LCD device having vertically aligned liquid crystal layer between first and second substrates in which the first substrate has a first opening and a second opening and/or cut in which the second opening and/or cut width is greater than the first opening width

• US 7,705,943 B2
• Filed: 04/03/2009
• Issued: 04/27/2010
• Est. Priority Date: 12/08/2003
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kurihara, Takashi, Kume, Yasuhiro, Tamai, Kazuhiko, Onishi, Noriaki, Nagae, Nobukazu
• Primary Examiner(s): HEYMAN, JOHN S
• Application Number:
  US12/385,279
• Publication Number:
  US 20090201454A1
• Time in Patent Office: 389 Days
• Field of Search: 349/114, 349128-130
• US Class Current: 349/130
• CPC Class Codes: G02F 1/133555 Transflectors
• 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 1/133753 with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• 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

Abstract

The liquid crystal display device includes a first substrate 1110a, a second substrate 1110b placed to face the first substrate, and a liquid crystal layer 1120 interposed between the first substrate and the second substrate. The liquid crystal display device has a plurality of pixels each including a first electrode 1111 formed on the first substrate, a second electrode 1131 formed on the second substrate, and the liquid crystal layer interposed between the first electrode and the second electrode. The second electrode 1131 has at least one opening 1114 formed at a predetermined position in the pixel, the first substrate has a shading region in gaps between the plurality of pixels, and a wall structure 1115 is placed regularly on the surface of the first substrate facing the liquid crystal layer in the shading region. The liquid crystal layer has at least one liquid crystal domain having axisymmetric alignment formed when at least a predetermined voltage is applied, and the center axis of the axisymmetric alignment of the at least one liquid crystal domain is formed in or near the at least one opening.

Claims

1. A liquid crystal display device comprising a first substrate, a second substrate placed to face the first substrate, and a vertically aligned liquid crystal layer interposed between the first substrate and the second substrate,

wherein the liquid crystal display device has a plurality of pixels each including a first electrode formed on the first substrate, a second electrode formed on the second substrate, and the liquid crystal layer interposed between the first electrode and the second electrode,

the liquid crystal layer has at least one liquid crystal domain having axisymmetric alignment formed when at least a predetermined voltage is applied,

the first electrode has at least one first opening formed at a position corresponding to about the center of the axisymmetric alignment of the at least one liquid crystal domain and at least one cut or second opening provided at a position corresponding to part of the periphery of the at least one liquid crystal domain, and

the at least one cut or second opening includes a rectangular portion, and the width EW of the rectangular portion of the at least one cut or second opening is greater than the width EC of the at least one first opening.

2. The liquid crystal display device of claim 1, wherein the liquid crystal layer has two or more liquid crystal domains each having axisymmetric alignment formed when at least a predetermined voltage is applied, and two or more first openings are formed at positions corresponding to about the center of the axisyinmetric alignment of the two or more liquid crystal domains.

3. The liquid crystal display device of claim 1, wherein the first electrode is a pixel electrode provided for each of the plurality of pixels, and the width EW of the at least one cut or second opening is equal to or greater than the space between the adjacent pixel electrodes.

4. The liquid crystal display device of claim 1, wherein the shape of the at least one first opening has rotation symmetry as viewed in the direction normal to the substrate plane.

5. The liquid crystal display device of claim 1, wherein the at least one cut or second opening comprises a plurality of cuts or second openings formed at predetermined positions, and comprises cuts or second openings arranged point-symmetrically with respect to the at least one first opening.

6. The liquid crystal display device of claim 1, further comprising a wall structure provided regularly on the surface of the first substrate facing the liquid crystal layer, and the wall structure includes a first wall portion formed in the rectangular portion of the at least one cut or second opening.

7. The liquid crystal display device of claim 6, wherein the wall structure includes a second wall portion extending from the first wall portion.

8. The liquid crystal display device of claim 6, wherein the wall structure includes a third wall portion provided in a region surrounding the first electrode.

9. The liquid crystal display device of claim 1, wherein the first electrode includes a transparent electrode defining a transmission region and a reflective electrode defining a reflection region, and the thickness dt of the liquid crystal layer in the transmission region is greater than the thickness dr of the liquid crystal layer in the reflection region.

10. The liquid crystal display device of claim 9, wherein the second substrate has a transparent dielectric layer in the reflection region.

11. The liquid crystal display device of claim 9, wherein the liquid crystal layer has two or more liquid crystal domains having axisymmetric alignment formed when at least a predetermined voltage is applied,

the two or more liquid crystal domains include a liquid crystal domain formed in the transmission region and a liquid crystal domain formed in the reflection region, and

the at least one first opening comprises two or more openings formed at positions corresponding to about the center of the axisymmetric alignment of the two or more liquid crystal domains.

12. The liquid crystal display device of claim 1, wherein at least one of the first substrate and the second substrate has a support for defining the thickness of the liquid crystal layer.

13. The liquid crystal display device of claim 1, wherein the first substrate further includes an active element provided for each of the plurality of pixels, the first electrode is a pixel electrode provided for each of the pixel electrodes and connected to the active element.

14. The liquid crystal display device of claim 1, further comprising:

a pair of polarizing plates placed to face each other via the first substrate and the second substrate; and

at least one biaxial optical anisotropic medium layer placed between the first substrate and one of the pair of polarizing plates and/or between the second substrate and the other polarizing plate.

15. The liquid crystal display device of claim 1, further comprising:

a pair of polarizing plates placed to face each other via the first substrate and the second substrate; and

at least one uniaxial optical anisotropic medium layer placed between the first substrate and one of the pair of polarizing plates and/or between the second substrate and the other polarizing plate.