Computer generated holographic microtags
US5729365A · kind A · utility
46Cited by
5References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Jan 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2260/63
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.