US Patent 6856764 Camera, lens apparatus, and camera system

A camera which drives a focusing lens to a target position in a short period of time while maintaining required stop accuracy in accordance with the status of an image-taking optical system, is disclosed. The camera comprises the image-taking optical system and a pulse generator that outputs pulse signals in accordance with movement of the focusing lens. A stop judging unit selectively carries out, in accordance with the status of the image-taking optical system, a first stop judgement of the focusing lens by detecting that the count value of pulse signals has reached a target count value, and a second stop judgement of the focusing lens by detecting that the output signal from the pulse generator does not change.