JP2008250151A - Focal plane shutter for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a focal plane shutter for camera where a driving member is properly stopped upon completion of operation in photography, by increasing the contact area of an abutting surface formed by the driving member with a surface to be abutted against a buffer member mounted on a shutter plate. <P>SOLUTION: A driving member 6 for a front blade and a driving member 8 for a rear blade have abutting parts 6e, 8e with a shape raised in the direction opposite to the shutter plate 1. The buffer members 2, 3 are mounted on wall-like mounts 1d, 1e outside a blade chamber of the shutter plate 1. Each of the driving members 6, 8 is stopped, when the abutting parts 6e, 8e abut the buffer members 2, 3 upon completion of operation of photographing. However, both the abutment surfaces of the abutting parts 6e, 8e and the surfaces to be abutted against the buffer members 2, 3 are formed on a flat surface with a large area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a focal plane shutter for a camera having one or two shutter blades.

  In the focal plane shutter for a camera, two blade chambers are formed between three plate members called a shutter base plate, an intermediate plate, and an auxiliary base plate. Two shutter blades, each of which is referred to as `` I '', are arranged separately, and one shutter blade is arranged in the blade chamber formed between the shutter base plate and the auxiliary base plate. It has been. The former focal plane shutter can be adopted for both a silver salt film camera and a digital camera, while the latter focal plane shutter can be adopted only for a digital camera.

  In any of the focal plane shutters, the shutter blades have substantially the same configuration, and have a plurality of arms that are rotatably attached to the shutter base plate at one end in the length direction. And at least one blade.

  The shutter blade drive member is rotatably attached to the outer surface of the shutter base plate of the shutter base plate, and the drive pin is extended into the blade chamber from an arc-shaped long hole formed in the shutter base plate. It is fitted in a hole formed in one of the arms. When the driving member reciprocates, the shutter blades open and close the exposure opening. Further, the drive member is usually configured to be rotated by a biasing force of a drive spring to one side and to be rotated by a set member that is rotatably attached to the shutter base plate. Recently, however, it is also known to rotate in both directions by an electromagnetic actuator without using such a drive spring.

  In the focal plane shutter having such a configuration, the shutter blades are operated at high speed at the time of photographing, but at the end of the operation, the driving member and the shutter blades are brought into contact with the stopper and stopped. However, if it bounces greatly when it comes into contact with the stopper, it may cause uneven exposure or cause damage to the shutter blades.Therefore, a buffer member made of an elastic material such as butyl rubber is used at the stop position. Usually, the drive member and the shutter blade are brought into contact with the drive member and the shutter blade. The present invention relates to a configuration in which the drive member is brought into contact with the buffer member, and an example of such a case is described in Patent Document 1 below.

JP 2001-42387 A

  In the conventional configuration in which the drive member is brought into contact with the buffer member, a buffer member having a substantially C-shaped planar shape is attached to one end of the arc-shaped elongated hole formed in the shutter base plate, and the drive member is provided there. In general, the drive pins are brought into contact with each other. In many cases, the contact surface of the drive pin is a convex arc surface and the contact surface of the buffer member is a concave arc surface. However, the contact surface of the drive pin described in the drawing of Patent Document 1 is formed as a flat surface, and the buffer member is also generally C-shaped, but only the contacted surface is formed as a flat surface. Has been.

  By the way, as one method for obtaining a large buffer effect, there is a method of increasing the contact area between the drive pin and the buffer member. Moreover, the contact surface is preferably a surface that is substantially orthogonal to the operating direction of the drive pin. From this point of view, it is preferable that the contact surface of the drive pin and the contacted surface of the buffer member are both formed on a flat surface as described in the drawing of Patent Document 1. However, when a flat surface is formed on the drive pin, the size of the drive pin is naturally limited.

  The present invention has been made to solve such problems, and the object of the present invention is to cover the contact surface formed on the drive member and the buffer member attached to the base plate. To provide a focal plane shutter for a camera in which a contact area with a contact surface is increased so that a driving member can be suitably stopped at the end of an operation during photographing.

  In order to achieve the above object, the focal plane shutter for a camera of the present invention comprises at least one blade chamber between the two, and at least one arc-shaped elongated hole is formed in one of them. At least one of a plurality of base plates, a plurality of arms and at least one blade pivotally supported by the arms, wherein one end of the arms is rotatably attached to the one ground plate in the blade chamber. A shutter blade, a drive pin that passes through the long hole and is connected to one of the arms, and the drive pin has a predetermined length that is approximately equal to or longer than the width of the long hole on the opposite side of the substantially same position. At least one drive member that has a contact portion that stands upright at a height and forms a flat contact surface and is rotatably attached to the one base plate outside the blade chamber; Outside the blade chamber of one base plate, it is attached in the vicinity of one end of the long hole, and has a flat abutting surface formed at a predetermined height over a length substantially equal to or longer than the width of the long hole. And a buffer member in which the contact surface comes into contact with the contacted surface when the rotation of the drive member to one side is completed.

