发明名称 |
LIGHT-DIFFRACTING BINARY GRATING STRUCTURE |
摘要 |
A light-diffractive binary grating structure has a microscopic mesa structure ( 2 ) whose plateaux ( 5 ) are separated by valleys ( 4 ) of substantially rectangular cross-section, wherein the arrangement of the valleys ( 4 ) is periodically repeated. Within a period (T) of the mesa structure ( 2 ) at least N valleys ( 4 ) separate the plateaux ( 5 ), N being an integer and greater than 2. The mesa structure ( 2 ) is an additive superimposition of N phase-shifted rectangular structures which have the same period (T) of the mesa structure ( 2 ). Each of the rectangular structures has a phase shift such that the plateaux ( 5 ) of the one rectangular structure fall into the valleys ( 4 ) of the N-1 other rectangular structures. In addition the resulting mesa structure ( 2 ) has only a single valley between two plateaux ( 5 ), which is of a width greater than a seventh of the period (T). The binary grating structures are suitable for use in optically diffractive security elements as the binary grating structures cannot be copied with holographic means. |
申请公布号 |
EP1356319(A2) |
申请公布日期 |
2003.10.29 |
申请号 |
EP20010992904 |
申请日期 |
2001.11.02 |
申请人 |
OVD KINEGRAM AG |
发明人 |
TOMPKIN, WAYNE, ROBERT;STAUB, RENE;SCHILLING, ANDREAS |
分类号 |
G02B5/18;(IPC1-7):G02B5/18 |
主分类号 |
G02B5/18 |
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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