JPH0990468A - Focal-plane shutter for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focal-plane shutter constituted so that a slit forming blade may not collide with the end face of an opening part formed on a shutter bottom board in order to save a mirror mechanism part. SOLUTION: An opening part 1m to save the mirror mechanism part is formed at the left upward part of the aperture for exposure 1a of the shutter bottom board 1. The slit forming blade 4a pivotally fit to an arm 2 through a coupling shaft 2a is constituted so that its elongation part 4a1 may face to the opening part 1m in the midst of traveling. When the blade 4a travels upward, the elongation part 4a1 is moved left upward. However, since the upper and the side edges of the opening part 1m are spread in a curved state, the blade 4a does not collide with the end face of the opening part 1m even when the elongation part 4a1 is bent.

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, in which a front blade group and a rear blade group are sequentially run in the same direction to perform shooting.

[0002]

2. Description of the Related Art A focal plane shutter in which a front blade group and a rear blade group are axially supported by a plurality of arms is well known.
Many shutters of this kind have openings formed in the shutter base plate at positions above and below the exposure aperture of the shutter base plate in order to escape a part of the mirror mechanism as the camera becomes smaller.
An example of this configuration will be described with reference to FIGS. 4 and 5. FIG.
, The shutter base plate 1 has a substantially rectangular exposure aperture 1a and arcuate holes 1b and 1c, and the axes 1d, 1e, 1f, 1g, 1h, 1i, 1j,
1k is planted. Then, openings 1m and 1n are provided in series at the upper left and right positions of the exposure aperture 1a.

The leading blade arms 2 and 3 are pivotally mounted on shafts 1j and 1k, and have slit forming blades 4a and cover blades 4b and 4b.
As is well known, the leading blade group 4 including 4c, 4d, and 4e is pivotally supported by two connecting shafts for each blade. The trailing blade arms 5 and 6 are pivotally attached to the shafts 1h and 1i, and the slit forming blade 7a and the covering blades 7b, 7c, 7d and 7e.
A rear blade group 7 composed of and is pivotally supported by a connecting shaft.
The arms 3 and 5 are formed with holes 3a and 5a, respectively,
As is well known, the drive pin of each drive lever (not shown) is fitted.

[0004] The slit forming blade 4a pivotally mounted on the cutting edge of the front blade arm 2, 3 has an extension portion 4a ₁ of the slit forming edge which protrudes beak to the left i.e. pivot side of FIG. There is. This is because while the leading blade arms 2 and 3 rotate, a slit cannot be always formed during traveling without a slit forming edge of a predetermined length, and the covering blade 4b is pivotally supported during traveling. This is because it must be prevented from hitting the connecting shaft that is present. In the illustrated example, when the leading blade group 4 is in the developed state as shown in the figure, the connecting shaft between the leading blade arm 2 and the covering blade 4b is the slit forming blade 4
Although it is distant from a, it is in a proximity state when it is stored below the exposure aperture 1a. In the figure, the rear blade group 7 is in that state.

The shafts 1f and 1g of the shutter base plate 1 are, in order from the rear side, a U-shaped front blade holding plate 8, an intermediate plate 9, and a U-shaped front blade holding plate 8 (not shown). A letter-shaped rear blade pressing plate and a cover plate (not shown) are attached. Of these, except the cover plate, the shaft 1
f, 1g are movable in the axial direction, and the intermediate plate 9 is
Also in e, it is attached so as to be movable in the axial direction.
The cover plate is also attached to the shafts 1d and 1e.

The leading blade group 4 is arranged between the shutter base plate 1 and the intermediate plate 9, and the leading end portion (right end portion) of each blade is sandwiched between the leading blade pressing plate 8 and the intermediate plate 9. Therefore,
A part of the leading blade pressing plate 8 is exposed in the opening 1n, but since such a component is not functionally required on the side of the opening 1m, a part of the arm 2 is provided in the opening 1m. Part of the slit forming blade 4a is exposed. Also, the rear blade group 7
Is arranged between the intermediate plate 9 and the cover plate, and the tip of each blade is sandwiched between the intermediate plate 9 and the rear blade pressing plate.

Next, the reason why the openings 1m and 1n are present will be described with reference to FIG. As shown in FIG. 5, the single-lens reflex mirror 10 is attached to a mirror frame 11.
A hinge portion 11a is formed on the mirror frame 11 so as to be rotatably attached to the camera body. By the way, recently, due to the necessity of downsizing the camera, there has been a demand to arrange such a mirror mechanism portion as close to the surface of the shutter base plate 1 as possible. Therefore, at first, a method of thinning the surface of the shutter base plate 1 by counterboring so that the hinge portion 11a does not hit the surface of the shutter base plate 1 was conceived, but this method requires a high processing cost, and therefore the present method is It is common to form the openings 1m and 1n as described above.

