JPH11174524A - Focal plane shutter for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focal plane shutter for a camera having a light shielding wall effective in preventing the leakage of light. SOLUTION: An intermediate plate 18 is placed between a shutter base plate l arranged on a lens side and an auxiliary base plate 26 arranged on the side of a film, to partition them and constitute two blade chambers. The light shielding wall 26t for shielding the peripheral parts of two base plates 1 and 26 is provided in the auxiliary base plate 26. The inside surface of the light shielding wall 26t is formed as a slope 26t2 , to make the distance from an optical axis greater as it goes from the auxiliary base plate 26 to the shutter base plate 1. Therefore, the light entering from the peripheral parts can be intercepted. Further, the light after entering into the gap between the base plate 1 and a blade group arranged in the blade chamber on the side of the base plate 1, from its aperture 1a is mainly reflected toward the base plate 1 by the slope 26t2 on purpose, to be attenuated, so that the light entering into the gap between the intermediate plate 18 and the auxiliary base plate 26 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In the present invention, in photographing, a front blade group and a rear blade group are sequentially operated in the same direction, and a film is exposed by slits formed by slit forming blades of both blade groups. The present invention relates to a focal plane shutter for a camera.

[0002]

2. Description of the Related Art A focal plane shutter mainly incorporated in a high-end camera has an opening for exposure at a substantially central portion and is provided with two base plates which are attached to each other. And the other main plate is referred to as a cover plate, an auxiliary main plate, or the like). Each blade group has a structure in which one end is pivotally connected to one arm of one main plate, and a plurality of blades are sequentially pivoted toward the other end thereof. The supported blade is a slit forming blade having the largest momentum. The pivot structure is such that the connecting shaft, which is a rivet component, is inserted into the hole of the arm so as to be rotatably fitted, and the inserted end is swaged to the blade.

[0003] One of the arms of each blade group has a long hole formed at a position close to the pivot portion. The space between the two base plates is partitioned by an intermediate plate (also referred to as a partition plate or the like) having an opening similar to the openings of the base plates. A blade chamber is formed, and the operating regions of the front blade group and the rear blade group are separated so that they do not interfere with each other in operation. Further, the plane area of the intermediate plate is slightly smaller than the above-mentioned two base plates, and the pivot portion of each arm and the operation region of the above-mentioned elongated hole are not partitioned and serve as a common space.

Further, a driving member for the front blade and a driving member for the rear blade are mounted on one of the base plates so as to be reciprocally rotatable, and the operating pins of the respective driving members are inserted into the elongated holes of the arm. Mated. Therefore, a plurality of blades of each blade group, when the arm is rotated in one direction by the operating pin,
When the unfolding is performed while reducing the overlap, and the rotation is performed in the other direction, the overlap is performed while increasing the overlap. When the shutter is set, the leading blade group is in the developed state and covers the opening for exposure, and the trailing blade group is in the overlapping state and is retracted from the opening for exposure. Immediately after the end of the operation, the front blade group is in a superimposed state and retreats from the opening, and the rear blade group is in a deployed state and covers the opening.

It is a matter of course that this type of focal plane shutter is also required to be reduced in size and increased in speed, but it is not unusual to meet the demand. As is well known, in order to reduce the size of the focal plane shutter, it is effective to minimize the plane area occupied by the blade group in the superimposed state. However, in order to do so, the number of blades in each blade group must be increased, so the number of overlapping surfaces of the blades in the deployed state increases, and the weight of the entire blade group increases. Results. Therefore, in order to obtain the conventional maximum speed with the conventional driving force, the weight of the blade must be reduced.

On the other hand, in order to increase the speed of the shutter,
The driving force must be increased or the weight of the blade must be reduced. However, increasing the driving force more than ever is extremely difficult from the viewpoint that it is necessary to stably obtain a predetermined performance. Therefore, it is necessary to reduce the weight of the blades in order to meet the demand for higher speed. Reducing the weight of the blade means reducing the plane area or reducing the thickness of each blade if no improvement in material is taken into account.

However, when the plane area of each blade is reduced, the overlapping area of the blades in the unfolded state is reduced, and when the camera is not used, light leaks from between the blades to expose the film. Sometimes. On the other hand, if the thickness of each blade is too small, the blade may bend due to vibration or the like when the camera is carried, and light may leak from the blade to expose the film. Further, when the blades are extremely thin, it is difficult to manufacture the blades such that the overlapping surfaces of the blades are completely in close contact with each other due to the influence of the caulking process of the connection shaft.
Inevitably a gap will be generated locally,
Even if the above-described vibration does not occur, the film is exposed.

Therefore, in order to reduce the size and speed of the shutter, it is necessary to proceed with development while always considering the problem of light leakage between the blades when the camera is not used. Many proposals have been made to prevent the film from being exposed to light due to light leakage between the blades, but each of them has advantages and disadvantages, and there is no breakthrough. Eventually, a certain amount of overlap must be ensured between the blades.

[0009] By the way, light leakage that exposes the film when the camera is not used includes not only the light leakage between the blades described above but also light leakage from other paths. Therefore, the film is exposed to light obtained by combining them. On the other hand, the shutter unit is a product that is assembled with the operating mechanical parts exposed to light, so that no matter what kind of light leakage countermeasures are taken, there is no countermeasure that can completely block all paths. Cannot exist. In other words, no matter how light leakage measures are taken, very little light reaches the film surface.

For this reason, in the case of light leakage prevention in the shutter unit, a measure may be taken to completely block the light incident path depending on the incident path of the light.
Rather, it is important to take measures to ensure that even if the total light incident from various routes reaches the film surface, it is practically attenuated to such a degree that the film is not exposed. . As described above, when considering the countermeasure against light leakage in the shutter unit, it is not sufficient to consider only the above-described countermeasure against light leakage between the blades. In other words, the countermeasure against light leakage from another path is not sufficient. If it is possible to achieve a fairly satisfactory result, it is not necessary to use unnecessary nerves only for light leakage between the blades.

Therefore, in addition to the light incident from the overlapping portion between the blades, incident light from two paths that must be considered will be described. One of them is incident from the peripheral portions of the above-mentioned two main plates, between them, mainly through the blade chamber between the intermediate plate and the main plate arranged on the film side, from the opening of the main plate. It is about the light that reaches the film surface. In order to prevent such light incidence, in the past, maltprene, flocking paper, and the like were interposed between the camera-side component and the shutter unit. However,
In this case, the cost increases, so recently, a light-shielding wall perpendicular to the surface of the base plate is formed on the periphery of the base plate arranged on the film side so as to minimize incidence from the periphery. It is thought that.

The incident light from the other path enters the gap between the base plate and the blade group arranged in the blade chamber on the base plate side from the opening of the base plate disposed on the lens side. Light. As is well known, the blade group in the blade chamber is manufactured such that the arm is on the base plate side, and each blade pivotally supported by the arm is on the intermediate plate side. The distal end of the arm is moved into or out of the opening every time the arm is actuated. For this reason, a gap at least as much as the thickness of the arm exists between the surface of the blade closest to the base plate and the surface of the base plate on the intermediate plate side. It is a configuration that cannot prevent incidence.

