Automatic and manual focusing exchangeable lens assembly

Abstract

An exchangeable lens assembly detachably mountable on a camera body having an automatic focusing device is selectively capable of either automatic focus adjustment by the operation of the automatic focusing device or manual focus adjustment by a manual operation. In two of the embodiments, the change-over between the automatic focus adjustment and the manual focus adjustment is made by operation of a change-over member provided on a stationary barrel separately from a manual focusing ring. A driven shaft coupled with a focus adjusting mechanism is disengaged from a driving shaft of the automatic focusing device in the case of the manual focus adjustment. In the remaining embodiments, a manual focusing ring rotatable and axially shiftable relative to a stationary barrel is axially shifted between an automatic focusing position and a manual focusing position for the change-over. When the ring is shifted to the automatic focusing position, a driven shaft coupled with a focus adjusting mechanism is engaged with a driving shaft of the automatic focusing device and the ring is un-coupled from the focus adjusting mechanism. When the ring is shifted to the manual focusing position, the engagement between the driven and driving shafts is interrupted and the ring is coupled with the focus adjusting mechanism by frictional engagement due to elastic deformation of a resilient member.