Patent ID: 8770487
Filing Date: 2014-07-08
Classification: B42D,B44F,G02B,G03H,G06K

Abstract:
1. An information recording medium, comprising: an arrangement of diffraction grating cells constituting cells each formed of a diffraction grating, wherein the information recording medium is formed of a paper base material and has an uneven surface and the diffraction grating cells are arranged on the uneven surface of the information recording medium, a plurality of types of the diffraction grating cells make up one information recording area, two or more types of the diffraction grating cells included in the diffraction grating cells making up the information recording area are information recording elements, two or more types of the diffraction grating cells included in the diffraction grating cells making up the information recording area are information hiding elements, at least one of the diffraction grating cells included in the diffraction grating cells making up the information recording area is dummy, the diffraction grating cells of different types included in the diffraction grating cells making up the information recording area are configured of diffraction gratings having different grating angles from each other, information is recorded in a two-dimensional arrangement of the diffraction grating cells constituting the information recording elements in the information recording area, when the diffraction grating cells are irradiated with an illumination light from a light source, only one diffraction grating light ray is emitted from one diffraction grating cell, and the illumination light is a diffused illumination light that irradiates the diffraction grating cell in a plurality of angles and the diffraction light ray diffracts and diverges in a certain degree.