  In the focal plane shutter for a camera of the present invention, the drive member has a contact portion on the opposite side of the drive pin connected to the shutter blade, and at the end of operation at the time of shooting, the contact portion is Since it is made to contact the buffer member attached to the base plate outside the blade chamber, the contact surface of the contact portion of the drive member and the contacted surface of the buffer member can be made a large flat surface. There is an advantage that the bounce is suitably suppressed and stopped.

  Embodiments of the present invention will be described with reference to the illustrated examples. The present invention can be applied to a focal plane shutter having two shutter blades as well as a focal plane shutter having one shutter blade as described above. And applied to a focal plane shutter having two shutter blades called rear blades. Further, as described above, the focal plane shutter having two shutter blades can be used for both a silver salt film camera and a digital camera, but the embodiment will be described when it is applied to a digital camera. To do.

  The present embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing the left half of the state immediately after the end of the exposure operation when viewed from the subject side. FIG. 2 is a side view of the leading blade drive member as seen from the lower side of FIG. 1 so that the contact surface of the contact portion can be seen. 3 and 4 are plan views viewed in the same manner as in FIG. 1. FIG. 3 shows the set state, and FIG. 4 shows the state immediately before the start of the exposure operation. It is a thing.

  First, the configuration of this embodiment will be described mainly with reference to FIGS. The shutter base plate 1 has an opening 1a for a subject optical path in which a rectangle is horizontally long at a substantially central portion thereof, but FIG. 1 shows an approximately left half when viewed from the subject side. Only part of the part 1a is also shown. Although not shown in the figure because it is well known, in FIG. 1, an intermediate plate and an auxiliary ground plate are sequentially attached to the back side of the shutter base plate 1, that is, the solid-state imaging device side, with a predetermined interval, by appropriate means. The blade chamber of the leading blade is configured between the shutter base plate 1 and the intermediate plate, and the blade chamber of the trailing blade is configured between the intermediate plate and the auxiliary ground plate. And the opening part slightly larger than the opening part 1a is formed also in those intermediate | middle boards and auxiliary | assistant ground boards in the place which overlaps with the opening part 1a. Therefore, in the case of the present embodiment, the opening 1a regulates the exposure opening.

  In the shutter base plate 1, two large elongated holes 1b and 1c having a substantially arc shape are formed in a region on the left side of the opening 1a. Further, a wall-like shape formed on the subject side surface of the shutter base plate 1 at a position near the lower ends of the long holes 1b and 1c so as to have a predetermined height over a length longer than the width of the long holes 1b and 1c. Mounting portions 1d and 1e are formed, and buffer members 2 and 3 made of butyl rubber having a rectangular parallelepiped shape are attached to one wall surface thereof with an adhesive. Therefore, the surfaces of these buffer members 2 and 3 are apparently flat surfaces.

  The shaft 1f, 1g, 1h is erected on the subject side surface of the shutter base plate 1, and the shafts 1i, 1j, 1k, 1m are erected on the blade chamber side surface. The shaft 1f and the shaft 1i, and the shaft 1g and the shaft 1k are erected so as to be concentric with each other. In addition, a plurality of other shafts (not shown) are erected on the surface of the shutter base plate 1 on the subject side, and are shown so as to be parallel to the shutter base plate 1 at their tips. There are no known support plates attached. The support plate is provided with a leading blade electromagnet and a trailing blade electromagnet on the shutter base plate 1 side. In FIGS. 1, 3, and 4, the iron core member 4 of the leading blade electromagnet and Only the iron core member 5 of the electromagnet for the rear blade is shown by a two-dot chain line.

  A synthetic resin front blade drive member 6 is rotatably attached to the shaft 1f of the shutter base plate 1 and is urged to rotate clockwise by a known front blade drive spring (not shown). Has been. The leading blade driving member 6 is provided upright on the cylindrical portion 6a fitted on the shaft 1f, the driven portion 6b, the attachment portion 6c formed thick on the subject side, and the shutter base plate 1 side. The drive pin 6d and the contact portion 6e formed so as to stand up to the object side are inserted into the long hole 1b. Moreover, the cavity part is formed in the attaching part 6c, and the iron piece member 7 is attached there as well known. The iron piece member 7 includes a shaft portion 7a, an iron piece portion 7b fixed to one end thereof, and a flange portion 7c formed at the other end, and is fitted to the shaft portion 7a in the cavity. It is urged | biased by the compression spring which is not shown in figure so that the iron piece part 7b may protrude outside a cavity. Further, the contact portion 6e has a shape standing so as to have a predetermined height over a length longer than the width of the long hole 1b, and the surface on the buffer member 2 side is shown in FIG. The flat surface of the rectangle is such that the buffer member 2 can be contacted over the entire surface.