Conventionally, with respect to the light incident as described above, no special consideration is given to the structure, and antireflection treatment is performed on the surface of each plate and the surfaces of members disposed therebetween. It was about. This is because the light incident in this manner initially travels toward the peripheral portion of each plate, and as a whole, is repeatedly reflected several times before returning to the exposure aperture side. This is because when the film surface was reached from the opening of the base plate arranged on the film side, the attenuation was sufficiently reduced, and it was determined that the film surface was not substantially affected.

[0014]

Under these circumstances, recently, high-sensitivity films such as, for example, ISO1600 have been favorably used.
Light leakage measures must be stricter than ever before. On the other hand, recently, market needs for a rangefinder type high-end camera have been increasing. As is well known, in a rangefinder camera, unlike a single-lens reflex camera, there is no member such as a mirror between the lens and the film. Also, because it is a high-end camera,
It is necessary that the lens can be freely changed. Therefore, a rangefinder camera is required to have a more effective light shielding property than a single-lens reflex camera. Therefore, when manufacturing a focal plane shutter, it is necessary to take stricter measures against light leakage than before, on the premise that the shutter may be built into such a range finder type camera.

Then, first, as in the above-mentioned conventional example,
It is necessary to prevent light from entering from the peripheral portion by forming a light shielding wall perpendicular to the surface of the main plate on the peripheral portion of the main plate arranged on the film side. However, if the inner surface of the light-shielding wall is formed perpendicular to the base plate surface as in the related art, there is a problem when a high-sensitivity film is used. That is, as described above, the light incident from the opening of the ground plate disposed on the lens side through the gap between the ground plate and the blade group travels to the peripheral portion, is reflected by the light shielding wall, and is It penetrates between the board and the ground plane arranged on the film side and reaches the film surface from the opening of the ground plane. This is because it cannot be done. In particular, as described above, the plane area of the intermediate plate is smaller than the two ground plates,
Since the area in the vicinity of the pivot portion of the arm of each blade group is not partitioned, light reflected by the light-shielding wall can easily enter between the intermediate plate and the ground plate arranged on the film side.

The present invention has been made in order to solve such a problem, and an object of the present invention is to mainly use the main plate through the opening of the main plate arranged on the lens side, and Light that has entered between the blade group arranged in the blade chamber on the main plate side is greatly attenuated after being reflected on the inner surface of the light shielding wall provided in the peripheral portion, and is arranged on the intermediate plate and the film side. An object of the present invention is to provide a focal plane shutter for a camera in which the focal plane shutter hardly enters the space between the main plate and the camera.

[0017]

In order to achieve the above object, a focal plane shutter for a camera according to the present invention comprises:
Two base plates, each having an opening formed therein and attached to each other with a predetermined space therebetween and arranged with one lens side and the other film side in the camera, and a rectangular exposure together with each opening. An opening forming an opening, the blades being arranged between the two ground plates, and a blade chamber is formed between the two ground plates except at least a partial area at a predetermined lateral position of the exposure opening. Intermediate plate,
The exposure opening is formed during exposure operation in one of the blade chambers, comprising a plurality of arms having one end pivotally attached at the predetermined lateral position and a plurality of blades sequentially pivoted toward the other end thereof. A front blade group that is operated to open the arm, a plurality of arms having one end pivotally attached at the predetermined lateral position, and a plurality of blades pivotally supported toward the other end thereof. And a rear blade group that is operated to close the exposure opening at the time of an exposure operation in the other blade chamber. A light-shielding wall is formed to close between the light-shielding wall and the ground plane disposed on the film side, and the inner surface of the light-shielding wall is moved from the optical axis center line toward the ground plane disposed on the lens side from the ground plane disposed on the film side. Inclined to increase the distance of So that is formed as a.
In the focal plane shutter for a camera according to the present invention, preferably, the light shielding wall is formed at least in a peripheral portion in the predetermined lateral position direction when viewed from the exposure opening side. In the focal plane shutter for a camera according to the present invention, it is preferable that an angle of the inclined surface formed on the light shielding wall is approximately 30 to 60 degrees with respect to an optical axis center line. In the focal plane shutter for a camera according to the present invention, preferably, the base plate disposed on the film side is provided between the opening of the base plate and the light-shielding wall. At least one thick part protruding toward is formed. In that case, preferably, the plurality of thick portions are formed at the predetermined lateral position, and are arranged so that at least some of them overlap when viewed from the exposure opening side. To In the focal plane shutter for a camera according to the present invention, preferably, the thick portion has a surface on the side of the exposure opening facing a ground plate arranged on the lens side from a ground plate arranged on the film side. The slope is formed so that the distance from the optical axis center line gradually increases. In this case, it is preferable that the angle of the inclined surface formed in the thick portion is approximately 30 to 60 degrees with respect to the optical axis center line.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to a first embodiment shown in FIGS. 1 to 6 and a second embodiment shown in FIGS. 1 is a plan view showing a set state of the first embodiment, and FIG. 2 is a plan view showing the first embodiment in a state in which an opening / closing drive mechanism is removed and shown transparently. 3 (a) to 3 (i) are plan views of main components constituting FIG. 2, and FIG. 4 is a plan view of FIG.
It is an enlarged plan view of (i). FIG. 5 is a plan view perspectively shown in the same manner as FIG. 2, but shows a state immediately after the end of the exposure operation. FIG. 6 is a sectional view of an essential part for explaining the operation and effect of the first embodiment.
FIG. 6A shows the case of the first embodiment, and FIG. 6B shows the case of the conventional example. FIG. 7 is a plan view of a second shutter base plate used in the second embodiment. 8 and 9 are perspective plan views showing the rear blade group superimposed on the second shutter base plate shown in FIG. 7, and FIG.
Shows the state immediately after the end of the exposure operation.

First, the configuration of the first embodiment will be described mainly with reference to FIGS. As shown in FIG. 3 (a), the shutter base plate 1 has an opening 1a formed in a substantially central portion thereof, and three holes 1 for attaching to the camera are formed in a peripheral portion thereof.
b, 1b, 1b are formed. In addition, three arc-shaped holes 1c, 1d, and 1 are located on the left side of the opening 1a.
e is formed, and a rectangular hole 1f is formed at the lower left. As is well known, cushion members 2 and 3 made of butyl rubber having a C-shaped planar shape are attached to the upper ends of the holes 1c and 1d.

The shutter base plate 1 has a shaft 1g,
1h, 1i, 1j, 1k, 1m, 1n, 1p are erected, and among them, axes 1h, 1j, 1m, 1n, 1
p stands on the back side. Also, the shafts 1g and 1i penetrate from front to back, the shaft diameter on the front side is larger than the shaft diameter on the back side, and a pedestal portion is formed at the root on the front side. Further, the shaft 1k is erected on the front side of the shutter base plate 1, and has a pedestal formed at the base thereof.
Although not shown, a driving member for the front blade and a driving member for the rear blade are rotatably mounted on the surface side of the shafts 1g and 1i, as is well known. A set member (not shown) is rotatably attached to the shaft 1k, and a part of the set member is fitted into the above-described arc-shaped hole 1e. Therefore, the set member rotates by a predetermined angle.

