Patent ID: 7782547
Filing Date: 2010-08-24
Classification: G02B

Abstract:
1. An optical element position control mechanism comprising: an optical element holding member which holds an optical element and is linearly movable; a lead screw rotatable on a rotational axis extending parallel to a direction of movement of said optical element holding member; a linearly moving nut which is screw-engaged with said lead screw; and a rotation prevention device which prevents said linearly moving nut from rotating about said rotational axis of said lead screw, wherein forward and reverse rotations of said lead screw cause said linearly moving nut to move forward and rearward along said rotational axis of said lead screw, respectively, a position of said optical element holding member being determined by said forward and rearward movements of said linearly moving nut, and wherein said optical element position control mechanism includes a biasing device, wherein said biasing device is resiliently deformable in a biasing plane substantially parallel to a plane which includes said rotational axis of said lead screw, and applies a biasing force against said linearly moving nut in a rotation-preventing direction in which said linearly moving nut is prevented from rotating by said rotation prevention device.