JP2010008647A - Focal-plane shutter for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a focal-plane shutter for camera provided with a brake mechanism capable of adjusting braking force of a driving member by a braking member finely and easily and having a very simple configuration. <P>SOLUTION: In this focal-plane shutter for camera, the braking member 4 rotated by a driving pin 2b at the end of operation of the driving member 2 for front blade to give braking force to the rotation of the driving member 2 for front blade is rotatably attached to a shaft 1f erected on a shutter blade 1. In addition, an annular member 5, a plain washer 7, a plate spring 8, a compression spring 9, and a nut member 11 are attached to the shaft 1f in this order, and the force for letting the plate spring 8 and the compression spring 9 press the annular member 5 against the braking member 4 can be adjusted by rotating the nut member 11. Although a tortion coil spring 10 is fitted into an outer side of a cylindrical member 6 fitted into the annular member 5 to energize the braking member 4 in the direction of rotation, the compression spring 9 is arranged between the shaft 1f and the cylindrical member 6 to prevent these two members from interfering with each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a focal plane shutter for a camera.

  Recent focal plane shutters include those with two shutter blades, which are referred to as the front blade and the rear blade, and those with only one shutter blade. These shutter blades are arranged between two ground plates called a shutter ground plate and an auxiliary ground plate. The former type can be used for both a camera using a film and a digital camera, while the latter type is used only for a digital camera.

  In any of the above types, the basic configuration of each shutter blade is the same, and two (some rarely three) arms having one end pivotally attached to the shutter base plate, and their arms. It consists of multiple blades (also known as a special case) that are pivotally supported in order toward the free end, which is the other end, and each blade is operated in the vertical direction of the camera. The exposure opening is opened and closed.

  Among them, those equipped with two shutter blades are composed of two blade chambers by partitioning the two ground plates with an intermediate plate so that they do not interfere with each other in operation. Normally, when configured as described in, for example, Japanese Patent Application Laid-Open No. 11-326992, an intermediate plate may not be provided in the same manner as that having one shutter blade.

  In addition, these focal plane shutters have a drive member for reciprocating the shutter blades rotatably mounted outside the blade chamber of the shutter base plate, and a drive pin provided on the drive member is inserted into the blade chamber. It is fitted in a hole provided in one of the arms constituting the shutter blade. The driving member is rotated by an urging force of the driving spring at the time of photographing, and is rotated against the urging force of the driving spring by a setting member using a motor as a driving source at the time of setting operation. ing. However, recently, there has been known one that is not provided with such a drive spring and is rotated by a motor even during photographing.

  The shutter blade of such a focal plane shutter is operated at a very high speed during photographing, and is stopped by abutting against the stopper at the end of the operation. However, if no measures are taken, the shutter blade abuts against the stopper. Due to the impact, the shutter blades are destroyed or greatly bounced. And when it bounces greatly, in the case of the shutter blade that opened the exposure aperture by the operation at the time of shooting, it would temporarily cover a part of the exposure aperture, and the shutter blade that closed the exposure aperture In this case, there arises a disadvantage that a part of the exposure opening is temporarily opened.

  Therefore, in order to prevent such inconvenience, conventionally, a braking force is applied to the operation of the shutter blades at the operation end stage during photographing. And the method of giving the braking force includes a method of giving directly to the driving member, a method of giving directly to the arm, and a method of giving directly to the blade. However, in practice, a plurality of them are often used together.

  Of these braking methods, a brake member (generally referred to as a brake lever) is rotatably attached to the shutter base plate so that a braking force is directly applied to the rotation of the drive member. At the end of the operation, the drive pin of the drive member comes into contact with the brake member, and the drive member itself is braked by rotating the brake member overcoming the frictional force applied by the leaf spring. There is something that was made. An example of such a configuration is described in the following Patent Document 1. The present invention relates to a focal plane shutter for a camera provided with a brake mechanism having this type of configuration.

