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:
Feb. 06, 1990
Filed:
Feb. 20, 1986
Seiko Epson Corporation, Tokyo, JP;
Abstract
In the matrix, a positive type liquid crystal of the twisted nematic type is driven by a thin film transistor arranged on a transparent substrate. The polarity of the video signal, originally generated for a cathode ray tube, is inverted within a driving circuit and the inverted negative video signal is used to drive the positive type liquid crystal display. In the range of voltages of the video signal which correspond to the white level, the active matrix panel is driven by stretching the voltage of the video signal such that comparable voltage-contrast characteristics are achieved with the liquid crystal display as with the cathode ray tube. Leakage current of the thin film transistor during off-periods is reduced by setting a gate voltage during the off-period which is within the range of voltage level of the power source.