Abstract: A video camera which is able to reverse the direction of the moving focus lens if appropriate evaluation data is not obtained within a certain period of time after an intermediate point is detected during the focus lens movement in one direction. This eliminates the redundant operation of the focus lens moving away from the just-focus point all the way to the extreme of the current direction before heading back to the just-focus point during an auto focus operation. An efficient auto focus operation is thus achieved. In addition, control is provided for not using a decrease in accumulated data as auto focus control information if that decrease is judged to be an abrupt drop from the accumulated data obtained in the immediately preceding focus lens position. This makes it possible to prevent the focus lens from being erroneously focused in cases of panning and other focus-disrupting operations. In this manner, the photographing of high quality is always made available.

Abstract: A video camera system has a movable focusing lens which is automatically focused to form a sharp subject image on a CCD. The CCD generates a video signal based on light from a subject transmitted through the movable focusing lens. Contrast data are produced from smaller and larger image frames in a field on the CCD based on the generated video signal. The movable focusing lens is controlled on the basis of the contrast data in order to maximize the contrast data simultaneously within the smaller and larger image frames.

Abstract: A video camera system has a movable focusing lens which is automatically focused to form a sharp subject image on a CCD. The CCD generates a video signal based on light transmitted from a subject through the movable focusing lens. Maximum contrast data are produced from each horizontal scanning line in an image frame in a field on the CCD, and are then integrated by an integrator. The movable focusing lens is controlled in order to maximize the integrated contrast data.