JP-A-8-110546

  By the way, the brake mechanism as described above can adjust the braking force, that is, the pressing force of the leaf spring against the brake member at the time of manufacture. Therefore, in the brake mechanism described in Patent Document 1, a brake member, a leaf spring, and a cylindrical member are attached to the same shaft erected on the shutter base plate from the shutter base plate side, and the tip of the shaft is attached. By rotating the nut member attached to the side, the cylindrical member is moved in the axial direction, and the leaf spring is deformed so that the adjustment can be performed.

  However, in general, it is difficult to finely adjust the pressing force by the leaf spring as compared with the pressing force by the compression coil spring. Therefore, as described above, the plate spring is not deformed via the cylindrical member, but instead of the cylindrical member, a compression coil spring is fitted to the shaft, and the brake is applied by both the compression coil spring and the plate spring. If the member is biased, fine adjustment is facilitated. Moreover, in that case, if the predetermined pressing force against the brake member can be obtained only by the compression coil spring, the leaf spring is not necessary.

  However, in the case of this type of brake mechanism, when the drive member returns to the next shooting standby state together with the shutter blades after shooting, the brake member rotated by the drive pin at the time of shooting is also returned to the shooting standby state. It is necessary to keep. For this reason, in the configuration described in Patent Document 1, a return spring for return is hung on the brake member. The return spring is a torsion coil spring and is fitted on a shaft to which the brake member is attached. However, since this torsion coil spring is tensioned when the brake member is rotated by the drive pin, it also serves for the braking action of the drive member. For this reason, a configuration is also known in which the torsion coil spring is merely used as an auxiliary means for braking, and the brake member is returned by a driving member that returns to the photographing standby state.

  Therefore, in a configuration in which such a torsion coil spring is present, there is a problem that if the compression coil spring is to be fitted as described above, it interferes with the torsion coil spring. In order to avoid such interference, if both springs are to be fitted at different positions in the length direction of the shaft, the length of the shaft must be increased. There is a problem that the arrangement configuration with the member becomes troublesome.

  The present invention has been made to solve such problems, and the object of the present invention is to reduce the pressing force of the compression coil spring despite the provision of the torsion coil spring as described above. A camera focal having a brake mechanism with an extremely simple configuration that makes it possible to finely adjust the braking force of the drive member by the brake member by using the brake member to brake the drive member. It is to provide a plain shutter.

  In order to achieve the above object, a focal plane shutter for a camera according to the present invention includes a plurality of arms pivotally attached to a shutter base plate in a blade chamber and at least one blade pivotally supported by the arms. At least one shutter blade, and is rotatably attached to the shutter base plate outside the blade chamber. The drive pin is inserted into the blade chamber and connected to one of the arms, and is rotated reciprocally. At least one driving member that causes the shutter blade to open and close the exposure opening, and a shaft that is rotatably mounted on the shaft outside the blade chamber of the shutter base plate, and is rotated at the end of the operation of the driving member at the time of photographing. A brake member that is pushed by a drive pin and rotated from an initial position; an annular member that is fitted to the shaft; and the ring A tubular member fitted to the outer periphery of the member, and a part that is between the shaft and the inner peripheral surface of the tubular member, and is loosely fitted to the shaft, and is on the brake member side A compression coil spring that presses the annular member to apply a frictional force to the rotation of the brake member, and a loosely fitted outer periphery of the cylindrical member, with one end hooked on the brake member, and the drive pin A torsion coil spring that is tensioned by the rotation of the brake member, and a nut member that is screwed into a threaded portion formed at the tip of the shaft and can be rotated to change the degree of compression of the compression spring. And so on.

  In that case, a leaf spring may be attached to the shaft so as to be disposed between the annular member and the compression spring, or disposed between the annular member and the brake member. In this manner, a leaf spring may be attached to the shaft.

  When the leaf spring is not attached to the shaft, or the leaf spring is attached to the shaft between the annular member and the compression spring, the brake member and the annular member are configured as one component. Alternatively, the brake member, the annular member, and the cylindrical member may be configured as one component.

