Holographically formed reflective display, liquid crystal display and projection system and methods of forming the same

• US 6,133,971 A
• Filed: 01/31/1997
• Issued: 10/17/2000
• Est. Priority Date: 01/31/1997
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Silverstein, Louis D., Crawford, Greg P., Fiske, Thomas G.
• Primary Examiner(s): Parker, Kenneth
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US08/792,268
• Time in Patent Office: 1,355 Days
• Field of Search: 349/86, 349/92, 349/193, 349/194, 349/195, 349/196, 349/93, 349/94, 349/78, 349/130, 349/132, 349/176, 349/172, 359/1, 359/3, 359/15, 359/22, 430/1, 430/2, 430/20
• US Class Current: 349/86
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13473 for wavelength filtering or for colour display without the use of colour mosaic filters
• CPC Class Codes: G02F 1/13718 based on a change of the texture state of a cholesteric liquid crystal
• CPC Class Codes: G02F 2203/02 reflective

Abstract

A holographically formed reflective display includes first and second substrates, a liquid crystal material located between the first and second substrates and a plurality of anisotropic polymer sheets separating the liquid crystal material into a plurality of liquid crystal material regions. The anisotropic polymer sheets reduce haze in the display and operates in the reverse mode when viewed from various viewing angles. The holographically formed reflective display may be used to form a color liquid crystal display and a color projection system.

Claims

1. A holographically formed reflective display, comprising:

first and second substrates;

a liquid crystal material located between the first and second substrates; and

a plurality of anisotropic polymer sheets, formed from at least a photo-active monomer and a photo initiator, that separate the liquid crystal material into a plurality of liquid crystal material regions wherein said display is reflective of at least one selected wavelength of light.

2. The holographically formed reflective display of claim 1, wherein the liquid crystal material is an anisotropic liquid crystal material.

3. The holographically formed reflective display of claim 1, wherein the liquid crystal material and polymer molecules forming the anisotropic polymer sheets are index matched so as to reduce haze in the display when viewed from various viewing angles.

4. The holographically formed reflective display of claim 1, wherein the display operates in a reverse mode in which when no electric field is applied, the liquid crystal display is transparent, and when an electric field is applied, the liquid crystal display is reflective of said at least one selected wavelength of light.

5. The holographically formed reflective display of claim 1, wherein the plurality of anisotropic polymer sheets are phase separated from the liquid crystal material by laser holography.

6. The holographically formed reflective display of claim 1, further comprising a rubbed polymer layer formed between the substrates and the liquid crystal material so as to cause homogeneous surface boundary conditions between polymer molecules within the polymer sheets and liquid crystal molecules within the liquid crystal material.

7. The holographically formed reflective display of claim 1, further comprising a material inducing homeotropic surface anchoring formed between the substrates and the liquid crystal material so as to cause homeotropic surface boundary conditions between polymer molecules within the polymer sheets and liquid crystal molecules within the liquid crystal material.

8. The holographically formed reflective display of claim 1, wherein the liquid crystal material is a chiral nematic liquid crystal material.

9. The holographically formed reflective display of claim 1, wherein the liquid crystal material is a ferroelectric liquid crystal material.

10. A color liquid crystal display which includes a first, a second and a third holographically formed reflective display of claim 1, the first, the second and the third holographically formed reflective displays operate to reflect light of first, second and third wavelengths, respectively.

11. The color liquid crystal display of claim 10, wherein the first, second and third wavelengths are approximately 465 nm, 545 nm and 620 nm, respectively.

12. A color projection system which includes a first, a second and a third holographically formed reflective display of claim 1, each of the first, the second and the third holographically formed reflective displays operate to reflect light of first, second and third wavelengths, respectively.

13. The color projection system of claim 12, wherein the first, second and third wavelengths are approximately 465 nm, 545 nm and 620 nm, respectively.

18. A color projection system which includes a first, a second and a third holographically formed reflective display of claim 1, each of the first, the second and the third holographically formed reflective displays operating to reflect light of first, second and third wavelengths, respectively.

14. A holographically formed reflective display, comprising:

first and second substrates;

an anisotropic liquid crystal material located between the substrates; and

a plurality of anisotropic polymer sheets formed from at least a photo-active monomer and a photo initiator that phase separate the liquid crystal material into a plurality of liquid crystal material regions, the anisotropic polymer sheets formed by application of a laser,

wherein the display operates in a reverse mode in which when no electric field is applied, the liquid crystal display is transparent, and when an electric field is applied, the liquid crystal display is reflective of at least one selected wavelength of light, and the liquid crystal material and polymer molecules forming the anisotropic polymer sheets are index matched so as to reduce haze in the display when viewed from various viewing angles.

15. The holographically formed reflective display of claim 14, wherein the liquid crystal material is a chiral nematic liquid crystal material.

16. The holographically formed reflective display of claim 14, wherein the liquid crystal material is a ferroelectric liquid crystal material.

17. A color liquid crystal display which includes a first, a second and a third holographically formed reflective display of claim 14, the first, the second and the third holographically formed reflective displays operating to reflect light of first, second and third wavelengths, respectively.

19. A method of forming a holographical reflective display, comprising:

forming first and second substrates;

forming a liquid crystal material between the first and second substrates; and

forming a plurality of anisotropic polymer sheets including at least a photo-active monomer and a photo initiator has been inserted; and

that phase separate the liquid crystal material into a plurality of liquid crystal material regions such that said display is reflective of at least one selected wavelength of light.

20. The method of forming a holographic reflective display of claim 19, wherein the liquid crystal material is an anisotropic liquid crystal material.

21. The method of forming a holographic reflective display of claim 19, further comprising index matching the liquid crystal material and the anisotropic polymer sheets so as to reduce haze in the display when viewed from various viewing angles.

22. The method of forming a holographic reflective display of claim 19, further comprising phase separating the plurality of anisotropic polymer sheets from the liquid crystal material by application of a laser.

23. The method of forming a holographic reflective display of claim 19, further comprising forming a rubbed polymer layer between the substrates and the liquid crystal material so as to cause homogeneous surface boundary conditions between polymer molecules within the polymer sheets and liquid crystal molecules within the liquid crystal material.

24. The method of forming a holographic reflective display of claim 19, further comprising forming a silane surfactant layer between the substrates and the liquid crystal material so as to cause homeotropic surface boundary conditions between polymer molecules within the polymer sheets and liquid crystal molecules within the liquid crystal material.

25. A method of forming a color liquid crystal display comprising:

forming a first, a second and a third holographically formed reflective display of claim 19;

forming the first, the second and the third holographically formed reflective displays so that each of the reflective displays operate to reflect light of first, second and third wavelengths, respectively.

26. A method of forming a projection system comprising:

forming a first, a second and a third holographically formed reflective display of claim 19;

forming the first, the second and the third holographically formed reflective displays so that each of the reflective displays operate to reflect light of first, second and third wavelengths, respectively.