Structured oriented films for use in displays

• US 20060274244A1
• Filed: 04/07/2006
• Published: 12/07/2006
• Est. Priority Date: 04/08/2005
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Johnson, Stephen A., Biernath, Rolf W., O'Neill, Mark B., Epstein, Kenneth A., Whitney, Leland R., Brott, Robert L., Bryan, William J., Battiato, James M., Merrill, William W., Black, William B., Kowitz, David A., Wilson, Dennis W., Johnson, Matthew B., Denker, Martin E., Hennen, Daniel W., O'Neill, Mitsuko T.
• Application Number:
  US11/400,557
• Publication Number:
  US 20060274244A1
• Time in Patent Office: Days
• US Class Current: 349/119
• CPC Class Codes: B29C 43/222 characterised by the shape of the surface
• CPC Class Codes: B29C 55/08 transverse to the direction of feed
• CPC Class Codes: B29C 55/16 simultaneously
• CPC Class Codes: B29D 11/00278 Lenticular sheets B29D11/00269 takes precedence
• CPC Class Codes: B29D 11/00663 Production of light guides
• CPC Class Codes: B29K 2995/0032 Birefringent
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

Films having a structured surface with an engineered feature, such as prism grooves, to be used in displays having a backlight. The films can be arranged in a stack having one or more of the following: birefringent brightness enhancement films, non-birefringent brightness enhancement films, polarizers, diffusers, birefringent turning films, and non-birefringent turning films. Those films can be arranged in any order from the backlight to a viewer.

Claims

1. An article for use in a display with a backlight, comprising as arranged in any order from the backlight toward a viewer:

a reflective polarizer; and

a birefringent brightness enhancement film having a birefringent structured surface.

2. The article of claim 1, further comprising an orthogonal birefringent brightness enhancement film or an orthogonal non-birefringent brightness enhancement film arranged after the birefringent brightness enhancement film.

3. The article of claim 1, further comprising another birefringent brightness enhancement film arranged after the reflective polarizer.

4. The article of claim 3, further comprising a non-birefringent brightness enhancement film arranged between the birefringent brightness enhancement film and the reflective polarizer.

13. The article of claim 11, further comprising a diffuser arranged after the birefringent turning film or the non-birefringent turning film.

5. An article for use in a display with a backlight, comprising as arranged in the following order from the backlight toward a viewer:

one or more birefringent diffusers each having a birefringent structured surface; and

a reflective polarizer.

6. The article of claim 5, further comprising one or more non-birefringent diffusers arranged between the one or more birefringent diffusers and the reflective polarizer.

7. The article of claim 5, further comprising a non-birefringent diffuser arranged before the one or more birefringent diffusers.

8. The article of claim 7, further comprising another non-birefringent diffuser arranged between the birefringent diffuser and the reflective polarizer.

9. The article of claim 7, further comprising one or more non-birefringent diffusers arranged after the reflective polarizer.

10. An article for use in a display with a backlight, comprising as arranged in the following order from the backlight toward a viewer:

a birefringent turning film or a non-birefringent turning film, each of the turning films having a birefringent structured surface; and

a reflective polarizer.

12. The article of claim 10, further comprising a diffuser arranged after the reflective polarizer.

14. The article of claim 10, further comprising a diffuser arranged between the birefringent turning film or the non-birefringent turning film and the reflective polarizer.

11. An article for use in a display with a backlight, comprising as arranged in the following order from the backlight toward a viewer:

a reflective polarizer; and

a birefringent turning film or a non-birefringent turning film, each of the turning films having a birefringent structured surface.

15. The article of claim 11, further comprising a brightness enhancement film at least partially laminated to the rear of the reflective polarizer.

16. A uniaxially oriented structured surface article, comprising:

(a) a birefringent film having (i) a first and a second surface, and (ii) first and second in-plane axes that are orthogonal with respect to each other and a third axis that is mutually orthogonal to the first and second in-plane axes in a thickness direction of the film; and

(b) a surface portion comprising an engineered feature disposed on the first surface of the film, the engineered feature being disposed on the body in a direction substantially parallel to the first in-plane axis of the film,

wherein an orientation of a highest index of refraction in the article is selected based upon particular criteria.

17. The article of claim 16, wherein the film is positively birefringent.

18. The article of claim 16, wherein the film is negatively birefringent.

19. The article of claim 16, further comprising a polarizer located adjacent the film.

20. The article of claim 19, wherein the article comprises a brightness enhancement film.

21. A method for making a uniaxially oriented structured surface article, comprising the steps of:

providing a birefringent body having a first and a second surface, and first and second in-plane axes that are orthogonal with respect to each other and a third axis that is mutually orthogonal to the first and second in-plane axes in a thickness direction of the body, and having a surface portion comprising a engineered feature disposed on the first surface of the body, the engineered feature being disposed on the body in a direction substantially parallel to the first in-plane axis of the body; and

orienting the body; and

including a reflective polarizer on the body.

22. The method of claim 21, wherein the orienting step includes uniaxially orienting the body.

23. The method of claim 21, wherein the orienting step includes biaxially orienting the body.

24. The method of claim 21, wherein the including step comprises laminating the reflective polarizer to the body.

25. A method for making a uniaxially oriented structured surface article, comprising the steps of:

providing a birefringent body having a first and a second surface, and first and second in-plane axes that are orthogonal with respect to each other and a third axis that is mutually orthogonal to the first and second in-plane axes in a thickness direction of the body, and having a surface portion comprising a engineered feature disposed on the first surface of the body, the engineered feature being disposed on the body in a direction substantially parallel to the first in-plane axis of the body; and

selecting an orientation of a highest index of refraction in the body based upon particular criteria.