Patent ID: 7660518

Claim:
An automatic focusing system comprising: a region configuring device which configures a main subject region including a main subject within a photographing screen; a focusing control device which controls focusing so that a focus state of the main subject included in the configured main subject region is a best focus state; a focus state obtaining device which divides the photographing screen into a plurality of regions and obtains a focus state from each region; a focus state storage device which stores the focus state obtained from each region; a movement detecting device which references the stored focus state of each region to detect the movement of a group of regions that are located either within the main subject region and its vicinity or within the main subject region and are in a best focus state; and a region moving device which moves the main subject region in accordance with the movement of the group of regions that are located either within the main subject region and its vicinity or within the main subject region and are in the best focus state.