Liquid crystal display having wide viewing angle

• US 9,041,891 B2
• Filed: 03/03/2014
• Issued: 05/26/2015
• Est. Priority Date: 05/29/1997
• Status: Expired due to Fees

• Current Assignee: TCL China Star Optoelectronics Technology Co. Ltd. (TCL Technology Group Corp.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lyu, Jae-Jin, Lee, Hea-Ri, Chen, Jian-Min, Kim, Kyeong Hyeon
• Primary Examiner(s): Rude, Timothy L
• Application Number:
  US14/194,962
• Publication Number:
  US 20140293200A1
• Time in Patent Office: 449 Days
• Field of Search: 349/144
• US Class Current: 349/144
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/137 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
• CPC Class Codes: G02F 1/13712 the liquid crystal having negative dielectric anisotropy
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/128 field shaping

Abstract

Apertures are formed in the common electrode or in the pixel electrode of a liquid crystal display to form a fringe field. Storage capacitor electrodes are formed at the position corresponding to the apertures to prevent the light leakage due to the disclination caused by the fringe field. The apertures extend horizontally, vertically or obliquely. The apertures in adjacent pixel regions may have different directions to widen the viewing angle.

Claims

1. A liquid crystal display comprising:

a first substrate comprising a common electrode;

a second substrate opposite the first substrate;

a pixel electrode formed on the second substrate;

a black matrix pattern formed along a boundary of a plurality of pixel regions defined on the first substrate substantially in a matrix form;

a light shielding part formed on the second substrate, and disposed inside the pixel region and under the pixel electrode;

a first domain divider and a second domain divider formed in each pixel region on at least one of the first substrate and the second substrate; and

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and aligned substantially in a vertical direction to the first substrate when no electric field is applied to the liquid crystal layer, and the liquid crystal layer being interposed between the pixel electrode and the common electrode, and divided into a plurality of domain areas by the first domain divider and the second domain divider inside the pixel region when an electric field is applied to the liquid crystal layer,

wherein the first domain divider and the second domain divider in each pixel region are linear, respectively, are arranged substantially in a shape of chevron and are slantingly extended with respect to the gate line or the data line, respectively,

wherein shapes collectively defined by the first domain divider and the second domain divider in adjacent pixel regions in a pixel row direction are different from each other, and

wherein at least one of the first and the second domain dividers is arranged in a parallel direction with an extending direction of the light shielding part.

2. A liquid crystal display of claim 1, further comprising:

a plurality of data lines extended in a first direction; and

a plurality of gate lines extended in a second direction perpendicular to the first direction;

wherein the pixel electrode overlaps adjacent data lines, and

wherein the light shielding part is extended in a direction different from the first direction and the second direction.

3. A liquid crystal display of claim 2, wherein the first domain divider is located at the upper area of the pixel electrode and the second domain divider is located at the lower area of the pixel electrode.

4. A liquid crystal display of claim 3, wherein the first and the second domain dividers have one width.

5. A liquid crystal display of claim 1, further comprising:

a branch electrode formed on the second substrate, extended in the first direction and electrically connected to the light shielding part.

6. A liquid crystal display of claim 1, wherein the first and the second domain dividers meet each other at end portions of domain dividers.

7. A liquid crystal display comprising:

a first substrate comprising a common electrode;

a second substrate opposite the first substrate;

a pixel electrode formed on the second substrate;

a black matrix pattern formed along a boundary of a plurality of pixel regions defined on the first substrate substantially in a matrix form;

a branch electrode formed on the second substrate, overlapping the pixel electrode and extending in a first direction;

a storage capacitor electrode formed on the second substrate, disposed inside the pixel region and under the pixel electrode, electrically connected to the branch electrode and extended in a slanting direction with respect to the first direction;

a first domain divider and a second domain divider formed in each pixel region on at least one of the first substrate and the second substrate; and

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and aligned substantially in a vertical direction to the first substrate when no electric field is applied to the liquid crystal layer, the liquid crystal layer being interposed between the pixel electrode and the common electrode and divided into four different domain areas by the first domain divider and the second domain divider inside the pixel region when electric field is applied to the liquid crystal layer,

wherein the first domain divider and the second domain divider in each pixel region are linear, respectively, are arranged substantially in a shape of chevron and extended in a slanting direction with respect to the first direction, and

wherein shapes collectively defined by the first domain divider and the second domain divider in adjacent pixel regions in a pixel row direction are different from each other.

8. A liquid crystal display of claim 7, wherein at least one of the first domain divider and the second domain divider is arranged in a parallel direction with an extending direction of the storage capacitor electrode.

9. A liquid crystal display of claim 8, wherein the first domain divider is located at the upper area of the pixel electrode and the second domain divider is located at the lower area of the pixel electrode.

10. A liquid crystal display of claim 8, wherein the first and the second domain dividers have one width.

11. A liquid crystal display of claim 7, wherein the first and the second domain dividers meet each other at end portions of domain dividers.

12. A liquid crystal display comprising:

a first substrate comprising a common electrode;

a second substrate opposite the first substrate;

a plurality of data lines extended in a first direction;

a plurality of gate lines extended in a second direction perpendicular to the first direction;

a pixel electrode formed on the second substrate;

a black matrix pattern formed along a boundary of a plurality of pixel regions defined on the first substrate substantially in a matrix form;

a storage capacitor electrode formed on the second substrate, and disposed inside the pixel region and under the pixel electrode;

wherein one of the pixel electrode and the common electrode comprises a first linear aperture and a second linear aperture inside each pixel region and the first and the second linear apertures are extended in directions different from the first and the second directions, and are arranged substantially in a shape of chevron,

wherein shapes collectively defined by the first linear aperture and the second linear aperture in adjacent pixel regions in a pixel row direction are different from each other, and

wherein at least one of the first and the second linear apertures is arranged in a parallel direction with an extending direction of the storage capacitor electrode.

