The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 04, 2008
Filed:
May. 24, 2004
Brian D. Cull, Glendale, AZ (US);
Dennis M. Davey, Glendale, AZ (US);
Eric D. Ronning, Glendale, AZ (US);
Brian D. Cull, Glendale, AZ (US);
Dennis M. Davey, Glendale, AZ (US);
Eric D. Ronning, Glendale, AZ (US);
Honeywell International, Inc., Morristown, NJ (US);
Abstract
Methods and apparatus are provided for a backlit display with variable luminance and chrominance. The apparatus comprises i groups of LEDs of different colors and one or more sensors optically coupled to the LEDs. The combined light produced by the LEDs is directed to a transmissive liquid crystal display, preferably through a diffusing layer. The sensors monitor the output Sof each group of LEDs. Sfor each group of LEDs is multiplied by a chrominance determining parameter Kto obtain K*Swhich is then compared to a commanded luminance signal Lto obtain L−K*S, which difference is used to adjust the drive current to each group of LEDs to achieve Lwith the desired chrominance set by K. By changing Kand Lthe chrominance and luminescence of the display may be varied and aging effects compensated.