Liquid crystal display

• US 6,456,350 B1
• Filed: 05/03/1999
• Issued: 09/24/2002
• Est. Priority Date: 05/08/1998
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Yanagawa, Kazuhiko, Ashizawa, Keiichiro, Kamoshida, Kenta, Hikiba, Masayuki
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, DUNG T
• Application Number:
  US09/303,429
• Time in Patent Office: 1,240 Days
• Field of Search: 349/141, 349/143, 349/139
• US Class Current: 349/141
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 2201/121 common or background

Abstract

Wave-form distortion of a reference signal or signals being supplied to an opposed electrode can be suppressed without suffering from an increase in the size of the it “window casing” structure. In a liquid crystal display device having respective pixel regions laid out in a matrix form in a display area on a liquid crystal-side surface of one transparent substrate of respective transparent substrates that are disposed opposite each other with a liquid crystal sandwiched therebetween, and also having a pixel electrode and an opposed electrode that are disposed so that these electrodes are spaced apart from each other in each of these pixel regions, the transmissivity of light travelling between respective electrodes is controlled by an electric field created between respective ones of these electrodes. In this display device, parallel opposed voltage signal lines which cause respective opposed electrodes within respective pixel regions to be connected together extend in a row direction, and a common bus line connecting respective ones of said opposed voltage signal lines is formed within said display area so that it extends in a column direction.

Claims

1. A liquid crystal display comprising respective pixel regions laid out in a matrix form in a display area on a liquid crystal-side surface of one transparent substrate of respective transparent substrates disposed opposite each other with a liquid crystal sandwiched therebetween, and a pixel electrode and an opposed electrode arranged so as to be spaced apart from each other in each of these pixel regions, wherein the transmissivity of light passing between respective electrodes is controlled by an electric field created between these respective electrodes, and

wherein parallel opposed voltage signal lines and parallel scan signal lines extend in a row direction of the pixel regions and a respective one of said opposed voltage signal lines is disposed between two of the scan lines extending in the row direction and connects together respective opposed electrodes within each of the pixel regions laid out in the row direction, and

wherein a common bus line connecting together respective ones of said opposed voltage signal lines is formed within said display area so that it extends in the column direction, and wherein at least on one end side of respective opposed voltage signal lines lying outside of the display area, a further common bus line is formed by which these opposed voltage signal lines are connected together.

2. A liquid crystal display according to claim 1, wherein a plurality of common bus lines are formed in the display area to extend in the column direction.

3. A liquid crystal display according to claim 2, wherein the common bus line is constituted by connecting an opposed electrode formed in a pixel region to a corresponding opposed electrode in a pixel region neighboring thereto in the column direction.

4. A liquid crystal display according to claim 1, wherein at one end side of respective opposed voltage signal lines lying outside of the display area, the further common bus line is formed by which these opposed voltage signal lines are connected together, and wherein this further common bus line does not cross over any of said scan signal lines.

5. A liquid crystal display according to claim 1, wherein image signal lines extending in the column direction are formed on the opposite sides of said pixel regions disposed in the column direction so that an image signal selected from one of the image signal lines is supplied to each pixel region, and

each of the pixel regions on one side of a boundary defined by the common bus line extending within the display area is arranged such that a pixel signal for a pixel electrode formed therein is taken from an image signal line disposed on said one sides whereas each pixel region on a remaining side allows a pixel signal for a pixel electrode formed therein to be taken from an image signal line laid out on the remaining side.

6. A liquid crystal display according to claim 5, wherein those opposed electrodes of respective pixel regions neighboring each other while defining as a boundary the common bus line extending within the display area include respective ones of respective opposed electrodes adjacent to the common bus line which are rendered integral with one another to cover a region between them while simultaneously letting the common bus line be formed overlying the integral opposed electrodes for connection to the opposed electrodes.

7. A liquid crystal display according to as claim 6, wherein supply of the selected image signal from the image signal line toward the pixel electrode is effected through a switching element.

8. A liquid crystal display according to claim 1, wherein those opposed electrodes of respective pixel regions disposed on the opposite sides of the common bus line extending within the display area are formed in close proximity to the common bus line and also are formed integrally with the common bus line.

9. A liquid crystal display according to claim 1, wherein video signal lines are provided, and wherein each of the video signal lines disposed on the left side of said common bus line are laid out on the left side of respective pixel electrodes which are supplied with a video signal via respective video signal lines, and each of the video signal lines disposed on the right side of said common bus line are laid out on the right side of respective pixel electrodes which are supplied with a video signal via respective video signal lines.

10. A liquid crystal display according to claim 1, wherein a respective one of said opposed voltage signal lines is disposed substantially in a center between two of the scan lines extending in the row direction.