| 摘要 |
PURPOSE:To minimize the quantity of defocusing following up the motion of an object effectively even when the distance to the object varies abruptly with time by providing a defocus quantity arithmetic means, a driving means, a driving and correcting means, etc. CONSTITUTION:An interchangeable lens LZ and a camera body BD are connected with each other mechanically through clutches 106 and 107 and electrically through connection terminals JL1-JL5, and JB1-JB5. An AF controller 113 calculates signals of the quantity L and direction of defocusing indicating the quantity of deviation from a focusing position on the basis of the signal from a CCD image sensor FLM. A motor MO1 is driven on the basis of those signals and its rotation is transmitted to the interchangeable lens IZ through a slip mechanism SLP, a driving mechanism LDR, and the clutch 107. Further, the driving and correcting means operate under specific condition where follow-up corrections are effective to correct the calculated quantity of defocusing so as to follow up the motion of the object, thereby minimizing the follow-up delay behind the motion of the object. |
