| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a copying preventing medium or the like which can prevent specified information from being copied and can make this information easily visible. <P>SOLUTION: The copying preventing medium has a constitution having an information displaying layer 1 for displaying information to be protected from copying, a prism layer formed into a polygonal pillar shape and among side faces of which a plurality of prisms 7 provided by facing the first face 10 and the second face 11 to the information displaying layer are arranged, and a low refractive index layer 8 which is brought into contact with the first face and the second face of the prism and has a lower refractive index than that of this prism 7. The first face 10 is arranged so that an angle of incidence of a document irradiating light of a copying machine entering into the prism 7 from an angle within a specified range which passes through this prism 7 and enters into the first face 10, is larger than the critical angle on the first face 10. Thereby, the component of the document irradiating light entering from the specified angle is totally reflected on the first face 10, and at least a part of the totally reflected light is reflected on the second face 11 and enters into a reading head of the copying machine, to make a copied image to be hardly readable. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
