Optical film assembly and display device

• US 7,622,164 B2
• Filed: 06/08/2006
• Issued: 11/24/2009
• Est. Priority Date: 06/17/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Goenner, Emily S., Jones, Clinton L., Kolb, Brant U., Hart, Shandon D., Olson, David B., Cowher, John T.
• Primary Examiner(s): Visconti; Geraldina
• Application Number:
  US11/422,900
• Publication Number:
  US 20060210726A1
• Time in Patent Office: 1,265 Days
• Field of Search: 428/1.1, 428/1.3, 428/500, 252/299.01, 430/20, 349/1, 349/2, 349/1.2
• US Class Current: 428/1.1
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08F 2/44 Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
• CPC Class Codes: C08F 222/1025 of aromatic dialcohols
• CPC Class Codes: C08F 222/103 of trialcohols, e.g. trimethylolpropane tri(meth)acrylate
• 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: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/031 Polarizer or dye
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• CPC Class Codes: Y10S 977/932 for electronic or optoelectronic application
• CPC Class Codes: Y10S 977/939 Electron emitter, e.g. spindt emitter tip coated with nanoparticles
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24372 : Particulate matter
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers

Abstract

Microstructured optical films, assemblies of films including at least one microstructured optical film, and (e.g. illuminated) display devices including a single microstructured optical film or assembly.

Claims

1. An optical film comprised of a light transmissible polymeric material having a microstructured surface wherein the film is a substantially non-polarizing film having a single sheet relative gain of at least 1.78.

2. The optical film of claim 1 wherein at least the microstructured surface comprises the reaction product of a polymerizable resin wherein the polymerizable resin has a refractive index of at least 1.61.

3. The optical film of claim 1 wherein the microstructured surface comprises a repeating pattern of linear prisms.

4. The optical film of claim 3 wherein the prisms have apexes that are sharp, rounded, or truncated.

5. The optical film of claim 3 wherein the prisms have apex angles that range from 80°

to 100°

.

6. The optical film of claim 3 wherein the prisms have an apex angle of about 90°

, a mean distance between adjacent apices of about 50 micrometers, and the prisms have heights that are substantially the same or vary.

7. The optical film of claim 1 wherein at least the microstructured surface comprises the reaction product of a polymerizable composition wherein the polymerizable composition has an absorbance of less than 2.5 for a wavelength of 450 nm and an absorbance of less than 1 for wavelengths ranging from about 575 nm to 800 nm.

8. The optical film of claim 1 wherein at least the microstructured surface comprises a polymerizable composition comprising fully condensed surface modified inorganic nanoparticles.

9. The optical film of claim 8 wherein the inorganic nanoparticles comprise zirconia.

10. The optical film of claim 1 wherein the film comprises a base layer coupled to the microstructured surface.

11. The optical film of claim 10, where the base layer has a high-index axis and the microstructured surface comprises parallel prisms aligned 90 degrees +/−

20 degrees to the high-index axis of the base layer.

12. The optical film of claim 10 wherein the base layer comprises styrene-acrylonitrile polymer, cellulose triacetate, polymethyl methacrylate, polyester, polycarbonate, polyethylene naphthalate, copolymers of naphthalene dicarboxylic acids, norbornene polymer, or mixtures thereof.

13. An assembly comprising the microstructured optical film of claim 1 proximate a second optical film.

14. The assembly of claim 13 wherein the second optical film is a turning film, a polarizing film, a diffuser film, or combination thereof.

15. An assembly comprising a first microstructured optical film proximate a non-structured reflective polarizing film wherein the assembly of the first film and polarizing film has a relative gain of at least 2.59.

16. The assembly of claim 15 wherein the first microstructured optical film comprises a pattern of substantially parallel prisms, the reflective polarizing film has a pass axis, and the prisms of the microstructured optical film are orthogonal to the pass axis of the reflective polarizing film.

17. An assembly comprising a first substantially non-polarizing microstructured optical film proximate a second substantially non-polarizing microstructured optical film wherein the assembly of the first and second films has a relative gain of at least 2.80.

18. The assembly of claim 17 wherein each optical film has an unstructured surface and the microstructured surface of the second film is proximate the unstructured surface of the first film.

19. The assembly of claim 18 wherein the microstructured surface of each film comprises a pattern of substantially parallel prisms and the second film is positioned such that the prisms of the second sheet are nonparallel to the prisms of the first film.

20. The assembly of claim 19 wherein the prisms of the second film are positioned at angles ranging from 90°

+/−

20°

relative to the prisms of the first film.

21. The assembly of optical films of claim 17 wherein the first microstructured optical film is the same or different than the second microstructured optical film.

22. The assembly of claim 17 further comprising a third optical film proximate the first or second optical film.

23. The assembly of claim 22 wherein the third optical film is a non-structured reflective polarizer.

24. The assembly of claim 23 wherein the assembly of the first, second, and third optical films has a relative gain of at least 3.40.

25. The assembly of claim 19 further comprising a non-structured reflective polarizer having a pass axis positioned above the assembly of substantially non-polarizing microstructured optical films wherein the prisms of the non-polarizing microstructured optical film adjacent the non-structured reflective polarizer are orthogonal to the pass axis of the reflective polarizing film.