Identity document difficult to falsify and a process for manufacturing such a document
US4790566A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 1985 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Oct 11, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/904
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An identity document has graphical information printed on a support and including uncoded alphanumerical information which is specific to a holder of the document or to the document. The surface of the support is broken down into a network of macropixels each having a predetermined average light absorption level. Each of the micropixels in turn consists of a dot pattern matrix of micropixels each having a light absorption level selected among at least two predetermined levels and distributed for the average absorption of each of the macropixels to be said predetermined average light absorption level and for constituting a screen which reproduces on a microscopic scale part at least of the uncoded specific information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.