Polarizer and liquid crystal display including the same

• US 9,097,933 B2
• Filed: 03/18/2013
• Issued: 08/04/2015
• Est. Priority Date: 11/20/2012
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Ki, Boo-Kan, Na, Gwan Young, Do, Hee Wook, Kim, Kwang-Hyun, Kim, Dae Won, Suh, Duck Jong, Shin, Na Young, Lee, Sang-Gu, Kim, Ji-Hoon, Kim, Teck Soo, Park, Seung Beom
• Primary Examiner(s): Qi, Mike
• Application Number:
  US13/846,018
• Publication Number:
  US 20140139787A1
• Time in Patent Office: 869 Days
• Field of Search: 349/96, 349/117, 349/9, 349/130, 359/485.03
• US Class Current: 1/1
• CPC Class Codes: G02B 5/205 Neutral density filters
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• 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

Abstract

A polarizer includes a reflective polarizer main body and an Rth compensation layer. The reflective polarizer main body includes a repetitively laminated structure, the repetitively laminated structure including two layers of different refractive indices repetitively disposed on one another. The Rth phase compensation layer is disposed at one side of the reflective polarizer main body. The Rth phase compensation layer is configured to compensate for a phase difference in an Rth direction.

Claims

1. A polarizer, comprising:

at least one first repetitively laminated structure comprising two layers of different refractive indices repetitively disposed on one another; and

a second repetitively laminated structure comprising two layers of different refractive indices repetitively disposed on one another,

wherein one of the at least one first repetitively laminated structures is configured as a light incident surface of the polarizer and the second repetitively laminated structure is configured as a light dispersion surface of the polarizer, and

wherein a thickness ratio of the two layers of the at least one first repetitively laminated structure differs from a thickness ratio of the two layers of the second repetitively laminated structure.

2. The polarizer of claim 1, wherein:

the different thickness ratios of the at least one first repetitively laminated structure and the second repetitively laminated structure are determined based on;

materials configuring a first refractive index layer and a second refractive index layer of each of the at least one first repetitively laminated structure and the second repetitively laminated structure, or

a thickness ratio between the first refractive index layer and the second refractive index layer.

3. The polarizer of claim 1, wherein:

a thickness ratio between the first refractive index layer and the second refractive index layer in association with the second repetitively laminated structure is larger than a thickness ratio between the first refractive index layer and the second refractive index layer in association with the at least one first repetitively laminated structure.

4. The polarizer of claim 3, wherein:

the thickness ratio between the first refractive index layer and the second refractive index layer in association with the second repetitively laminated structure is greater than 0.644 and less than 10.

5. The polarizer of claim 1, further comprising:

a plurality of buffer layers,

wherein;

the polarizer comprises two first repetitively laminated structures and one second repetitively laminated structure,

a first one of the two first repetitively laminated structures is disposed on a first one of the plurality of buffer layers,

a second one of the plurality of buffer layers is disposed between at least one of the two first repetitively laminated structures and the second repetitively laminated structure, and

a third one of the plurality of buffer layers is disposed on the second repetitively laminated structure.

6. A liquid crystal display, comprising:

an upper panel comprising;

an upper polarizer configured as an absorptive polarizer, and

an upper insulation substrate;

a lower panel comprising;

a lower polarizer, and

a lower insulation substrate;

a liquid crystal layer disposed between the upper panel and the lower panel; and

a backlight providing unit configured to supply light,

wherein the lower panel is disposed on the backlight providing unit,

wherein the lower polarizer comprises;

at least one first repetitively laminated structure comprising two layers of different refractive indices repetitively disposed on one other, and

a second repetitively laminated structure comprising two layers of different refractive indices repetitively disposed upon one another,

wherein the second repetitively laminated structure is disposed closer to the liquid crystal layer than the at least one first repetitively laminated structure, and

wherein a thickness ratio of the two layers of the at least one first repetitively laminated structure differs from a thickness ratio of the two layers of the second repetitively laminated structure.

7. The liquid crystal display of claim 6, wherein:

the different thickness ratios of the at least one first repetitively laminated structure and the second repetitively laminated structure are determined based on;

materials configuring a first refractive index layer and a second refractive index layer of each of the at least one fist repetitively laminated structure and the second repetitively laminated structure, or

a thickness ratio between the first refractive index layer and the second refractive index layer.

8. The liquid crystal display of claim 6, wherein:

a thickness ratio between the first refractive index layer and the second refractive index layer in association with the second repetitively laminated structure is larger than a thickness ratio between the first refractive index layer and the second refractive index layer in association with the at least one first repetitively laminated structure.

9. The liquid crystal display of claim 6, wherein:

the thickness ratio between the first refractive index layer and the second refractive index layer in association with the second repetitively laminated structure is greater than 0.644 and less than 10.

10. The liquid crystal display of claim 6, wherein:

the lower polarizer further comprises a plurality of buffer layers;

the lower polarizer comprises two first repetitively laminated structures and one second repetitively laminated structure;

a first one of the two first repetitively laminated structures is disposed on a first one of the plurality of buffer layers;

a second one of the plurality of buffer layers is disposed between at least one of the two first repetitively laminated structures and the second repetitively laminated structure;

a third one of the plurality of buffer layers is disposed on the second repetitively laminated structure.

11. The liquid crystal display of claim 6, wherein:

the liquid crystal layer comprises liquid crystal molecules vertically aligned when an electric field is not applied and horizontally aligned when a vertical electric field is imposed on the liquid crystal layer;

or

the liquid crystal layer comprises liquid crystal molecules horizontally aligned when an electric field is not applied and rotate in a horizontal surface when a horizontal electric field is imposed on the liquid crystal layer.