US RE40,771 E1 · Liquid crystal display device and method of driving the same

Abstract

A liquid crystal display device is formed by arranging a plurality of scanning lines 31, 32, . . . to which scanning signals are successively applied and a plurality of signal lines 41, 42, . . . to which data signals are successively applied to intersect at right angles. Mounted in the vicinity of each of the intersections of the scanning lines 31, 32, . . . and signals lines 41, 42, . . . are a TFT 5 electrically connected to both of the lines, and a pixel electrode 6 connected to the TFT 5. A common electrode is placed to face the pixel electrode 6 with liquid crystals 2 therebetween. One of electrodes of a pixel capacitance formed by the pixel electrode 6 is connected to a common line 9 for supplying a common signal to the common electrode 7. A dummy scanning line 30 for forming a capacitance is arranged outside of the scanning line 31 located at the outermost position on a scanning start side of scanning signal. In this structure, since an equal parasitic capacitance is generated in the pixels irrespectively of their positions, it is possible to eliminate defects, such as deterioration of display quality due to an appearance of a bright line in particular pixels.

Claims27

Dependent claims

A liquid crystal display device comprising:

a pair of substrates sandwiching liquid crystals therebetween;
a plurality of scanning lines to which scanning signals are successively applied;
a plurality of signal lines to which data signals are successively applied, said signal lines intersecting said scanning lines at right angles;
a switching element which is arranged in a vicinity of each of intersections of said scanning lines and said signal lines, and electrically connected to both of said scanning and signal lines;
a pixel electrode connected to each of said switching elements;
said scanning lines, signals lines, switching elements and pixel electrodes being formed on one of said substrates,
a common electrode formed on the other of said substrates so that said common electrode faces said pixel electrode with said liquid crystals therebetween;
a common line for supplying a common signal to said common electrode;
a pixel capacitance, one of electrodes of said pixel capacitance formed by said pixel electrode being connected to said common line;
and
a dummy scanning line formed outside of one of said scanning lines located at an outermost position on either a scanning start side or a scanning end side of scanning signal, for producing a parasitic capacitance between said dummy scanning line and the pixel electrode connected to the scanning line located at the outermost position.

8 more elements

A method of driving a liquid crystal display device including a plurality of scanning line to which scanning signals are successively applied, a plurality of signal lines to which data signals are successively applied, a switching element which is arranged in a vicinity of each of intersections of the scanning lines and the signal lines and connected to both of the scanning and signal lines, a pixel electrode connected to each of the switching element, a pixel capacitance formed by the pixel electrode, a common electrode which is arranged to face the pixel electrode, liquid crystals placed between the pixel electrode and the common electrode, and a dummy scanning line formed outside of one of the scanning lines located at an outermost position on either a scanning start side or a scanning end side of scanning signal to produce a parasitic capacitance between the dummy scanning line and the pixel electrode connected to the scanning line located at the outermost position, said method comprising the steps of:

supplying the scanning signal and the data signal to the switching element and supplying a common signal to one of electrodes of the pixel capacitance so as to change an electric potential between the pixel electrode and the common electrode and vary a transmittance of the liquid crystals;
and
inputting a signal to the dummy scanning line.

A pair of substrates sandwiching liquid crystals therebetween;

a plurality of scanning lines to which scanning signals are successively applied;
a plurality of signal lines to which data signals are successively applied, said signal lines intersecting said scanning lines at right angles;
a switching element which is arranged in a vicinity of each of intersections of said scanning lines and said signal lines, and electrically connected to both of said scanning and signal lines;
a pixel electrode connected to each of said switching elements;
said scanning lines, signal lines, switching elements and pixel electrodes being formed on one of said substrates,
a common electrode formed on the other of said substrates so that said common electrode faces said pixel electrode with said liquid crystals therebetween;
a common line to which a common signal is applied;
a pixel capacitance, one of electrodes of said pixel capacitance being connected to said common line;
and
a dummy scanning line formed outside of one of said scanning lines located at an outermost position on either a scanning start side or a scanning end side of scanning signal, for producing a parasitic capacitance between said dummy scanning line and the pixel electrode connected to the scanning line located at the outermost position.

7 more elements

Dependencies are inferred from the claim text.

Liquid crystal display device and method of driving the same

Life of this patent

Liquid crystal display device and method of driving the same

Life of this patent

Abstract

Claims27