| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a concealed information verifying device for an information recording medium, for safely and reliably verifing concealed information, by preventing a lighting pattern regarding reading of the concealed information from being known, even through the observation of a reader and the lighting pattern in reading of the concealed information, when reading the concealed information by irradiating illumination light in the lighting pattern that corresponds to a diffraction grating element placed on the information recording medium. <P>SOLUTION: The device is provided with a lighting means for irradiating the illumination light from a specific divided lighting area. From the divided lighting area, the illumination light is irradiated also to the diffraction grating element, corresponding to diffraction light information that is not relevant to the synthesis of the concealed information. <P>COPYRIGHT: (C)2007,JPO&INPIT |
