Power system and scan method for liquid crystal display
CA 2062759 C · Owner: Poqet Computer Corporation · Inventors: Klinger, Lance T.; Yuan, Andy C.; Fairbanks, John P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A structure and method for controlling a liquid crystal display takes advantage of the sharp reflectance change over a small voltage change for new liquid crystal display materials applying ON and OFF pixel voltages very close to the transition voltage of the liquid crystal material and regulating the applied voltage to remain reliably near and on the desired side of this transition voltage. Also, a net zero DC voltage across pixels of the crystal is maintained using a switching mode close to half the frequency of prior art modes. Driving voltages are provided by a switching regulator rather than the prior art voltage divider, resulting in a significant reduction in operating power. The …
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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 June 29, 1990 and granted January 20, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 2012.
- 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.