Self-adapting vertical scan circuit for raster-scanned cathode ray tube displays
CA 2000011 C · Owner: International Business Machines Corporation · Inventors: Morrish, Andrew John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A vertical scan circuit for a display is described which allows automatic picture height and centering. The deflection voltages at the start and end of active video time, are stored by capacitors fed via switches activated by signal pulses. These stored voltages are compared to margin reference voltages Vtmref and Vbmref which correspond to the desired top and bottom of the picture as displayed for a particular monitor. The maximum deflection voltage on flyback (Vmax) and the slope of the signal (dv/dt) are adjusted so that the top margin voltage (Vtm) and the bottom margin voltage (Vbm), bear desired relationships to these reference voltages (Vtmref and Vbmref respectively) thus, ensuring …
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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 October 2, 1989 and granted November 29, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 2, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 2, 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.