| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the use of a structure in which a mirror member is pressed downward at both ends around a rotation axis and comes into contact with a mirror receptacle at both sides of the tip might prevent the mirror plane from being defined uniquely and invite occurrence of backlash thereon, which might give rise to various troubles including deterioration of AF accuracy.SOLUTION: A mirror unit comprises: a mirror part that turns around a rotation axis between a first state in which it is obliquely disposed in an incident light flux and a second state in which it moves away from the incident light flux; a receptacle that receives the mirror part on the side of one end of the rotation axis and positions the mirror part in the first state; a first pressing part that presses the mirror part on the side of one end of the rotation axis in the direction of turning the mirror part from the second state to the first state; and a second pressing part that presses the mirror part on the side of the other end of the rotation axis and in the direction of turning the mirror part from the second state to the first state. The torque created around the rotation axis by the pressing force of the second pressing part is smaller than the torque created around the rotation axis by the pressing force of the first pressing part. |
