IN-PLANE SWITCHING TYPE LIQUID CRYSTAL DISPLAY DEVICE

• US 20100157222A1
• Filed: 03/03/2010
• Published: 06/24/2010
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Unified Innovative Technology, LLC
• Original Assignee: Casio Computer Company Limited
• Inventors: Kobayashi, Kunpei, ARAI, Norihiro, Nishino, Toshiharu
• Granted Patent: US 8,436,972 B2
• Time in Patent Office: Days
• US Class Current: 349/123
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A liquid crystal display device comprises a pair of substrates subjected to an aligning treatment in mutually parallel but opposite directions, a liquid crystal layer interposed between the pair of substrates, a first electrode bent into a “<” shape, and a second electrode formed via an insulating film with the first electrode. The first electrode comprises one linear section and another linear section that extend in directions that intersect the alignment treatment direction at different angles, a bent section that is provided at each end where the one linear section and the other linear section adjacent to each other and that extends in a direction that intersects the alignment treatment direction at an angle that is greater than each of the intersecting angles of the one linear section and the other linear section and the alignment treatment direction with respect to the alignment treatment directions.

Claims

1. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein the slit comprises a plurality of pairs of the opening regions, and each of the pairs of the opening regions comprises two opening regions that extend at respective angles that are symmetrical to each other with respect to a direction orthogonal to the directions of the aligning treatment.

2. The liquid crystal display device according to claim 1, wherein outside dimensions of the first electrode are larger than outside dimensions of the second electrode.

3. The liquid crystal display device according to claim 1, wherein the slit is formed so that opening regions whose degree of parallelism to the directions of the aligning treatment is higher than the degree of parallelism of other opening regions to the directions of the aligning treatment, are sandwiched by the other opening regions.

4. The liquid crystal display device according to claim 1, wherein the slit is formed so that opening regions whose degree of parallelism to the directions of the aligning treatment is lower than the degree of parallelism of other opening regions to the directions of the aligning treatment, are sandwiched by the other opening regions.

5. The liquid crystal display device according to claim 1, wherein the first electrode is formed of a transparent conductive film, and the transparent conductive film surrounds the slit.

6. The liquid crystal display device according to claim 1, wherein a plurality of the slits are formed for each display pixel of the liquid crystal display device.

7. The liquid crystal display device according to claim 1, wherein the liquid crystal layer is aligned so that long axes of liquid crystal molecules become parallel with the aligning-treated surfaces of the opposed substrates.

8. The liquid crystal display device according to claim 1, wherein the liquid crystal layer comprises liquid crystal molecules having positive dielectric anisotropy.

9. The liquid crystal display device according to claim 1, wherein the first electrode is positioned closer to the liquid crystal layer than the second electrode.

10. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein the slit comprises a plurality of opening regions extending at respective different angles to a first diagonal direction of a display pixel and a plurality of opening regions extending at respective different angles to a second diagonal direction of the display pixel.

11. The liquid crystal display device according to claim 10, wherein the slit is formed so that opening regions whose degree of parallelism to the directions of the aligning treatment is higher than the degree of parallelism of other opening regions to the directions of the aligning treatment, are sandwiched by the other opening regions.

12. The liquid crystal display device according to claim 10, wherein the first substrate of the pair of opposed substrates further comprises a signal line which extends in a direction parallel to the directions of the aligning treatment and a scan line which extends in a direction orthogonal to the directions of the aligning treatment.

13. The liquid crystal display device according to claim 12, wherein the first electrode is a pixel electrode connected to the signal line and the scan line via a thin film transistor, and the second electrode is a common electrode which is set to an equal potential between display pixels.

14. The liquid crystal display device according to claim 10, wherein a plurality of the slits are formed for each display pixel of the liquid crystal display device.

15. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein the slit comprises a plurality of pairs of the opening regions, and each of the pairs of the opening regions comprises two opening regions that extend at respective angles that are symmetrical to each other with respect to a direction orthogonal to an extending direction of a scan line; and

wherein the slit is formed so that opening regions whose degree of parallelism to an extending direction of a signal line is higher than the degree of parallelism of other opening regions to the extending direction of the signal line, are sandwiched by the other opening regions.

16. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein the slit comprises a plurality of pairs of the opening regions, and each of the pairs of the opening regions comprises two opening regions that extend at respective angles that are symmetrical to each other with respect to a direction orthogonal to an extending direction of a scan line; and

wherein the slit is formed so that opening regions whose degree of parallelism to an extending direction of a signal line is lower than the degree of parallelism of other opening regions to the extending direction of the signal line, are sandwiched by the other opening regions.

17. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein outside dimensions of the first electrode are larger than outside dimensions of the second electrode.

18. The liquid crystal display device according to claim 17, wherein one said first electrode and one said second electrode are disposed for each pixel of the liquid crystal display device;

and

wherein the second electrodes of adjacent pixels are electrically connected to each other by a common connection section.

19. The liquid crystal display device according to claim 17, wherein the first electrode is connected to a thin film transistor, and the second electrode is arranged so as to avoid a position where the thin film transistor is arranged.

20. A liquid crystal display device comprising a liquid crystal layer and a pair of opposed substrates, each of the opposed substrates having an aligning-treated surface that has been subjected to an aligning treatment, the opposed substrates being arranged so that their respective aligning-treated surfaces are opposed to each other with the liquid crystal layer therebetween;

wherein a first substrate of the pair of opposed substrates comprises;

a first electrode having a slit comprising a plurality of opening regions that are formed so as to be serially continuous, wherein the opening regions extend in directions different from each other and different from directions of the aligning treatment; and

a second electrode that covers the slit via an insulating layer;

wherein outside dimensions of the second electrode are smaller than outside dimensions of the first electrode.