Tamper evident document and use thereof
US4846502A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1986 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Jun 24, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S462/903
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A tamper evident document comprising a support bearing an autogenous coating including chromogenic material isolated from an electron-acceptor color developer material in which the autogenous coating bears a principal image comprising visible indicia of a transfer medium imprinted on the surface of the localized autogenous coating. Tampering with the principal image causes chromogen to react with the electron-acceptor color developer material to provide a color indication of tampering. The tamper evident document can be part of a multi-ply record system comprising a plurality of sheets in superposed relationship, comprising a first sheet including a support bearing an autogenous coating including chromogenic material isolated from an electron-acceptor color developer material, said localized autogenous coating bearing a principle image comprising invisible indicia of a transfer medium imprinted on the surface of said localized autogenous coating, and a second sheet including a support bearing a coating of a transfer medium on the first side of said support, said second sheet being positioned adjacent said first sheet with said first side adjacent and in superposed relationship to s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.