| 摘要 |
PROBLEM TO BE SOLVED: To provide an information recording medium which can securely perform authenticity determination even when a substrate having a fine diffraction grating element with a diffraction grating disposed on its surface has poor surface smoothness and has a higher-level forgery prevention effect. SOLUTION: The information recording medium is provided which keeps a plurality of fine diffraction grating elements 11 each having a diffraction grating disposed on a substrate surface, and a grating space and a grating angle set so that all or a part of the diffraction light 37 obtained by diffracting illumination light 36 emitted from a light source 39 by the diffraction grating elements 11 enters into a predetermined region 38, and makes a total of reproduction information in the predetermined region 38 appear as a predetermined confidential information when all or a part of the diffraction light 37 from a diffraction grating element group 31 consisting of a combination of at least two diffraction grating elements 11 enters into the predetermined region 38. COPYRIGHT: (C)2008,JPO&INPIT |
