Liquid crystal display device with electrode having opening over thin film transistor

• US 8,804,081 B2
• Filed: 10/06/2010
• Issued: 08/12/2014
• Est. Priority Date: 12/18/2009
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Song, Jang-Kun, Ham, Yeon-Sik, Kim, Kang-Woo, Jeon, Yeon-Mun, Lee, Jeong Hyun
• Primary Examiner(s): Nguyen, Hoan C
• Application Number:
  US12/899,019
• Publication Number:
  US 20110149186A1
• Time in Patent Office: 1,406 Days
• Field of Search: 349 42- 43
• US Class Current: 349/141
• CPC Class Codes: G02F 1/1343 Electrodes reflective electrodes G02F1/133553
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• 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 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1552 Inner electrode, e.g. the electrochromic layer being sandwiched between the inner electrode and the support substrate
• CPC Class Codes: G02F 2201/50 Protective arrangements

Abstract

A liquid crystal display device includes a first substrate, a second substrate facing the first substrate, a dual passivation layer disposed between the first substrate and the second substrate. The dual passivation layer includes a first passivation layer and a second passivation layer. A refractive index of the first passivation layer is different from a refractive index of the second passivation layer.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a second substrate facing the first substrate;

a liquid crystal layer interposed between the first substrate and the second substrate;

a gate line disposed between the first substrate and the liquid crystal layer;

a data line disposed between the first substrate and the liquid crystal layer;

a pixel connected to the gate line and the data line, the pixel comprising;

a thin film transistor disposed on the first substrate and connected to a first portion of the data line;

a pixel electrode connected to the thin film transistor and including an opening formed therein overlapping the thin film transistor; and

a reference electrode disposed on the first substrate and overlapping the pixel electrode, the reference electrode comprising;

a first connection part disposed substantially parallel to the data line;

a second connection part disposed substantially parallel to the gate line and connected to the first connection part;

a branch electrode, comprising;

a first part;

a second part connected to the first part; and

a third part connected to the first part and the second connection part, wherein the second part forms a first angle with the first part,

the third part forms a second angle with the first part and a third angle with the second connection part,

wherein the thin film transistor comprises a source electrode being a portion of the data line, a drain electrode parallel the data line, and a channel area disposed under the data line and the drain electrode,

wherein a first opening is formed in the reference electrode overlapping the channel area between the source electrode and the drain electrode.

2. The liquid crystal display device of claim 1, wherein the first connection part overlaps a second portion of the data line.

3. The liquid crystal display device of claim 1, wherein a second opening is formed in the first connection part of the reference electrode and overlaps a second portion of the data line.

4. The liquid crystal display device of claim 1, wherein the pixel further comprises a shielding electrode disposed under the data line and on the first substrate and overlapping a second portion of the data line.

5. The liquid crystal display device of claim 4, wherein

a ratio of a distance between the shielding electrode and the pixel electrode to a width of the shielding electrode is 10:

17,

a ratio of a width of the data line to the width of the shielding electrode is 7;

17,

a ratio of a width of the second opening of the reference electrode to the width of the shielding electrode is 9;

17, and

a ratio of a width of the branch electrode of the reference electrode to the width of the shielding electrode is 9;

17.

6. The liquid crystal display device of claim 1, further comprising a plurality of pixels, wherein the pixel, which is connected to the gate line and the data line, of the plurality of pixels is one of a green pixel, a red pixel and a blue pixel.

7. The liquid crystal display of claim 6, further comprising a reference voltage line disposed on the first substrate, and

wherein the reference voltage line is disposed adjacent to the gate line and includes an expanded portion connected to at least one of the red pixel and the blue pixel.

8. The liquid display device of claim 6, further comprising

a reference voltage line disposed on the first substrate;

and

a plurality of gate lines disposed on the first substrate, and

wherein the reference voltage line is disposed between two adjacent gate lines of the plurality of gate lines and includes an expanded portion connected to the green pixel.

9. The liquid display device of claim 8, wherein the pixel electrode of the pixel does not overlap the expanded portion of the reference voltage line.

10. The liquid display device of claim 6, wherein an aperture ratio of the green pixel is less than at least one of an aperture ratio of the red pixel and an aperture ratio of the blue pixel.

11. The liquid display device of claim 1, further comprising a dual passivation layer disposed between the reference electrode and the pixel electrode, the dual passivation layer comprising:

a first passivation layer; and

a second passivation layer, wherein

a refractive index of the first passivation layer is different from a refractive index of the second passivation layer.

12. The liquid crystal display device of claim 11, wherein a nitrogen content of the first passivation layer is different from a nitrogen content of the second passivation layer.

13. The liquid crystal display device of claim 12, wherein the nitrogen content of the first passivation layer is greater than the nitrogen content of the second passivation layer.

14. The liquid crystal display device of claim 11, wherein a thickness of the dual passivation layer is in a range of about 5500 angstroms through about 6500 angstroms.

15. The liquid crystal display device of claim 11, wherein

the refractive index of the first passivation layer is in a range of about 1.4 through about 1.6, and

the refractive index of the second passivation layer is in a range of about 1.6 through about 2.2.

26. The liquid crystal display device of claim 1, wherein

the reference electrode has a second opening overlapping the data line.

16. A liquid crystal display device comprising:

a first substrate;

a second substrate facing the first substrate;

a liquid crystal layer interposed between the first substrate and the second substrate;

a data line disposed on the first substrate; and

a pixel disposed adjacent to the data line, the pixel comprising;

a pixel electrode disposed on the first substrate;

a passivation layer disposed on the first substrate and the pixel electrode; and

a reference electrode disposed on the first substrate and on the passivation layer, and

wherein the reference electrode has an opening overlapping the data line, and

wherein the pixel electrode does not overlap the data line.

17. The liquid crystal display device of claim 16, wherein a distance, measured along a plane defined by the first substrate, between the data line and the reference electrode is less than a distance, measured along the plane defined by the first substrate, between the data line and the pixel electrode.

18. The liquid crystal display device of claim 16, wherein the distance between the data line and the reference electrode is less than the distance between the data line and the pixel electrode by about 3 micrometers.

19. The liquid crystal display device of claim 16, wherein

a distance between the data line and the reference electrode is about 2.5 micrometers, and

a distance between the data line and the pixel electrode is about 5.5 micrometers.

20. The liquid crystal display device of claim 16, further comprising a plurality of pixels, wherein

reference electrodes of two adjacent pixels of the plurality of pixels are connected to each other via a connection member, and

the connection member overlaps at least a portion of the data line disposed between the reference electrodes.

21. The liquid display device of claim 16, wherein the passivation layer comprises

a first passivation layer;

and

a second passivation layer, wherein

a refractive index of the first passivation layer is different from a refractive index of the second passivation layer.

22. The liquid crystal display device of claim 21, wherein a nitrogen content of the first passivation layer is different from a nitrogen content of the second passivation layer.

23. The liquid crystal display device of claim 22, wherein the nitrogen content of the first passivation layer is greater than the nitrogen content of the second passivation layer.

24. The liquid crystal display device of claim 21, wherein a thickness of the dual passivation layer is in a range of about 5500 angstroms through about 6500 angstroms.

25. The liquid crystal display device of claim 21, wherein

the refractive index of the first passivation layer is in a range of about 1.4 through about 1.6, and

the refractive index of the second passivation layer is in a range of about 1.6 through about 2.2.