Patent ID: 7359534

Claim:
A fingerprint identification device comprising: an image acquiring unit configured to acquire a plurality of registered fingerprint images corresponding to different overlapping portions of a registered fingerprint by reading the fingerprint a plurality of times, the registered fingerprint images including a first registered fingerprint, and to acquire a read fingerprint image of a portion of a user's fingerprint; a relative position calculating unit that calculates a relative coordinate point of each registered fingerprint image relative to a coordinate point of the first registered fingerprint image, and defines an authenticating area used for authentication broader than an area of the registered fingerprint covered by the registered fingerprint images; a matching degree calculating unit configured to: compare the read fingerprint image with a corresponding area of the authenticating area at every coordinate point of the authenticating area, select a most broadly overlapping registered fingerprint image that most broadly overlaps the read fingerprint image if there is any registered fingerprint image that overlaps with at least half of an area of the read fingerprint image, at every coordinate point of the authenticating area, and calculate a matching degree between the read fingerprint image and each most broadly overlapping registered fingerprint image; and an authenticating unit that authenticates the read fingerprint image if a maximum of the matching degrees calculated is equal to or greater than a predetermined value.