Process for making machine readable images
US6068691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1997 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Sep 29, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Finely divided embossed metal particles are prepared by forming an embossment on a carrier surface in which the embossment comprises a machine readable image produced by a diffraction grating pattern, a holographic image pattern or an image visible solely by optical magnification. A layer of metal is applied to the surface so the layer adopts the complement or the embossment. The layer is then separated from the surface and reduced to embossed particles. Alternatively, the embossment can be formed on the carrier sheet directly or on the outer surface of a release coating formed on the carrier sheet. When removing the film of metal from the release-coated carrier, the carrier sheet with the release coating and film of metal can be passed through a release environment which causes the release coating to separate the film and carrier, but which is nondestructive of the metal. The metal particles can be collected in a solvent which is nonreactive with the metal, and the metal particles can be broken further into pigment particles. The diffraction grating can have from about 5,000 to about 11,000 grooves per cm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.