Gradation corrector
CA 2069366 C · Owner: Kageyama, Atsuhisa · Inventors: Kageyama, Atsuhisa; Tsuji, Toshiaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A gradation corrector for use in a television receiver which can subject a signal at any luminance level to non-linear correction to provide optimum image quality. Memory stores therein luminance histogram of an input signal. On the basis of the data a circuit, detects a total frequency, a circuit detects luminance distribution, and a circuit detects the expanse of the luminance distribution. A circuit calculates a fixed value to be added. Further, a circuit detects a minimum luminance level, and a circuit detects an average luminance level. A circuit calculates an accumulation starting point and a circuit calculates an accumulation stopping point. An adder adds the calculated fixed value …
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 25, 1992 and granted April 20, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 25, 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.