Method and apparatus for validating character strings
CA 2006230 C · Owner: Bell-Northern Research Ltd. · Inventors: Littlewood, Timothy James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a method of and apparatus for validating character sequences, for example strings of characters generated by keyboards or keypads in telephone systems computers, and the, like, increased speed and reduced memory requirements are achieved by comparing the characters with a database representing valid sequences of characters, the database comprising one or more segments each comprising valid character sequences. A potential range of characters is extrapolated from a character of the input character sequence taking into account possible values of possible succeeding characters. This potential range of sequences is than compared with a database segment. If there is intersection between the …
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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 December 20, 1989 and granted October 26, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2011.
- 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.