US 5,459,596 A · Active matrix liquid crystal display with supplemental capacitor line which overlaps signal line

Abstract

An active matrix type liquid crystal display device having a plurality of scan lines, a plurality of signal lines intersected with the plurality of scan lines, the plurality of scan lines being insulated from the plurality of signal lines, a thin film transistor element having a gate portion and a drain portion and disposed at each intersection of the plurality of scan lines and the plurality of signal lines, the gate portion being connected to a scan line at the intersection, the drain portion being connected to a signal line at the intersection, an array substrate formed in the intersection and having a pixel electrode, the pixel electrode being electrically connected to the source portion of the thin film transistor element, an opposite substrate having an opposite electrode opposed to the array substrate, a liquid crystal layer disposed between the array substrate and the opposite substrate, and a shield electrode disposed on the array substrate, the shield electrode being overlaid through an insulation layer with at least part of the pixel electrode and with at least part of at least either the scan line or signal line.

Claims6

Dependent claims

An active matrix type liquid crystal display device, comprising:

an array substrate, said array substrate including;
a first substrate,
a plurality of scan lines and a plurality of signal lines formed on said first substrate,
said plurality of signal lines intersecting said plurality of scan lines and insulated from said plurality of scan lines,
a thin film transistor element having a gate portion, drain portion and source portion, and disposed at each intersection of said plurality of scan lines and signal lines, said gate portion being connected to said scan line, and said drain portion being electrically connected to said signal line,
a separate pixel electrode electrically connected to said source portion of each said thin film transistor element,
a shield electrode layer extending in lapped relation with at least one side of said pixel electrode and in lapped relation with a portion of a signal line, the intersecting ones of said scan and signal lines being in proximate relation to adjacent sides of said pixel electrode, said shield electrode layer extending in lapped relation with at least one side of a plurality of said pixel electrodes, and
an insulation layer disposed between said shield electrode layer and said pixel electrode and said portion of said signal line;
a second substrate having an opposite electrode and disposed in opposed relation with said array substrate;
and
a liquid crystal layer disposed between said array and second substrates.

8 more elements

An active matrix type liquid crystal display device, comprising:

an array substrate, said array substrate including;
a first substrate,
a plurality of scan lines and a plurality of signal lines formed on said first substrate,
said plurality of signal lines intersecting said plurality of scan lines and insulated from said plurality of scan lines,
a thin film transistor element having a gate portion, drain portion and source portion, and disposed at each intersection of said plurality of scan lines and signal lines, said gate portion being connected to said scan line, and said drain portion being electrically connected to said signal line,
a separate pixel electrode electrically connected to said source portion of each said thin film transistor element,
a shield electrode layer extending in lapped relation with at least one side of said pixel electrode and with a portion of one of intersecting ones of said scan lines and signal lines, the intersecting ones of said scan and signal lines being in proximate relation to adjacent sides of said pixel electrode, said shield electrode layer extending in lapped relation with at least one side of a plurality of said pixel electrodes,
an insulation layer disposed between said shield electrode layer and said pixel electrode and said portion of said one of said scan and signal lines, and
a storage capacitor formed at a location where said shield electrode is lapped with the side of said pixel electrode;
a second substrate having an opposite electrode and disposed in opposed relation with said array substrate;
and
a liquid crystal layer disposed between said array and second substrates,
wherein a width W.sub.cs of said shield electrode layer and said pixel electrode in lapped relation, is given by the following equation:
0. 7 W.sub.cs.sup.opt <W.sub.cs <2W.sub.cs.sup.opt
where W.sub.cs.sup.opt is an optimum lap width having a minimum deviation of a pixel voltage shift,
where
W.sub.cs.sup.opt =(L.sub.g .multidot.L.sub.cs .multidot.C.sub.si -2.beta..multidot.C.sub.1c-max) / (2L.sub.cs .multidot.C.sub.si)
where
L.sub.g is the width of the gate electrode;
L .sub.cs is the length of the center line of the portion where the pixel electrode and the shield electrode which forms a storage capacitor is overlapped;
C .sub.si is the capacitance of the storage capacitor per unit si area;
C.sub.1c--max is the maximum capacitance of one pixel of the LCD;
C.sub.1c--min is the minimum capacitance of one pixel of the LCD;
and
.beta. is a constant (where .beta.=(C.sub.1c-max +C.sub.1c--min) /2C.sub.1c-max).

22 more elements

Dependencies are inferred from the claim text.

Active matrix liquid crystal display with supplemental capacitor line which overlaps signal line

Life of this patent

Active matrix liquid crystal display with supplemental capacitor line which overlaps signal line

Life of this patent

Abstract

Claims6