Method and apparatus for providing error correction to symbol level codes
CA 2013386 C · Owner: International Business Machines Corporation · Inventors: Hsiao, Mu Y.; Chen, Chin L.; Bossen, Douglas C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure An error correction coding system employs a single check symbol from an arbitrary sequence of information symbols to provide single error correction at the symbol level. The sequence of information symbols may in fact also be arbitrarily long. The coding system of the present invention provides both a method and apparatus for encoding the check symbol and a method and apparatus for error correction based upon the single coded symbol character. The system is particularly applicable for use in conjunction with bar code recognition systems but is in fact applicable to a broad range of coding systems, including optical character recognition and ordinary alphanumeric …
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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
- Filed March 29, 1990 and granted March 29, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 29, 2012.
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Timeline
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.