  Further, when a leaf spring is not attached to the shaft, or a leaf spring is attached to the shaft between the annular member and the compression spring, or between the annular member and the brake member, The brake member and the cylindrical member may be configured as one part, or the annular member and the cylindrical member may be configured as one part.

  In the present invention, the compression coil spring is disposed inside the cylindrical member, and the torsion coil spring is fitted to the outside of the cylindrical member, so that the braking force of the compression coil spring is used to brake the drive member by the brake member. Therefore, the configuration of the brake mechanism is extremely simple and the braking force by the brake member can be easily finely adjusted.

  The embodiment of the present invention will be described with reference to two illustrated examples. 1 and 2 are plan views of the first embodiment showing about half of the left side when viewed from the subject side in a state where the camera is incorporated in the camera, and FIG. 1 shows a shooting standby state. FIG. 2 shows a state immediately after the end of shooting. FIG. 3 is a cross-sectional view of the main part taken along line AA in FIG. 1 and viewed in the direction of the arrow. Further, FIG. 4 is a cross-sectional view of an essential part of the second embodiment shown in the same manner as FIG.

  The focal plane shutter of this embodiment has two shutter blades and can be used for both a silver salt camera and a digital camera. As is well known, in the focal plane shutter, the drive member is directly attracted and held by the electromagnet against the biasing force of the drive spring in the state immediately before the start of operation after the release. When the power is cut off, the holding force is lost and the operation starts, so-called direct type, and before the operation starts, the locking member resists the urging force of the drive spring. There is a so-called locking type in which a member that is locked and operates when the holding force of the electromagnet is lost starts operation by releasing the locking. The present invention can be applied to any of these types, but the present embodiment is configured as a locking type focal plane shutter.

  First, the configuration of this embodiment will be described. In FIG. 1, the shutter base plate 1 is formed with an opening 1 a having a rectangular shape that is horizontally long at a substantially central portion thereof. However, as described above, FIG. 1 shows only about half of the left side when the shutter is viewed from the subject side, and therefore only a part of the left side is shown for the opening 1a. Although not shown, the intermediate plate and the auxiliary ground plate are sequentially attached to the rear surface side of the shutter base plate 1 with a predetermined interval, as is well known, for example, in Japanese Patent Laid-Open No. 2000-267152. In this embodiment, a rear blade chamber is formed between the shutter base plate 1 and the intermediate plate, and a front blade chamber is formed between the intermediate plate and the auxiliary base plate. The intermediate plate and the auxiliary ground plate are also formed with openings having a shape similar to the opening 1a so as to overlap the opening 1a, and the exposure opening is regulated by one or more of them. However, in this embodiment, the description will be made assuming that the exposure opening is restricted only by the opening 1a.

  In FIG. 1, two arc-shaped long holes 1b and 1c are formed on the left side of the opening 1a. Usually, a buffer member having a substantially C-shaped planar shape is attached to the lower ends of the long holes 1b and 1c, but in the case of this embodiment, it is not attached. However, the focal plane shutter of the present invention may be installed in one direction even if such a buffer member is attached. Further, shafts 1d, 1e, 1f, 1g and spring hooking pins 1h, 1i are erected on the subject side surface of the shutter base plate 1. In addition to this, on the subject side surface of the shutter base plate 1, a shaft for attaching a known set member for rotation and a support plate for attaching a known electromagnet are attached in parallel to the shutter base plate 1. A plurality of shafts and the like are erected. However, they are not shown because they are not directly related to the present invention.

  A synthetic resin front blade drive member 2 is rotatably attached to the shaft 1d erected on the shutter base plate 1 and is rotated clockwise by a known front blade drive spring (not shown). It is biased to rotate to. The leading blade driving member 2 has a locked portion 2a, and has a driving pin 2b and a roller 2c on the shutter base plate 1 side. Among them, the drive pin 2b is composed of a large-diameter portion on the root side and a small-diameter portion on the tip side, and the large-diameter portion is in contact with the lower end of the long hole 1b. In the blade chamber, it is connected to the leading blade described later.

