Movement detection and control device

摘要

A movement detection and control device has a lens frame holding a lens. The lens frame is movable in a direction of an optical axis of the lens. A revolving cam moves the lens frame in the direction of the optical axis. A driving source drives the cam. A pattern-rotating member having patterns for pulse generation, is rotated by the driving source. A detector detects the patterns, and generates pulse signals in response to driving by the driving source. A control circuit counts the pulse signals, and drives the driving source in a controlled manner to move the lens frame by a predetermined amount. The revolving cam is provided with a light-sealing member for intercepting the detector from generating pulse signals in an area where the cam starts or finishes its movement.