Method for maintaining the white colour point in a field-sequential lcd over time
CA 2519967 C · Owner: Research In Motion Limited · Inventors: Drader, Marc; Mailloux, Jerry; Robinson, James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A field sequential liquid crystal display maintains its white colour point through compensation values to at least one colour light emitting diode that illuminates the display. The compensation values may be impedances to control the current or pulsing of the current source according to a pulse width modulation technique. A degradation curve may be used to calculate extrapolate the theoretical forward voltage of the light emitting diode. Additional complexity arises from the need for calculating uptime for multiple light emitting diodes of different colours. Brightness levels may also be factored in.
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 September 16, 2005 and granted November 27, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 16, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.