Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-10067379-B2
Application number	US-201314389419-A
Country	US
Kind code	B2
Filing date	Apr 2, 2013
Priority date	Apr 2, 2012
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A liquid crystal display device includes a liquid crystal panel that includes a liquid crystal cell including a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a pair of polarizers arranged on a light incident side and a light emission side of the liquid crystal layer; an illumination device that is arranged on the light incident side of the liquid crystal cell, and emits light toward the liquid crystal cell; and a light control member that is arranged on the light emission side of the liquid crystal panel, and controls an emission direction of light emitted from the liquid crystal panel by anisotropically diffusing the light in an azimuthal direction as viewed from a direction normal to the liquid crystal panel. The light control member is arranged such that an azimuthal direction in which a luminance viewing angle of the liquid crystal panel is relatively narrow and an azimuthal direction in which diffusivity of the light control member is relatively high approximately coincide with each other.

First claim

The invention claimed is:

1. A liquid crystal display device comprising:
a liquid crystal panel that includes a liquid crystal cell including a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a pair of polarizers arranged one each on a light incident side and a light emission side of the liquid crystal layer, respectively;
an illumination device that is arranged on the light incident side of the liquid crystal cell, and emits light toward the liquid crystal cell; and
a light control member that is arranged on the light emission side of the liquid crystal panel, and controls an emission direction of light emitted from the liquid crystal panel by anisotropically diffusing the light in an azimuthal direction as viewed from a direction normal to the liquid crystal panel, wherein
the light control member is arranged such that an azimuthal direction in which a luminance viewing angle of the liquid crystal panel is relatively narrow and an azimuthal direction in which diffusivity of the light control member is relatively high approximately coincide with each other,
the light control member includes a substrate having light transmissivity, a plurality of light absorbing layers on one surface of the substrate, and a light diffusion portion on a region other than a region where the light absorbing layers are on the one surface of the substrate,
the light diffusion portion has a light emission end surface in contact with the substrate, a light incident end surface which is opposite the light emission end surface and has an area greater than an area of the light emission end surface, and a reflecting surface which is in contact with the light emission end surface and the light incident end surface and reflects light incident from the light incident end surface,
a height from the light incident end surface to the light emission end surface of the light diffusion portion is greater than a thickness of the light absorbing layer,
air is in a space defined by the light absorbing layer and the light diffusion portions, the air having a first refractive index lower than a second refractive index of the light diffusion portions, and
each of the plurality of light absorbing layers has an elliptical shape or a circular shape as viewed from the direction normal to the substrate.

2. The liquid crystal display device according to claim 1 , wherein
the light diffusion portion includes a first reflecting surface corresponding to the azimuthal direction in which a luminance viewing angle of the liquid crystal panel is relatively narrow, and a second reflecting surface on an opposite side to the first reflecting surface, and
an inclination angle of the first reflecting surface and an inclination angle of the second reflecting surface are different from each other.

3. The liquid crystal display device according to claim 2 ,
wherein the inclination angle of the first reflecting surface is greater than the inclination angle of the second reflecting surface, when the light emitted from the liquid crystal panel is incident obliquely toward the first reflecting surface.

4. The liquid crystal display device according to claim 1 ,
wherein a planar shape of a portion at which the light absorbing layer is in contact with one surface of the substrate is an anisotropic shape having at least a major axis and a minor axis.

5. The liquid crystal display device according to claim 1 ,
wherein a planar shape of a portion at which the light absorbing layer is in contact with one surface of the substrate is an ellipse or a shape inscribed in the ellipse.

6. The liquid crystal display device according to claim 4 ,
wherein the minor axis direction of the light absorbing layer and the azimuthal direction in which a luminance viewing angle of the liquid crystal panel is relatively narrow approximately coincide with each other.

7. The liquid crystal display device according to claim 1 ,
wherein among the plurality of light absorbing layers, a size or a shape of at least one light absorbing layer is different from a size or a shape of another light absorbing layer.

8. The liquid crystal display device according to claim 1 ,
wherein among the plurality of light absorbing layers, a major axis of at least one light absorbing layer faces a direction different from that of another light absorbing layer.

9. The liquid crystal display device according to claim 1 ,
wherein among the plurality of light absorbing layers, at least one light absorbing layer is connected to at least a part of another light absorbing layer.

10. The liquid crystal display device according to claim 1 ,
wherein a length in the major axis direction of the light absorbing layer is 100 μm or less.

11. The liquid crystal display device according to claim 10 ,
wherein a length in the major axis direction of the light absorbing layer is 40 μm or less.

12. The liquid crystal display device according to claim 1 ,
wherein the inclination angle of the reflecting surface of the light diffusion portion is continuously changed, and a cross-sectional shape of the reflecting surface is a curved inclined surface.

13. The liquid crystal display device according to claim 1 ,
wherein the reflecting surface of the light diffusion portion has a plurality of different inclination angles, and a cross-sectional shape of the reflecting surface is an inclined surface of a polygonal line.

14. The liquid crystal display device according to claim 10 , wherein
a discotic liquid crystal is included in a retardation plate, and
an angle between an azimuthal direction in which the discotic liquid crystal is inclined as viewed from the direction normal to the retardation plate, and the azimuthal direction in which diffusivity of the light control member is relatively high is approximately 45°.

15. The liquid crystal display device according to claim 1 , wherein
the each of the plurality of light absorbing layers has the elliptical shape as viewed from the direction normal to the substrate.

Assignees

• Sharp Kk

Inventors

• Sakuragi Kazuyoshi
• Kamada Tsuyoshi
• Kanno Toru
• Ueki Shun
• Maeda Tsuyoshi
• Yamamoto Emi

Classifications

• G02F2413/02

  Number of plates being 2 · CPC title

• G02F1/133504

  Diffusing, scattering, diffracting elements (associated to illuminating devices G02F1/133606) · CPC title

• G02B5/3083 Primary

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• G02F1/1336 Primary

  Illuminating devices · CPC title

• G02F2001/133562

  Physics · mapped topic