Compensator for liquid crystal display
A compensator element for a liquid crystal display is provided comprising at least one layer of negative biaxial burefringement material formed by at least one polycyclic organic compound.
1. A compensator for a liquid crystal display comprising at least one layer of a birefringent material
wherein the birefringent material has a crystal structure formed by at least one polycyclic
organic compound with conjugated π-system, and an intermolecular spacing of 3.4±0.3 Å is in the direction of at least one of optical axes, wherein the organic compound is an acenaphtho[1.2-b]quinoxaline sulfoderivative of the general structural formula:
where n is an integer in the range of 1 to 4;
m is an integer in the range of 0 to 4;
z is an integer in the range of 0 to 6, and m+z+n≦10;
X and Y are individually selected from the group consisting of CH 3 , C 2 H 5 , OCH 3 , OC 2 H 5 , Cl, Br, OH, and NH 2 ;
M is a counterion; and
j is the number of counterions in the molecule.
2. The compensator according to claim 1 , wherein said optical axis lies in a plane of the layer of the birefringent material and coincide with direction of said optical axis.
3. The compensator according to claim 1 , wherein the structural formula of acenaphtho[1,2-b]quinoxaline sulfoderivative is chosen from the group consisting of structures I-VIII:
where m is an integer in the range of 0 to 3, and z is an integer in the range of 0 to 6;
where m is an integer in the range of 0 to 4, and z is an integer in the range of 0 to 5;
where m is an integer in the range of 0 to 2, and z is an integer in the range of 0 to 6;
where m is an integer in the range of 0 to 4, and z is an integer in the range of 0 to 4;
where m is an integer in the range of 0 to 3, and z is an integer in the range of 0 to 5;
where m is an integer in the range of 0 to 3, and z is an integer in the range of 0 to 4;
where m is an integer in the range of 0 to 2, and z is an integer in the range of 0 to 5;
where m is an integer in the range of 0 to 2, and z is an integer in the range of 0 to 4;
and where X, Y are individually selected from the group consisting of CH 3 C 2 H 5 , OCH 3 , OC 2 H 5 , Cl, Br, OH, and NH 2 , M is a counterion, and j is the number of counterions in the molecule.
4. The compensator according to claim 1 , wherein the said compensator operates as a negative A-plate.
5. The compensator according to claim 1 , comprising at least two layers of the birefringent material, wherein said optical axes of two adjacent layers of birefringent material are mutually perpendicular.
6. The compensator according to claim 5 , wherein said compensator operates as positive C-plate.
7. The compensator according to claim 5 , wherein said compensator operates as negative C-plate.