Drive appts. for camera lens

摘要

The drive appts. is applied to a camera lens or similar where focusing is achieved by moving the lens longitudinally along its axis. The appts. comprises a control ring (44) which comes into contact with a sliding surface (45a) which offers relatively high resistance to movement when the control ring (44) is operated by hand and engages a second sliding surface (45b) which offers relatively low resistance to movement when the control ring (44) is motor driven. A means of driving the lens assembly such as an electric motor (42,43) utilises the second low resistance slide when the control ring is rotated by the drive mechanism.