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. 03, 2001
Filed:
Jun. 30, 1998
Shigeki Okutani, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A halftone-level reference voltage is generated by a resistance-type potential divider circuit from a potential between a high-potential grayscale voltage and a low-potential grayscale voltage on the side of positive polarity, and a halftone-level grayscale voltage, which is capable of being varied, is generated from the halftone reference voltage by an amplifier, which uses a variable resistor as a feedback resistor. All grayscale voltages on the side of positive polarity are inverted with respect to the ground potential of a liquid crystal panel and amplified by the same ratio by amplifiers. As a result, grayscale voltages on the side of negative polarity are produced as outputs. Potentials to which feed-through correction values have been added are set individually as liquid crystal ground potentials on low- and high-potential sides. With regard to halftone levels, feed-through correction values are adjusted automatically in conformity with amount of change in grayscale voltage.