Numbered documents
US4645240A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1985 |
| Grant date | Feb 24, 1987 |
| Priority date | — |
| Expiry date | Apr 23, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F3/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to documents, such as banknotes, which are produced and used in large numbers and which, for a given series, are identical one with another except for a unique multi-digit number upon each individual document, the number thus uniquely identifying that document within the series. According to the present invention, to render unauthorized reproduction of the document more difficult, on each document, at least two characters in the identifying number differ from each other (in addition to any differences in the letters or digits which they represent) in one or more visible characteristics. Thus the differing characters may have different heights or widths or be in different styles of type. Preferably, the identifying number appears twice on each document, in diagonally opposite corners, and preferably the variation of physical characteristics of the characters along the length of one of the numbers is reversed in direction in the other of the numbers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.