Further, these three axes 1g, 1i, 1k
A screw hole is formed at the tip of the shaft in the axial direction. As shown in FIG. 1, a support plate 5 and a printed wiring board 6 are attached to the shutter base plate 1 substantially in parallel with three screws 4, 4, and 4. I have. An opening / closing drive mechanism including an electromagnet is disposed between the shutter base plate 1 and the support plate 5 in addition to the above-described front blade drive member, rear blade drive member, and set member. Since the typical configurations are well known and have no direct relation to the present invention, their illustration and detailed description are omitted. Although not shown in FIG. 3A,
As shown in the cross-sectional view of FIG. 6A, an inclined surface 1q is formed on the back side around the opening 1a of the shutter base plate 1 as is well known. , The formation area thereof is indicated by a broken line.

Each of the members shown in FIGS. 3B to 3I is mounted on the rear side of the shutter base plate 1 in the order of the figure numbers. Before explaining the specific mounting structure, FIG. An outline of the overall configuration will be described below. On the back side of the shutter base plate 1, an intermediate plate 18 (FIG. 3 (g)) and an auxiliary base plate 26 (FIG. 3 (i)) are attached at predetermined intervals, respectively. A space area between the intermediate plate 18 and the intermediate plate 18 becomes a blade chamber of the front blade group 9 (FIG. 3C).
The space between the auxiliary ground plate 26 and the rear blade group 19 is
(H)). The intermediate plate 18 and the auxiliary base plate 26 are also formed with openings 18a and 26a at substantially the center, and these openings 18a and 26a are normally formed by combining the openings 18a and 26a with the openings 1a of the shutter base plate 1. Although a rectangular exposure opening as a unit is formed, in this embodiment, the opening 1a regulates the shape of the exposure opening.

Now, the shaft 1m of the shutter base plate 1,
1n, the holding plate 7 for the front blade shown in FIG.
a, 7b are fitted and attached, and then the shaft 1m
The spacer 8 shown in FIG. The front blade holding plate 7 and the spacer 8 are both axially movable with respect to their respective axes. However, when the shutter base plate 1 is made of synthetic resin, such a configuration is such that the shape portions corresponding to the front blade holding plate 7 and the spacer 8 are formed integrally with the shutter base plate 1. No problem.

The front blade group 9 shown in FIG.
Basically, it is composed of two arms 10, 11 and four blades 12, 13, 14, 15 pivotally supported at one end thereof. The blades 12 are slit forming blades. As can be seen from FIG. 3D, the arms 10, 11 are provided on the shutter base plate 1 side, and the blades 12, 13, 14, 15 are provided on the rear side, that is, toward the intermediate plate 18 side. In order.

The arms 10 and 11 have holes 10a and 1
The arm 1 is pivotally connected to the shafts 1g and 1h of the shutter base plate 1, and the arm 10 has a long hole 10b. The operating pin of the leading blade driving member (not shown) fits into the hole 10b. Therefore, in FIG. 2, when the leading blade driving member rotates counterclockwise by a predetermined angle, the arm 10 is rotated counterclockwise, and the respective blades 12, 13, 14, 15 increase their overlap with each other. When the driving member for the leading blade rotates clockwise after reaching the superimposed state by operating upward, the blades 12, 13, 14, and 15 operate downward while reducing their overlap with each other, as shown in FIG. The deployment state will be reached.

Next, an auxiliary holding plate 16 shown in FIG. 3E is attached to the shafts 1m and 1n by fitting the holes 16a and 16b, and the shaft 1p is attached to the shafts 1m and 1n.
The ring-shaped cushioning member 17 made of butyl rubber shown in FIG.
Are fitted, and further, on their shafts 1m, 1n, 1p,
The intermediate plate 18 having the opening 18a shown in FIG.
Are attached by fitting the holes 18b, 18c, 18d. And, on the intermediate plate 18,
An overhang portion 18e supported by a part of an auxiliary base plate 26 described later.
Are formed in the opening 18a.
a ₁ is formed. The recess 18a _1, as is known, the vanes 22 of the slit formed in the rear blade group 19, without colliding to the edge surface of the opening portion 18a at the time of exposure operation, is intended to allow smooth travel.

The auxiliary holding plate 16 is provided with
The a ₁ in which is provided to cover the blade chamber side of the first blade group 9. Then, the role is, and for reinforcing the portion which became easily bent locally by forming the recess 18a _1, when not in use of the camera, the light that enters the light leakage is from the blade chamber side of the first blade groups 7 This is to prevent any entry into the blade chamber side of the rear blade group. Therefore,
The front blade group 9 includes the shutter base plate 1 and the intermediate plate 1 as a whole.
8, but in the case of this embodiment, strictly speaking, the blades 12, 13, 14, 1
The leading end of 5 (the right end in FIG. 3D) is disposed between the front blade holding plate 7 and the auxiliary holding plate 16 that sandwich the spacer 8. Incidentally, in the case of not forming the recess 18a ₁ to the intermediate plate 18 is not particularly necessary to provide an auxiliary holding plate 16.

As described above, in this embodiment, the spacer 8 is attached to the shaft 1 m between the front blade holding plate 7 and the auxiliary holding plate 16.
No special spacer is attached to n. In other words,
In the upper part of the opening 18a, the holding plate 8 for the leading blade is provided.
The distance between the support 1 and the auxiliary holding plate 16 is regulated by the spacer 8, and a predetermined dimension is ensured. However, the interval of the shaft 1n below the opening 18a is smaller than the above dimension. I am getting it. This is because the respective blades of the front blade group 9 are superimposed on each other, so that an interval of at least four blades is required in the optical axis direction above, but in the deployed state, the overlap of each blade is approximately two. This is because if the intervals are the same, the tips of the blades become particularly unstable.

Further, the cushioning member 1 fitted to the shaft 1p
Reference numeral 7 is such that when the blades of the front blade group 9 are superimposed upward during the exposure operation, the arm 10 comes into contact at the final stage of the operation. Thereby, the buffer member 17 functions to absorb the impact received from the arm 10 and prevent the front blade group 9 from bouncing. The cushioning member 17 has the opening 1 in the same manner as the spacer 8 described above.
8a, the shutter base plate 1 and the intermediate plate 18
It also serves to secure the interval between them.

On the back side of the intermediate plate 18, a rear blade group 19 shown in FIG. After this, the feather group 19
It has a configuration similar to that of the above-mentioned front blade group 9, and has two arms 20, 21 and, as can be clearly seen from FIG. 5, four arms each having one end pivotally supported by the arms 20, 21. The blades 22, 23, 24, and 25 are configured such that the blades 22 pivotally supported at the leading ends of the arms 20 and 21 are slit forming blades. The arms 20 and 21 are provided on the auxiliary base plate 26 side, and the blades 22, 23, 24 and 25 are arranged in the order of the intermediate plate 18 side.

