Drive system for rotatable optical element

Abstract

A drive system includes a rotational driving member, a rotational driven member, to which a rotational resistance is applied, a holding member of a rotatable optical element supported by the rotational driving member and the rotational driven member, an insertion controller preventing the holding member from rotating when the holding member is in an inserted position, and a removal controller allowing the holding member to move to a fully removed position and prevents the holding member from rotating at a limited removed position. An insertion/removal operation of the holding member is performed by relative rotation between the rotational driving member and the rotational driven member, and when the holding member is prevented from rotating by the insertion controller and the removal controller, the rotational driven member and the holding member rotate with the rotational driving member about the optical axis.