Security devices
US4290630A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 27, 1978 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | Feb 27, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/904
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A sheet element, such as a banknote, having an authenticating device in the form of a strip extending across the sheet and having at least one edge provided with a non-rectilinear portion or portions providing difficulty in copying for the forger and preferably shaped to provide coded information relating to the sheet element. In the case of a banknote, one or both edges of the strip may have wavy-shaped portion or portions, of which characteristics such as amplitude and periodicity can be employed to encode such information as the issuing authority, currency, denomination and serial number. Other aspects of the invention concern a method of verification comprising providing a sheet element as above and sensing the non-rectilinear edge or edges to derive the coded information, and a method of slitting a sheet comprising operating a slitting assembly to slit the sheet along a number of slitting lines into a plurality of strips as aforesaid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.