Video signals
CA 2078431 A1 · Owner: British Broadcasting Corporation · Inventors: Weston, Martin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cross talk between luminance and chrominance is eliminated in a Weston Clean PAL codec by replacing the band pass filter used in a conventional codec with a high pass filter (L) and introducing a compensating low pass filter (X) into the chrominance path the , filters being chosen such that L=4F'*(1-F') and X(f)=(F'(f):(1-F'(f)) where F'=F(2fsc-f) and L is a low pass (5.5 MHz) filter 248 applied before transmission in the PAL channel.
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 January 24, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 24, 2014.
- 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.