The positions where the openings 1m and 1n are formed are basically above and below the exposure aperture 1a, but the positions are different depending on the design of the camera such as the shape of the hinge 11a. In addition to those shown in FIG. 3, a typical example thereof is shown in FIG. 3 used for explaining the embodiment. Further, although the openings 1m and 1n are both connected to the exposure aperture 1a, it is also known that they are formed independently of the exposure aperture 1a.

FIG. 4 shows the charged state of the shutter. When the shutter is released in this state, the leading blade arm 3 is rotated clockwise by the leading blade driving lever (not shown), and the leading blade group 4 is formed with slits. The blade 4a moves downward while keeping the slit forming edge substantially horizontal. At this time, the slit forming blade 4a passes through the opening 1m with the tip (the corner portion including the upper left upper end and the side end) of the extended portion 4a ₁ facing. Subsequently, the trailing blade arm 5 is rotated clockwise by a trailing blade driving lever (not shown), and the trailing blade group 7 moves downward while keeping the slit forming edge of the slit forming blade 7a substantially horizontal, and the exposure traveling is completed. To do.

Therefore, even when the shutter is charged, the slit forming blade 4a passes with the tip of the extension 4a ₁ facing the opening 1m. The slit forming blade 4a has the opening _{1 at} the tip of the extension 4a 1.
It is possible to drive the vehicle so that it does not come within m. In that case, the extension portion 4a ₁ may be formed longer, but in order to do so, the extension portion 4a ₁ should be prevented from hitting the connecting shaft of the arm 2 and the cover blade 4b. Connecting shaft and slit forming blade 4a
The length between the connecting shaft and the connecting shaft may be set longer.

However, in this case, in the developed state shown in FIG. 4, the slit forming blade 4a and the covering blade 4b are formed.
There is less overlap with and there is concern about light leakage. To prevent this, if the widths of the slit forming blade 4a and the cover blade 4b (the vertical dimension in the drawing) are increased, when the storage position is set below the exposure aperture 1a,
The storage space becomes large, and the vertical dimension of the shutter base plate 1 becomes large. Moreover, since the arms 2 and 3 also become long, the lateral dimension of the shutter base plate 1 also becomes large, which eventually leads to an increase in the size of the entire shutter. Therefore, when trying to reduce the size of the entire shutter, the tip of the extended portion 4a ₁ of the slit forming blade 4a inevitably faces the opening 1m during the traveling.

The shutter shown in FIG. 4 has been described as a type in which the leading blade group 4 and the trailing blade group 7 run from the upper side to the lower side during the exposure run, but the shutter has almost the same structure. However, there is also a type that is designed to run from the bottom to the top. With the shutter configuration shown,
When using that type of shutter, the rear blade group 7 may be the front blade group and the front blade group 4 may be the rear blade group. Therefore, when doing so, in the final stage of the exposure run,
The slit forming blade 4a allows the tip of the extended portion 4a ₁ to face the opening 1m and rapidly pass therethrough.
Further, in the configuration of the leading blade group 4 shown in FIG. 4, the leading blade arms 2 and 3 are provided on the foremost side (close to the shutter base plate 1) in the figure, and then the trailing blades 4a, 4b, 4c, 4d and 4e are arranged in this order. It is arranged, but conversely from the front side, the blades 4e, 4d,
There is also a shutter in which 4c, 4b, 4a and arms 2, 3 are arranged in this order. The present invention is directed to all these types of shutters.

[0013]

However, in recent shutters, while demands for miniaturization have increased more and more as described above, demands for higher speed and continuous shooting are also great, and the traveling speed of the shutter blades is Not only during the exposure run, but also rapidly during the run to the charge position. On the other hand, shutter blades are becoming lighter and thinner. For this reason, the tip of the extended portion of the slit-forming blade described above has come to collide with the end face of the opening formed to escape the mirror mechanism portion during traveling.

The reason for this is that, as is well known, the shutter blades are more or less pushed or deflected in the direction orthogonal to the plane of the shutter blade during its travel. In particular, when the slit forming blade is the slit forming blade of the rear blade group, it comes into contact with a brake device having various configurations as is well known in the final stage of the exposure traveling, or vibration when the front blade group stops. It is known that, due to such influences as described above, it is more largely and irregularly bent, and that a rotating action works around the connecting shaft, although slightly. Therefore, it has become necessary to devise a means for preventing the above-mentioned collision.

The present invention has been made to solve such a problem, and an object thereof is to make an opening formed in a shutter base plate into a predetermined shape so as to escape the mirror mechanism section. An object of the present invention is to provide an enlarged focal plane shutter for a camera.

