OPTICAL FILM, POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY DEVICE

• US 20090096961A1
• Filed: 11/14/2006
• Published: 04/16/2009
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Nagai, Michio, Ikeda, Akira
• Granted Patent: US 7,944,530 B2
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02F 1/133632 with refractive index ellipsoid inclined relative to the LC-layer surface
• CPC Class Codes: G02F 1/1395 Optically compensated birefringence [OCB]- cells or PI- cells
• CPC Class Codes: G02F 2413/105 with varying inclination in thickness direction, e.g. hybrid oriented discotic LC
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length

Abstract

An optical film, which is an optically compensatory film that comprises: at least two optically anisotropic layers comprising a first optically anisotropic layer and a second optically anisotropic layer, wherein the first optically anisotropic layer is formed by mixing two or more liquid crystal compounds having different structures with each other.

Claims

1. An optical film, which comprises:

at least two optically anisotropic layers comprising a first optically anisotropic layer and a second optically anisotropic layer,

wherein the first optically anisotropic layer is formed by mixing two or more liquid crystal compounds having different structures with each other.

2. The optical film according to claim 1,

wherein the first optically anisotropic layer satisfies numerical expression (1):

Re(450)/Re(650)<

1.25 

 

(1)

wherein Re (450) and Re (650) represent in-plane retardation values (unit;

nm) of the first optically anisotropic layer at a wavelength of 450 nm and 650 nm, respectively.

3. The optical film according to claim 1,

wherein at least one of the two or more liquid crystal compounds constituting the first optically anisotropic layer is a discotic liquid crystal compound.

4. The optical film according to claim 1,

wherein at least one of the two or more liquid crystal compounds is a trisubstituted benzene skeleton discotic liquid crystal compound.

5. The optical film according to claim 1,

wherein at least one of the two or more liquid crystal compounds is a triphenylene skeleton discotic liquid crystal compound.

6. The optical film according to claim 1,

wherein the second optically anisotropic layer comprises a cellulose acylate film.

7. A polarizing plate, which comprises:

a polarizing film; and

at least two protective films disposed on the both sides of the polarizing film,

wherein at least one of the at least two protective films is an optical film according to claim 1.

8. A liquid crystal display device, which comprises:

a liquid crystal cell; and

a polarizing plate according to claim 7.

9. The liquid crystal display device according to claim 8, which is of OCB mode.