Polarization control system and display device

• US 8,035,775 B2
• Filed: 07/18/2007
• Issued: 10/11/2011
• Est. Priority Date: 09/07/2006
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), LG Electronics, Inc. (LG Corporation)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sakai, Akira
• Primary Examiner(s): QI, ZHI QIANG
• Application Number:
  US12/377,183
• Publication Number:
  US 20100171906A1
• Time in Patent Office: 1,546 Days
• Field of Search: 349/96, 349/112, 349/194, 359/485
• US Class Current: 349/96
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• 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 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 2413/12 Biaxial compensators

Abstract

A polarization control system which includes an E-type polarizer and therefore can provide excellent dark state at a wide azimuth and viewing angle. Further, the polarization control system includes a viewing angle control element for controlling a traveling direction of light which has passed through the E-type polarizer and therefore can provide excellent bright state at a wide azimuth and viewing angle. Further a display device is disclosed including such a polarization control system. The polarization control system is a polarization control system including a plurality of polarizers, wherein the polarization control system includes an E-type polarizer and a viewing angle control element, and the viewing angle control element controls a traveling direction of light which has passed through the E-type polarizer.

Claims

1. A polarization control system comprising a plurality of polarizer,

wherein the polarization control system includes an E-type polarizer and a viewing angle control element, and

the viewing angle control element controls a traveling direction of light which has passed through the E-type polarizer by switching part of the light which has entered the viewing angle control element, so that the intensity of the light transmitted at each azimuth is uniform, wherein

the viewing angle control element outputs part of light which has entered the viewing angle control element from an azimuth parallel to an absorption axis azimuth in a plane of the E-type polarizer into an azimuth substantially parallel to a transmission axis azimuth in the plane of the E-type polarizer.

2. The polarization control system according to claim 1,

wherein the viewing angle control element is at least one optical element selected from the group consisting of a lens film, a scattering film, a light diffraction film, and an anti-glare film.

3. The polarization control system according to claim 1, further comprising an O-type polarizer.

4. The polarization control system according to claim 3,

wherein the E-type polarizer and the O-type polarizer are disposed in Cross-Nicol arrangement.

5. A display device comprising the polarization control system of claim 1.

6. The display device according to claim 5,

comprising a liquid crystal display panel and a viewing angle control element on an observation surface side of the liquid crystal display panel,

the liquid crystal display panel including a liquid crystal layer between a pair of polarizers, and

at least one of the pair of polarizers being an E-type polarizer.

7. The display device according to claim 6,

wherein one of the pair of polarizers is an E-type polarizer, and the other is an O-type polarizer.

8. The display device according to claim 7,

wherein the E-type polarizer and the O-type polarizer are disposed in Cross-Nicol arrangement.

9. The display device according to claim 5,

wherein the display device provides display using a light source device,

an amount of light which is emitted by the light source device into an azimuth parallel to an absorption axis azimuth in a plane of the E-type polarizer is larger than an amount of light which is emitted by the light source device into an azimuth parallel to a transmission axis azimuth in a plane of the E-type polarizer.

10. A polarization control system comprising a plurality of polarizers,

wherein the polarization control system includes an E-type polarizer and a viewing angle control element, and

the viewing angle control element is arranged in such a way that an azimuth where opaque state is observed is parallel to an absorption axis azimuth in a plane of the E-type polarizer, wherein

the viewing angle control element shows anisotropic transmission and diffusion properties, and

a diffusion major axis azimuth of the viewing angle control element is parallel to the absorption axis azimuth in the plane of the E-type polarizer.

11. The polarization control system according to claim 10,

wherein the viewing angle control element includes optical element units for controlling an output direction of an incident light beam, the optical element units being arrayed in plane, and

an array direction of the optical element units is parallel or perpendicular to the absorption axis azimuth in the plane of the E-type polarizer.

12. The polarization control system according to claim 10,

wherein the viewing angle control element is at least one optical element selected from the group consisting of a microlens array film, a lenticular lens film, and a light diffraction film.

13. The polarization control system according to claim 10, further comprising an O-type polarizer.

14. The polarization control system according to claim 13,

wherein the E-type polarizer and the O-type polarizer are disposed in Cross Nicol arrangement.

15. A display device comprising the polarization control system of claim 10.

16. The display device according to claim 15,

comprising a liquid crystal display panel and a viewing angle control element on an observation surface side of the liquid crystal display panel,

the liquid crystal display panel including a liquid crystal layer between a pair of polarizers, and

at least one of the pair of polarizers being an E-type polarizer.

17. The display device according to claim 16,

wherein one of the pair of polarizers is an E-type polarizer, and the other is an O-type polarizer.

18. The display device according to claim 17,

wherein the E-type polarizer and the O-type polarizer are disposed in Cross Nicol arrangement.

19. The display device according to claim 15,

wherein the display device provides display using a light source device,

an amount of light which is emitted by the light source device into an azimuth parallel to the absorption axis azimuth in the plane of the E-type polarizer is larger than an amount of light which is emitted by the light source device into an azimuth parallel to a transmission axis azimuth in the plane of the E-type polarizer.