Abstract: In order to perform an autofocus operation, a controller of a focus control device selects subject information relating to the current magnification from subject information including previous focus states stored in a storage unit in advance, and determines a focus lens driving range on the basis of a focal length associated with the selected subject information. After the focus lens driving range is determined, a contrast-based autofocus operation is performed within that driving range. Therefore, it is possible to reduce the time taken to obtain the focus state and improve reliability of the focusing.

Abstract: A focus control apparatus reduces the degree of out-of-focus of an image of an intense point light source during zooming in contrast-based autofocus control. A zooming lens moves in an optical axis direction to perform magnification change and a focusing lens moves in the optical axis direction to perform focus adjustment and is driven in accordance with a trace curve corresponding to the distance to a subject. A controller evaluates, during the magnification change operation, based on the rate of change in the number of high-luminance pixels at which the number of high-luminance pixels in an output image from the imaging apparatus changes with the zoom magnification, whether or not the focusing lens is driven in accordance with a trace curve corresponding to the distance to the subject before the magnification change operation is performed or a trace curve corresponding to a distance to the subject of infinity.

Abstract: A controller sets a plurality of detection regions within an imaging area. The controller then compares a difference in a contrast signal level between a maximum contrast signal level and a minimum contrast signal level calculated from among contrast signal levels of contrast signals generated for the plurality of detection regions with a level difference threshold. The controller then sets a priority level in subject information concerning a subject on the basis of a comparison result. The controller then stores the subject information in a storage unit in accordance with the priority level set in the subject information. The controller then drives a focus lens on the basis of the subject information read from the storage unit so as to bring the focus lens into focus.

Abstract: A focus control apparatus reduces the degree of out-of-focus of an image of an intense point light source during zooming in contrast-based autofocus control. A zooming lens moves in an optical axis direction to perform magnification change and a focusing lens moves in the optical axis direction to perform focus adjustment and is driven in accordance with a trace curve corresponding to the distance to a subject. A controller evaluates, during the magnification change operation, based on the rate of change in the number of high-luminance pixels at which the number of high-luminance pixels in an output image from the imaging apparatus changes with the zoom magnification, whether or not the focusing lens is driven in accordance with a trace curve corresponding to the distance to the subject before the magnification change operation is performed or a trace curve corresponding to a distance to the subject of infinity.