- 专利标题： METHOD OF AUTHENTICATING A POLYMER FILM BY THICKNESS MEASUREMENT WITH A WHITE LIGHT INTERFEROMETER
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申请号： US15638723申请日： 2017-06-30
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公开(公告)号： US20170299374A1公开(公告)日： 2017-10-19
- 发明人: Robert Laird STEWART
- 申请人： INNOVIA FILMS LIMITED
- 优先权： GB0807668.9 20080428
- 主分类号： G01B11/06
- IPC分类号： G01B11/06 ; G01N21/23
摘要：
A method of authenticating a polymer film comprises measuring the thickness of a layer therein by white light interferometry and/or measuring the birefringence of a layer therein. The method, and devices to carry out the method, may be used in security applications, for example to test for counterfeit bank notes.