Liquid crystal display device

• US 8,228,469 B2
• Filed: 09/20/2011
• Issued: 07/24/2012
• 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: Kubo, Masumi, Narutaki, Yozo, Fujioka, Shogo, Maruyama, Yuko, Shimada, Takayuki, Yoshimura, Youji, Katayama, Mikio, Ishii, Yutaka, Yamakawa, Shinya, Ban, Atsushi
• Primary Examiner(s): PAK, SUNG H
• Application Number:
  US13/137,885
• Publication Number:
  US 20120013826A1
• Time in Patent Office: 308 Days
• Field of Search: None
• US Class Current: 349/114
• 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 in each of a plurality of pixels area 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 to the first substrate and the second substrate when no voltage is applied, and wherein the plurality of pixel areas are provided for display;

wherein an optical alignment defines alignment of at least some liquid crystal molecules in the liquid crystal layer,

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

wherein a first phase compensation element is provided between the first polarizer and the liquid crystal layer, and

wherein a second phase compensation element is 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.

2. The liquid crystal display device according to claim 1, wherein the first polarizer and the second polarizer have transmission axes perpendicular to each other.

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

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

4. The 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 third phase compensation element make an angle of about 45 degrees.

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

6. The 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 third phase compensation element converts linearly polarized light from the second polarizer into circularly polarized light.

7. The 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.

8. 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.

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

10. The liquid crystal display device according to claim 1, wherein the second substrate 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.

11. The liquid crystal display device according to claim 10, further including an insulating layer between at least the transmissive electrode and the reflective electrode in at least one pixel area.

12. The liquid crystal display device according to claim 11, wherein the insulating layer has a wave-like surface.

13. The 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.

14. The liquid crystal display device according to claim 13, wherein at least one of the transmissive electrode, reflective electrode, and the conductive layer is formed of a material identical with one of the materials forming the plurality of gate electrodes or the plurality of source electrodes.

15. The liquid crystal display device according to claim 1, wherein the reflective region includes at least one reflective electrode and the transmissive region includes at least one transmissive electrode.