Optical devices incorporating photo reactive polymers

• US 20040141706A1
• Filed: 01/17/2003
• Published: 07/22/2004
• Est. Priority Date: 01/17/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Escuti, Michael J., Allen, Richard C., Crawford, Gregory P.
• Granted Patent: US 7,006,747 B2
• Time in Patent Office: Days
• US Class Current: 385/132
• CPC Class Codes: G02F 1/0115 in optical fibres
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/313 in an optical waveguide structure
• CPC Class Codes: G03F 7/001 Phase modulating patterns, e.g. refractive index patterns
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A method for forming a display device including generating a face plate element by providing a first substrate with a photoactive resin thereon and exposing the photoactive resin to a light interference pattern formed by three collimated and coherent light sources, resulting in columnar features. A display device including an optical display element and a polymer face plate that receives or directs light to the optical display element. The face plate includes columnar areas where an index of refraction of the columnar areas is different from the index of refraction of a cladding area surrounding the columnar areas. The columnar areas are formed by exposure of a photoactive resin to a light interference pattern formed by three collimated and coherent light sources. A method of manufacturing a wave guide including providing a first substrate with a photoactive resin thereon and creating a wave guide channel in a wave guide template. The wave guide channel is filled with a liquid crystal material that is exposed to a light grating to create a variation in an index of refraction of the liquid crystal material in the wave guide channel.

Claims

1. A method for forming a display device comprising:

generating a face plate element by

(i) providing a first substrate with a photoactive resin thereon;

(ii) exposing the photoactive resin to a light interference pattern formed by three collimated and coherent light sources to generate, according to the light interference pattern, first light regions and second dark regions in the photoactive resin wherein the photoactive resin of the first light region is altered by exposure to light of the light interference pattern and wherein either the first regions or the second regions form columnar features; and

combining the face plate with an optical display element to form a display device,

wherein the face plate receives or directs light to the optical display element.

2. The method of claim 1, wherein the columnar features are substantially hexagonally symmetrical in a plane approximately parallel to a plane of the first substrate.

3. The method of claim 1 wherein after exposure to the light interference pattern, the photoactive resin of either the first or second region is altered to be solidified to form solid columnar features while the photoactive resin of either the first or second regions is soluble, further comprising the step of dissolving the photoactive resin that is soluble.

4. The method of claim 3 further comprising:

filling a cladding area surrounding the solid columnar features with a liquid crystal material; and

exposing the liquid crystal material in the cladding area to a plurality of coherent light sources to solidify the liquid crystal material,

wherein the cladding area has an index of refraction that is less than an index of refraction of the columnar features.

5. The method of claim 4 wherein the plurality of coherent light sources are selected to cause a variation in the index of refraction in the liquid crystal material in the cladding area, wherein the resulting structure reflects substantially all wavelengths of visible light.

6. The method of claim 1 wherein after exposure to the light interference pattern, the photoactive resin of either the first or second region is altered to be solidified to form a solid cladding area surrounding the columnar features, while the photoactive resin in the columnar features is soluble, further comprising the step of dissolving the soluble photoactive resin in the columnar features.

7. The method of claim 6 further comprising:

filling the columnar features with a liquid crystal material; and

exposing the liquid crystal material to a plurality of coherent light sources to solidify the liquid crystal material,

wherein the cladding area has an index of refraction that is less than an index of refraction of the columnar features.

8. The method of claim 7 wherein the coherent light sources are selected to cause a variation in the index of refraction in the liquid crystal material in the columnar features, wherein the resulting structure reflects some wavelengths of light.

9. The method of claim 6 wherein the cladding area absorbs light.

10. A display device comprising:

an optical display element; and

a polymer face plate that receives or directs light to the optical display element comprising columnar areas where an index of refraction of the columnar areas is different from the index of refraction of a cladding area surrounding the columnar areas, wherein the columnar areas are formed by exposure of a photoactive resin to a light interference pattern formed by three collimated and coherent light sources, wherein the light interference pattern includes first light regions and second dark regions in the photoactive resin wherein the photoactive resin of the first light region is altered by exposure to light of the light interference pattern and wherein either the first regions or the second regions form the columnar areas.

11. The display device of claim 10, wherein the columnar areas are substantially hexagonally symmetrical in a plane approximately parallel to a plane of the first substrate.

12. The display device of claim 10 wherein the columnar areas or the cladding area are void areas.

13. The display device of claim 10 wherein the columnar areas are void areas.

14. The display device of claim 10 wherein the cladding area is a void area.

15. The display device of claim 10 wherein columnar areas are solid columnar areas and the face plate further comprises:

a cladding material in the cladding area surrounding the solid columnar areas, the cladding material formed by exposing a liquid crystal material to a plurality of coherent light sources to solidify the liquid crystal material, wherein the cladding material has an index of refraction that is less than an index of refraction of the columnar areas.

16. The display device of claim 13 wherein the index of refraction of the cladding material is non-uniform, wherein the face plate reflects substantially all wavelengths of visible light.

17. The display device of claim 10, the face plate further comprising a cladding material in the cladding area formed by photoactive resin of either the first or second region being altered to be solidified surrounding the columnar areas after exposure to the light interference pattern, wherein the columnar areas are void of material.

18. The display device of claim 17 wherein the columnar areas of the face plate further comprise a liquid crystal material that has been exposed to a plurality of coherent light sources to solidify the liquid crystal material, wherein the cladding area has an index of refraction that is less than an index of refraction of the columnar areas.

19. The display device claim 18 wherein the columnar areas have a variation in the index of refraction, wherein the face plate reflects some wavelengths of light.

20. The display device of claim 17 wherein the cladding area of the face plate absorbs light.

21. A method of manufacturing a wave guide comprising:

providing a first substrate with a photoactive resin thereon;

creating a wave guide channel in a wave guide template comprising exposing the photoactive resin to a light pattern having a first light region and a second dark region, wherein after exposure to the light pattern, the photoactive resin of either the first or second region is altered to be solidified to form the wave guide template while the photoactive resin of either the first or second regions is soluble, further comprising the step of dissolving the photoactive resin that is soluble to define the wave guide channel in the wave guide template;

filling the wave guide channel of the wave guide template with a liquid crystal material;

exposing the liquid crystal material to a light grating to create a variation of an index of refraction of the liquid crystal material in the wave guide channel.

22. The method of manufacture of claim 21 wherein the first substrate includes an electrode and further comprising positioning a second substrate with a second electrode opposite the first substrate, so that the second and first electrodes contact the liquid crystal material in the wave guide channel, wherein when an electrical field is applied to the liquid crystal material in the wave guide channel, the variation in the index of refraction is modified.

23. The method of manufacture of claim 22 wherein when an electrical field is applied to the liquid crystal material in the wave guide channel, the variation in the index of refraction is eliminated.

24. The method of manufacture of claim 21 wherein the wave guide channel forms a right angle.