  Further, a synthetic resin rear blade drive member 3 is rotatably attached to the shaft 1e erected on the shutter base plate 1, and a known rear blade drive spring (not shown) It is biased to rotate clockwise. Similarly to the leading blade driving member 2, the trailing blade driving member 3 also has a locked portion 3a, and has a driving pin 3b and a roller 3c on the shutter base plate 1 side. The drive pin 3b is also composed of a large-diameter portion on the base side and a small-diameter portion on the tip side, like the drive pin 2b, and the large-diameter portion is in contact with the lower end of the long hole 1c. The small-diameter portion is connected to a rear blade described later in the blade chamber.

  As shown in FIG. 3, the shaft 1 f standing on the shutter base plate 1 is made of metal and is standing on the shutter base plate 1 by caulking, and has a cylindrical shaft portion. 1f-1 has a spacer portion 1f-2 on the shutter base plate 1 side, and has a screw portion 1f-3 on the tip side. A brake member 4, an annular member 5, a cylindrical member 6, a flat washer 7, a plate spring 8, a compression coil spring 9, a torsion coil spring 10, and a nut member 11 are attached to the shaft 1f.

  Among them, the brake member 4 is rotatably attached to the shaft portion 1 f-1 and has two driven portions 4 a and 4 b at the tip and middle as shown in FIG. 1. In addition, a spring hooking portion 4c is provided in the vicinity of the shaft portion 1f-1. In the present embodiment, the brake member 4 is made of metal, but can be made of synthetic resin.

  In the case of the present embodiment, the annular member 5 is made of synthetic resin and is rotatably attached to the shaft portion 1f-1. However, the annular member 5 may be made of metal. Moreover, you may manufacture this annular member 5 with the said brake member 4 as one component with the same material. Further, in the present embodiment, the annular member 5 is rotatably attached to the shaft portion 1f-1, but when the member is different from the brake member 4 as in the present embodiment, the annular member 5 is not necessarily rotatable. It does not have to be, and only needs to be fitted to the shaft portion 1f-1 so as to be movable in the axial direction.

  The cylindrical member 6 is rotatably fitted to the outer periphery of the annular member 5. In this embodiment, the cylindrical member 6 is made of synthetic resin, but may be made of metal. The cylindrical member 6 may be manufactured as one part with the same material as the annular member 5 or may be manufactured as one part with the same material as the brake member 4. Furthermore, you may manufacture the three of the brake member 4, the annular member 5, and the cylindrical member 6 as one component with the same material.

  As described above, the fact that at least two parts of the brake member 4, the annular member 5, and the cylindrical member 6 are manufactured as one part is also applicable to the second embodiment described below. .

  In addition, a flat washer 7, a leaf spring 8, and a compression coil spring 9 are sequentially attached to the shaft 1f. Of these, the flat washer 7 has an annular member 5 made of a synthetic resin. Since the leaf spring 8 is made of metal, it is attached and is not particularly required if the annular member 5 is made of metal. Even if the annular member 5 is made of synthetic resin, the synthetic resin material Depending on the type of surface treatment and surface treatment, this is not always necessary. Further, the plain washer 7 and the leaf spring 8 are disposed between the shaft portion 1f-1 of the shaft 1f and the inner peripheral surface of the cylindrical member 6, but the compression coil spring 9 is a part thereof. Are disposed between the shaft portion 1f-1 of the shaft 1f and the inner peripheral surface of the cylindrical member 6, and are loosely fitted to the shaft 1f.

