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:
Jan. 19, 1999
Filed:
May. 19, 1995
Terry J Scheffer, Portland, OR (US);
Arlie R Conner, Tualatin, OR (US);
Benjamin R Clifton, Oregon City, OR (US);
Dennis W Prince, Banks, OR (US);
In Focus Systems, Inc., Wilsonville, OR (US);
Abstract
Method and apparatus for providing gray level addressing for passive liquid crystal display (LCD) panels having overlapping row and column electrodes defining pixels are disclosed. Depending upon whether the rows are being addressed by 'standard' or 'Swift' addressing, the signals for applying to the column electrodes are determined by different calculations, in all of which modes the amplitudes of the column signals are related to the gray level desired to be displayed by the individual pixels. For a split interval system, column signals of appropriate amplitude and polarity are applied during different subintervals of a characteristic time interval of the display panel depending upon the method of addressing the rows. In the full interval mode, the column signals applied over a full time interval are based on the desired gray level of all the pixels in the column, adjusted to provide the proper rms voltage across all the pixels so that they display the desired gray levels. The adjustment can be spread across multiple addressing intervals and can be added into the column signal when rows are selected or can be applied to the column electrode when no row is selected.