| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively realize a sub-wavelength diffracting grating structure with a narrow width and a high aspect ratio by improving a diffraction effect through an enhancement of regular arrangement of spherical particulates. <P>SOLUTION: A forgery prevention structure comprises: a grating layer 3 formed in a corrugated shape made up of groove sections 21 and bank sections 22; a particulate layer 4, in the groove sections 21 of the grating layer 3, formed by arranging spherical particulates having a particle size distribution where an average particle diameter is equal to or less than 2.5 μm and particles with diameters 0.8 to 1.2 times the average particle diameter accounts for equal to or larger then 70% of the total particles; and a reflective layer 5 which is a single layer and fixed to the grating layer 3 totally or partially in an arbitrary shape so that the reflective layer 5 immerses the spherical particulates of the particulate layer 4 therein with a depth less than a half height of the spherical particulates but covers at least a portion of an area of the spherical particulates which is not immersed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
