Self-clocking glyph shape codes
CA 2044404 C · Owner: Flores, L. Prasadam · Inventors: Hecht, David L.; Flores, L. Prasadam; Bloomberg, Dan S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention provides self-clocking glyph shape codes for encoding digital data in the shapes of glyphs that are suitable for printing on hardcopy recording media. Advantageously, the glyphs are selected so that they tend not to degrade into each other when they are degraded and/or distorted as a result, for example, of being photocopied transmitted via facsimile, and/or scanned-in to an electronic document processing system. Moreover for at least some applications, the glyphs desirably are composed of printed pixel patterns containing nearly the same number of ON pixels and nearly the same number of OFF pixels, such that the code that is rendered by printing such glyphs on substantially …
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
- Filed June 12, 1991 and granted June 23, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 2013.
- 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.