Display system
CA 2043175 C · Owner: International Business Machines Corporation · Inventors: Beeteson, John S.; Pietrzak, Christopher C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A display system for displaying a visual image in response to a video signal comprising a liquid crystal display panel divided into a plurality of addressable variable brightness sections, address means for generating a section address corresponding to a section in response to a timing signal, driver means for varying the brightness of the section in response to the brightness signal derived from the video signal, characterized in that the display system further comprises a memory for storing a predetermined correction signal corresponding to the section, and control means coupled to the driver means for varying the brightness signal to reduce brightness non-uniformities in the displayed …
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 May 24, 1991 and granted March 5, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 24, 2013.
- 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.