  Furthermore, the torsion coil spring 10 is loosely fitted on the outer periphery of the cylindrical member 6, and one end is hung on the spring hooking portion 4 c of the brake member 4 and the other end is a spring hooking pin 1 h erected on the base plate 1. The brake member 4 is biased to rotate clockwise in FIG. Further, the nut member 11 screwed into the threaded portion 1f-3 of the shaft 1f uses the elasticity of the compression coil spring 9 and the leaf spring 8 to connect the annular member 5 to the brake member 4 via the plain washer 7. Thus, a frictional force is applied to the rotation of the brake member 4. The adjustment of the pressing force is performed by rotating the nut member 11. In the case of the present embodiment, the change of the pressing force with respect to the rotation amount of the nut member 11 is small due to the presence of the compression coil spring 9. Fine adjustment work is extremely easy.

  In the present embodiment, the leaf spring 8 is disposed between the flat washer 7 and the compression coil spring 9, but may be disposed between the brake member 4 and the annular member 5. However, as described above, when the brake member 4 and the annular member 5 are made as one component, or when the three members of the brake member 4, the annular member 5 and the cylindrical member 6 are made as one component, they are arranged as such. It is difficult to do.

  Next, a brake mechanism for the rear blade drive member 3 is attached to the shaft 1g erected on the shutter base plate 1, and the structure thereof is the brake mechanism for the front blade drive member 2 described above. Is substantially the same. Therefore, although detailed description using drawing is abbreviate | omitted, in FIG. 1, the brake member 12, the torsion coil spring 13, and the nut member 14 are shown. The brake member 12 has two driven portions 12a and 12b at the tip and the middle, and has a spring hooking portion 12c near the shaft 1g. Further, one end of the torsion coil spring 13 is hung on the spring hooking portion 12c of the brake member 12, and the other end is hung on the spring hooking pin 1i erected on the base plate 1, and the brake member 12 is rotated clockwise. It is energized to let you.

  Finally, the configuration of the leading blade and the trailing blade disposed on the back side of the shutter base plate 1 will be described. The configuration is exactly the same as a known configuration. Therefore, a brief description will be given. First, as described above, the leading blade is arranged between an intermediate plate (not shown) and an auxiliary ground plate, and one end of each of the leading blades is pivotally attached to two shafts erected on the shutter ground plate 1. 1, and five blades pivoted in turn toward the tips of the arms, in FIG. 1, the five blades 15, 16, 17, Only 18, 19 are shown. And among these, the blade | wing 19 is a slit formation blade | wing supported by the front-end | tip of two arms. Of the two arms, an arm pivoted on a shaft concentric with the shaft 1d is formed with a hole, and the tip of the drive pin 2b is fitted in the hole.

  On the other hand, the rear blade is arranged between the shutter base plate 1 and an intermediate plate (not shown) as described above. In this embodiment, the configuration is the same as that of the leading blade. As is well known, the leading blade is turned over, and one end of the two arms is pivotally attached to the shutter base plate 1. Therefore, in the case of the above-mentioned front blade, the two arms overlap the auxiliary base plate side with respect to the five blades 15 to 19, and thus cannot be visually observed in the state of FIG. 2, the two arms overlap on the shutter base plate 1 side with respect to the five blades. Therefore, in the state of FIG. 23, 24, 25 and 26 are visible. In the case of the rear blade, the blade 26 pivotally supported at the tips of the two arms 20 and 21 is a slit forming blade and is formed on the arm 20 pivotally attached to the shaft concentric with the shaft 1e. The tip of the drive pin 3b is fitted in the hole.

  Next, the operation of the present embodiment configured as described above will be described. FIG. 1 shows a shutter set state, that is, a photographing standby state. Therefore, the leading blade drive member 2 is locked to the locked portion 2a by a locking member (not shown), and is prevented from rotating clockwise by the biasing force of the leading blade drive spring (not shown). Yes. At this time, the five blades 15 to 19 of the leading blade are developed to cover the opening 1a. Further, the brake member 4 has a driven portion 4 a at the tip thereof in contact with the roller 2 c of the leading blade drive member 2. That is, a force that rotates in the clockwise direction by the torsion coil spring 10 acts on the brake member 4, but since the frictional force applied by the leaf spring 8 and the compression coil spring 9 is larger, this state is Maintained.

