Patent ID: 8285003

Claim:
A personal authentication method comprising imaging, on an image sensor as a laser speckle using an optical system, light reflected from retinal blood vessels of the ocular fundus and a blood vessel layer in ocular fundus internal tissue when a laser beam is expanded and made to irradiate the ocular fundus, calculating a quantity that represents the rate of change with respect to time of the amount of light received for each pixel of the laser speckle, obtaining an ocular fundus blood flow map as a two-dimensional map of numerical values of the quantity, and comparison-checking the blood flow map against pre-registered personal data, wherein the blood flow map obtained from reflected light is measured using a laser beam that can reach the internal tissue of the ocular fundus, and comparison-checking against pre-registered personal data is carried out utilizing at least one, observed in the blood flow map, of blood flow distribution data, a pattern reflecting the course of retinal blood vessels, a pattern reflecting the course of blood vessels in ocular fundus internal tissue observed superimposed thereon, and data on change thereof over time.