| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical diffraction structure having a latent image which can be discriminated by means of a discrimination tool although the discrimination of the latent image incorporated in an optical diffraction structure by means of visual observation is extremely difficult. <P>SOLUTION: The optical diffraction structure having the latent image is constituted as follow. The whole region containing the optical diffraction structure is divided into a discriminable partial region and a partial zone containing the latent image, the partial region at least containing the latent image is composed of fine stripes arranged in parallel, the fine stripes are composed of a pair of belts on which the diffraction grating is formed and a pixel based on the diffraction grating is partially formed on the one side belt of a pair of the belts. <P>COPYRIGHT: (C)2004,JPO</p> |
