Patent ID: 7657169

Claim:
A focus detection method for detecting a focus state based on an object image formed through a photographing optical system in one of a single-point distance measuring mode and a multi-point distance measuring mode while performing a search operation in which a focusing lens group of said photographing optical system is moved between a near extremity and a far extremity, said focus detection method comprising: moving, in said multi-point distance measuring mode, said focusing lens group always from said near extremity toward said far extremity in said search operation, and stopping said focusing lens group upon first detecting an in-focus state to determine an in-focus position of said focusing lens group when detecting a focus state in each of a plurality of focus detection areas while performing said search operation, and moving, in said single-point distance measuring mode, said focusing lens group firstly to one of said near extremity and said far extremity which is closer to a current position of said focusing lens group, and subsequently toward the other of said near extremity and said far extremity in said search operation, and stopping said focusing lens group upon first detecting an in-focus state to determine an in-focus position of said focusing lens group when detecting a focus state in said single focus detection area while performing said search operation.