Automatic system and interchangeable optical instrument therefor

摘要

A driving force transmitting arrangement in an interchangeable optical type optical unit in an optical system including a driving shaft and a driven shaft respectively provided in one part and the other part of the optical instrument which are engageable with or disengageable from each other so that the driving shaft and the driven shaft are connected with or disconnected from each other following the engagement or disengagement between the one part and the other part of the optical instrument. The driving force transmitting arrangement includes a motor for rotating the driving shaft for focusing of the optical system interchangeable optical instrument, and a circuit having a controller of the motor, and a switch to be closed according to connection between the driving shaft and driven shaft. The one part of the optical instrument may be a photographic camera, while its other part may be an interchangeable lens barrel for the camera, and the interchangeable lens barrel is provided with a focusing operation mechanism for the optical system.