[0016]

In order to achieve the above object, a focal plane shutter for a camera according to the present invention has a substantially rectangular exposure aperture and an opening formed as a mirror mechanism escape portion at the left and right upper positions thereof. A shutter base plate having a portion, and a first blade arranged adjacent to the shutter base plate so that the slit forming blade is at an upper position when the exposure aperture is opened and closed in the vertical direction and is closed. Group, a first actuating member pivotally mounted at a lateral position of the exposure aperture to open and close the first blade group, and open and close the exposure aperture in the vertical direction in cooperation with the first blade group. The second blade group is pivotally attached to a second blade group configured such that the slit forming blade is located at a lower position when closed, and to a lateral position on the same side as the lateral position. A second actuating member for opening and closing, and the slit forming blade of the first blade group has an extending portion in which the slit forming edge is extended to the side position side. The opening on the side position side,
At least one of the upper side of the opening and the side surface opposite to the exposure aperture is formed to be larger than the other opening.

Further, in the focal plane shutter for a camera according to the present invention, preferably, the opening on the side position side is formed so that the upper side thereof becomes larger as the distance from the exposure aperture increases. Further, in the focal plane shutter for a camera according to the present invention, it is preferable that the opening on the side position side is formed so that the side surface side opposite to the exposure aperture becomes larger as it goes upward. Further, in the focal plane shutter for a camera according to the present invention, preferably, the opening portion on the side of the lateral position is formed so as to be enlarged substantially along the locus of the tip of the extension portion.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to four examples shown in FIGS. In these drawings, the same reference numerals are used for substantially the same parts and portions as those of the conventional example shown in FIG.
Although the shape and the function of m are completely different, the same reference numeral is used for easy understanding of the relationship with the conventional example.

First, a first embodiment will be described with reference to FIGS. FIG. 1 is a front explanatory view of the first embodiment.
[Fig. 2] is an enlarged explanatory view of a portion A in Fig. 1. FIG. 1 shows only the relationship between the shutter base plate 1 and the slit forming blades 4a, and other configurations are omitted. Although the shape of the shutter base plate 1 is slightly different from that shown in FIG. 4, the openings 1 are formed at positions above and below the exposure aperture 1a.
m, 1n are formed. Further, arcuate holes 1b, 1c are also formed, and shafts 1d, 1e, 1f, 1g, 1 are formed in the rearward direction.
h, 1i, 1j, 1k are also planted.

Further, on the back surface of the shutter base plate 1, a chamfered portion 1p is formed by milling so as to surround the exposure aperture 1a. Slit forming blade 4a
Is arranged on the back surface of the shutter base plate 1 as described above, but in FIG. 1, its outer shape is shown by a solid line, and at seven positions so that the movement process of the extension 4a ₁ with respect to the opening 1m can be understood. It is shown.

The shape and function of the opening 1m, which is a feature of the present invention, will be described with reference to FIG. In this figure, a slit forming blade 4a pivotally attached to the arm 2 by a connecting shaft 2a.
Is indicated by a stop position above which the exposure aperture 1a is completely covered, and three positions during running are indicated by a chain double-dashed line. The connecting shaft 2a is actually a rivet component, and a chamfered portion 2a ₁ is formed on the head thereof, and the tip end thereof penetrates the hole of the arm 2 and is caulked to the slit forming blade 4a.

The shape of the opening 1m is such that the upper edge thereof is curved upward as it moves away from the exposure aperture 1a as shown by a plurality of crosses, and the side edge is As indicated by a plurality of diagonal lines, the curve is inclined in a direction away from the exposure aperture 1a as it goes upward. Further, the upper end edge and the side end edge of the conventional opening 1m are shown by a dashed line for reference.
In this way, the shape of the enlarged part expanded to the upper left is
Tip part of the extension part 4a ₁ (corner region including upper end and side end)
It roughly agrees with the operating trajectory of.

Next, the slit forming blades 4a are moved from the bottom to the top.
The case where the vehicle is traveling toward will be described. As you know
In addition, the slit forming blade 4a has a
It moves upward while keeping it flat, but the arm 2 and 3
Since it is moved by movement, it is also moved to the left.
Therefore, the extension portion 4a₁The tip part of draws an arcuate trajectory
Will be. Therefore, when the opening 1m has a conventional shape,
Is the extension part 4a during traveling. ₁Is bent toward the front of the figure
The tip of the opening is less than the top and side edges of the opening 1m.
Both collide with one. However, according to the shape of this embodiment,
There is no risk of collision on the side end face,
Is the extension 4a₁The slit forming edge of the
From the exposure aperture 1a side to the rear side of the shutter base plate 1
It will be pushed gradually and the deflection will be corrected, so it will collide
I have no worries.