  A synthetic resin rear blade drive member 8 is rotatably attached to the shaft 1g of the shutter base plate 1 and is urged to rotate clockwise by a known rear blade drive spring (not shown). Has been. The rear blade drive member 8 includes a cylindrical portion 8a fitted to the shaft 1g, a roller 8b rotatably attached, a mounting portion 8c formed thick on the support plate 6 side, and a shutter base plate 1. It has a drive pin 8d erected on the side and a contact portion 8e formed so as to stand up toward the subject, and the drive pin 8d is inserted into the long hole 1c. Moreover, the cavity part is formed in the attaching part 8c, and the iron piece member 9 is attached there. And the iron piece member 9 consists of the axial part 9a, the iron piece part 9b, and the collar part 9c similarly to said iron piece member 7, The figure fitted to the axial part 9a in the cavity is shown. The iron piece 9b is urged out of the cavity by a non-compressed spring. Further, the abutting portion 8e has a shape standing up to a predetermined height over a length longer than the width of the long hole 1c, and the surface on the buffer member 3 side is Like 6e, it is a rectangular flat surface, and the entire surface thereof can come into contact with the buffer member 3.

  A synthetic resin set member 10 is rotatably attached to the shaft 1h of the shutter base plate 1 and is urged to rotate counterclockwise by a well-known return spring (not shown). FIG. 1 shows a state where the rotation is blocked by means not shown. Hereinafter, this position is referred to as an initial position. The set member 10 includes a pushing portion 10a that pushes the driven portion 6b of the leading blade driving member 6, a pushing portion 10b that pushes the roller 8b of the trailing blade driving member 8, and a camera (not shown). And a pushed portion 10c pushed by a member on the main body side.

  Finally, the configuration of the two shutter blades will be described. First, as described above, the leading blades arranged between the shutter base plate 1 and the intermediate plate (not shown) are two arms 11 and 12 and three pieces that are pivotally supported in order in the length direction thereof. The arms 11 and 12 are arranged on the shutter base plate 1 side of the blades 13, 14 and 15, and one end thereof is erected on the shutter base plate 1. The shafts 1i and 1j are attached so as to be rotatable. And the blade | wing 25 is a slit formation blade | wing, Comprising: The drive pin 6d of said drive member 6 for leading blades is fitting in the hole which is formed in the arm 11 and which is not illustrated.

  On the other hand, as described above, the rear blade disposed between the intermediate plate and the auxiliary ground plate (not shown) has two arms 16 and 17 and three pieces pivoted in order in the length direction thereof. The arms 16, 17 are arranged on the auxiliary base plate side of the blades 18, 19, 20, and one end thereof stands on the blade chamber side of the shutter base plate 1. The shafts 1k and 1m are provided so as to be rotatable. The blade 20 is a slit-forming blade, and the drive pin 8d of the rear blade drive member 8 is fitted in a hole (not shown) formed in the arm 16.

  Incidentally, the shutter blade of this embodiment has two arms for each of the front blade and the rear blade, but three or more shutter blades are also known. In the case of this embodiment, the leading blade and the trailing blade are pivotally supported by three blades. However, it is also known that one blade or two blades other than three are used. It is also known that the number of front and rear blades is different. The shutter blades of the present invention may have any configuration among them.

  Next, the operation of this embodiment will be described. FIG. 1 shows a state immediately after the leading blade and the trailing blade have finished the exposure operation. Therefore, the three blades 13 to 15 of the leading blade are overlapped and stored in a position below the opening 1a, and the three blades 18 to 20 of the rear blade are deployed to cover the opening 1a. . In this state, when the imaging information is transferred from the solid-state imaging device to the storage device, the set operation is performed immediately.

