Liquid crystal display device

• US 7,952,667 B2
• Filed: 07/15/2010
• Issued: 05/31/2011
• Est. Priority Date: 12/26/1997
• 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: Shimada, Takayuki, Ishii, Yutaka, Yoshimura, Youji, Narutaki, Yozo, Maruyama, Yuko, Yamakawa, Shinya, Katayama, Mikio, Fujioka, Shogo, Kubo, Masumi, Ban, Atsushi
• Primary Examiner(s): Pak; Sung H
• Application Number:
  US12/805,163
• Publication Number:
  US 20100283950A1
• Time in Patent Office: 320 Days
• Field of Search: None
• US Class Current: 349/119
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133557 Half-mirrors
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/13712 the liquid crystal having negative dielectric anisotropy
• CPC Class Codes: G02F 2203/09 transflective

Abstract

A liquid crystal display device includes a first substrate; a second substrate; a liquid crystal layer interposed between the first substrate and the second substrate; a first polarizer provided on a surface of the first substrate which is on the opposite side to the liquid crystal layer; a second polarizer provided on a surface of the second substrate which is on the opposite side to the liquid crystal layer; a first phase compensation element provided between the first polarizer and the liquid crystal layer; and a second phase compensation element provided between the second polarizer and the liquid crystal layer. A plurality of pixel areas are provided for display. The first substrate includes at least one transmissive electrode, and the second substrate includes a reflective electrode region and a transmissive electrode region in correspondence with each of the plurality of pixel areas.

Claims

1. A liquid crystal display device comprising:

a first substrate including at least one counter electrode;

a second substrate including at least one reflective region and at least one transmissive region associated with each of a plurality of pixel areas and wherein the reflective region includes at least one reflective electrode and the transmissive region includes at least one transmissive electrode, and wherein each of the reflective and transmissive regions contribute to display of images;

a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules which exhibit negative dielectric anisotropy and are aligned substantially vertically to surfaces of the first substrate and the second substrate when no voltage is applied, and wherein the plurality of pixel areas are provided for display, wherein in a given pixel area said transmissive electrode and said reflective electrode are both electrically connected to a switching element; and

wherein a shape of at least one of the counter electrode, the transmissive electrode and the reflective electrode defines alignment of at least some liquid crystal molecules in the liquid crystal layer.

2. A liquid crystal display device according to claim 1, wherein the liquid crystal display device further comprises:

a first polarizer provided on a surface of the first substrate which is opposite the liquid crystal layer;

a second polarizer provided on a surface of the second substrate which is opposite the liquid crystal layer; and

wherein the first polarizer and the second polarizer have transmission axes perpendicular to each other.

3. A liquid crystal display device according to claim 2, wherein the liquid crystal display device further comprises:

a first phase compensation element provided between the first polarizer and the liquid crystal layer; and

a second phase compensation element provided between the second polarizer and the liquid crystal layer.

4. A liquid crystal display device according to claim 3, wherein a transmission axis of the first polarizer and an optic axis of the first phase compensation element make an angle of about 45 degrees, and a transmission axis of the second polarizer and an optic axis of the second phase compensation element make an angle of about 45 degrees.

5. A liquid crystal display device according to claim 3, wherein the first phase compensation element and the second phase compensation element have slow optic axes perpendicular to each other.

6. A liquid crystal display device according to claim 3, wherein the first phase compensation element converts linearly polarized light from the first polarizer into circularly polarized light, and the second phase compensation element converts linearly polarized light from the second polarizer into circularly polarized light.

7. A liquid crystal display device according to claim 3, wherein the liquid crystal display further includes a third phase compensation element provided between the first polarizer and the liquid crystal layer for compensating for wavelength dependency of refractive index anisotropy of the first phase compensation element.

8. A liquid crystal display device according to claim 1, wherein in at least one pixel area said reflective electrode and said transmissive electrode of said second substrate at least partially overlap one another.

9. The liquid crystal display device of claim 1, wherein a shape of at least the transmissive electrode, and not rubbing, defines alignment of at least some liquid crystal molecules in the liquid crystal layer.

10. A liquid crystal display device according to claim 1, wherein the reflective region is separate from the transmissive region.

11. A liquid crystal display device according to claim 1, wherein the second substate further includes, a plurality of gate lines, a plurality of source lines substantially perpendicular to the plurality of gate lines, and a plurality of switching elements.

12. A liquid crystal display device according to claim 11, further including an insulating layer between at least the transmissive electrode and the reflective electrode in at least one pixel area.

13. A liquid crystal display device according to claim 12, wherein the insulating layer has a wave-like surface.

14. A liquid crystal display device according to claim 1, wherein the transmissive electrode and the reflective electrode are electrically connected to each other through a conductive layer.

15. A liquid crystal display device according to claim 14, wherein at least one of the transmissive electrode, reflective electrode, and the conductive layer is formed of a material identical with one of materials forming the plurality of gate electrodes or the plurality of source electrodes.

16. A liquid crystal display device comprising:

a first substrate including at least one counter electrode;

a second substrate including at least one reflective region and at least one transmissive region associated with each of a plurality of pixel areas and wherein the reflective region includes at least one reflective electrode and the transmissive region includes at least one transmissive electrode, and wherein each of the reflective and transmissive regions contribute to display of images;

a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules which exhibit negative dielectric anisotropy and are aligned substantially vertically to surfaces of the first substrate and the second substrate when no voltage is applied, and wherein the plurality of pixel areas are provided for display,

wherein a shape of at least one of the counter electrode, the transmissive electrode and the reflective electrode defines alignment of at least some liquid crystal molecules in the liquid crystal layer;

a first polarizer provided on a surface of the first substrate which is opposite the liquid crystal layer;

a second polarizer provided on a surface of the second substrate which is opposite the liquid crystal layer;

wherein the first polarizer and the second polarizer have transmission axes perpendicular to each other;

a first phase compensation element provided between the first polarizer and the liquid crystal layer; and

a second phase compensation element provided between the second polarizer and the liquid crystal layer.

17. A liquid crystal display device comprising:

a first substrate including at least one counter electrode;

a second substrate including at least one reflective region and at least one transmissive region associated with each of a plurality of pixel areas and wherein the reflective region includes at least one reflective electrode and the transmissive region includes at least one transmissive electrode, and wherein each of the reflective and transmissive regions contribute to display of images;

a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules which exhibit negative dielectric anisotropy and are aligned substantially vertically to surfaces of the first substrate and the second substrate when no voltage is applied, and wherein the plurality of pixel areas are provided for display,

wherein a shape of at least one of the counter electrode, the transmissive electrode and the reflective electrode defines alignment of at least some liquid crystal molecules in the liquid crystal layer;

wherein the second substate further includes a plurality of gate lines, a plurality of source lines substantially perpendicular to the plurality of gate lines, a plurality of switching elements, wherein the transmissive electrode and the reflective electrode are electrically connected to a corresponding switching element in at least one pixel area; and

an insulating layer between at least the transmissive electrode and the reflective electrode in at least one pixel area.