US 5,598,285 A · Liquid crystal display device

A liquid crystal display device having a plurality of pixel elements and means for applying electrical signals to said plurality of pixel elements for varying the optical transmissivity thereof, said liquid crystal display device including:

a polarizer having at least one polarizing plate;
a liquid crystal layer extending in a plane parallel to said at least one polarizing plate;
a plurality of pixel electrodes, signal wiring electrodes and scanning wiring electrodes forming a plurality of thin film transistor devices corresponding to the plurality of pixel elements, said pixel electrodes extending in a common direction within each pixel element and said signal wiring electrodes extending in said common direction over more than one of said plurality of pixel elements;
and
common electrodes spaced from said plurality of thin film transistor devices, said common electrodes extending in said common direction over said more than one of said plurality of pixel elements;
wherein said means for applying electrical signals is arranged to apply said electrical signals in such a way that electric fields between said pixel electrodes and said common electrodes have components in a direction parallel to the plane of said liquid crystal layer, thereby to vary the optical transmissivity of light passing through said at least one polarizing plate and said liquid crystal layer for each pixel element;
and
wherein at least one of:
(a) there are a pair of pixel electrodes for each pixel element, said signal wiring electrodes extending between said pair of pixel electrodes at each pixel element, and said pair of pixel electrodes being disposed between a pair of common electrodes at each pixel element;
(b) said common electrodes are on an opposite side of said liquid crystal layer from said pixel electrodes;
(c) there is an insulating film between said pixel electrode and the common electrodes at each pixel element, and wherein said means for applying signals is arranged to apply a driving signal to said scanning wiring electrodes, said driving signal having a scanning period which is shorter than a time constant formed by a product of a specific resistance of said insulating film and a dielectric constant of said insulating film;
(d) at least one of said common electrodes is common to two adjacent ones of said plurality of pixel elements;
and
(e) said liquid crystal display device has an optical anisotropic medium with a phase difference less than a product of a thickness of the liquid crystal layer and a refractive index anisotropy of the liquid crystal layer, a difference between an absolute value of the product of the thickness of the liquid crystal layer and the refractive index anisotropy of the liquid crystal layer and an absolute value of the phase difference of the anisotropic medium being between 0.21 .mu.m and 0.36 .mu.m, and wherein the angles between components of electric fields in a direction parallel to the plane of said liquid crystal layer and the direction of orientation of molecules at opposite surfaces of the liquid crystal layer are the same.

11 more elements

A liquid crystal display device comprising:

a pair of substrates;
a liquid crystal layer interposed between said pair of substrates;
signal electrode lines and scanning electrode lines formed on one substrate of said pair of substrates and crossing each other in a matrix form, wherein a plurality of pixels are formed by adjoining said signal electrode lines and said scanning electrode lines;
wherein each pixel of said pixels comprises:
a semiconductor switching element formed proximate to a crossing point between a corresponding signal electrode line and scanning electrode line;
at least one common electrode line of a plurality of common electrode lines formed on said one substrate within said pixel and having a connection portion connecting said plurality of common electrode lines to one another over more than one of said plurality of pixels, one of said at least one common electrode line being disposed adjacent to one of said signal electrode lines;
at least one pixel electrode line formed on said substrate within a display area of said pixel, said at least one pixel electrode line being connected to said semiconductor switching element and disposed adjacent to said one of said signal electrode lines so that said one of said at least one common electrode line is interposed therebetween;
and
wherein a distance between said one of said at least one common electrode line and said one of said signal electrode lines of said pixel is smaller than a distance between portions of said at least one pixel electrode line adjacent to said one of said signal electrode lines and said one of said signal electrode lines.

6 more elements

Liquid crystal display device

Life of this patent

Liquid crystal display device

Life of this patent

Abstract

Claims81