Security document and method for making same using an alternating dot pattern
US4351547A · kind A · utility
49Cited by
6References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1979 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Oct 11, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/902
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An improved copy-proof document is disclosed having a cancellation phrase with an alternating dot pattern which enhances both the detail rendition and protection of such documents. The method of making such a document by preprinting the cancellation phrase in a single tone pattern of alternating dot sizes is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.