Optical film laminate, method for producing the same, and liquid crystal display panel using the same

• US 8,902,398 B2
• Filed: 06/08/2012
• Issued: 12/02/2014
• Est. Priority Date: 06/09/2011
• Status: Expired due to Fees

• Current Assignee: Hayashi Telempu Corporation
• Original Assignee: Hayashi Engineering Inc.
• Inventors: Sakai, Takeya
• Primary Examiner(s): DUONG, THOI V
• Application Number:
  US13/491,927
• Publication Number:
  US 20120314159A1
• Time in Patent Office: 907 Days
• Field of Search: 349117-119, 349/96, 349/122, 349/193, 349/194, 349/123, 349/187, 428/1.1, 428/1.5, 252/299.01, 353/8, 430/20
• US Class Current: 349/187
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133632 with refractive index ellipsoid inclined relative to the LC-layer surface
• CPC Class Codes: G02F 1/133633 using mesogenic materials
• 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 1/133726 made of a mesogenic material
• CPC Class Codes: G02F 2202/023 curable
• CPC Class Codes: G02F 2413/02 Number of plates being 2
• CPC Class Codes: G02F 2413/06 Two plates on one side of the LC cell

Abstract

Provided is an optical film laminate with a thinner thickness having an optical compensation function. According to the present invention is provided an optical film laminate comprising (i) a positive C plate comprising a liquid crystal material having a photosensitive group and (ii) a positive A plate, an optically biaxial plate, or an O plate, these plate comprising a liquid crystal material having a photosensitive group; wherein the both plates are directly bonded with each other to be firmly laminated without adhesive.

Claims

1. A method for producing an optical film laminate comprising:

providing a positive C plate (layer A) comprising a homeotropic alignment layer of a liquid crystal material (or material A) having a photosensitive group, the layer not being subjected to alignment fixation;

forming on the positive C plate, a positive A plate, an optically biaxial plate, or an O plate (layer B) of a liquid crystal material (or material B) having a photosensitive group, to obtain a laminate of the layer A and the layer B,

irradiating an un-polarized UV light to the laminate so as to fix the alignment of the layer A and the layer B, as well as directly laminate and bond both layers without adhesive.

2. The method as claimed in claim 1, wherein the layer A is formed by applying a solution dissolving a material A in a solvent on a support film to form a coated layer, followed by drying and heating the coated layer.

3. The method as claimed in claim 1, wherein the layer B, is formed by applying a solution dissolving the material B in a solvent on the layer A to form a coated layer, followed by drying, and subsequently irradiating a linear polarized UV light.

4. The method as claimed in claim 1, wherein the photosensitive groups of both material A and material B are a photosensitive group reacting with each other when exposed to light.

5. The method as claimed in claim 4, wherein the photosensitive groups of both material A and material B are the same photosensitive group.