发明名称 |
Coin provided with diffraction structures |
摘要 |
A coin (1) with a metal surface (2, 3) has macroscopic reliefs (5) which serve for visually specifying the value of the coin and as an authenticity feature. Microscopically fine relief structures (8) with a diffraction effect are formed directly in at least one of the surfaces (2, 3). The relief structures (8) are preferably arranged in a recessed relationship and are covered with a lacquer (9). It is also advantageous if at least a part of the relief structures (8) entails an asymmetrical profile shape and/or the grating vectors in a radial orientation. The release structures (8) may also include a machine-readable coding which is recognized by inexpensive optical reading devices for installation in coin testers. The application of the microscopic relief structure (8) to a hard material surface (2, 3) can be effected by the removal of material by means of exposure of the material surface (2, 3) with a laser beam. In that operation the laser beam passes through a mask for determining the form of the relief structures (8) and then an optical image-forming system for reduction purposes. The exposure procedure can also be implemented in accordance with the dual beam interference method. In a further method the microscopic relief structures (8) are etched into the material surface (2, 3).
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申请公布号 |
US2002154290(A1) |
申请公布日期 |
2002.10.24 |
申请号 |
US20020936935 |
申请日期 |
2002.01.31 |
申请人 |
TOMPKIN WAYNE ROBERT;STAUB RENE;HASLER ANDREAS;JUTZ JAKOB;MULLER MARTIN |
发明人 |
TOMPKIN WAYNE ROBERT;STAUB RENE;HASLER ANDREAS;JUTZ JAKOB;MULLER MARTIN |
分类号 |
A44C21/00;(IPC1-7):G06K9/74 |
主分类号 |
A44C21/00 |
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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