Method and apparatus for providing periodic subscription television services
CA 2136957 C · Owner: Blonder Tongue Laboratories, Inc. · Inventors: Rustagi, Vibha; Parikh, Himanshu; Edwards, Robert J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus of providing periodic subscription television services where a microprocessor (300) controls a service denying switch (389) and a high frequency amplifier (387) such that service may be denied using the service denying switch (389) of the high frequency amplifier (387). In addition the high frequency amplifier (387) may be set by the microprocessor (300) at various amplitude levels depending upon the number of television receivers and VCR's at the subscriber location. Also the high frequency amplifier (387) may include bandpass filter circuits under microprocessor control for limiting service to the subscriber.
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 June 1, 1993 and granted May 11, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 1, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 1, 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.