TRANSFLECTIVE LIQUID CRYSTAL PANEL AND METHOD OF MAKING THE SAME

• US 20080014372A1
• Filed: 09/29/2006
• Published: 01/17/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Sun, Chia-Hsing, Chen, Chih-Chuan, Sie, Fu-Cheng, Wu, Jin-Jei, Chiang, Chun-Hung, Lin, Tzu-Yuan
• Granted Patent: US 7,588,805 B2
• Time in Patent Office: Days
• US Class Current: 428/1.1
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: C09K 2019/546 creating a polymeric network
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13345 Network or three-dimensional gels
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence

Abstract

A transflective liquid crystal panel includes a first substrate, a second substrate, a first polarizer disposed on the first substrate, a second polarizer disposed on the second substrate having a transmission axis perpendicular to that of the first polarizer and a polymer dispersed liquid crystal layer sandwiched between the substrates. The polymer dispersed liquid crystal layer includes a plurality of liquid crystal molecules and at least one polymer network. When a voltage difference between the substrates is equal to 0V, the liquid crystal molecules do not reflect incident light beams and are not pervious to incident light beams. When the voltage difference between the substrates is not equal to 0V, the crystal molecules reflect incident light beams and are pervious to incident light beams.

Claims

1. A transflective liquid crystal panel, comprising:

a first substrate;

a second substrate;

a first polarizer disposed on the first substrate;

a second polarizer, disposed on the second substrate, having a transmission axis perpendicular to that of the first polarizer; and

a polymer dispersed liquid crystal layer, sandwiched between the substrates, comprising a plurality of liquid crystal molecules and at least one polymer network.

2. The transflective liquid crystal panel of claim 1, wherein when a voltage difference between the first and the second substrates is not equal to 0V, the liquid crystal molecules reflect and/or are pervious to the incident light, and wherein when the voltage difference is equal to 0V, the liquid crystal molecules do not reflect and/or are not pervious to the incident light.

3. The transflective liquid crystal panel of claim 2, wherein the liquid crystal molecules are negative liquid crystal molecules.

4. The transflective liquid crystal panel of claim 3, wherein the liquid crystal molecules are vertically aligned, the substrates are horizontally aligned, and two horizontally aligned directions of the substrates are perpendicular to each other so that the liquid crystal molecules have pretilt angles, respectively relative to the substrates, and the two pretilt angles are perpendicular to each other.

5. The transflective liquid crystal panel of claim 3, wherein the liquid crystal molecules are vertically aligned, the substrates are horizontally aligned, and two horizontally aligned directions of the substrates are parallel to each other so that the liquid crystal molecules have pretilt angles, respectively relative to the substrates, and the two pretilt angles are parallel to each other.

6. The transflective liquid crystal panel of claim 1, wherein the polymer network comprises a plurality of precursors.

7. The transflective liquid crystal panel of claim 6, wherein the birefringence of the polymer network is substantially equal to that of the liquid crystal molecules.

8. The transflective liquid crystal panel of claim 6, wherein the precursor comprises at least one ultraviolet-polymerizable compound.

9. The transflective liquid crystal panel of claim 6, wherein the precursor comprises at least one heat-polymerizable compound.

10. The transflective liquid crystal panel of claim 1, wherein when a voltage difference between the first and the second substrates is equal to 0V, the liquid crystal molecules reflect and/or are pervious to the incident light, and wherein when the voltage difference is not equal to 0V, the liquid crystal molecules do not reflect and/or are not pervious to the incident light.

11. The transflective liquid crystal panel of claim 10, wherein the liquid crystal molecules are positive liquid crystal molecules.

12. The transflective liquid crystal panel of claim 11, wherein the substrates are horizontally aligned, and two horizontally aligned directions of the substrates are parallel to each other.

13. The transflective liquid crystal panel of claim 10, wherein the liquid crystal molecules are nematic liquid crystal molecules.

14. The transflective liquid crystal panel of claim 13, wherein the substrates are horizontally aligned, and two horizontally aligned directions of the substrates are perpendicular to each other.

15. The transflective liquid crystal panel of claim 10, wherein the polymer network comprises a plurality of precursors.

16. The transflective liquid crystal panel of claim 15, wherein the birefringence of the polymer network is substantially equal to that of the liquid crystal molecules.

17. The transflective liquid crystal panel of claim 15, wherein the precursors comprise at least one ultraviolet-polymerizable compound.

18. The transflective liquid crystal panel of claim 15, wherein the precursors comprise at least one heat-polymerizable compound.

19. A transflective liquid crystal panel, comprising:

a first substrate;

a second substrate;

a first polarizer disposed on the first substrate;

a second polarizer, disposed on the second substrate, having a transmission axis perpendicular to that of the first polarizer; and

a polymer dispersed liquid crystal layer, sandwiched between the substrates, comprising liquid crystal molecules and a polymer network, wherein the polymer network is polymerized by a plurality of precursors, each precursor including;

fluoride; and

hydrocarbon having benzene or biphenyl, and an aliphatic hydrocarbon chain, having one to twenty-two carbon atoms, served as a linking group.

20. The transflective liquid crystal panel of claim 19, wherein the precursors are substantially in the range of 2% to 20% of the liquid crystal molecules by weight.

21. The transflective liquid crystal panel of claim 19, wherein when a voltage difference between the first substrate and the second substrate is equal to 0V, the liquid crystal molecules do not reflect and/or are not pervious to the incident light, and wherein when the voltage difference is not equal to 0V, the liquid crystal molecules reflect and/or are pervious to the incident light.

22. The transflective liquid crystal panel of claim 19, wherein when a voltage difference between the first substrate and the second substrate is equal to 0V, the liquid crystal molecules reflect and/or are pervious to the incident light, and wherein when the voltage difference is not equal to 0V, the liquid crystal molecules do not reflect and/or are not pervious to the incident light.

23. The transflective liquid crystal panel of claim 19, wherein the precursors comprise at least one ultraviolet-polymerizable compound.

24. The transflective liquid crystal panel of claim 19, wherein the precursors comprise at least one heat-polymerizable compound.

25. The transflective liquid crystal panel of claim 19, wherein the precursor has one to eight fluorine atoms.