The arms 20 and 21 have holes 20a and 2
The arm 1a is pivotally connected to the shafts 1i and 1j of the shutter base plate 1, and a long hole 20b is formed in the arm 20. An operating pin of a rear blade driving member (not shown) is fitted into the hole 20b. When the rear blade driving member rotates counterclockwise by a predetermined angle in FIG. Is also rotated in the counterclockwise direction, and the respective blades 22, 23, 24, 25 operate upward to reach the deployed state while minimizing the mutual overlap. Thereafter, when the rear blade driving member rotates clockwise, the blades 22, 23, 24, and 25 operate downward while increasing the overlap, and return to the superimposed state shown in FIG. I have.

The rearmost side of the shutter base plate 1 is shown in FIG.
The auxiliary base plate 26 made of synthetic resin shown in (i) is attached. The shape of each part of the auxiliary base plate 26 will be described with reference to the enlarged plan view shown in FIG. First, the auxiliary base plate 26 is attached according to a well-known attachment method. Therefore, although the specific shapes of the shafts 1m, 1n, 1p necessary for the attachment are not shown, an annular groove is formed on the circumferential surface near the tip of the shafts 1m, 1n, and A hole into which a tapping screw is screwed in the axial direction is formed in the tip end surface. At the time of attachment, the claw portion 26u formed on the auxiliary base plate 26
Is inserted into the long hole 1f, the large hole portions of the gourd-shaped holes 26b and 26c are inserted into the distal ends of the shafts 1m and 1n, and then the auxiliary base plate 26 is moved to the left, so that the holes 26b , 26c are fitted into the above-mentioned annular grooves. After that, a tapping screw is passed through the hole 26d, and screwed into the hole formed on the shaft 1p to be fixed.

As is well known, an inclined surface 26e is formed on the periphery of the opening 26a on the blade chamber side. This is because if the edge of the opening 26a is formed on an end surface perpendicular to the plate surface of the auxiliary base plate 26, light incident into the shutter unit will be reflected toward the film when the light hits the end surface. However, when the inclined surface 26e is formed as in the present embodiment, the area of the end surface can be reduced. In FIG. 4, two cylindrical portions 26f and 26g, two receiving portions 26h and 26i, and two arc-shaped grooves 26j and 26k are formed at left lateral positions of the opening 26a.

Of the two cylindrical portions 26f and 26g,
The ends of the shafts 1h and 1j of the shutter base plate 1 are fitted, and the height of the arms 11 and 21 relative to the plate surface of the auxiliary base plate 26 (position control in the optical axis direction) is controlled by the annular front end surface.
It is carried out. Also, the two receiving portions 26h and 26i are:
The shutter base plate 1 protrudes toward the distal end surfaces of the shafts 1g and 1i, and the top surface regulates the height of the arms 10 and 20. Further, the two arc-shaped grooves 26j and 26k do not penetrate and are formed so as to overlap with the arc-shaped holes 1c and 1d formed in the shutter base plate 1, and the operation of each of the driving members described above is formed there. The tip of the pin is inserted.
For this reason, the fitting between the holes 10b and 20b of the arms 10 and 20 and the respective operation pins is prevented. Further, conventionally, since the grooves 26j and 26k are through holes, the grooves 26j and 26k serve as a light path to the back side. However, according to this embodiment,
That route will be completely blocked.

At the right side of the opening 26a, a thick part 26m thicker than the reference plane on the front side of the auxiliary base plate 26 is formed. Holes 26b and 26c are formed. Also,
In the vicinity of the hole 26c, a further thickened spacer 26 is provided.
n is formed. The thick portion 26m has the same function as the front blade holding plate 7 in the blade chamber of the front blade group 9. That is, since the arms 20 and 21 are not arranged in the region where the thick portion 26m is formed, at least the space corresponding to the thickness of the arm is filled, and the blades 22, 23, 24 and 25 in the unfolded state are brought into close contact with each other. In addition to improving the performance, the operation of the rear blade group 19 is stabilized. The spacer 26n has the same function as the spacer 8, and secures a space in the optical axis direction when the blades 22, 23, 24, and 25 overlap. Therefore, the thick portion 26m and the spacer portion 26n may be manufactured as separate parts and separately attached to the shafts 1m and 1n.

The upper surface of the thick portion 26m has two inclined surfaces 26 toward the reference surface of the auxiliary base plate 26.
p and 26q are formed, and an inclined surface 26r is formed from the position between them to the opening 26a. A receiving portion 26s raised from the left-right direction by the inclined surface is formed at a substantially central portion of the inclined surface 26p, and the intermediate plate 18 is received by a substantially square top surface.

A plurality of light-shielding walls having different heights toward the shutter base plate 1 are formed in the peripheral portion of the auxiliary base plate 26 in order to close the space between the auxiliary base plate 26 and the shutter base plate 1. First, the light shielding wall 26t formed from the upper left to the lower left in FIG.
The top surface so as to contact the back of the shutter base plate 1, three inclined surfaces 26t _1, 26t _2, 26t ₃ is formed on the inner surface. As can be seen from the cross-sectional view shown in FIG. 6A, the shapes of these inclined surfaces are formed such that the distance from the optical axis center line gradually increases from the auxiliary base plate 26 toward the shutter base plate 1. Have been. Also, the light shielding wall 26t
The property has a missing portion 26t ₄ on the lower left side position in FIG. 4, where is adapted to receive the projecting portion 18e of the intermediate plate 18 as described above.

A light-shielding wall 26v is formed in a peripheral portion above the auxiliary base plate 26, a light-shielding wall 26w is formed in a right peripheral portion, and a light-shielding wall 26x is formed in a lower peripheral portion, respectively. inner surface is formed as an inclined surface _{26v 1, 26w 1, 26x 1} , has a top surface so as to contact the back of the shutter base plate 1. Then, the inclined surfaces 26v _1, 26w _1, 2
6x ₁ are all the distance from the optical axis center line is formed so as to gradually increase from the auxiliary base plate 26 in the shutter base plate 1.

Furthermore, the light shielding walls 26v, 26
Walls 26y and 26z are formed outside x. The heights of the walls 26y and 26z toward the shutter base plate 1 are higher than the heights of the light shielding walls 26t, 26v, 26w, and 26x, and the inner surface is formed perpendicular to the plate surface of the auxiliary base plate 26. . Therefore, as can be seen from FIG. 1, the upper end surface and the lower end surface of the shutter base plate 1 are arranged to face the inner surfaces of the walls 26y and 26z. In addition, a portion of the inner surface of the wall 26y facing the blade chamber of the front blade group 9 includes:
As shown in FIG. 2, cushioning members 27 and 28 made of cubic rubber and having a rectangular parallelepiped shape are adhered to each other. As shown in FIG.
5 comes into contact.