  In the state of FIG. 1, in the state of FIG. 1, a member on the camera body side (not shown) presses the driven portion 10c of the set member 10 to resist the urging force of the return spring (not shown). This is done by rotating it clockwise. As a result, the set member 10 first has its pushing portion 10a pushing the pushed portion 6b of the leading blade drive member 6 and resists the biasing force of the leading blade drive spring (not shown). The drive member 6 is started to rotate counterclockwise. After that, when the leading blade slit forming blade 15 overlaps the trailing blade slit forming blade 20 by a predetermined amount, the other pushing portion 10b of the set member 10 is attached to the trailing blade driving member 8. By pushing the roller 8b, the trailing blade driving member 8 starts to rotate counterclockwise against the biasing force of a trailing blade driving spring (not shown). Therefore, thereafter, the three blades 13 to 15 of the leading blade operate upward while reducing the overlap between the blades, and the blades 18 to 20 of the rear blade move upward while increasing the overlap between the blades. It works.

  In this way, the set operation is performed, and the three blades 13 to 15 of the leading blade are deployed to cover the opening 1a, and the three blades 18 to 20 of the rear blade are overlapped to open the opening 1a. When the iron pieces 7b and 9b of the iron piece members 7 and 9 attached to the drive members 6 and 8 are stored in the upper position, the iron core member 4 of the leading blade electromagnet and the trailing blade electromagnet 5 comes into contact. However, after each drive member 6 and 8 is rotated slightly counterclockwise than that, it is stopped by stopping the pushing of the member on the camera body (not shown) with respect to the set member 10, The set state shown in FIG. 3 is obtained. Therefore, although not understood from FIG. 3, in this state, the compression springs (not shown) accommodated in the mounting portions 6c and 8c of the drive members 6 and 8 are actually compressed and the iron pieces The flange portions 7c and 9c of the members 7 and 9 are slightly separated from the attachment portions 6c and 8c of the drive members 6 and 8, respectively. The set member 10 is maintained in this state until the next photographing is performed.

  When the release button is pressed during the next shooting, first, the coils of the leading blade electromagnet and the trailing blade electromagnetic magnet are energized. The parts 7b and 9b are sucked and held. Thereafter, the restraining force by a member on the camera main body (not shown) on the pushed portion 10c of the set member 10 is released, and the set member 10 is counterclockwise from the position of FIG. 3 by the biasing force of the return spring (not shown). Rotated in the direction. In the initial stage of the rotation, the pushing portions 10a and 10b of the set member 10 are separated from the pushed portion 6b of the leading blade driving member 6 and the roller 8b of the trailing blade driving member 8. In the stage, the drive members 6 and 8 have already been attracted and held by the iron core members 4 and 5 as described above, so that their mounting portions 6c and 8c are slightly separated from each other. The iron piece members 7 and 9 are stopped in contact with the flange portions 7c and 9c, and the exposure operation is not started. Then, the state in which the set member 10 has returned to the initial position is the state shown in FIG.

  When the state shown in FIG. 4 is reached, first, the current supply to the coil of the leading blade electromagnet is cut off. As a result, the suction force of the iron core member 4 with respect to the iron piece member 7 is lost, so that the leading blade driving member 6 is rapidly rotated clockwise by the biasing force of the leading blade driving spring (not shown). Therefore, the three blades 13 to 15 of the leading blade are moved substantially downward while increasing the overlap between the blades, and open the opening 1a from above. Next, when the energization of the coil of the rear blade electromagnet is cut off, the attraction force of the iron core member 5 with respect to the iron piece member 9 is lost. Therefore, the rear blade drive member 8 is not shown. It is rapidly rotated clockwise by the urging force. Therefore, the three blades 18 to 20 of the rear blade are moved substantially downward while reducing the overlap between the blades, and close the opening 1a from above. Therefore, thereafter, the imaging surface of the solid-state imaging device is sequentially exposed by the slit formed between the slit forming blade 15 of the leading blade and the slit forming blade 20 of the trailing blade.

  After that, when the three blades 13 to 15 of the front blade are completely retracted from the opening 1a, the front blade drive member 6 has a flat contact surface of the contact portion 6e and a flat contacted surface of the buffer member 2. It abuts on the surface and is braked and stopped while compressing the buffer member 2. Subsequently, the rear blade drive member 8 also has a flat contact surface of the contact portion 8e when the three blades 18 to 20 of the rear blade completely cover the opening 1a. Comes into contact with the flat contacted surface of the buffer member 3 and is braked and stopped while compressing the buffer member 3. The state is the state shown in FIG. 1, and when this state is reached, imaging information is transferred from the solid-state imaging device to the storage device, and the set operation is started as described above.

