Direct current restorer
CA 2003291 C · Owner: Nohara, Kazunori · Inventors: Nohara, Kazunori
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a direct current restorer applied to a pedestal clamp circuit of a television receiver or the like, in which an input video signal is compared with a pedestal level setting reference signal for every pedestal period and, based, on difference between the pedestal level of the input video signal and the level of the reference signal the direct current level of the input video signal is shifted. In this direct current restorer a direct, current according to the level variation of the reference signal may be superposed on the input video signal so that the direct current level of the input video signal is corrected according to the level variation of the reference …
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 November 17, 1989 and granted July 20, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 17, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 17, 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.