Electronic validation machine for documents
US5471039A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1994 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | Jun 22, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/086
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Information can be obtained from a document having printed electronic circuits by using an electronic verification machine that determines the electrical characteristics or signatures of the circuits printed on the document. The electronic verification machine electronically couples with the circuit and applies an excitation signal such as an AC signal having a predetermined frequency to the circuit. A detection circuit in the electronic verification machine then generates a detection signal in response to the excitation signal which represents the characteristics of the circuit printed on the document. The electronic verification machine can also be used to stigmatize the document by applying a signal to the electronic circuits having sufficient strength to alter the electronic circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.