  By the way, as already described, in order to stop the operation of the drive members 6 and 8 at the time of photographing, conventionally, the drive pins 6d and 8d are attached to the buffer members attached to the lower ends of the long holes 1b and 1c. Was abutting. That is, the drive pins 6d and 8d having a convex curved surface are brought into contact with the contacted surface of the buffer member formed in the concave curved surface. On the other hand, in the case of the focal plane shutter shown in the drawing of Patent Document 1, the contact surface of the buffer member attached to the lower end of the long hole is perpendicular to the operating direction of the drive pin. The surface where the driven pin abuts against the buffer member is also a surface perpendicular to the operating direction of the driving pin. As a result, the buffer member receives the force of the drive member by the contact between the flat surfaces, so the buffer effect is superior to the case of the contact between the curved surfaces described above. However, when a flat surface is formed on the drive pin, the area is naturally limited.

  On the other hand, the contact surfaces of the contact portions 6e and 8e provided on the drive members 6 and 8 of this embodiment have two sides parallel to the surface of the shutter base plate 1 than the width of the long holes 1b and 1c. Further, it is formed on a rectangular flat surface whose two vertical sides are longer than the thickness of the shutter base plate 1 at the part where the long holes 1b and 1c are formed. On the other hand, the contact surfaces of the buffer members 2 and 3 are formed as flat surfaces having the same shape as the contact surfaces. Therefore, the buffering effect is characterized by being significantly larger than that of the configuration shown in the drawing of Patent Document 1.

  In the present embodiment, the contact portions 6e and 8e of the drive members 6 and 8 are formed longer than the width of the long holes 1b and 1c, but are substantially the same as the width of the long holes 1b and 1c. Even if it is the same, a larger effect than the conventional one can be obtained. Further, the height of the standing contact portions 6e and 8e may be approximately the same as the thickness of the shutter base plate 1 or may be small in some cases. In short, it is only necessary to avoid interference with other components and to obtain a larger contact surface than in the past. Therefore, if a flat and large contact surface can be obtained, the shape of the contact portions 6e and 8e may not be a shape obtained by bending a plate as in this embodiment, and the contact surface is also rectangular. Need not be. Furthermore, in the case of the present embodiment, it has been described that the shape of the abutted surface of the buffer members 2 and 3 is the same as the abutting surface of the abutting portions 6e and 8e. There is no need.

  As described above, the description of the present embodiment has been described in the case where the focal plane shutter of the present embodiment is employed in a digital camera, but it is needless to say that the present embodiment can also be employed in a camera using a silver salt film. In the above description, the focal plane shutter according to the present embodiment has been described in the case where the shutter base plate is attached to the camera with the shutter base plate on the subject side. In some cases, it is arranged on the subject side. Further, in the configuration of the above-described embodiment, when the leading blade driving member, the leading blade, and the leading blade electromagnet are removed, a focal plane shutter for a digital camera having a single shutter blade is obtained. Accordingly, the present invention is also included in the present invention.

It is a top view of the Example which showed about the left half seeing the state immediately after completion | finish of exposure operation | movement from the to-be-photographed object side. FIG. 2 is a side view showing the leading blade drive member as seen from below in FIG. 1 so that the contact surface of the contact portion can be seen. It is the top view which looked and showed the set state similarly to FIG. It is the top view which looked at the state just before the start of exposure operation | movement similarly to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a Opening part 1b, 1c Long hole 1d, 1e, 6c, 8c Attaching part 1f, 1g, 1h, 1i, 1j, 1k, 1m Axis 2, 3 Buffer member 4,5 Iron core member 6, Lead blade drive Member 6a, 8a Cylinder part 6b, 10c Driven part 6d, 8d Drive pin 6e, 8e Abutting part 7, 9 Iron piece member 7a, 9a Shaft part 7b, 9b Iron piece part 7c, 9c Ling part 8 Rear blade drive member 8b Roller 10 Set member 10a, 10b Pushing part 11, 12, 16, 17 Arm 13, 14, 15, 18, 19, 20 Blade

Claims (1)

  At least one blade chamber between the two, two ground plates each having at least one arc-shaped elongated hole formed therein, a plurality of arms, and at least one piece pivotally supported by these arms At least one shutter blade that is rotatably attached to the one base plate in the blade chamber, and is connected to one of the arms through the long hole. The drive pin and the drive pin that are erected at a predetermined height over a length substantially equal to or greater than the width of the long hole on the opposite side of the substantially same position to form a flat contact surface And at least one drive member rotatably attached to the one base plate outside the blade chamber, and attached near one end of the elongated hole outside the blade chamber of the one base plate, A flat abutting surface formed at a predetermined height over a length substantially equal to or greater than the width of the hole, and the abutting surface is in contact with the abutting surface when rotation of one of the drive members is completed A focal plane shutter for a camera, comprising: a buffer member that abuts against the contact surface.

Images