Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9229284-B2
Application number	US-201214009754-A
Country	US
Kind code	B2
Filing date	Apr 13, 2012
Priority date	Apr 20, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A liquid crystal display device of the present invention is provided with: an array substrate ( 10 ) in which a pixel electrode ( 41 ), a TFT ( 20 ), and a storage capacitor element ( 30 ) are provided for each pixel (P); an opposite substrate ( 50 ) in which a plurality of common electrodes ( 59 A, 59 B) are provided for each pixel (P); a liquid crystal layer ( 81 ); and a driver circuit ( 4 ) that dividedly drives the liquid crystal layer ( 81 ) of each pixel (P) through each of the common electrodes ( 59 A, 59 B) by supplying a predetermined potential to each pixel electrode ( 41 ) and supplying different potentials to the respective common electrodes ( 59 A, 59 B) in each pixel (P). The liquid crystal display device according to the present invention has improved viewing angle dependency of the gamma characteristics, while increasing the aperture ratio of each pixel.

First claim

The invention claimed is:

1. A liquid crystal display device, having a display region provided with a plurality of pixels arranged in a prescribed pattern, each of the plurality of pixels being a smallest unit of a displayed image, the liquid crystal display device comprising:
an array substrate in which a pixel electrode, a switching element, and a storage capacitance element is provided for each of the pixels;
an opposite substrate disposed to face the array substrate, the opposite substrate having a plurality of common electrodes provided for each of the pixels;
a liquid crystal layer disposed between the array substrate and the opposite substrate so as to be interposed between each pixel electrode and a plurality of common electrodes facing said pixel electrode, thereby constituting each of the pixels; and
a driver circuit that supplies a prescribed potential to each pixel electrode, the driver circuit supplying different potentials to the respective common electrodes in each of the pixels so that the liquid crystal layer in each of the pixels separated in accordance with the respective common electrodes is separately driven,
wherein the plurality of pixels are arranged in a matrix, and
wherein, in each of the pixels, the plurality of common electrodes are aligned along a first direction that is one of a row direction and a column direction along which the pixels are arrayed, and each of the plurality of common electrodes is made of the same electrode in a group of pixels that are arrayed along a second direction that is perpendicular to the first direction.

2. The liquid crystal display device according to claim 1 ,
wherein the plurality of common electrodes in the respective pixels are separated from each other in each pixel group including a plurality of the pixels arrayed along the second direction, and
wherein the driver circuit conducts line inversion driving in which, in one display frame, respective adjacent common electrodes in pixels that are adjacent to each other along the first direction are supplied with different potentials, and a polarity of the potentials supplied to respective pixel electrodes is reversed for every pixel group made of a plurality of the pixels arrayed along the first direction.

3. The liquid crystal display device according to claim 1 ,
wherein the plurality of common electrodes in the respective pixels are separated from each other in each pixel group including a plurality of the pixels arrayed along the second direction, and
wherein the driver circuit conducts line inversion driving and common inversion driving, thereby reversing a relationship of the pixel electrodes and the common electrodes between high and low levels of potentials, to drive the liquid crystal layer separately for each of the common electrodes through AC driving, said line inversion driving being a driving method in which, in one display frame, polarities of potentials applied to the respective pixel electrodes are reversed for every pixel group made of a plurality of pixels arrayed along the second direction, and, in every display frame, polarities of potentials applied to the respective pixel electrodes are made opposite to the polarities of the respective pixel electrodes in a last display frame, said common inversion driving being a driving method in which a polarity of a potential supplied to at least one of the common electrodes in each of the pixels is reversed so as to be made opposite to a polarity of a potential supplied to a corresponding pixel electrode in synchronization with polarity inversion for a potential of said pixel electrode.

4. The liquid crystal display device according to claim 1 ,
wherein respective adjacent common electrodes of pixels that are adjacent to each other along the first direction are made of the same electrode, and
wherein the driver circuit conducts dot inversion driving in which, in one display frame, polarities of potentials supplied to the respective pixel electrodes are reversed for every one of pixels adjacent to each other.

5. The liquid crystal display device according to claim 1 ,
wherein the switching element is a thin film transistor, and
wherein the thin film transistor includes a semiconductor layer made of an oxide semiconductor.

6. The liquid crystal display device according to claim 5 , wherein the oxide semiconductor is an indium gallium zinc oxide.

7. A liquid crystal display device having a display region provided with a plurality of pixels arranged in a prescribed pattern, each of the plurality of pixels being a smallest unit of a displayed image, the liquid crystal display device comprising:
an array substrate in which a pixel electrode, a switching element, and a storage capacitance element is provided for each of the pixels;
an opposite substrate disposed to face the array substrate, the opposite substrate having a plurality of common electrodes provided for each of the pixels;
a liquid crystal layer disposed between the array substrate and the opposite substrate so as to be interposed between each pixel electrode and a plurality of common electrodes facing said pixel electrode, thereby constituting each of the pixels; and
a driver circuit that supplies a prescribed potential to each pixel electrode, the driver circuit supplying different potentials to the respective common electrodes in each of the pixels so that the liquid crystal layer in each of the pixels separated in accordance with the respective common electrodes is separately driven,
wherein a plurality of said pixel electrodes are arranged in a matrix,
wherein a plurality of common electrodes in each of the pixels are arranged along a first direction that is one of a row direction or a column direction along which the pixels are arrayed,
wherein respective common electrodes positioned at respective two ends of each of the pixels are each electrically connected to an adjacent common electrode of a pixel that is adjacent to said pixel along the first direction,
wherein, in each of the pixels, other common electrodes than a common electrode positioned at one end of the pixel are each electrically connected to a common electrode positioned one electrode closer to said one end in one of pixels that are adjacent to said pixel along a second direction that is perpendicular to the first direction, and
wherein, in each of the pixels, other common electrodes than a common electrode positioned at another end of the pixel are each electrically connected to a common electrode positioned one electrode closer to said another end in another of said adjacent pixels along the second direction.

8. The liquid crystal display device according to claim 7 ,
wherein the driver circuit conducts line inversion driving in which, in one display frame, polarities of potentials supplied to the respective pixel electrodes are reversed for every pixel group made of a plurality of pixels arrayed along the second direction.

9. The liquid crystal display device according to claim 7 ,
wherein the switching element is a thin film transistor, and
wherein the thin film transistor includes a semiconductor layer made of an oxide semiconductor.

10. The liquid crystal display device according to claim 9 , wherein the oxide semiconductor is an indium gallium zinc oxide.

11. A liquid crystal display device having a display region provided with a plurality of pixels arranged in a prescribed pattern, each of the plurality of pixels being a smallest unit of a displayed image, the liquid crystal display device comprising:
an array substrate in which a pixel electrode, a switching element, and a storage capacitance element is provided for each of the pixels;
an opposite substrate dispose

Assignees

• Uchida Seiichi
• Sharp Kk

Inventors

• Uchida Seiichi

Classifications

• G09G3/3655 Primary

  Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors · CPC title

• G02F2001/134345

  Physics · mapped topic

• G09G2300/0447

  for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA] · CPC title

• G09G2320/028

  by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction · CPC title

• G09G2300/0465

  Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness · CPC title