Method of manufacturing a liquid crystal display having high response speed
First alignment is performed by forming an alignment layer that includes a photopolymerizable monomer or oligomer on a substrate and the like, introducing liquid crystal, and bringing the liquid crystal into contact with the alignment layer including the photopolymerizable monomer or oligomer. The liquid crystal is then subjected to secondary alignment by photopolymerizing the photopolymerizable monomer or oligomer including the alignment layer to form an alignment regulator in a state in which an electric field is applied to the liquid crystal to hange the alignment of the liquid crystal.
1. A method for manufacturing a liquid crystal display, comprising:
forming a first alignment layer that comprises an alignment base layer and a plurality of alignment regulators on a first substrate;
assembling the first substrate and a second substrate interposing a liquid crystal layer therebetween; and
irradiating non-polarizing light to the first alignment layer while applying a voltage between a first electrode and a second electrode formed on at least one of the first substrate and the second substrate so that the alignment regulators in the first alignment layer form a pretilt state according to an electric field between the first electrode and the second electrode
wherein the plurality of alignment regulators formed in the first alignment layer having the pretilt state are fixed to have a predetermined pretilt angle with respect to the alignment base layer irrespective of applying an electric field after irradiating light to the first alignment layer, and
wherein the forming of the first alignment layer comprises:
coating a liquid film on the first substrate, the liquid film comprising the alignment base layer and the alignment regulators directly extending from an inside of the alignment base layer,
wherein the predetermined pretilt angle is inclined with respect to a direction substantially perpendicular to the first substrate or the second substrate, and
wherein the alignment base layer comprises a different material from the alignment regulators.
2. The method of claim 1 , wherein the forming the first alignment layer comprises:
coating a mixture comprising an alignment base material and a plurality of monomers or oligomers photopolymerizable by an irradiation of the non-polarizing light on the first substrate.
3. The method of claim 2 , wherein the forming the first alignment layer comprises:
performing heat treatment of the mixture coated on the first substrate to cure the first alignment layer, the heat treatment is performed at a temperature in the range of 100° C. to 180° C. for 0.5 hour to 1 hour.
4. The method of claim 3 , further comprising, before the assembling of the first substrate and the second substrate, forming a second alignment layer that comprises an alignment base layer and a plurality of alignment regulators on the second substrate.
5. The method of claim 4 , wherein the forming the second alignment layer comprises:
coating a mixture comprising an alignment base material and the plurality of monomers or oligomers photopolymerizable by the irradiation of non-polarizing light on the second substrate.
6. The method of claim 5 , wherein the forming the second alignment layer comprises:
performing heat treatment of the mixture coated on the second substrate to cure the second alignment layer,
wherein the heat treatment is performed at a temperature in the range of 100° C. to 180° C. for 0.5 hour to 1 hour.
7. The method of claim 3 , wherein the assembling the first substrate and the second substrate comprises:
coating a sealant on any one of the first substrate and the second substrate and dripping a liquid crystal; and
aligning the first substrate and the second substrate to perform attachment.
8. The method of claim 7 , wherein the assembling of the first substrate and the second substrate comprises:
coating a sealant on either one of the first substrate and the second substrate so as to have a liquid crystal injection hole,
aligning the first substrate and the second substrate to perform attachment, and
injecting the liquid crystal into a space formed by the first substrate, the second substrate, and the sealant.
9. The method of claim 8 , wherein the plurality of alignment regulators are formed of reactive mesogens (RM).
10. The method of claim 9 , wherein the reactive mesogen is represented by the following formula: P1-A1-(Z1-A2)n-P2, wherein P1 and P2 are independently selected from acrylate, methacrylate, vinyl, vinyloxy, and epoxy groups, A1 and A2 are independently selected from 1,4-phenylene and naphthalene-2,6-diyl groups, Z1 is any one of COO—, OCO—, and single bonds, and n is any one of 0, 1, and 2.
11. The method of claim 10 , wherein the reactive mesogen is represented by any one of the following formulas:
wherein P1 and P2 are independently selected from acrylate, methacrylate, vinyl, vinyloxy, and epoxy groups.
12. The method of claim 9 , wherein the alignment base layer comprises at least one of a poly-amic acid, a poly-imide, lecithin, nylon, and PVA (polyvinyl alcohol).
13. The method of claim 2 , further comprising injecting a liquid crystal material between the first substrate and the second substrate after polymerizing the monomers or oligomers included in the first alignment layer.
14. The method of claim 13 , further comprising:
before the assembling of the first substrate and the second substrate, forming a second alignment layer including an alignment base layer and a plurality of monomers or oligomers on a second substrate,
wherein the plurality of monomers or oligomers included in the second alignment layer are polymerized when the plurality of monomers or oligomers included in the first alignment layer are polymerized.
15. The method of claim 14 , wherein the first alignment layer further includes a polymerization initiator.
16. The method of claim 15 , wherein the second alignment layer includes a polymerization initiator.
17. The method of claim 16 , wherein the polymerization initiator includes at least one of methyl ethyl kotone peroxide, benzoyl peroxide, cumene hydroperoxide, t-butyl peroctoate, dicumyl peroxide, or benzoyl alkyl ether based compounds, acetophenone based compounds, benzophenone based compounds, xanthone based compounds, benzoin ether based compounds, and benzyl ketal based compounds.
18. The method of claim 1 , wherein the first electrode is formed on the first substrate, the second electrode is formed on the second substrate, and the first electrode comprises a first cutout.
19. The method of claim 18 , wherein the second electrode comprises the second cutout.
20. The method of claim 18 , further comprising forming an organic material protrusion on the second electrode.
21. The method of claim 20 , further comprising forming an organic material protrusion on the first electrode.
22. A method for manufacturing a liquid crystal display, comprising: The method of claim 1 ,
forming a first alignment layer that comprises an alignment base layer and a plurality of alignment regulators on a first substrate;
assembling the first substrate and a second substrate interposing a liquid crystal layer therebetween; and
irradiating non-polarizing light to the first alignment layer while applying a voltage between a first electrode and a second electrode formed on at least one of the first substrate and the second substrate so that the alignment regulators in the first alignment layer form a pretilt state according to an electric field between the first electrode and the second electrode,
wherein the plurality of alignment regulators formed in the first alignment layer having the pretilt state are fixed to have a predetermined pretilt angle with respect to the alignment base layer irrespective of applying an electric field after irradiating light to the first alignment layer, and
wherein the forming of the first alignment layer comprises:
coating a liquid film on the first substrate, the liquid film comprising the alignment base layer and the alignment regulators directly extending from the alignment base layer,
wherein the predetermined pretilt angle is inclined with respect to a direction substantially perpendicular to the first substrate or the second substrate,
wherein the predetermined pretilt angle of the alignment regulators corresponding to a same domain of the liquid crystal layer are a substantially same acute angle with respect to a surface of the alignment base layer.
23. The method of claim 1 , wherein the plurality of alignment regulators includes a photopolymerizable monomer or oligomer and the liquid crystal does not include the photopolymerizable monomer or oligomer.
24. The method of claim 22 , wherein the plurality of alignment regulators includes a photopolymerizable monomer or oligomer and the liquid crystal does not include the photopolymerizable monomer or oligomer.