发明名称 |
Optical device |
摘要 |
PCT No. PCT/GB90/01613 Sec. 371 Date Apr. 8, 1992 Sec. 102(e) Date Apr. 8, 1992 PCT Filed Oct. 19, 1990 PCT Pub. No. WO91/06925 PCT Pub. Date May 16, 1991.An optical security device for use on a security article comprises a number of layers including an optically diffracting layer and an at least partially reflective layer which together generate a first image. A non-optically diffracting second image is provided within the device in association with the first image.
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申请公布号 |
US5310222(A) |
申请公布日期 |
1994.05.10 |
申请号 |
US19920856141 |
申请日期 |
1992.04.08 |
申请人 |
DE LA RUE HOLOGRAPHICS LIMITED |
发明人 |
CHATWIN, CHARLES E.;KAY, RALPH;GOMME, MARTIN C.;EZRA, DAVID |
分类号 |
G06K19/02;(IPC1-7):B42D15/00 |
主分类号 |
G06K19/02 |
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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