Patent ID: 7738782
Filing Date: 2010-06-15
Classification: G02B

Abstract:
1. A lens position detector for detecting a position of a movable lens group in an optical axis direction, said lens position detector comprising: a manual operating ring which is screw-engaged with a barrel so as to be manually rotatable about said optical axis and movable in the optical axis direction, a rotation of said manual operating ring causing said movable lens group to move in said optical axis direction; a code plate fixed to one of said barrel and said manual operating ring; and a conductive brush fixed to the other of said barrel and said manual operating ring so that said code plate faces said conductive brush in substantially the optical axis direction, said rotation of said manual operating ring causing relative rotation between said conductive brush said code plate about said optical axis while relatively sliding thereon, wherein a surface of said code plate with which said conductive brush is in sliding contact is inclined to a plane orthogonal to said optical axis at an angle of inclination substantially equal to a lead angle of male and female screw threads engaged with each other which are formed on said manual operating ring and said barrel, respectively.