Apparatus and method for modulation/demodulation with consecutive minimum runlength limitation
CA 2680404 C · Owner: Kahlman, Joseph A. H. M. · Inventors: Van Den Enden, Gijsbert J.; Schouhamer Immink, Kornelis A.; Kahlman, Joseph A. H. M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Problem: how to record and play back data at a high line density. Means for solving the problem: a DSV control bit determining/inserting unit (11) inserts DSV control bits for execution of DSV control into an input data string and outputs the data string including the DSV control bits to a modulation unit (12). The modulation unit (12) converts the data string with a basic data length of 2 bits into variable length code with a basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unit (13). The conversion table used by the modulation unit (12) includes substitution codes for limiting the number of consecutive …
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 May 25, 1999 and granted November 19, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 25, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 25, 2021.
- 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.