Optically scanned document with fail-safe marking
CA 1316601 C · Owner: National Computer Systems, Inc. · Inventors: Koch, Vernon F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, 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 extent sufficient to connect at least two adjacent control marks on said first surface were such, control marks on the second surface of said sheet in a …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 20, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 20, 2010.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.