发明名称 |
OPTICALLY VARIABLE DEVICES, THEIR PRODUCTION AND USE |
摘要 |
Security documents often incorporate optically variable devices to prevent or hinder counterfeiters. Disclosed herein are layered optically variable devices such as colour-shift foils, and methods for their production and use. Such devices afford new techniques for a user of a security document to check quickly and easily whether the security document is a legitimate document or a counterfeit copy. |
申请公布号 |
CA2796937(A1) |
申请公布日期 |
2011.10.27 |
申请号 |
CA20112796937 |
申请日期 |
2011.04.21 |
申请人 |
FORTRESS OPTICAL FEATURES LTD. |
发明人 |
MACPHERSON, CHARLES DOUGLAS;HARDWICK, BRUCE ALFRED |
分类号 |
G02B5/00;B42D15/00;B42D15/10;G02B5/28 |
主分类号 |
G02B5/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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