IP Library › Granted Patent US 6,841,654
Granted Patent B2
US 6,841,654 · App. 09/855,921 · Granted Jan 11, 2005

Polymide-free alignment layer for LCD fabrication and method

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 6,841,654
App. No.
09/855,921
Granted
Jan 11, 2005
Kind
B2
Abstract

An inexpensive polyimide-free alignment layer comprising a mixture of an epoxy and a reactive liquid crystal material is used for fabricating liquid crystal displays (LCDs). The alignment layer can be cast onto a previously aligned layer, without destroying the alignment of the underlying layer, thus allowing for monolithic fabrication of compensator stacks, without film transfer lamination.

Claims (14)

1. An alignment layer for a liquid crystal display, comprising a cured isotropic transparent and non-birefringent polymer film formed from a mixture of:

a curable epoxy and

a reactive mesogen

the cured mixture of said epoxy and reactive mesogen constituting an isotropic transparent and non-birefringent polymer film comprising polymerized liquid crystal molecules randomly oriented in cured epoxy, said polymerized liquid crystal molecules at an exposed surface of the isotropic transparent and non-birefringent polymer film capable of being subsequently aligned.

2. The alignment layer of claim 1 , wherein said composition is polyimide free.

3. The alignment layer of claim 1 , wherein the epoxy is UV curable.

4. The alignment layer of claim 1 , further comprising a photo-initiator mixed with said epoxy.

5. The alignment layer of claim 4 , further comprising a thermal-inhibitor mixed with said epoxy, reactive mesogen and photo-initiator.

6. The alignment layer of claim 1 , wherein said epoxy comprises between 10% and 80% by weight of said isotropic alignment layer.

7. The alignment layer of claim 1 wherein the randomly oriented liquid crystals in the cured film are capable of being azimuthally oriented by rubbing the film.

8. The alignment layer of claim 1 wherein the reactive mesogen is a UV curable monoacrylate or diacrylate monomer or oligomer.

9. The alignment layer of claim 1 wherein the cured polymer film is formed from the curable epoxy and reactive mesogen dissolved in a solvent which does not damage other layers of the liquid crystal device upon which it is coated.

10. The alignment layer of claim 9 wherein the solvent is a ketone.

11. The alignment layer of claim 9 wherein the solvent is chosen from the group consisting of cyclohexanone, methylethylketone, acetone, cyclopentanone, toluene and chlorobenzene.