| 摘要 |
PROBLEM TO BE SOLVED: To increase S/N, to facilitate manufacture, and to increase the flexibility in light source arrangement. SOLUTION: A lens 3 and a CCD 4 are arranged in an area, where neither of stray light A1 which enters a sheet prism 6 through a fingerprint collection surface 6B and is totally reflected by a prism surface 6A2 in a direction which is opposite from the direction in which is CCD 4 is arranged between one-side and other-side prism surfaces 6A1 and 6A2 of triangular-sectioned prisms 6-1 to 6-n, constituting a prism surface 6A of the sheet prism 6 and a stray light A2 which is refracted does not, reach. Namely, the lens 3 and CCD 4 are arranged in the area S3, where neither the stray light A1 nor A2 generated by both the boarder line LA1 of the arrival area S1 of the stray light A1 and the border line LA2 of the arrival area S2 of the stray light A2 cross each other, does not reach. |
