Focusing means for cathode ray tubes
CA 2104875 A1 · Owner: Banbury, John Randolph · Inventors: Banbury, John Randolph
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A cathode ray tube comprising a cathode (K) for emitting a beam of electrons; a grid (G) for controlling the intensity of the beam; three or more anodes (A1, A3, A4); means for varying the potential of at least one of the anodes (A3) for focusing the beam to form a spot on a screen; and an additional dynamic focus, electrode (A2) maintained generally at a potential close to the cathode/grid potential. Suitable means may be included for applying to said dynamic focus electrode a high frequency signal to provide a rapid focus control means. Said dynamic focus means may comprise a plurality of circumferentially disposed segments and include means for applying a separate high voltage to each …
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 February 27, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 27, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 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.