Patent ID: 7708480

Claim:
A focal plane shutter for a digital camera, the focal plane shutter comprising: a base plate provided with an exposure aperture section, the base plate having a first shaft, a second shaft, a third shaft, and a fourth shaft; a first driving member for a first blade, the first driving member having a part to be restrained and being connected to a first blade assembly and rotatably mounted to the first shaft; a second driving member for the first blade, the second driving member being rotatably mounted to the first shaft and actuated, together with the first driving member for the first blade, by a biasing force of a driving spring for the first blade in an exposure operation to cause the first blade assembly to perform the exposure operation; a set spring configured to apply a biasing force for actuating the first driving member for the first blade and the first blade assembly toward starting positions of the exposure operation at least when the second driving member for the first blade is located at a set position; a driving member for a second blade, the driving member for the second blade being connected to a second blade assembly, rotatably mounted to the second shaft, and actuated by a biasing force of a driving spring for the second blade in the exposure operation to cause the second blade assembly to perform the exposure operation; a set member having a projection, the set member being rotatably mounted to the third shaft and actuated from an initial position to a set position in a set operation to actuate the second driving member for the first blade and the driving member for the second blade to set positions against biasing forces of the driving spring for the first blade and the driving spring for the second blade, respectively, and being restored to the initial position prior to the exposure operation of the first blade assembly when a release button of the digital camera is pushed; and a restraining member having a restraining part and an engaging part, the restraining member being rotatably mounted to the fourth shaft, and configured to reciprocally rotate in association with the set member by a direct engagement of the engaging part of the restraining member with the projection of the set member so that, when the set member is located at the set position, the restraining part of the restraining member comes in contact with the part to be restrained of the first driving member for the first blade and restrains a rotation of the first driving member for the first blade due to the biasing force of the set spring, to keep the exposure aperture section in a fully opened state, and so that, when the set member is restored to the initial position, the restraining member does not contact the part to be restrained of the first driving member and does not restrain the rotation of the first driving member for the first blade due to the biasing force of the set spring.