Normal vector acquisition system, normal vector acquisition method, and authentication method using normal vector

摘要

PPROBLEM TO BE SOLVED: To provide a system and a method for acquiring a normal vector. PSOLUTION: First to third light emitting parts 11 to 13 are installed in a light source. The first to third light emitting parts 11 to 13 emit light to an object 5. Intensity of light is modulated in sine wave shapes whose phases differ by 2/3 by similar frequency. The first to third light emitting parts 11 to 13 are arranged in positions becoming apexes of equilateral triangles. A sensor part 2 receives light reflected by the object 5. The sensor part 2 creates first to third correlation signals by time correlations between an intensity signal of received light with first to third reference signals. The reference signals are made into the sine wave shapes whose phases differ by 2/3 by the same frequency. An analysis part 3 creates normal vector information by using the first to third correlation signals. PCOPYRIGHT: (C)2004,JPO&NCIPI