As can be seen from the above description of the structure, the basic structure of this type of shutter is such that the shutter base plate 1 disposed on the lens side when assembled to the camera and the auxiliary base plate 26 disposed on the film side. The space is partitioned by an intermediate plate 18 to form two blade chambers, and each blade chamber has a leading blade group 9.
And the rear blade group 19 are arranged, and the opening / closing drive mechanism is attached to the front side of the shutter base plate 1 (the lens side of the camera) at a position lateral to the exposure opening.
In such a configuration, since the opening / closing drive mechanism needs to operate both the front blade group 9 and the rear blade group 19, the rear blade group 19 arranged in the blade chamber on the auxiliary main plate 26 side.
We need to be able to get an interlocking relationship with them. Therefore, the two ground plates 1 and 26 can have substantially the same planar shape, but the intermediate plate 18 cannot have the same size.

Each drawing in FIG. 3 is drawn at the same magnification, but as can be seen from the comparison of FIGS. 3 (a), 3 (g) and 3 (i), the shutter base plate 1 and the auxiliary The left side of the openings 1a, 26a is substantially the same as the main plate 26, but the intermediate plate 18 is about half the size. This is because the operation pin of the rear blade drive member can be fitted into the hole 20b of the arm 20 and does not affect the operation of the operation pin. Further, in order to reliably maintain the fitting relationship between the operating pin of the leading blade drive member and the hole 10 b of the arm 10, the tip of the operating pin extends rearward from the surface of the intermediate plate 18. However, this is so as not to affect the operation of the operating pin.

The structural relationship between the ground plates 1 and 26 and the intermediate plate 18 is such that the driving source of each driving member is a spring.
The same applies to the motor, and the same applies when the leading blade group 9 is disposed in the blade chamber on the auxiliary base plate 26 side and the rear blade group 19 is disposed in the blade chamber on the shutter base plate 1 side. In addition, depending on the shutter, it is considered that the shafts (the shafts 1g and 1i in the present embodiment) on which the respective driving members are mounted are erected on the auxiliary base plate 26. This is the same as long as it protrudes toward the front surface side of the shutter base plate 1 and each drive member is attached thereto. Therefore, a common space area that cannot be separated by the intermediate plate 18 is formed at the side position of the exposure opening.

Next, the operation of this embodiment will be described. FIG. 2 shows the setting state of the shutter, and the arms 10 and 20 are shown.
Are rotated clockwise by operating pins of respective driving members (not shown). Therefore, the blades 12, 13, 14, and 15 of the front blade group 9 are in a developed state and cover the exposure opening, that is, the opening 1a, and the blades 22, 23, 24, and 25 of the rear blade group 19 are in a superimposed state. Opening 1
a, and is stored at a position below the opening 1a. In such a set state, when the shutter is released, the front blade drive member and the rear blade drive member rotatably mounted on the shafts 1g and 1i are sequentially rotated counterclockwise at a predetermined timing. Will do.

First, the exposure operation of the front blade group 9 operated by the front blade driving member will be described. When the leading blade drive member rotates counterclockwise about the shaft 1g, the arm 10 is rapidly rotated counterclockwise by the operating pin fitted in the hole 10b. Thereby, the blades 12, 13, 14, 15 of the front blade group 9 are operated upward to open the opening 1a. In this upward movement,
The blades 12, 13, 14, and 15 increase the amount of overlap with the adjacent blades, but when the opening 1a is opened, that is, when the lower edge (slit forming edge) of the blade 12 that is a slit forming blade is opened. Around the upper edge of the opening 1a,
The overlapping amount of each blade is almost maximum. Almost at the same time, the operating pin of the driving member for the leading blade is inserted into the arc-shaped hole 1.
c, which abuts on the cushioning member 2 attached to the upper end portion, and in which the arm 10 is
And the upper edges of the blades 12, 13, 14, 15 are attached to the auxiliary base plate 26.
, And the exposure operation of the front blade group 9 ends.

Next, the exposure operation of the rear blade group 19 operated by the rear blade driving member will be described. When a rear blade driving member (not shown) rotates counterclockwise about the shaft 1i, the arm 20 is rapidly rotated counterclockwise by the operating pin fitted in the hole 20b. As a result, the blades 22, 23, 24, 25 of the rear blade group 19 are operated upward to cover the opening 1a. In the process, each blade reduces the amount of overlap with the adjacent blade, but the upper edge (slit forming edge) of the blade 22 that is a slit forming blade passes through the upper edge of the opening 1a and the opening 1a is closed. Immediately after the cover is completely covered, the operating pin of the rear blade driving member comes into contact with the buffer member 3 attached to the upper end of the arc-shaped hole 1d, and the exposure operation of the rear blade group 19 is completed. This state is shown in FIG.

When the exposure operation is completed, the shutter is set in conjunction with the film winding. In the case of the present embodiment, as shown in FIG. 5, at the end of the exposure operation, the two blades 12, 22 serving as the slit forming blades are sufficiently overlapped with each other. The member and the rear blade drive member are simultaneously rotated clockwise, and the arms 10, 20 are rotated clockwise by the operating pins. Therefore, the blades 12, 1 of the front blade group 9
The blades 3, 14, 15 operate downward while reducing the mutual overlap, and the blades 22, 23, 24, 25 of the rear blade group 19 are arranged.
Operate downward while increasing their mutual overlap. Then, the blades 12, 13, 14, 15 of the front blade group 9 are in the deployed state and completely cover the opening 1a, and the blades 22, 23, 24, 25 of the rear blade group 19 are in the overlapping state, and the opening is 1
By being stored at a position below “a”, the set state shown in FIG. 2 is obtained.

When the photographing is completed in this manner, the shutter unit is left in this state for a long time, apart from the case where the photographing is continuously performed, during which the film is exposed by light leakage. Could be Further, in the case where the lens is replaced regardless of whether or not to continue shooting, when the lens is removed, the film may be exposed due to light leakage. The present embodiment is configured so that there is no need to worry about such a problem in a normal case, which will be described in detail below.

First, according to the present embodiment, light shielding walls 26t, 26v, 26w, 26x and walls 26y, 26z are formed around the auxiliary base plate 26. Therefore, there is no need to worry about light incident from between the peripheral portion of the shutter base plate 1 and the peripheral portion of the auxiliary base plate 26. For example, the projecting portion 18e of the intermediate plate 18 is provided on the light shielding wall 26t of the auxiliary base plate 26.
26t ₄ for receiving the light is formed, but even if there is such a gap, the light in the peripheral portion is not so strong due to the structure of the camera, so that even if light enters therefrom, it is almost ignored. be able to. However, if, in the case can not be ignored, closing the missing portion 26t _4, the receiving portion similar to the receiving portion 26s, may be formed at positions that do not affect the operation of the rear curtain group 19.

