Abstract: When a rotation member is rotated clockwise by a stepping motor, one main operation member is rotated counterclockwise through a link member and the other main operation member is rotated clockwise by said main operation member through the link member. Also, one sub operation member is rotated counterclockwise by said main operation member through the link member, and the other sub operation member is rotated clockwise by the other main operation member through the link member. This causes the amount of overlap between a main split blade mounted to said main operation member and a sub split blade mounted to said sub operation member to be increased and also causes the amount of overlap between a main split blade mounted to the other main operation member and a sub split blade mounted to the other sub operation member to be also increased. As a result, the aperture opening formed between the two main split blades is increased.

Abstract: When a rotation member is rotated clockwise by a stepping motor, one main operation member is rotated counterclockwise through a link member and the other main operation member is rotated clockwise by said main operation member through the link member. Also, one sub operation member is rotated counterclockwise by said main operation member through the link member, and the other sub operation member is rotated clockwise by the other main operation member through the link member. This causes the amount of overlap between a main split blade mounted to said main operation member and a sub split blade mounted to said sub operation member to be increased and also causes the amount of overlap between a main split blade mounted to the other main operation member and a sub split blade mounted to the other sub operation member to be also increased. As a result, the aperture opening formed between the two main split blades is increased.

Abstract: A first drive member which rotates with a rotor includes a first cam portion and a second cam portion, and a second drive member which connects a drive pin with a shutter blade includes a first cam portion and a second cam portion. A circular hole of the link member is fitted to a shaft member which is fixed to the first drive member and an elongated hole thereof is fitted to the shaft member fixed to the second drive member. The first drive member rotates the second drive member first via the link member and subsequently rotates the same directly so that when an abutting portion of the second drive member comes into abutment with an edge of the elongated hole, a generated repulsive force acts toward an axis of rotation of the first drive member irrespective of the direction of rotation of a rotor 7.

Abstract: A drive member attached to the output shaft of a DC motor placed on a shutter base board includes a drive pin connected to the arm of a shutter blade within a blade chamber for driving the shutter blade to open and close an exposure opening with the reciprocal rotation of the DC motor. A brake member rotatably attached to the shutter base board and having a frictional force applied thereto by a spring washer brakes the rotation of the drive member when a bent portion is pushed by the drive pin to rotate.

Abstract: A first drive member which rotates with a rotor includes a first cam portion and a second cam portion, and a second drive member which connects a drive pin with a shutter blade includes a first cam portion and a second cam portion. A circular hole of the link member is fitted to a shaft member which is fixed to the first drive member and an elongated hole thereof is fitted to the shaft member fixed to the second drive member. The first drive member rotates the second drive member first via the link member and subsequently rotates the same directly so that when an abutting portion of the second drive member comes into abutment with an edge of the elongated hole, a generated repulsive force acts toward an axis of rotation of the first drive member irrespective of the direction of rotation of a rotor 7.

Abstract: A drive member attached to the output shaft of a DC motor placed on a shutter base board includes a drive pin connected to the arm of a shutter blade within a blade chamber for driving the shutter blade to open and close an exposure opening with the reciprocal rotation of the DC motor. A brake member rotatably attached to the shutter base board and having a frictional force applied thereto by a spring washer brakes the rotation of the drive member when a bent portion is pushed by the drive pin to rotate.

Abstract: A focal-plane shutter for a camera is provided with two blade chambers into which a space between two base plates is partitioned by an intermediate plate having an aperture for exposure. A shutter blade group placed in each of the blade chambers is constructed with a plurality of arms whose ends are pivotally mounted to one of the two base plates on the side of the aperture and at least one blade pivotally supported by the arms through individual joint shanks so that working paths of the joint shanks does not run inside the apertures. A wall is provided on at least one of the two base plates so as to project toward the blade chamber side, along the edge of the aperture, and has an inclined face directed toward the aperture of an opposite base plate.

Abstract: A focal-plane shutter for cameras is provided with a single blade chamber between two base plates, each having an aperture for exposure at about the middle thereof, or two blade chambers into which the single blade chamber is partitioned between the two base plates by an intermediate plate having an aperture for exposure at about the middle thereof. A shutter blade group placed in each of the blade chambers is constructed with a plurality of arms whose ends are pivotally mounted to one of the two base plates on the side of the aperture and at least one blade pivotally supported by the arms through individual joint shanks so that working paths of the joint shanks does not run inside the apertures of the base plates.