Display Incorporating Reflective Polarizer

• US 20070121034A1
• Filed: 01/31/2007
• Published: 05/31/2007
• Est. Priority Date: 12/21/1993
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weber, Michael, Ouderkirk, Andrew, Benson, Olester
• Application Number:
  US11/669,666
• Publication Number:
  US 20070121034A1
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• 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 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

A display includes a liquid crystal display panel, an optical cavity producing substantially collimated light and a birefringent reflective polarizer.

Claims

1. A display comprising:

a liquid crystal display panel;

a light source generating light; and

a birefringent reflective film positioned between the liquid crystal display panel and the light source to receive incident light generated by the light source and reflecting incident light having a first polarization, and partially reflecting and transmitting incident light having a second polarization different than the first polarization.

2. A display according to claim 1 wherein the birefringent reflective film has an average transmission of the second polarization of at least 50% and an average transmission of the first polarization of less than 40%.

3. A display according to claim 1 wherein the birefringent reflective polarizer is an asymmetric mirror.

4. A display according to claim 3 wherein the birefringent reflective film has an average transmission of the second polarization of less than 50% and an average transmission of the first polarization of less than 20%.

5. A display according to claim 1 wherein the display further comprises a structured surface element disposed between the liquid crystal display panel and the light source.

6. A display according to claim 1 further comprising a reflective layer positioned to reflect light generated by the light source toward the birefringent reflective film.

7. A display according to claim 6 wherein the reflective layer comprises a multilayer polymeric film.

8. A display according to claim 6 wherein the reflective layer comprises a multilayer birefringent mirror film.

9. A display according to claim 5 wherein the light source is positioned between the light source and the birefringent reflective film.

10. A display according to claim 1 wherein the birefringent reflective polarizer comprises a multilayer polymeric film.

11. A display according to claim 1 wherein the light source comprises an edge lit backlight.

12. A display according to claim 1 wherein the light source comprises a backlight having a diffusively reflective surface.

13. A display according to claim 1 wherein the birefringent reflective film has a % RMS color of less than 10% at 30 degrees from normal.

14. A display according to claim 1 wherein the birefringent reflective film has a % RMS color of less than 8% at 30 degrees from normal.

15. A display according to claim 1 wherein the birefringent reflective film has a % RMS color of less than 3.5% at 30 degrees from normal.

16. A display according to claim 1 wherein the birefringent reflective film is planar.