REFLECTIVE POLARIZER CONFIGURATION FOR LIQUID CRYSTAL DISPLAYS

• US 20080129930A1
• Filed: 12/01/2006
• Published: 06/05/2008
• Est. Priority Date: 12/01/2006
• Status: Abandoned Application

• Current Assignee: Agoura Technologies, Co.
• Original Assignee: Agoura Technologies, Co.
• Inventors: Little, Michael J.
• Application Number:
  US11/566,103
• Publication Number:
  US 20080129930A1
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 2201/16 series; tandem

Abstract

A direct view display apparatus is disclosed. The direct view display apparatus comprises a source of backlight, a liquid crystal array; a tandem reflective polarizer having two or more reflective polarizer elements disposed in tandem between the source of backlight and the liquid crystal array; and a second polarizer. The liquid crystal array is disposed between the tandem reflective polarizers and the second polarizer. The second polarizer is an absorptive polarizer.

Claims

1. A direct view display apparatus, comprising:

a source of backlight;

a liquid crystal array;

a tandem reflective polarizer having two or more reflective polarizer elements disposed in tandem between the source of backlight and the liquid crystal array; and

a second polarizer, wherein the liquid crystal array is disposed between the tandem reflective polarizers and the second polarizer, wherein the second polarizer is an absorptive polarizer.

2. The apparatus of claim 1 wherein the two or more reflective polarizer elements include one or more wire grid polarizers.

3. The apparatus of claim 2 wherein the one or more wire grid polarizers include a plurality of substantially-straight metallic lines of predetermined periodicity A formed on a thin film substrate, wherein the lines cover a region approximately 4 centimeters to about 200 centimeters in length and approximately 4 centimeters to about 200 centimeters in width, wherein the periodicity A is between about 50 nanometers and about 500 nanometers.

4. The apparatus of claim 1 wherein the two or more reflective polarizer elements include one or more stacks of isotropic/anisotropic pairs of polymer films.

5. The apparatus of claim 1 wherein the two or more reflective polarizer elements include one or more chiral liquid crystal polarizer films.

6. The apparatus of claim 1 wherein the two or more reflective polarizer elements include at least two wire grid polarizers arranged in tandem.

7. The apparatus of claim 1 wherein the tandem reflective polarizer is characterized by a contrast ratio greater than about 300 as a result of a combined effect of the two or more reflective polarizers.

8. The apparatus of claim 1 wherein the tandem reflective polarizer includes a first reflective polarizer and a second reflective polarizer with an air gap between the first and second reflective polarizers.

9. The apparatus of claim 8 wherein the first or second reflective polarizer includes a reflective polarizer layer on a transparent substrate.

10. The apparatus of claim 1 wherein the tandem reflective polarizer includes a first reflective polarizer bonded to a second reflective polarizer without an air gap between the first and second reflective polarizers.

11. The apparatus of claim 10 wherein the first and second reflective polarizers are joined face-to-face.

12. The apparatus of claim 10 wherein the first and second reflective polarizers are joined back-to-back.

13. The apparatus of claim 10 wherein the first and second reflective polarizers are joined front-to-back.

14. The apparatus of claim 1 wherein the tandem reflective polarizer includes a first reflective polarizer and a second reflective polarizer bonded to a transparent substrate, wherein the transparent substrate is between the first and second reflective polarizers.

15. The apparatus of claim 1 wherein the tandem reflective polarizer includes a first reflective polarizer bonded to a transparent substrate and a second reflective polarizer bonded to the first reflective polarizer, wherein the first reflective polarizer is between the transparent substrate and the second reflective polarizer.