A lens held by a lens holding member is centered easily and correctly by a mechanism
in which a guide pin is inserted into a guide hole for positioning the lens holding
member with respect to the main body unit of the lens barrel in a plane perpendicular
to the optical axis of the lens and for mounting the lens holding member for movement
in a direction along the optical axis. Adjustment pins are rotationally mounted
on at least three sites on the outer peripheral surface of the main body unit of
the lens barrel. If each adjustment pin is rotated, an offset portion of the adjustment
pin which is relative to the center of rotation of the adjustment pin, is rotated,
as the offset portion is engaged in an engagement hole of the lens holding member.
In this way the lens holding member on each site is displaced in the direction
along the optical axis to adjust the tilt of the lens held by the lens holding member.
