Optically scanned document with fail-safe marking
US5001330A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1988 |
| Grant date | Mar 19, 1991 |
| Priority date | — |
| Expiry date | Mar 2, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/06009
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processing form used with photosensing apparatus that senses the presence of indicia in indicia-receiving locations on the form comprises a sheet of paper or like material. The form has a first control mark column containing a plurality of control marks in specified relation to a plurality of indicia-receiving locations on a first surface of said sheet. On the second surface of the sheet is a fail-safe mark opposite to and aligned with the first control mark column. The fail-safe mark has a continuous extend sufficient to connect at least two adjacent marks on said first surface, were such control marks on the second surface of said sheet in a location immediately opposite their location on said first surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.