13. A liquid crystal display of claim 12, further comprising:

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and interposed between the first and the second substrates.

14. A liquid crystal display of claim 13, wherein the first linear aperture is located at the upper area of the pixel electrode and the second linear aperture is located at the lower area of the pixel electrode.

15. A liquid crystal display of claim 14, wherein the first and the second linear apertures have one width.

16. A liquid crystal display of claim 12, wherein the first and the second linear apertures meet each other at end portions of apertures.

17. A liquid crystal display comprising:

a first substrate comprising a common electrode;

a second substrate opposite the first substrate;

a pixel electrode formed on the second substrate;

a black matrix pattern formed along a boundary of a plurality of pixel regions defined on the first substrate substantially in a matrix form;

a storage capacitor electrode formed on the second substrate, and disposed inside the pixel region and under the pixel electrode;

a first domain divider and a second domain divider formed in each pixel region on at least one of the first substrate and the second substrate; and

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and aligned substantially in a vertical direction to the first substrate when no electric field is applied to the liquid crystal layer, the liquid crystal layer being interposed between the pixel electrode and the common electrode,

wherein the first domain divider and the second domain divider are linear, respectively, are arranged substantially in a shape of chevron, and are slantingly extended with respect to one of boundaries of the pixel electrode,

wherein shapes collectively defined by the first domain divider and the second domain divider in adjacent pixel regions in a pixel row direction are different from each other,

wherein the liquid crystal layer is divided into four different domain areas by the first domain divider and the second domain divider inside the pixel region when electric field is applied to the liquid crystal layer,

wherein the first domain divider is located at the upper area of the pixel electrode and the second domain divider is located at the lower area of the pixel electrode, and

wherein no other linear domain divider crosses over the first domain divider or the second domain divider, and no other linear domain divider is arranged in a shape of Y with the first domain divider or the second divider.

18. A liquid crystal display of claim 17, wherein the first and the second domain dividers meet each other at end portions of domain dividers.

19. A liquid crystal display comprising:

a first substrate comprising a common electrode;

a second substrate opposite the first substrate;

a pixel electrode formed on the second substrate;

a black matrix pattern formed along a boundary of a plurality of pixel regions defined on the first substrate substantially in a matrix form;

a storage capacitor electrode formed on the second substrate, and disposed inside the pixel region and under the pixel electrode; and

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and aligned substantially in a vertical direction to the first substrate when no electric field is applied to the liquid crystal layer, the liquid crystal layer being interposed between the pixel electrode and the common electrode,

wherein the liquid crystal layer is divided into four different domain areas inside each pixel region when electric field is applied to the liquid crystal layer,

wherein the storage capacitor electrode is arranged inside the pixel region along boundaries between a plurality of domain areas,

wherein the boundaries between a plurality of domain areas are arranged substantially in a shape of chevron, and

wherein shapes collectively defined by the boundaries between the domain areas in adjacent pixel regions in a pixel row direction are different from each other.

20. The liquid crystal display of claim 19, further comprising:

a plurality of data lines which extend in a first direction;

a plurality of gate lines which extend in a second direction substantially perpendicular to the first direction;

wherein the pixel electrode overlaps adjacent data lines of the plurality of data lines.

21. The liquid crystal display of claim 20, further comprising:

a branch electrode disposed on the second substrate, wherein the branch electrode extends in the first direction and electrically connects to the storage capacitor electrode.

22. The liquid crystal display of claim 20, further comprising:

an organic insulating layer disposed on the plurality of data lines and the plurality of gate lines, wherein the pixel electrode is disposed on the organic insulating layer.

23. The liquid crystal display of claim 22, wherein the organic insulating layer is equal or more than about 3 μ

in thickness.

24. The liquid crystal display of claim 23, further comprising:

an organic spacer disposed between the first substrate and the second substrate.

25. The liquid crystal display of claim 19, wherein the liquid crystal layer comprises a chiral nematic liquid crystal.

26. The liquid crystal display of claim 25, further comprising:

two alignment layers disposed on the first substrate and the second substrate respectively and the alignment layers are in a non-rubbed state.

27. The liquid crystal display of claim 26, further comprising:

an organic insulating layer of equal or more than about 3 μ

in thickness disposed on the second substrate.

28. A liquid crystal display comprising:

a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and aligned substantially in a vertical direction to the first substrate when no electric field is applied to the liquid crystal layer, the liquid crystal layer being divided into four different domain areas inside in each of a plurality of pixel regions defined therein and arranged substantially in a matrix form when electric field is applied to the liquid crystal layer; and

a light shielding part arranged inside each pixel region along at least one boundary between a plurality of domain areas;

wherein the at least one boundary between a plurality of domain areas is arranged substantially in a shape of chevron, and

wherein shapes collectively defined by the at least one boundaries between the domain areas in adjacent pixel regions in a pixel row direction are different from each other.

29. The liquid crystal display of claim 28, wherein the liquid crystal layer comprises a nematic liquid crystal including chiral dopant of about 0.01 wt % to about 3.0 wt %.