Method and apparatus for authenticating documents utilizing poled polymeric material
US4792667A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1987 |
| Grant date | Dec 20, 1988 |
| Priority date | — |
| Expiry date | Mar 27, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for authenticating documents, utilizing the ferroelectric properties of poled polymeric materials. The properties displayed by the poled materials are detected in order to authenticate the documents to which they are affixed. The poled polymeric material can be used as a protective coating or covering for an indentifying photograph and/or signature and can be applied to a document in such a fashion that heat is needed to remove it. The ferroelectric properties of the poled polymeric material virtually disappear when the material is subjected to critical temperatures, such as those necessary to remove the material from the document. The absence of these properties therefore, signifies that the document has been tampered with.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.