Also, depending on the design of the camera, a considerable measure against light leakage may be provided on the camera body side.
Therefore, depending on such measures, the light shielding walls 26t, 26t
It is not necessary to provide all of v, 26w, 26x and walls 26y, 26z as in the present embodiment, and there may be a case where each light shielding wall and a part of each wall may be omitted. The present invention covers all those cases.

Furthermore, this embodiment is effective against light that reaches the opening 1a from the lens direction, enters between the shutter base plate 1 and the front blade group 9, and travels in the blade chamber toward the periphery. It has a simple configuration. That is, in FIG. 2, most of the light traveling upward through the blade chambers of the front blade group 9 from the opening 1 a is reflected toward the shutter base plate 1 by the inclined surface 26 v ₁ of the light shielding wall 26 v, and It is difficult to enter the blade chamber. Similarly, from the opening 1a, by the inclined surface 26w ₁ of the light shielding wall 26w towards the blade chamber to the right of the first blade group 9, also, the inclined surface of the light downward light shielding wall 26x 26x ₁ As a result, the light heading leftward is further reduced by the inclined surfaces 26t ₁ , 26t ₂ , 2 of the light shielding wall 26t.
Due to 6t ₃ , each is reflected to the shutter base plate 1 side, and it is difficult to enter the blade chamber of the rear blade group 19.

Of the light traveling toward the respective peripheral portions in this manner, the light traveling leftward of the opening 1a does not reach the position near the light shielding wall 26t because the left end of the intermediate plate 18 does not reach the position near the light shielding wall 26t for the above-described reason. The light is reflected by the light shielding wall 26t, and is most likely to enter the blade chamber of the rear blade group 19. Thus, taking as an example the case of light traveling to the left of the opening 1a, how it is difficult to enter the blade chamber of the rear blade group 19 with reference to FIG. FIG.
The cross-sectional view of FIG. 2A is a partial cross-sectional view of FIG. 2 cut in a lateral direction at a position immediately above the shaft 1i, and omits members and parts that are not necessary for description. FIG. 6B shows FIG. 6 for comparison with the present embodiment.
It is sectional drawing of the conventional example shown similarly to (a),
For the sake of convenience, members and parts corresponding to the present embodiment are indicated by the same reference numerals as in the present embodiment, but with dashes ('). Symbols F and F 'are films.

As can be seen by comparing FIGS. 6A and 6B, the difference between the two is in the shape of the inner surfaces of the light shielding walls 26t and 26t '. Shape of the inner surface of this embodiment is formed as an inclined surface 26t _2, such as the distance from the optical axis center line toward the shutter base plate 1 disposed from the auxiliary base plate 26 disposed on the film F side toward the lens increases Have been. On the other hand, in the shape of the inner surface in the conventional example, the distance to the optical axis center line is constant from the auxiliary base plate 26 to the shutter base plate 1. That is, the inner shape of the light shielding wall 26t 'is
6 is formed so as to be perpendicular to the plate surface 26t ₂ ′.

Therefore, first, the case of the conventional example will be described. As described above, in the set state, the front blade group 9 covers the exposure opening. Although not shown, the front blade group 9 is disposed between the shutter base plate 1 'and the intermediate plate 18' in FIG. 6B, and the light passing through the opening 1a 'is directly It prevents entry into the sections 18a ', 26a'. At this time, since the rear blade group 19 (not shown) is in an overlapping state, it does not exist between the opening 18a 'and the opening 26a'. Therefore, what matters here is the light that has entered between the shutter base plate 1 'and the front blade group 9 (not shown) after passing through the opening 1a'.

In FIG. 6B, a typical light path which enters in this manner is indicated by a solid line, and is indicated by an arrow. Of course, in addition to this, there is also light traveling while repeating reflection between the shutter base plate 1 'and the front blade group 9 (not shown), but even such light is attenuated by reflection. As a whole, it will proceed along such a route. Thereafter, the light is reflected by the vertical surface 26t ₂ ′ and turns to the lower right. Opening 26 as described above
a 'is not covered by the rear blade group 19 not shown. For this reason, the light traveling in the lower right direction is transmitted to the intermediate plate 1
8 'and the auxiliary base plate 26', and pass through the opening 26a 'to reach the film F'.

As described above, some light does not travel linearly as shown by the solid arrow but travels while repeating reflection, but even such light is not divided by the intermediate plate 18 '. In this space, the number of reflections is small as a whole, so that light entering between the intermediate plate 18 'and the auxiliary base plate 26' is not effectively attenuated. for that reason,
Light summed with the above-mentioned light becomes a factor for exposing the film F '. As described above, the light that causes the film to be exposed is not limited to such light. For example, light that enters from between the blades of the leading blade group 9 cannot actually be completely shielded, and minute light enters. This is because the exposure of the film F 'is performed by the amount of all the light.

In the case of the present embodiment, the entering light can be effectively attenuated as compared with such a conventional example. As shown in FIG. 6A, the same applies to the present embodiment until the light enters from the opening 1a into the common space not partitioned by the intermediate plate 18.
However, the light is reflected on the inclined surface 26t _{2 of the} light shielding wall 26t.
Thus, the light is reflected toward the shutter base plate 1. Therefore, the light that has reached the inner surface of the light shielding wall 26t is intentionally reflected repeatedly in the common space. Therefore,
No light is linearly reflected from the inner surface of the light shielding wall 26t to the film F surface. Also, of course, the light that reaches the inner surface of the light-shielding wall 26t after being reflected several times,
The number of subsequent reflections is larger than in the past. As a result, light entering between the intermediate plate 18 and the auxiliary ground plate 26 is greatly attenuated.

Incidentally, in this embodiment, the inclined surface 2
6t ₂ not only all of the inclined surface is formed such that the distance from the optical axis center line increases toward the auxiliary base plate 26 in the shutter base plate 1. However, the inclined surfaces 26t ₁ , 26t ₂ , 26t ₃ formed on the light shielding wall 26t are reversely inclined so that the distance from the optical axis center line from the auxiliary base plate 26 to the shutter base plate 1 becomes smaller. Even if formed, substantially the same effect can be obtained. However,
If formed in this way, even if the auxiliary base plate 26 is made of metal or synthetic resin as in this embodiment, the production is troublesome and the cost is increased. For the other inclined surfaces, light is guided to the blade chamber on the auxiliary base plate 26 side, so that it is problematic to make the inclined surfaces reverse. Further, when the inclination angle θ shown in FIG. 6A was examined for several types of shutters produced so far, it was found that the inclination angle was approximately 30 to 60.
Degrees have been found to be preferred.

In this embodiment, when the exposure operation is completed,
The case where the shutter is immediately set in conjunction with the film winding has been described. However, in rare cases, depending on the specifications of the camera, it may not be set immediately but set before shooting. Although the shutter of the present embodiment has an inferior light-shielding effect even when mounted on such a camera, the shutter has a better light-shielding effect than when the conventional shutter is mounted on a camera of the same specification. It will be. Therefore, the leading blade group 9 in this embodiment is disposed in the blade chamber between the intermediate plate 18 and the auxiliary base plate 26, and when the exposure operation is completed, the leading blade group 9 is set immediately in association with the winding of the film. However, even if it is used, a certain effect can be obtained.

