Missing copy detector
CA 1310091 C · Owner: Roulin, Daniel · Inventors: Roulin, Daniel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical scanner scans the surface of printed material at a particular position of the surface to determine if the surface is properly marked. The output level of the scanner at that position is compared with the output level of a differential signal level generator. If the two levels are substantially the same, then no error is indicated. If the two levels are different then an error, is indicated and the process is stopped to correct the error.
Read the whole patent
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 November 10, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 10, 2009.
- 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.