| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a discriminating method for a hidden pattern which is highly effective in counterfeit prevention and cannot easily be discriminated by a visual means. <P>SOLUTION: In the method for discriminating a hidden pattern by using a discrimination pattern formed on the surface of a transparent film, the hidden pattern is a pattern of optical diffraction structure characterized in that the optical diffraction structure forming a design with a plane pattern, comprising a first pattern and a second pattern of fine striation of diffraction grating, incorporated in N pieces of plane pattern consisting of diffraction grating and forming a design is divided into reticula and the respective reticulum composes N+1 pixels in relation to the design, while the discrimination pattern is a pattern of striation parallelling the striation constituting the hidden pattern. <P>COPYRIGHT: (C)2004,JPO</p> |