  On the other hand, the trailing blade drive member 3 is locked by the latching member (not shown) to be locked, and the clockwise rotation due to the biasing force of the trailing blade drive spring (not shown) is prevented. Yes. At this time, the five blades 22 to 26 of the rear blade are overlapped and stored at a position above the opening 1a. Moreover, the brake member 12 has the driven part 12a at the tip thereof in contact with the roller 3c of the rear blade drive member 3 for the same reason as in the case of the brake member 4 described above.

  When the release button of the camera is pressed during shooting, current is supplied to a well-known leading blade electromagnet and trailing blade electromagnet (not shown), and the leading blade iron member and trailing blade iron member (not shown) are held by suction. The Thereafter, the energization of the leading blade electromagnet is turned off first, and the energization of the trailing blade electromagnet is turned off after a predetermined time. As a result, the iron piece members adsorbed on the electromagnets are separated from the electromagnets by the biasing force of the springs, respectively, and the locking members are rotated to sequentially turn the leading blade driving member 2 and Unlock the rear blade drive member 3.

  As a result, the leading blade drive member 2 previously unlocked is rotated clockwise by the biasing force of a leading blade driving spring (not shown), and the leading blade is not shown by the driving pin 2b. Since the arm is rotated in the clockwise direction, the five blades 15 to 19 of the leading blade move downward while increasing the overlap between adjacent blades, and open the opening 1a from above. The roller 2c of the leading blade drive member 2 moves away from the driven portion 4a of the brake member 4, but the posture of the brake member 4 is not changed by the frictional force.

  On the other hand, after a predetermined time, the unlocked rear blade drive member 3 is rotated clockwise by the biasing force of the rear blade drive spring (not shown), and the arm 20 is rotated clockwise by the drive pin 3b. Since it rotates, the five blades 22 to 26 of the rear blades move downward while reducing the overlap between adjacent blades, and close the opening 1a from above. At this time, the roller 3c of the rear blade drive member 3 moves away from the driven portion 12a of the brake member 12, but the posture of the brake member 12 does not change as in the case of the brake member 4 described above. . After that, the imaging surface is exposed by a slit between the slit forming blade 19 of the leading blade and the slit forming blade 26 of the trailing blade.

  In this way, when the exposure operation is performed and it is at the end stage, first, the drive pin 2b of the leading blade drive member 2 is pressed against the pushed portion 4b of the brake member 4, The brake member 4 is rotated counterclockwise. At this time, the drive member 2 rotates the brake member 4 against the frictional force applied by the leaf spring 8 and the compression spring 9 and the rotational force applied by the torsion coil spring 10. Therefore, it brakes suitably, and it stops, when the drive pin 2b contact | abuts to the lower end of the long hole 1b. For this reason, the leading blade is not destroyed by the impact at the time of stopping, and it bounces greatly, and a part of the slit forming blade 19 is temporarily faced in the opening 1a, and one of the openings 1a. There is no such thing as covering the part. In this manner, the five blades 15 to 19 of the leading blade are overlapped, and are placed in a retracted state at a position below the opening 1a.

  On the other hand, the driving pin 3 b of the rear blade driving member 3 comes into contact with the driven portion 12 b of the brake member 12 after the leading blade driving member 2. As a result, the brake member 12 resists the frictional force applied by the leaf spring and the compression spring (not shown) and the rotational force applied by the torsion coil spring 13 as in the case of the brake member 4 described above. Thus, the rear blade driving member 3 is braked while being rotated counterclockwise. As a result, the rear blade drive member 3 is preferably stopped when the drive pin 3b contacts the lower end of the long hole 1c. Therefore, the rear blade does not break due to the impact at the time of stopping, and does not bounce greatly and the slit forming blade 26 does not temporarily open a part of the opening 1a. FIG. 2 shows a state in which the trailing blade driving member 3 is stopped in this manner. At this time, the five blades 22 to 26 of the trailing blade are deployed and completely cover the opening 1a. ing.

