US Patent 7382901 Eye image imaging device

An eye image taking device comprises: an imaging unit for taking an eye of a user as an eye image; a focusing degree calculating unit for calculating the magnitude of high-frequency components from the eye image; a threshold setting unit for setting a focusing threshold intrinsic to an authorized user; and a focus deciding unit for deciding a focus by comparing the magnitude of the high-frequency components and the focusing threshold, so that the optimum focusing threshold is set for the authorized user.