Semi-transmissible reflector, semi-transmission type polarizer and liquid-crystal display device using the sames

• US 6,876,414 B2
• Filed: 02/07/2002
• Issued: 04/05/2005
• Est. Priority Date: 04/09/2001
• Status: Expired due to Fees

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Osuka, Tatsuya, Sakuramoto, Takafumi, Miyatake, Minoru, Hara, Kazutaka
• Primary Examiner(s): Parker, Kenneth
• Application Number:
  US10/067,292
• Publication Number:
  US 20020145690A1
• Time in Patent Office: 1,153 Days
• Field of Search: 349/96, 349/113, 349/114
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

A semi-transmissible reflection layer is formed on a light-transmissible polymer substrate uniaxially drawn to have uniaxial orientation characteristic to thereby form a semi-transmissible reflector.

Claims

1. A semi-transmission type polarizer comprising:

a semi-transmissible reflector comprising a light-transmissible polymer substrate uniaxially drawn to have uniaxial orientation characteristic, and a semi-transmissible reflection layer formed directly on said light-transmissible polymer substrate, and

a polarzer stuck onto said semi-transmissible reflector,

wherein the anale between a retardation axis of said light-transmissible polymer substrate in said semi-transmissible reflector and an absorption axis of said polarizer is not larger than 9 degrees.

2. A semi-transmission type polarizer according to claim 1, wherein said semi-transmissible reflection layer is made of a metal vapor-deposited film or metal thin film having light transmissibility.

3. A liquid-crystal display device comprising a liquid-crystal cell, at least one semi-transmission type polarizer defined in claim 1 and disposed on at least one of opposite surfaces of said liquid-crystal cell, and a backlight having polarizing characteristic and combined with said semi-transmission type polarizer.

4. A liquid-crystal display device according to claim 3, wherein the backlight comprises a reflection polarizing element.

5. A semi-transmissible reflector type polarizer according to claim 1, wherein, when polarized light is incident on at least one surface of said semi-transmissible reflector type polarizer, the light transmitted through said semi-transmissible reflector type polarizer is reduced by at most 10%, as compared to incident polarized light.

6. A semi-transmissible reflector type polarizer according to claim 5, wherein the light transmitted through said semi-transmissible reflector type polarizer is reduced by at most 5%.

7. A semi-transmissible reflector type polarizer according to claim 1, wherein the light transmitted through said semi-transmissible reflector type polarizer is not reduced by more than 1%.

8. A semi-transmissible reflector type polarizer according to claim 1, wherein the angle between a retardation axis of said light-transmissible polymer substrate in said semi-transmissible reflector and an absorption axis of said polarizer is not larger than 6.4 degrees.

9. A semi-transmissible reflector type polarizer according to claim 1, wherein the angle between a retardation axis of said light-transmissible polymer substrate in said semi-transmissible reflector and an absorption axis of said polarizer is not larger than 2.8 degrees.