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:
Sep. 30, 1997
Filed:
Mar. 06, 1995
Sherman Weisbrod, Skillman, NJ (US);
Thomson Consumer Electronics, S.A., Courbevoie, FR;
Abstract
A video display driver applies a video signal to pixels arranged in columns and rows of a liquid crystal display. A given column or data line driver includes a field effect transistor that operates as a comparator. The comparator is responsive to the video signal and to a reference ramp signal. A triggering voltage of the comparator is automatically and periodically adjusted. A drain voltage of the transistor that is equal to a threshold voltage of the transistor is developed in a stray capacitance, during the automatic adjustment period. A pulse signal, is coupled via the capacitance to increase the drain voltage. The drain voltage is applied to a gate electrode of a second field effect transistor that applies a data ramp voltage to the pixels. The pulse signal provides a small amount of drive in the second transistor.