  In this way, when the exposure operation is completed, in the case of a silver salt camera, the set operation is started immediately. In the case of a digital camera, the set operation is started after imaging information is stored in the storage device. . The set operation is performed by rotating a known set member attached to the shutter base plate 1 from the initial position by a member on the camera body side. In this embodiment, the locking type focal plane is used. Since it is a shutter, a set member that directly rotates the leading blade drive member 2 and a set member that directly rotates the trailing blade drive member 3 are provided separately. And these set members start the setting operation | movement of each drive member at a different timing.

  Therefore, in the state of FIG. 2, one set member first starts rotating the leading blade driving member 2 counterclockwise against the biasing force of the leading blade driving spring (not shown) The five blades 15 to 19 of the leading blade stored in the lower position of the part 1a are operated upward while reducing the overlap between adjacent blades. At this time, because the brake member 4 cannot be rotated clockwise only by the urging force of the torsion coil spring 10 for the reason described above, the drive pin 2b is separated from the driven portion 4b. However, immediately after that, since the roller 2c of the leading blade drive member 2 presses the driven portion 4a, the brake member 4 is rotated clockwise thereafter.

  Thereafter, when the slit forming blade 19 having the largest operating amount of the leading blades overlaps with the slit forming blade 26 of the rear blade by a predetermined amount, the other set member serves as the rear blade driving member 3. It begins to rotate counterclockwise against the urging force of the trailing blade drive spring not shown. Accordingly, the five blades 22 to 26 of the rear blades that have covered the opening 1a are moved upward while increasing the overlap between the adjacent blades while maintaining the overlap between the slit forming blades 19 and 26 described above. It works. At this time, since the brake member 12 cannot be rotated clockwise only by the urging force of the torsion coil spring 13, the drive pin 3b is separated from the driven portion 12b, but immediately after that, the driven portion 12a is moved to the rear blade. It is pushed by the roller 3c of the driving member 3 and rotated clockwise.

  Then, when the five blades 22 to 26 of the rear blade are superimposed and stored in the upper position of the opening 1a, and the five blades 15 to 19 of the leading blade are deployed to cover the opening 1a, The locked portion 2a of the leading blade drive member 2 and the locked portion 3a of the trailing blade drive member 3 can be locked by respective locking members (not shown). Therefore, in this state, the two set members (not shown) are reversed and returned to their initial positions. Therefore, the leading blade driving member 2 and the trailing blade driving member 3 rotate slightly in the clockwise direction following this, but are stopped when the locked portions 2a and 3a are locked by the respective locking members. Be made. FIG. 1 shows a state in which the camera has returned to the next shooting standby state.

  In the present embodiment, the rotational force applied to the brake members 4 and 12 by the torsion coil springs 10 and 13 is based on the frictional force applied to the brake members 4 and 12 by the plate spring and the compression coil spring. However, in the present invention, the rotational force of the torsion coil springs 10 and 13 is increased, and the brake members 4 and 12 follow the drive pins 2b and 3b in the clockwise direction during the set operation. It may be rotated and stopped at a predetermined rotational position by each stopper.

  Next, Example 2 will be described with reference to FIG. In this embodiment, the leaf spring 8 is removed from the brake mechanism described in the first embodiment. Therefore, the symbols used in FIG. 3 are used as they are for the members and portions shown in FIG. Further, the operation of the brake mechanism of the present embodiment is substantially the same as that of the first embodiment. Therefore, description of the operation is omitted.

  The configuration of the present embodiment is different from the first embodiment in that the leaf spring 8 is not provided as described above. Therefore, the inherent spring pressure of the compression spring 9 is increased correspondingly, and the thickness of the annular member 5 is also increased. However, if the pressing force of the annular member 5 against the brake member 4 is obtained in substantially the same manner as in the first embodiment, the thickness of the annular member 5 is changed, or the number of turns and the thickness of the compression spring 9 are changed. Needless to say, it may be replaced.

