A sector drive apparatus for use in an optical apparatus, the sector drive
apparatus includes a sector having a first engagement opening engaged
with an operation member that reciprocates in a given range and a second
engagement opening engaged with a spindle fixed to a shutter substrate,
the sector opening and closing a shutter opening formed in the shutter
substrate in accordance with a movement of the operation member. The
operation member has an engagement pin that is engaged in the first
engagement opening, the first engagement opening is substantially
circular that permits the operation member to rotate, and the second
engagement member is an elongate opening, and swings the sector centering
around the spindle to move to a position where the shutter opening is
opened and closed, when the first engagement opening moves in accordance
with the movement of the operation member.