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:
Apr. 08, 2008
Filed:
May. 21, 2004
Marshall J. Bell, Chandler, AZ (US);
Richard I. Mccartney, Scotts Valley, CA (US);
Marshall J. Bell, Chandler, AZ (US);
Richard I. McCartney, Scotts Valley, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method and circuit for providing analog voltages to an LCD panel based on digital voltages. A gamma curve defining a relationship between the applied voltage and a luminescence of the liquid crystals is implemented in a timing controller through a look-up table, an algorithm, and the like. The digital grey level voltages provided by the timing controller are converted to analog voltages by a linear digital-analog-converter (DAC) in each column driver. Implementation of the gamma curve in the timing controller and use of linear DAC allows accommodation of higher bit rate without significant die area increase. Furthermore, look-up table style implementation of the gamma curve allows for easy modification of the curve for temperature, color temperature, different color schemes, and the like.