LIQUID CRYSTAL DISPLAY DEVICE
A liquid crystal display device is provided. The liquid crystal display device includes a first substrate having a pixel unit with a pixel electrode. A second substrate has an opposite electrode. A first polarizer is disposed under the first substrate. A second polarizer is disposed above the second substrate. A liquid crystal (LC) layer with chiral dopants is disposed between the first and second substrates. A parameter of the LC rotations of d/p ratios of the liquid crystal layer with chiral dopants is between 0.2 and 0.3. A parameter of the optical phase retardation factor R of the LC layer with chiral dopants is larger than 0.6 and less than 0.95.
1 . A liquid crystal display device, comprising:
a first substrate having a pixel unit;
a second substrate disposed opposite to the first substrate, having an opposite electrode;
a first polarizer disposed under the first substrate;
a second polarizer disposed under the second substrate, wherein a polarization axis of the second polarizer is vertical to that of the first polarizer; and
a liquid crystal (LC) layer with chiral dopants disposed between the first and second substrates, wherein a parameter of the LC rotations (d/p ratio) of the LC layer with chiral dopants is between 0.2 and 0.3, and a parameter of the optical phase retardation factor R of the LC layer with chiral dopants is larger than 0.6 and less than 0.95, wherein
R
=
Δ
nd
λ
,
wherein d is a thickness of the LC layer with chiral dopants, p is a pitch of chiral dopants, Δn is a birefringence coefficient of the LC layer with chiral dopants, and λ is a wavelength of an incident light.
2 . The liquid crystal display device as claimed in claim 1 , wherein the first substrate is a thin film transistor (TFT) substrate, and the second substrate is a color filter substrate.
3 . The liquid crystal display device as claimed in claim 1 , wherein the LC layer with chiral dopants is formed by a nematic LC material.
4 . The liquid crystal display device as claimed in claim 1 , wherein the liquid crystal display device is operated by an incident light having a wavelength between 380 nm and 780 nm.
5 . The liquid crystal display device as claimed in claim 1 , wherein a parameter of the gray-level inversion is not larger than 0.02 at a 45-degree
6 . The liquid crystal display device as claimed in claim 1 , wherein a parameter of the gray-level inversion is not larger than 0.04 at a 90-degree viewing-angle.
7 . A liquid crystal display device, comprising:
a first substrate having a pixel unit;
a second substrate disposed opposite to the first substrate, having an opposite electrode;
a first polarizer disposed under the first substrate;
a second polarizer disposed under the second substrate, wherein a polarization axis of the second polarizer is vertical to that of the first polarizer; and
a liquid crystal (LC) layer with chiral dopants disposed between the first and second substrates, wherein a parameter of the optical path difference ( 66 nd) of the LC layer with chiral dopants is between 330 and 600, and a parameter of the LC rotations (d/p ratio) of the LC layer with chiral dopants is between 0.2 and 0.3, wherein Δn is a birefringence coefficient of the LC layer with chiral dopants, d is a thickness of the LC layer with chiral dopants, and p is a pitch of chiral dopants.
8 . The liquid crystal display device as claimed in claim 7 , wherein the first substrate is a thin film transistor (TFT) substrate, and the second substrate is a color filter substrate.
9 . The liquid crystal display device as claimed in claim 7 , wherein the LC layer with chiral dopants is formed by a nematic LC material.
10 . The liquid crystal display device as claimed in claim 7 , wherein the liquid crystal display device is operated by an incident light having a wavelength between 380 nm and 780 nm.
11 . The liquid crystal display device as claimed in claim 7 , wherein a parameter of the gray-level inversion is not larger than 0.02 at a 45-degree viewing-angle.
12 . The liquid crystal display device as claimed in claim 7 , wherein a parameter of the gray-level inversion is not larger than 0.04 at a 90-degree viewing-angle.