Patent ID: 7526192

Claim:
A focus detection method for detecting a focus state of an object image in accordance with a contrast of the object image that is formed in a focus detection area, the focus detection method comprising: capturing a plurality of object images while moving a focusing lens group of a photographing lens stepwise within a predetermined range of movement of said focusing lens group; determining contrast values of the plurality of object images in the focus detection area; determining whether a contrast value of the contrast values of the plurality of object images is a peak contrast value, wherein a particular contrast value is determined to be a peak contrast value when a first predetermined number of consecutive contrast values preceding the particular contrast value increase in value and a second predetermined number of consecutive contrast values succeeding the particular contrast value decrease in value, the determination being made when the focusing lens group is moved stepwise in a predetermined direction; and moving the focusing lens group to a position in which a maximum contrast value is determined when a peak contrast value is not detected, the maximum contrast value being determined at one of at the closest focusing position and within a close vicinity of the closest focusing position.