  Even in this embodiment, since the driving member can be braked by the brake member by using the pressing force of the compression coil spring, the braking force is finely adjusted by the rotation of the nut member 11. It is easy. In addition, since the number of parts is smaller than in the case of the first embodiment, the assembling work is facilitated accordingly.

  Each of the above embodiments is based on the assumption that a focal plane shutter having two shutter blades is used, and the same brake mechanism is used for both the leading blade driving member 2 and the trailing blade driving member 3. However, even if the focal plane shutter of the present invention is provided with two shutter blades, it does not have to be configured as such, and may be adopted only for one drive member. Further, as described above, it goes without saying that the present invention can be applied to a focal plane shutter having only one shutter blade.

FIG. 3 is a plan view of the first embodiment showing approximately half of the left side when viewed from the subject side, and shows a shooting standby state. FIG. 2 is a plan view of the first embodiment shown in the same manner as FIG. 1 and shows a state immediately after the end of photographing. It is principal part sectional drawing cut | disconnected by the AA line of FIG. FIG. 4 is a cross-sectional view of a main part of Example 2 shown in the same manner as FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a Opening part 1b, 1c Long hole 1d-1g Shaft 1f-1 Shaft part 1f-2 Spacer part 1f-3 Screw part 1h, 1i Spring hook pin 2 Lead blade drive member 2a, 3a Locked part 2b, 3b Drive pin 2c, 3c Roller 3 Rear blade drive member 4, 12 Brake member 4a, 4b, 12a, 12b Non-pushing part 4c, 12c Spring hook part 5 Annular member 6 Cylindrical member 7 Plain washer 8 Leaf spring 9 Compression coil spring 10, 13 Torsion coil spring 11, 14 Nut member 15-19, 22-26 Blade 20, 21 Arm

Claims (7)

  At least one shutter blade composed of a plurality of arms pivotally attached to the shutter base plate in the blade chamber and at least one blade pivotally supported on the shutter base plate, and rotatable to the shutter base plate outside the blade chamber And at least one drive member that inserts a drive pin into the blade chamber and is connected to one of the arms and reciprocally rotates to cause the shutter blade to open and close the exposure opening, and A brake member that is rotatably attached to a shaft standing outside the blade chamber of the shutter base plate and is pushed by the drive pin and rotated from an initial position at the end of operation of the drive member at the time of photographing, and the shaft An annular member that is fitted, a cylindrical member that is fitted to the outer periphery of the annular member, and a part of the shaft and the cylindrical member A compression coil spring that is loosely fitted to the shaft so as to be between the peripheral surface and presses the annular member toward the brake member side to apply a frictional force to the rotation of the brake member; and the tubular member A torsion coil spring that is loosely fitted to the outer periphery of the brake shaft and has one end hooked on the brake member and tensioned by the rotation of the brake member by the drive pin, and a screw portion formed at the tip of the shaft. And a nut member capable of changing the degree of compression of the compression spring by being rotated, and a focal plane shutter for a camera.   The focal plane shutter for a camera according to claim 1, wherein a leaf spring is attached to the shaft so as to be disposed between the annular member and the compression spring.   The focal plane shutter for a camera according to claim 1, wherein a leaf spring is attached to the shaft so as to be disposed between the annular member and the brake member.   3. The focal plane shutter for a camera according to claim 1, wherein the brake member and the annular member are configured as one part and are rotatably attached to the shaft.   3. The camera focal according to claim 1, wherein the brake member, the annular member, and the cylindrical member are configured as one component and are rotatably attached to the shaft. Plane shutter.   The focal plane for a camera according to any one of claims 1 to 3, wherein the brake member and the cylindrical member are formed as one component and are rotatably attached to the shaft. Shutter.   4. The focal plane for a camera according to claim 1, wherein the annular member and the cylindrical member are configured as one part and are rotatably attached to the shaft. 5. Shutter.

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