Liquid crystal display apparatus

Patent metadata

Field	Value
Publication number	US-9618794-B2
Application number	US-201514686385-A
Country	US
Kind code	B2
Filing date	Apr 14, 2015
Priority date	May 22, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

There is provided a liquid crystal display apparatus in which a retardation Δnd of a liquid crystal layer is greater than 2 μm. Absorbing axes of the first polarizer and the second polarizer are in parallel to an alignment direction of the liquid crystal molecules on surfaces of the first substrate or the second substrate. A slow axis of the optical film and the absorbing axes of the first polarizer and the second polarizer are in parallel to each other or orthogonal to each other. An in-plane retardation of the optical film is from 300 nm to 430 nm.

First claim

What is claimed is:

1. A liquid crystal display apparatus comprising:
a first substrate which includes a first electrode;
a second substrate which is disposed opposite to and approximately parallel to the first substrate and includes a second electrode;
a twisted nematic liquid crystal layer which is disposed between the first substrate and the second substrate, and is formed of a liquid crystal material of which a dielectric anisotropy is positive, and in which liquid crystal molecules are approximately horizontally aligned on the first substrate and the second substrate, and an alignment state of the liquid crystal molecules is twisted by approximately 90° between the first substrate and the second substrate;
a first polarizer which is disposed on one side of the first substrate, opposite to the other side of the first substrate facing the liquid crystal layer;
a second polarizer which is disposed on one side of the second substrate, opposite to the other side of the second substrate facing the liquid crystal layer, and is disposed in the manner of an approximately parallel Nicol arrangement with respect to the first polarizer; and
an optical film which is disposed between the first substrate and the first polarizer, and has a positive uniaxial optical anisotropy;
wherein a display portion is defined on an overlapping position between the first electrode and the second electrode when seen in a normal direction of the first substrate and the second substrate, and the display portion includes at least a segment display portion,
wherein a retardation Δnd of the liquid crystal layer is greater than 2 μm,
wherein absorbing axes of the first polarizer and the second polarizer are in parallel to an alignment direction of the liquid crystal molecules on surfaces of the first substrate or the second substrate,
wherein a slow axis of the optical film is in parallel to or orthogonal to the absorbing axes of the first polarizer and the second polarizer,
wherein an in-plane retardation of the optical film is from 300 nm to 430 nm, and
wherein when seen from viewing angles of 40° to 50° of two directions which are orthogonal to an alignment direction of the liquid crystal molecules located at the center in the thickness direction of the liquid crystal layer, a transmitted light intensity in a non-display portion and a display portion in which voltage is not applied between the first electrode and the second electrode is lower than a transmitted light intensity of a case where the optical film is not disposed.

2. The liquid crystal display apparatus according to claim 1 ,
wherein when seen from viewing angles of 40° to 50° of the two directions which are orthogonal to the alignment direction of the liquid crystal molecules located at the center in the thickness direction of the liquid crystal layer, a transmitted light intensity in a display portion in which a drive waveform is applied between the first electrode and the second electrode to form a darkness display is lower than a transmitted light intensity of a case where the optical film is not disposed.

3. The liquid crystal display apparatus according to claim 1 ,
wherein an in-plane retardation of the optical film is from 300 nm to 405 nm, and
wherein when seen from viewing angles of 40° to 50° of one direction which is orthogonal to the alignment direction of the liquid crystal molecules located at the center in the thickness direction of the liquid crystal layer, a transmitted light intensity in a display portion in which a drive waveform is applied between the first electrode and the second electrode to form a brightness display is higher than a transmitted light intensity of a case where the optical film is not disposed.

4. The liquid crystal display apparatus according to claim 3 ,
wherein an in-plane retardation of the optical film is from 345 nm to 375 nm, and
wherein when seen from viewing angles of 40° to 50° of two directions which are orthogonal to the alignment direction of the liquid crystal molecules located at the center in the thickness direction of the liquid crystal layer, a transmitted light intensity in a display portion in which a drive waveform is applied between the first electrode and the second electrode to form a brightness display is higher than a transmitted light intensity of a case where the optical film is not disposed.

5. The liquid crystal display apparatus according to claim 1 , further comprising:
a drive device which is electrically connected to the first electrode and the second electrode and applies a multiplex drive waveform having ¼ or less duty or a static drive waveform between the first electrode and the second electrode; and
a light source which is disposed on one side of the first polarizer or the second polarizer opposite to the other side of the first polarizer or the second polarizer facing the liquid crystal layer, and emits blue light.

6. The liquid crystal display apparatus according to claim 5 ,
wherein the light source includes a light emitting source which emits light having a center wavelength of 490 nm.

7. The liquid crystal display apparatus according to claim 5 ,
wherein the light source includes a light emitting source which emits white light, and a blue color filter of a center wavelength of 490 nm.

8. The liquid crystal display apparatus according to claim 1 ,
wherein at least one of the first substrate and the second substrate is provided with an unevenness on a surface of the substrates facing the liquid crystal layer.

Assignees

• Stanley Electric Co Ltd

Inventors

• Hamamoto Manabu
• Iwamoto Yoshihisa

Classifications

• G02F2413/13

  Positive birefingence · CPC title

• G02F1/1337

  Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers · CPC title

• G02F2001/133531

  Physics · mapped topic

• C09K19/0208

  Twisted Nematic (T.N.); Super Twisted Nematic (S.T.N.); Optical Mode Interference (O.M.I.) · CPC title

• G02F1/133528

  Polarisers · CPC title