Method and device for marking and method for identifying a document using unique imprint derived from unique marking variations characterized using frequency analysis
US8638476B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2013 |
| Grant date | Jan 28, 2014 |
| Priority date | — |
| Expiry date | Jun 26, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/902
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A process for securing a document including a step of printing a distribution of dots on said document, said printing, as a result of unanticipated unknowns in printing, causing an unpredictable variation, dot by dot, of at least one geometric characteristic of the printed dots and prior to said print step, a step generating said distribution of dots so that at least half the dots of said distribution are not laterally juxtaposed to four other dots of said dot distribution, and at least one dimension of at least one part of the dots of said distribution of dots is of the same order of magnitude as the average for the absolute value of said unpredictable variation. In embodiments, during the step generating the dot distribution, more than half the dots do not touch any other dot of said distribution. In embodiments, during the step of generating the dot distribution, dots are produced of which at least one geometric characteristic is variable, the geometric amplitude of the generated variation having the order of magnitude of the average dimension of at least one part of the dots.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.