Next, the second embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described. The first embodiment is different from the first embodiment only in the shape of the auxiliary base plate 26 described above.
The operation as the shutter is the same even if the shape of the auxiliary base plate 26 is different. Therefore, the configuration and operation other than the auxiliary base plate 26 will be described in the first embodiment.
The same applies to the present embodiment. Further, the effects of the light-shielding wall mainly described with reference to FIG. 6 and those described in relation thereto are also applicable to the present embodiment, and thus description thereof is omitted.

Therefore, the shape of the auxiliary base plate in this embodiment will be described with reference to FIG.
To make it easier to understand the difference from the auxiliary base plate 26 in the embodiment, the reference numeral 26 is used for the auxiliary base plate, and the same parts as those of the auxiliary base plate 26 in the first embodiment are denoted by the same reference numerals. Therefore, in principle, the shape and the operation and effect will be described only for different portions.

Although the auxiliary base plate 26 in this embodiment is also made of synthetic resin, the shape of the front side in FIG. 7 is considerably more complicated than the auxiliary base plate 26 of the first embodiment. Therefore, the reference surface is provided with dots. Accordingly, the bottom surfaces of the arc-shaped grooves 26j and 26k are located behind the reference surface, and the inclined surface 26e is gradually inclined from the reference surface to the rear side.
Although a part of the inclined surface 26r is also formed on the back side of the reference surface, the other surface is located higher than the reference surface, that is, higher on the surface side in FIG. 7 (hereinafter, the reference surface in this direction). Distance is simply referred to as height).

First, in this embodiment, the opening 26a
Of the light shielding wall 26v in the upper position, the inclined surface 26v ₁ is not formed in the first embodiment. Instead, a receiving portion 26A is formed. The height of the receiving portion 26A is the same as the height of the receiving portion 26s, and the receiving portion 26s
And the intermediate plate 18. The plate surface on which the receiving portion 26A is formed is hatched, but other surfaces having the same height are similarly hatched. Then, the receiving portions 26h, 26 described in the first embodiment.
The height of i is formed at an intermediate height between this height and the reference plane.

[0063] From the above receiving section 26A, the inclined surface 26A ₁ toward the reference plane on the left side is formed. Also,
Inclined surfaces 26A ₂ so as to surround the well receiving portion 26A to the other three sides are formed. Then, in the assembled state, the intermediate plate 18 have been bent slightly in the direction in contact with the inclined surface 26A ₁ formed toward the left, that is because the present invention and are not directly related description Is omitted.

[0064] On the other hand, the inclined surface 26A ₂ are primarily intended to reflect light from the two directions, it is less likely to affect the film surface. That is, a part of the light that enters the opening 1a of the shutter base plate 1, is reflected by the light shielding wall 26v, bypasses the end surface of the intermediate plate 18, and travels the blade chamber of the rear blade group 19 toward the opening 26a. It will be reflected to the intermediate plate 18 direction by the inclined surface 26A _2. Therefore, even if a part of them reaches the film surface from the opening 26a after the traveling direction is changed and the reflection is repeated, it is greatly attenuated at that time, so that there is no problem. Has become.

The other is effective for light entering the blade chamber of the rear blade group 19 and near the opening 26a. As mentioned above, light enters from everywhere. Further, it is impossible to completely shield them from light. Therefore, although the light is attenuated by repeating the reflection, some light inevitably enters the vicinity of the opening 26a. These lights have different traveling directions. Therefore, in order to prevent a part of the light from traveling to the film surface at all, an inclined surface 26e is formed, and the area of the end surface of the opening 26a is reduced to reduce reflection on the film surface. In addition, the light is reflected by the inclined surface 26e in a direction slightly away from the opening 26a. Also in this embodiment,
The inclined surface 26A ₂ are therewith be adapted to the similar role, 7, the light traveling upward from the side of the opening 26a, not reflected so as to enter the openings 26a, The light is reflected toward the intermediate plate 18.

A receiving portion 26B and four thick portions 26C, 26D, 26E, 26 are located on the left side of the opening 26a.
F is formed. Among them, the height of the receiving portion 26B receives portions 26A of slightly lower than the height, the inclined surface 26B ₁ extending to the reference plane so as to be along the grooves 26j are formed. The receiving portion 26B and the inclined surface 26B ₁
Has a vertical surface on the left and an opening 26a on the right.
Inclined surfaces 26B ₂ toward formed. The receiving portion 26B be adapted to receive the intermediate plate 18, the inclined surface 26B ₁ is formed with the same purpose as the inclined surface 26A _1. Further, the inclined surface 26B _2, the opening 2 as described above
This is for reflecting the light traveling from the side 6a toward the intermediate plate 18 without reflecting it so as to enter the opening 26a.

Four thick portions 26C, 26D, 26E, 2
The height of 6F is the same, higher than the hatched surface
In addition, it is formed lower than the height of the receiving portion 26B. Minute
To make it easier to illuminate,
There are multiple crosses. And these thick portions 26
The left side of C, 26D, 26E, 26F is a vertical plane
The right side has an inclined surface 26C facing the opening 26a.₁,
26D₁, 26E₁, 26F₁Are formed. Soshi
And those inclined surfaces 26C₁, 26D₁, 26E ₁, 2
6F₁Proceeds from the opening 26a as described above.
The incoming light is reflected so as to enter the opening 26a.
Not to reflect the light toward the intermediate plate 18.
It is.

The thus formed inclined surface 26A
_{2, 26B 2, 26C 1,} 26D 1, 26E 1, 26F
Angle of inclination of ₁ is also the same as such inclined surface 26t _2, is preferably substantially 30 to 60 degrees to the optical axis center line.
Further, in the present embodiment, when the left side is viewed from the opening 26a, the above-described receiving portion 26B, the inclined surface 26B ₁ , and the four thick portions 26C, 26D, 26E, 26F form at least a part thereof. By overlapping, they are arranged as if they are continuous. The surfaces facing the light shielding wall 26t are all vertical surfaces. Therefore, these vertical planes repeatedly reflect between the two ground plates 1 and 26 as described with reference to FIG. 6A, and block most light entering between the intermediate plate 18 and the auxiliary ground plate 26. It is supposed to.

The plurality of thick portions 26C, 26D, 26
By arranging the E and 26F in this manner, the posture of the rear blade group 19 is maintained well, and the operation is performed without any trouble. That is, FIG. 8 is a drawing in which the rear blade group 19 is overlaid on the auxiliary base plate 26 shown in FIG. 7, and shows a shutter set state. FIG. 9 shows a state immediately after the end of the exposure operation. As can be seen from these figures, the arms 20, 21 of the rear blade group 19 are always in any of the thick portions 26C, 26D, 26E, 26F regardless of the state, that is, during operation. The arms 20 and 21 are attached to the auxiliary base plate 2
It is difficult to bend to the 6 side. Therefore, in the state shown in FIG. 9, the adhesion of the overlapped portions of the blades 22, 23, 24, 25 is maintained, the operation can be performed stably, and the entire rear blade group 19 due to the impact at the end of the exposure operation is complicated. It is possible to suppress undesired movement.

