Patent ID: 8018667

Claim:
An optical apparatus comprising: a first member which holds a lens; a second member which supports the first member so as to be movable in an optical axis direction via a plurality of balls; and a biasing device which has a biasing force acting on the first member for pressing the plurality of balls with respect to the second member, wherein the plurality of balls include two first balls which are arranged at positions away from each other in the optical axis direction and a second ball arranged at a phase different from that of the first balls in a direction around the optical axis, wherein the first and second members includes a guide section which is configured to engage with the first balls so as to permit a rolling motion of the first balls in the optical axis direction and prevent a displacement of the first member with respect to the second member in a direction different from the optical axis direction and a rotation preventing section which is configured to permit a rolling motion of the second ball in the optical axis direction and prevent a rotation of the first member with respect to the second member around the guide section, and wherein the interval between both sides in the optical axis direction of the guide section is set to more than a movable range of the ball when the ball moves in the optical axis direction of the lens.