Liquid crystal display device and manufacturing method thereof

• US 7,812,905 B2
• Filed: 08/28/2007
• Issued: 10/12/2010
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Hara, Koji, Sano, Yasushi, Matsuura, Hiroyasu, Takanosu, Keiji, Sekiguchi, Shinji
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): NGUYEN, THANH NHAN P
• Application Number:
  US11/845,806
• Publication Number:
  US 20080074588A1
• Time in Patent Office: 1,141 Days
• Field of Search: 349/114, 349/141, 349117-119, 349/187
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133565 inside the LC elements, i.e. between the cell substrates
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133631 with a spatial distribution of the retardation value
• CPC Class Codes: G02F 1/133633 using mesogenic materials

Abstract

The present invention relates to a method of manufacturing a transflective liquid crystal display device including a color filter substrate having a plurality of pixels, each including a reflective display part and a transmissive display part, and retardation plates each built in areas on a principal surface of the color filter substrate opposed to a liquid crystal layer, which correspond to the reflective display parts. The manufacturing method is characterized by including in the following order: a first step of applying a photosetting resin composition on the principal surface of the color filter; a second step of partially curing areas of a photosetting resin film, which correspond to the reflective display parts, respectively, by light exposure through a mask; a third step of removing uncured portions of the photosetting resin film remaining in the second step by development; a fourth step of selectively forming unevenness in areas of a principal surface of the cured photosetting resin film, which correspond to the reflective display parts; and a fifth step of applying a material of the retardation plate onto the photosetting resin film having the unevenness, to form the retardation plates in the respective areas corresponding to the reflective display parts, by anchoring energy of a part having the unevenness, for the material of the retardation plate.

Claims

1. A method of manufacturing a transflective liquid crystal display device including a liquid crystal layer sealed between a principal surface of a first substrate, in which a retardation plate is built, and a second substrate, comprising:

a first step of applying a photosetting resin composition serving as an underlayer of the retardation plate, onto the principal surface of the first substrate;

a second step of selectively forming unevenness on a part of the applied photosetting resin composition, in which the retardation plate is provided, by a partial curing process of an applied film of the photosetting resin composition by exposure to light through a mask, and a development process which removes an uncured portion of the applied film remaining after the partial curing process; and

a third step of applying material of the retardation plate onto the cured applied film of the photosetting resin composition to form the retardation plate by anchoring energy of the part of the cured applied film on which the unevenness is formed.

2. A method of manufacturing a transflective liquid crystal display device including a color filter substrate including color filters corresponding to a plurality of pixels, which are formed on a principal surface thereof, each of the color filters corresponding to the plurality of pixels, including a reflective display part and a transmissive display part, the reflective display part of the color filter substrate including a retardation plate built therein, the method comprising in the following order:

a leveling layer application step of applying a photosetting resin composition on upper surfaces of colored resist layers formed as the color filters, respectively, on the principal surface of the color filter substrate, as a leveling layer of the colored resist layers;

a leveling layer curing step of partially exposing the photosetting resin composition to light, to cure the photosetting resin composition;

a development step of removing an uncured portion of the photosetting resin composition;

a step of applying a material of the retardation plate onto a layer made of the photosetting resin composition;

a heating step of heating the applied material of the retardation plate; and

a retardation plate curing step of exposing the material of the retardation plate to light, to cure the material of the retardation plate,

wherein the leveling layer curing step comprises performing light exposure through a mask to alternately arrange exposed parts and unexposed parts in an area of the photosetting resin composition where the retardation plate is provided.

3. A method of manufacturing the transflective liquid crystal display device according to claim 2, wherein the heating step comprises heating the material of the retardation plate at a temperature higher than a melting point of the material of the retardation plate and lower than a nematic isotropic phase shift temperature.

4. A transflective IPS liquid crystal display device comprising:

a first substrate including color filters formed on a principal surface thereof;

a second substrate opposed to the principal surface of the first substrate, the second substrate being bonded to the first substrate; and

a liquid crystal layer sealed between the first substrate and the second substrate, each of areas of the color filters, corresponding to each pixel, including a reflective display part and a transmissive display part;

wherein the color filters, a first resin layer, and a second resin layer are formed in this order on the principal surface of the first substrate;

wherein the second resin layer is in contact with the first resin layer, and each of the first resin layer and the second resin layer extends from the reflective display part to the transmission display part for each of the areas corresponding to each pixel;

wherein the second resin layer has a phase difference property in the reflective display part, the phase difference property of the second resin layer being obtained by curing a liquid crystal material having a birefringence; and

wherein a structure which aligns liquid crystal molecules which form the second resin layer, is formed in a part of the first resin layer in contact with the part of the second resin layer which has the phase difference property.