In the present embodiment, the cylindrical portions 26f, 2
A wall 26G of an appropriate height is formed so as to surround 6 g. Since the hollow holes of the cylindrical portions 26 f and 26 g pass through the auxiliary base plate 26, the light coming from the hollow hole is used by the arm 11. , 21 are provided for safety so as to prevent the light from being reflected toward the opening 26a. Therefore, such a wall 26G is not always necessary. In particular, when the hollow hole is a blind hole, it is completely unnecessary. In this embodiment, the inclined surfaces 26C ₁ and 26D
₁ and 26F ₁ are also formed on the left side so as to go around the lower portion of the thick portions 26C and 26D and the upper portion of the thick portion 26F, respectively, but this portion reflects light. However, this is not the main purpose, but is to enable the end faces of the arms 11 and 21 to operate smoothly without collision during operation.

[0071]

As described above, according to the present invention, in a focal plane shutter for a camera in which two blades are partitioned by an intermediate plate to form two blade chambers, when mounted on the camera. On the main plate placed on the film side,
A light-shielding wall is provided so as to cover at least a part of a peripheral portion of the two ground plates, and an inner surface shape of the light-shielding wall is directed to an optical axis center line from the ground plate arranged on the film side to the ground plate arranged on the lens side. Since it is formed as an inclined surface so that the distance from the base plate becomes large, it is possible to block light that enters from the periphery of the two base plates, and furthermore, it is possible to mainly open the base plate located on the lens side. From the part, the light that has entered between the base plate and the blade group arranged in the blade chamber on the base plate side,
By reflecting the light from the inner surface of the light-shielding wall toward the ground plate disposed on the lens side, light entering between the intermediate plate and the ground plate disposed on the film side can be suppressed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a set state of a first embodiment of the present invention.

FIG. 2 is a plan view showing a perspective view with the opening / closing drive mechanism removed from FIG. 1;

FIG. 3 is a plan view of main components constituting FIG. 2, and FIG. 3 ( a)
3 to FIG. 3 (i).

FIG. 4 is an enlarged plan view of a second shutter base plate shown in FIG. 3 (i).

FIG. 5 is a plan view perspectively shown in the same manner as in FIG. 2, showing a state immediately after the end of the exposure operation.

6A and 6B are cross-sectional views of main parts for describing the operation and effect of the first embodiment, and FIG. 6A illustrates a case of the first embodiment;
(B) shows the case of the conventional example.

FIG. 7 is a plan view of a second shutter base plate used in the second embodiment of the present invention.

FIG. 8 is a perspective plan view showing a rear blade group in a set state superimposed on a second shutter base plate shown in FIG. 7;

FIG. 9 is a perspective plan view showing a rear blade group in a state immediately after the end of the exposure operation over the second shutter base plate shown in FIG. 7;

[Explanation of symbols]

1 Shutter base plate 1a, 18a, 26a Opening 1b, 1c, 1d, 1e, 1f, 7a, 7b, 10a,
10b, 11a, 18b, 18c, 18d, 20a, 2
0b, 21a, 26b, 26c, 26d holes 1g, 1h, 1i, 1j, 1k, 1m, 1n, 1p shaft 1q, 26e, 26p, 26q, 26r, 26t 1, 2
6t ₂ , 26t ₃ , 26v ₁ , 26w ₁ , 26x ₁ , 2
_{6A 1, 26A 2, 26B 1} , 26B 2, 26C 1, 2
6D ₁ , 26E ₁ , 26F ₁ Inclined surface 2, 3, 17, 27, 28 Buffer member 4 Screw 5 Support plate 6 Printed wiring board 7 Front blade holding plate 8 Spacer 9 Front blade group 10, 11, 20, 21 Arms 12, 13, 14, 15, 22, 23, 24, 25 Blade 16 Auxiliary holding plate 18 Intermediate plate 18a ₁ Recess 18e Overhang 19 Rear blade group 26 Auxiliary ground plate 26f, 26g Tube portion 26h, 26i, 26s, 26A , 26B receiving part 26j, 26k groove 26m, 26C, 26D, 26E, 26F thick part 26n spacer part 26t, 26v, 26w, 26x light shielding wall 26t ₄ missing part 26u claw part 26y, 26z, 26G wall

Claims (7)

[Claims] 1. Two base plates each having an opening formed therein and attached to each other with a predetermined space therebetween, wherein one of the base plates is arranged in the camera with one on the lens side and the other on the film side; And an opening that forms a rectangular exposure opening together with the portion. The opening is formed between the two base plates, and at least a part of the exposure opening at a predetermined lateral position is left between the two base plates. An intermediate plate forming a blade chamber, a plurality of arms having one end pivotally attached at the predetermined lateral position, and a plurality of blades pivotally supported sequentially toward the other end thereof. At the time of exposure operation in one of the blade chambers, a front blade group which is operated to open the exposure opening, a plurality of arms having one end pivotally attached at the predetermined lateral position, and sequentially toward the other end thereof. Composed of pivoted blades And a rear blade group that is operated to close the exposure opening at the time of exposure operation in the other blade chamber, and the base plate disposed on the film side has at least a part of a peripheral portion thereof with the lens. A light-shielding wall that blocks between the ground plate arranged on the side is formed,
An inner surface of the light-shielding wall is formed as an inclined surface such that a distance from an optical axis center line increases toward a ground plate disposed on the lens side from a ground plate disposed on the film side. Focal plane shutter for cameras. 2. The focal plane shutter for a camera according to claim 1, wherein the light shielding wall is formed at least in a peripheral portion in a direction of the predetermined lateral position when viewed from the exposure opening side. . 3. The focal plane shutter for a camera according to claim 1, wherein an angle of the inclined surface formed on the light shielding wall is approximately 30 to 60 degrees with respect to an optical axis center line. . 4. The base plate arranged on the film side includes:
4. The device according to claim 1, wherein at least one thick portion protruding toward the ground plate disposed on the lens side is formed between the opening of the ground plate and the light shielding wall. A focal plane shutter for a camera according to any one of the above. 5. A method according to claim 5, wherein a plurality of said thick portions are formed at said predetermined lateral position, and are arranged such that at least a part thereof overlaps when viewed from said exposure opening side. The focal plane shutter for a camera according to claim 4, wherein 6. A method according to claim 1, wherein the thick portion has a surface on the side of the exposure opening.
The inclined surface is formed such that a distance from an optical axis center line gradually increases from a ground plane disposed on the film side to a ground plane disposed on the lens side. 6. The focal plane shutter for a camera according to 5. 7. The method according to claim 4, wherein an angle of the inclined surface formed in the thick portion is approximately 30 to 60 degrees with respect to an optical axis center line. Focal plane shutter for camera.