Liquid crystal display device

• US 7,679,698 B2
• Filed: 04/25/2005
• Issued: 03/16/2010
• Est. Priority Date: 04/23/2004
• 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: Sonoda, Tooru, Fujioka, Kazuyoshi
• Primary Examiner(s): Kim; Richard H
• Application Number:
  US11/113,117
• Publication Number:
  US 20050237455A1
• Time in Patent Office: 1,786 Days
• Field of Search: 349/114
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• 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 1/13373 Disclination line; Reverse tilt
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• 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

A vertical alignment liquid crystal display device includes: a pair of substrates which are arranged opposite each other; a liquid crystal layer which is interposed between the paired substrates; an interlayer insulating film which is formed on at least either the first substrate or the second substrate and provided with an aperture which is rectangular when viewed in plan and opened toward the other substrate; a transmissive region provided within the periphery of the aperture and performs transmissive display; and a reflective electrode which is arranged along the periphery of the aperture. The liquid crystal display device further includes a light shield for preventing light from passing through discontinuity regions which are included in a portion of the liquid crystal layer corresponding to the aperture and where liquid crystal molecules are oriented in a discontinuous manner.

Claims

1. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region;

a light shield which prevents light emitted by the backlight from reaching a viewer through discontinuity regions included in a portion of the liquid crystal layer corresponding to the aperture, the discontinuity regions being regions where the orientation of liquid crystal molecules controlled by the orientation control means is discontinuous from the orientation of liquid crystal molecules above the sloping face of the insulating layer, and wherein at least a majority of said light shield is located interior of an inside periphery of said sloping face of the aperture in each of said pixels;

the transmissive region performing transmissive display by transmitting light coming from the backlight through the aperture in the insulating layer,

the reflective region performing reflective display by reflecting ambient light; and

wherein the light shield comprises different material than the reflective electrode.

2. A vertical alignment liquid crystal display device according to claim 1, wherein the aperture is rectangular when viewed in cross section parallel to the substrate on which the insulating layer is formed.

3. A vertical alignment liquid crystal display device according to claim 1, wherein the light shield is provided along the entire periphery of the aperture.

4. A vertical alignment liquid crystal display device according to claim 1, wherein the light shield is part of the reflective electrode and formed of a connecting part which connects the second transparent electrode and the reflective electrode.

5. A vertical alignment liquid crystal display device according to claim 1, wherein the second substrate is provided with a plurality of switching elements and the light shield is formed of part of wiring material connected to the switching elements.

6. A vertical alignment liquid crystal display device according to claim 1, wherein the first substrate is provided with a black matrix for preventing light from passing through regions between pixels and the light shield is made of the same material as the black matrix.

7. A vertical alignment liquid crystal display device according to claim 1, wherein the aperture includes a receding region formed by shifting part of the wall surface of the insulating layer outward and the light shield is provided in the receding region.

8. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region; and

a light shield which prevents light emitted by the backlight from reaching a viewer through discontinuity regions included in a portion of the liquid crystal layer corresponding to the aperture, the discontinuity, regions being regions where the orientation of liquid crystal molecules controlled by the orientation control means is discontinuous from the orientation of liquid crystal molecules above the sloping face of the insulating layer,

the transmissive region performing transmissive display by transmitting light coming from the backlight through the aperture in the insulating layer,

the reflective region performing reflective display by reflecting ambient light;

wherein the aperture is rectangular when viewed in cross section parallel to the substrate on which the insulating layer is formed; and

wherein the light shield comprises four light shields arranged proximate the four corners, respectively, of the aperture.

9. A vertical alignment liquid crystal display device according to claim 8, wherein the light shields are elongated rectangular in shape.

10. A vertical alignment liquid crystal display device according to claim 9, wherein the light shields for the discontinuity regions located along the long sides of the aperture are elongated more than those arranged along the short sides of the aperture.

11. A vertical alignment liquid crystal display device according to claim 8, wherein the light shields are triangular in shape.

12. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region; and

a light shield which prevents light emitted by the backlight from reaching a viewer through discontinuity regions included in a portion of the liquid crystal layer corresponding to the aperture, the discontinuity regions being regions where the orientation of liquid crystal molecules controlled by the orientation control means is discontinuous from the orientation of liquid crystal molecules above the sloping face of the insulating layer, and wherein at least a majority of said light shield is located interior of an inside periphery of said sloping face of the aperture in each of said pixels;

the transmissive region performing transmissive display by transmitting light coming from the backlight through the aperture in the insulating layer;

the reflective region performing reflective display by reflecting ambient light; and

wherein the light shield is arranged within the periphery of the aperture and a predetermined distance away from the edge of the reflective electrode arranged around the periphery of the aperture.

13. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region;

a light shield arranged along at least part of the periphery of the aperture to prevent light emitted by the backlight from reaching a viewer, and wherein at least a majority of said light shield is located interior of an inside periphery of said sloping face of the aperture in each of said pixels;

the transmissive region performing transmissive display by transmitting light coming from the backlight through the aperture in the insulating layer,

the reflective region performing reflective display by reflecting ambient light; and

wherein the light shield is arranged within the periphery of the aperture and a predetermined distance away from the edge of the reflective electrode arranged around the periphery of the aperture.

14. A vertical alignment liquid crystal display device according to claim 13, wherein the aperture is rectangular when viewed in cross section parallel to the substrate on which the insulating layer is formed.

15. A vertical alignment liquid crystal display device according to claim 13, wherein the light shield is provided along the entire periphery of the aperture.

16. A vertical alignment liquid crystal display device according to claim 13, wherein the light shield is part of the reflective electrode and formed of a connecting part which connects the second transparent electrode and the reflective electrode.

17. A vertical alignment liquid crystal display device according to claim 13, wherein the second substrate is provided with a plurality of switching elements and the light shield is formed of part of wiring material connected to the switching elements.

18. A vertical alignment liquid crystal display device according to claim 13, wherein the first substrate is provided with a black matrix for preventing light from passing through regions between pixels and the light shield is made of the same material as the black matrix.

19. A vertical alignment liquid crystal display device according to claim 13, wherein the aperture includes a receding region formed by shifting part of the wall surface of the insulating layer outward and the light shield is provided in the receding region.

20. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region;

a light shield arranged along at least part of the periphery of the aperture to prevent light emitted by the backlight from reaching a viewer,

the transmissive region performing transmissive display by transmitting light coming from the backlight through the aperture in the insulating layer,

the reflective region performing reflective display by reflecting ambient light;

wherein the aperture is rectangular when viewed in cross section parallel to the substrate on which the insulating layer is formed; and

wherein the light shield comprises four light shields arranged proximate the four corners, respectively, of the aperture.

21. A vertical alignment liquid crystal display device according to claim 20, wherein the light shields are elongated rectangular in shape.

22. A vertical alignment liquid crystal display device according to claim 21, wherein the light shields for the discontinuity regions arranged along the long sides of the aperture are elongated more than those arranged along the short sides of the aperture.

23. A vertical alignment liquid crystal display device according to claim 20, wherein the light shields are triangular in shape.

24. A vertical alignment liquid crystal display device including a plurality of pixels each having a transmissive region for transmissive display and a reflective region for reflective display surrounding the transmissive region, the vertical alignment liquid crystal display device comprising:

a first substrate;

a second substrate;

a liquid crystal layer which is arranged between the first substrate and the second substrate;

a backlight which is arranged to face a surface of the second substrate opposite to the first substrate and the liquid crystal layer;

a first transparent electrode which is formed on the first substrate and functions as a counter electrode;

an insulating layer which is formed on at least either the first substrate or the second substrate and provided with an aperture such that the wall surface of the insulating layer facing to the aperture forms a sloping face which is inclined to form an acute angle with the substrate on which the insulating layer is formed;

a second transparent electrode which is arranged on part of the second electrode corresponding to the transmissive region and functions as a pixel electrode;

a reflective electrode which is arranged on part of the second substrate corresponding to the reflective region and connected to the second transparent electrode at least at the periphery of the transmissive region and functions as a pixel electrode;

an orientation control means which is arranged on part of either the first substrate or the second substrate located at the center of the transmissive region;

wherein;

the transmissive region performs transmissive display by transmitting light coming from the backlight,

the reflective region performs reflective display by reflecting ambient light,

the aperture has a polygonal cross-sectional shape in direction parallel to the substrate on which the insulating layer is formed, and

at a corner region of the aperture, a light shield preventing light emitted by the backlight from reaching a viewer is provided, and wherein the light shield comprises different material than the reflective electrode.