As can be seen from the above description, in this embodiment, the side edge is formed in a curved shape as shown by a plurality of slanted lines, but originally, the tip of the extending portion 4a ₁ is formed. Since it is only necessary to escape the locus of the part, any shape may be used if it is possible. Also, regarding the upper edge, it is ideal to have a curved shape as in the embodiment or an inclined linear shape from the viewpoint that the opening 1m is not too large, but in an extreme case, this The opening 1m may be formed large so that the upper edge is located above the slit forming edge of the stopped slit forming blade 4a. Further, as described above, since the position and shape of the opening 1m depend on the configuration of the mirror mechanism section, it may be necessary to widen only one of the upper edge side and the side edge side of the opening 1m.

Next, another embodiment will be described with reference to FIGS. 3 (a) to 3 (c). These figures are all 1m opening
Only the shape of is shown. FIG. 3A shows a second embodiment of the present invention. Also in this figure, the conventional upper edge and the side edge are shown by a dashed line. Exposure aperture 1a
Regarding the position of the opening with respect to, there are many positions shown in the first embodiment and those shown in the present embodiment. Since the curved shapes of the upper edge and the side edge are substantially the same as those in the first embodiment, their modifications are also as described in the first embodiment.

FIG. 3B shows a third embodiment of the present invention. The position of the opening 1m is the same as in the case of the second embodiment, and the conventional side edge is shown by a dashed line. In this case, it is necessary that the slit forming edge of the slit forming blade 4a is not formed in a straight line shape, but is formed in a curved shape downward at least in the extension portion 4a ₁ . Therefore, although it is unlikely to be carried out, in this case, it suffices that the side edge be shaped so as to escape from the locus of the extending portion 4a ₁ .

FIG. 3C shows a fourth embodiment of the present invention. The position of the opening 1m is different from that of the conventional one, and the conventional upper edge and side edge are shown by a chain line.
In this case, as in the first and second embodiments,
The curved portion on the upper edge side may be formed from the conventional position of the upper edge toward the upper left, but from the viewpoint of manufacturing the shutter base plate 1, it is advantageous to form it as in this embodiment. . Since the curved shapes of the upper edge and the side edge are substantially the same as those in the first embodiment, their modifications are also as described in the first embodiment.

[0028]

As described above, according to the present invention, among the openings formed at the left and right upper positions of the exposure aperture for escaping the mirror mechanism portion, the operation member for moving the shutter blade is pivotally attached. Since the opening on the side that is formed is enlarged to have a predetermined shape, the slit forming blade does not collide with the end surface of the opening during traveling.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a portion A in FIG.

3 (a), FIG. 3 (b), and FIG. 3 (c) are explanatory views of a second embodiment, a third embodiment, and a fourth embodiment of the present invention, respectively.

FIG. 4 is a front view of a conventional focal plane shutter.

FIG. 5 is a perspective explanatory view showing a relationship between a conventional focal plane shutter and a mirror mechanism section.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 shutter base plate 1a exposure aperture 1m, 1n opening 2a connecting shaft 2,3 leading blade arm 4 leading blade group 4a, 7a slit forming blade 4a ₁ extension 4b, 4c, 4d, 4e, 7b, 7c, 7d, 7e
Cover blades 5, 6 Rear blade arm 7 Rear blade group 10 Mirror 11 Mirror frame 11a Hinge part

Claims (4)

[Claims] 1. A substantially rectangular exposure aperture, a shutter base plate having openings formed in the left and right upper positions thereof as a mirror mechanism clearance, and an exposure aperture which is arranged adjacent to the shutter base plate. A first blade group configured such that the slit forming blade is in an upper position when traveling by opening and closing in the vertical direction and being closed, and traveling by opening and closing the first blade group pivotally mounted at a lateral position of the exposure aperture. And a second blade group configured such that the slit forming blade is located at a lower position when the exposure aperture is opened and closed in the up-down direction in cooperation with the first blade group. A second actuating member pivotally mounted at a lateral position on the same side as the lateral position to open and close the second blade group, and the slit forming blade of the first blade group has a slit forming edge thereof. Has an extension portion extending toward the side position side, and the opening portion on the side position side of the opening portion is a side surface side opposite to the upper side of the opening portion and the exposure aperture. A focal-plane shutter for a camera, characterized in that at least one of the above is formed larger than the opening of the other. 2. The focal-plane shutter for a camera according to claim 1, wherein the opening on the side of the lateral position is formed such that the upper side of the opening increases as the distance from the exposure aperture increases. . 3. The opening according to claim 1, wherein the opening on the side of the lateral position is formed so as to become larger as the side surface opposite to the exposure aperture becomes upward. Focal-plane shutter for camera. 4. The opening portion on the side of the lateral position is formed so as to be enlarged substantially along a locus of a tip of the extension portion. Focal plane shutter for the described camera.