Television tuning apparatus
CA 2117255 C · Owner: Thomson Consumer Electronics, Inc. · Inventors: Badger, David M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns an arrangement including a microprocessor controller PROM memory, and a digital to analog, converter (DAC) arrangement for generating a plurality of control voltages for trimming respective ones of a plurality of varactor controlled tunable filters. The controller couples digital control signals to the respective DACs which generate respective analog control voltages which are applied to the respective tunable filters. A tuning voltage generated by a closed control loop such as, phased locked loop also under the control of the controller is combined with the output control voltages generated by the respective DAC's in a resistance divider arrangement.
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 August 30, 1993 and granted November 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 30, 2015.
- 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.