Method and apparatus for checking the authenticity of documents
US4820912A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1986 |
| Grant date | Apr 11, 1989 |
| Priority date | — |
| Expiry date | Sep 19, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/086
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method and an apparatus for checking the authenticity of documents, such as banknotes or credit-cards. The documents comprise a number of randomly distributed conductive fibres of which the distribution is scanned by microwaves and the response is transformed into a digital coded signal. A digital mark on the document, which is representative for the distribution of an individual document, is read off, transcoded, and compared with said coded signal for producing an approval signal. The use of a microwave scanning system in conjunction with documents having a random distribution of suitable fibres ensures a great repetitivity and security of the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.