Normally white, supertwist nematic liquid crystal display of reflective type

1. A normally white supertwist nematic liquid crystal display comprising:

a reflector,

a layer of chiral nematic liquid crystal having a front aligning surface facing a light source and a rear aligning surface facing the reflector, said nematic liquid crystal having an optical retardation (Δnd) of the layer and a distribution of directors, wherein said chiral nematic liquid crystal has a twist angle (Φ) between an alignment direction of a director at the front aligning surface and an alignment direction of a director at the rear aligning surface; and

a front polarizer disposed between the layer of the chiral nematic liquid crystal and the light source, said front polarizer has a transmission axis forming an angle (α) with the alignment direction of the director at the front aligning surface of the chiral nematic liquid crystal layer;

wherein the optical retardation (Δnd) and the angle (α) are defined by the following formulas:

α(Φ)=sign(Φ)·(47.0−0.4936 |Φ|+2.6786×10 −3 ·Φ 2 )±5, deg, and

Δ nd (Φ)=−11.674+0.1915·|Φ|−9.8393×10 −4 ·Φ 2 +1.6667×10 −6 ·|Φ| 3 ±0.05, μm; and

wherein the front polarizer is made out of an optically anisotropic dichroic thin crystal film material which comprises aromatic rings and has an intermolecular spacing of 3.4±0.3 Å in the direction of one of optical axes.

2. The liquid crystal display according to claim 1 , wherein the twist angle (Φ) is in the range of approximately 180 to 260 degree.

3. The liquid crystal display according to claim 1 , wherein the chiral nematic liquid crystal is further characterized by a helix natural pitch (P) having a value of approximately 360° d/Φ, wherein (d) is a thickness of the liquid crystal layer.

4. The liquid crystal display according to claim 1 , wherein the chiral nematic liquid crystal director at the front surface coincides with a pretilt angle.

5. The liquid crystal display according to claim 1 , wherein the front polarizer has a thickness that is sufficient to provide an interference extremum and a maximum contrast ratio in a spectral range corresponding to the maximum sensitivity of a human eye.

6. The liquid crystal display according to claim 1 , wherein the optically anisotropic dichroic thin crystal film comprises metal ions of two- and/or three-valence.

7. The liquid crystal display according to claim 1 , wherein the thin crystal film material comprises heterocycles.

8. The liquid crystal display according to claim 1 , wherein the optically anisotropic dichroic thin crystal film is made of lyotropic liquid crystal based on at least one dichroic dye.

9. The liquid crystal display according to claim 1 , wherein the optically anisotropic dichroic thin crystal film material is characterized by imaginary (K 1 , K 2 , K 3 ) and real (n 1 ,n 2 ,n 3 ) components of complex refraction index, said components satisfy the following relationships:

K 1 ≧K 2 >K 3 , and

( n 1 +n 2 )/2 >n 3 .