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. 28, 1998
Filed:
May. 01, 1995
Akira Tomiyoshi, Nara, JP;
Takafumi Kawaguchi, Yamatotakada, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A gray scale signal duty ratio conversion section employs D flip-flops and AND gates so as to generate detection pulses for rises and falls of the gray scale signal T based on the gray scale signal T input from the control circuit and the clock signal CKT. Among the rise-detection pulses and fall-detection pulses, only the fall-detection pulses are delayed by the D flip-flop by one clock, and the delayed fall-detection pulses and the rise-detection pulses are input to an RS flip-flop so that the altered gray scale signal T' is obtained as an output of the RS flip-flop. The altered gray scale signal T' thus obtained is a signal whose HIGH period is longer than the input gray scale T by one clock. Thus, it is possible to compensate for the phenomenon associated with a TFT liquid crystal display device driven by the gray-scale driving method where a voltage applied to a liquid crystal capacitance may vary with the turning off of the TFT is from the voltage it was charged with. As a result, the liquid crystal material is prevented from being deteriorated, whereby the display quality and the reliability of the liquid crystal display device are improved.