows the bent state of the front blade group, and the amount of bending is larger at the tip of the blade. Since the intermediate plate 10 is usually made of a thin metal plate or a sheet made of synthetic resin, the intermediate plate 10 is pushed downward in FIG. The portions 12c, 12d, and 12e are blocked by the distal end surfaces, and are prevented from bending downward. Therefore, the slit forming blades 7 of the rear blade group, which have traveled following the front blade group, end the exposure operation without colliding with the intermediate plate 10.

In the above embodiment, the hole 11b of the rear blade holding plate 11 is a round hole. However, since the hole 11b is provided as a relief for the protruding portion 12c, the hole 11b is not limited to a round hole. In the figure, it may be formed as a notch that opens downward. In the embodiment, the protrusion 12
Although the hole c and the hole 11b are formed below the lower edge of the exposure opening 1a, they may be shifted to the right position and formed at a position below the right side of the exposure opening 1a. It does not matter. Furthermore, the present invention can be applied to a shutter of a type in which the arrangement positions of two sets of blades separated by an intermediate plate are interchanged, and a shutter of a type in which the blades travel upward during exposure travel. Also applicable to

[0014]

As described above, according to the present invention, the protrusion provided on one of the two substrates penetrates the relief provided on the rear blade holding plate so that it can contact the intermediate plate. Even if the front blade group is greatly wavy at the end of the exposure travel, the protrusion supports the intermediate plate at a position adjacent to the front end of the front blade group, and the intermediate plate is not deformed. Therefore, it is possible to prevent the slit forming blades of the rear blade group following the front blade group from colliding with the intermediate plate.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the present invention showing a charged state of a shutter.

FIG. 2 is a diagram of main components excluding a blade group in the embodiment shown in FIG. 1;

FIG. 3 is a main part front view showing a position of the front blade group immediately before the end of exposure travel.

FIG. 4 is a bottom view of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Exposure opening 1b, 1c Arc-shaped hole 1d, 1e, 1f, 1g, 1h, 1i axis 1j, 12h, 12i Projection 2,3 Front blade drive arm 3a, 5a, 11b Hole 4,7 Slit forming blade 5, 6 Rear blade drive arm 8 Front blade holding plate 9 Auxiliary holding plate 9a, 11a Overhanging portion 10 Intermediate plate 10a Notch groove 11 Rear blade holding plate 12 Auxiliary substrate 12a, 12b Bifurcated portion 12c, 12d, 12e Projecting portion 12f, 12g recess

Claims (3)

(57) [Claims] 1. A front blade group pivotally supported by a front blade drive arm and arranged between a first substrate and an intermediate plate, and a front blade group pivotally supported by a rear blade drive arm and between the intermediate plate and a second substrate. A rear blade group arranged, and a rear blade holding plate arranged so as to sandwich the tip of the rear blade group between the intermediate plate and one side of the exposure opening, and the second substrate includes A projection is provided toward the intermediate plate at a position outside the exposure opening in the exposure traveling direction of the rear blade group and on the one side, and a tip of the projection is provided on the rear blade holding plate at the intermediate position. A focal plane shutter for a camera, wherein a relief portion through which the protrusion penetrates is provided so as to make contact with the plate. 2. A plurality of protruding portions that are in contact with the intermediate plate along a length direction of the rear blade group outside the exposure opening in an exposure traveling direction of the rear blade group on the second substrate, 2. The focal plane shutter for a camera according to claim 1, wherein at least one of the plurality of holes penetrates through the escape portion provided in the rear blade holding plate. 3. The projection according to claim 1, wherein the projection is formed by projecting the second substrate so that the tip is flat, and the relief is a round hole. Focal plane shutter for camera.