SHEET WITH FORGERY-PROOF FUNCTION AND ITS MANUFACTURING METHOD, ARTICLE, CERTIFICATION CARD, BAR CODE LABEL AND CERTIFICATION SYSTEM

摘要

PPROBLEM TO BE SOLVED: To provide a sheet with a forgery-proof function which is highly difficult to forge, in case certification information is recorded taking advantage of the characteristics of a cholesteric liquid crystal. PSOLUTION: This sheet with a forgery-proof function has a cholesteric liquid crystal layer 110 which includes a selective reflected wavelength zone in at least a visible light region and is a single layer with an almost equal thickness. In addition, the sheet has a certification region 112 with a different selective reflected wavelength zone formed in at least one spot, and preferably has an adhesive layer 130 formed on one side of the cholesteric liquid crystal layer 100. Further, preferably a base material 120 is formed between the cholesteric liquid crystal layer 110 and the adhesive layer 130. Preferably, an optical absorption layer 140 is formed on the adhesive layer 130 side of the cholesteric liquid crystal layer 110. PCOPYRIGHT: (C)2006,JPO&NCIPI