Security devices
Abstract
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.
Inventors
- 👤 Peter D. Lee
Bibliographic Details
Claims Analysis
Total Claims: 11References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |