Retardation substrate, method of manufacturing the same, and liquid crystal display

Abstract

A retardation layer that includes regions causing different retardations can be manufactured easily. A retardation substrate includes a substrate and a solidified liquid crystal layer supported by the substrate. The solidified liquid crystal layer includes first to third regions. The first to third regions re arranged on the substrate and different in degree of orientation of mesogens.

1 - 17 . (canceled) 
   
   
       18 . A retardation substrate comprising:
 a substrate; and   a solidified liquid crystal layer placed on the substrate, the solidified liquid crystal layer having an optical anisotropy, the solidified liquid crystal layer being provided such that it includes a region in a low orientation state and a region in a high orientation state having different refractive index anisotropies due to different degrees of orientation, and the solidified liquid crystal layer being formed by subjecting a liquid crystal phase to a heating process at or higher than a temperature at which a phase transition to an isotropic phase occurs.   
   
   
       19 . The retardation substrate according to  claim 18 , wherein the solidified liquid crystal layer is a continuous layer. 
   
   
       20 . The retardation substrate according to  claim 18 , wherein the solidified liquid crystal layer is formed by polymerizing and/or crosslinking a compound including a thermotropic liquid crystal. 
   
   
       21 . The retardation substrate according to  claim 18 , wherein one of glass, plastic and film substrates is used as the substrate. 
   
   
       22 . The retardation substrate according to  claim 18 , wherein the solidified liquid crystal layer has predetermined retardations for respective colors such that incident lights transmitted by a color filter are optically compensated for respective colors of the opposing color filter. 
   
   
       23 . The retardation substrate according to  claim 18 , wherein the solidified liquid crystal layer has a uniform thickness. 
   
   
       24 . The retardation substrate according to  claim 18 , wherein a thin film transistor (TFT) is provided between the solidified liquid crystal layer and the substrate. 
   
   
       25 . The retardation substrate according to  claim 18 , wherein a thin file transistor (TFT) is further provided above the solidified liquid crystal layer. 
   
   
       26 . A liquid crystal display comprising:
 a retardation substrate including
 a substrate; and 
 a solidified liquid crystal layer placed on the substrate, the solidified liquid crystal layer having an optical anisotropy, the solidified liquid crystal layer being provided such that it includes a region in a low orientation state and a region in a high orientation state having different refractive index anisotropies due to different degrees of orientation, and the solidified liquid crystal layer being formed by subjecting a liquid crystal phase to a heating process at or higher than a temperature at which a phase transition to an isotropic phase occurs. 
   
   
   
       27 . A retardation substrate constituted at least by a substrate and a solidified liquid crystal layer produced by a manufacturing method including:
 applying a solution containing a compound having properties of thermotropic liquid crystal and polymerizable and/or crosslinkable in a photo-induced manner on a substrate to form a thin film in a state where the liquid crystal compound is aligned in a predetermined direction;   irradiating the substrate with light such that regions thereof have different exposure values so as to make uncured-residue contents of the regions different correspondingly with the exposure values;   heating the liquid crystal compound at or higher than a temperature at which a phase transition to an isotropic phase occurs; and   curing the uncured liquid crystal compound to obtain a solidified liquid crystal layer including a low orientation region and a high orientation region.   
   
   
       28 . The retardation substrate according to  claim 27 , wherein one of glass, plastic and film substrates is used as the substrate. 
   
   
       29 . The retardation substrate according to  claim 27 , wherein the solidified liquid crystal layer has predetermined retardations for respective colors such that incident lights transmitted by a color filter are optically compensated for respective colors of the opposing color filter. 
   
   
       30 . The retardation substrate according to  claim 27 , wherein the solidified liquid crystal layer has a uniform thickness. 
   
   
       31 . The retardation substrate according to  claim 27 , wherein a thin film transistor (TFT) is provided between the solidified liquid crystal layer and the substrate. 
   
   
       32 . The retardation substrate according to  claim 27 , wherein a thin film transistor (TFT) is further provided above the solidified liquid crystal layer. 
   
   
       33 . A liquid crystal display comprising:
 a retardation substrate constituted at least by a substrate and a solidified liquid crystal layer produced by a manufacturing method including
 applying a solution containing a compound having properties of thermotropic liquid crystal and polymerizable and/or crosslinkable in a photo-induced manner on a substrate to form a thin film in a state where the liquid crystal compound is aligned in a predetermined direction, 
 irradiating the substrate with light such that regions thereof have different exposure values so as to make uncured-residue contents of the regions different correspondingly with the exposure values, 
 heating the liquid crystal compound at or higher than a temperature at which a phase transition to an isotropic phase occurs, and 
 curing the uncured liquid crystal compound to obtain a solidified liquid crystal layer including a low orientation region and a high orientation region. 
   
   
   
       34 . A retardation substrate constituted at least by a substrate and a solidified liquid crystal layer formed by a manufacturing method including:
 applying a solution containing a compound having properties of thermotropic liquid crystal and polymerizable and/or crosslinkable in a photo-induced manner on a substrate to form a thin film in a state where the liquid crystal compound is aligned in a predetermined direction;   irradiating the substrate with light such that regions thereof have different exposure values so as to make uncured-residue contents of the regions different correspondingly with the exposure values;   heating the liquid crystal compound at or higher than a temperature at which a phase transition to an isotropic phase occurs; and   exposing whole the substrate to light while keeping it at or higher than a temperature at which the liquid crystal compound is kept in the isotropic phase to obtain a solidified liquid crystal layer including a region in a low orientation state and a region in a high orientation state.   
   
   
       35 . The retardation substrate according to  claim 34 , wherein one of glass, plastic and film substrates is used as the substrate. 
   
   
       36 . The retardation substrate according to  claim 34 , wherein the solidified liquid crystal layer has predetermined retardations for respective colors such that incident lights transmitted by a color filter are optically compensated for respective colors of the opposing color filter. 
   
   
       37 . The retardation substrate according to  claim 34 , wherein the solidified liquid crystal layer has a uniform thickness. 
   
   
       38 . The retardation substrate according to  claim 34 , wherein a thin film transistor (TFT) is provided between the solidified liquid crystal layer and the substrate. 
   
   
       39 . The retardation substrate according to  claim 34 , wherein a thin film transistor (TFT) is further provided above the solidified liquid crystal layer. 
   
   
       40 . A liquid crystal display comprising:
 a retardation substrate constituted at least by a substrate and a solidified liquid crystal layer formed by a manufacturing method including
 applying a solution containing a compound having properties of thermotropic liquid crystal and polymerizable and/or crosslinkable in a photo-induced manner on a substrate to form a thin film in a state where the liquid crystal compound is aligned in a predetermined direction, 
 irradiating the substrate with light such that regions thereof have different exposure values so as to make uncured-residue contents of the regions different correspondingly with the exposure values, 
 heating the liquid crystal compound at or higher than a temperature at which a phase transition to an isotropic phase occurs, and 
 exposing whole the substrate to light while keeping it at or higher than a temperature at which the liquid crystal compound is kept in the isotropic phase to obtain a solidified liquid crystal layer including a region in a low orientation state and a region in a high orientation state. 
   
   
   
       41 . A method of manufacturing a retardation substrate including a substrate and a solidified liquid crystal layer placed on the substrate, comprising the steps of:
 (a) applying on the substrate a solution containing a compound that exhibits properties of thermotropic liquid crystal and is polymerizable and/or crosslinkable in a photo-induced manner so as to form a film in a state where the liquid crystalline compound is oriented in a predetermined direction;   (b) irradiating the liquid crystalline compound with light such that regions having different exposure values are produced so as to make uncured-residue contents of the regions different correspondingly with the exposure values;   (c) heating the substrate at or higher than a phase transition temperature at which the liquid crystalline compounds changes to an isotropic phase; and   (d) irradiating the whole substrate with light while keeping a temperature high enough for the liquid crystal compound to be maintained in the isotropic phase so as to form a solidified liquid crystal layer including a region in a low orientation state and a region in a high orientation state.   
   
   
       42 . The method according to  claim 41 , wherein the step (a) is performed such that the film has a uniform thickness throughout the substrate. 
   
   
       43 . The method according to  claim 41 , wherein a thin film transistor (TFT) is formed above the substrate before performing the step (a). 
   
   
       44 . The method according to  claim 41 , wherein a thin film transistor (TFT) is formed above the substrate after performing the step (d). 
   
   
       45 . A method of manufacturing a retardation substrate including a substrate and a solidified liquid crystal layer placed on the substrate, comprising the steps of:
 (a) applying on the substrate a solution containing a compound that exhibits properties of thermotropic liquid crystal and is polymerizable and/or crosslinkable in both photo-induced and heat-induced manners so as to form a film in a state where the liquid crystalline compound is oriented in a predetermined direction;   (b) irradiating the liquid crystalline compound with light such that regions having different exposure values are produced so as to make uncured-residue contents of the regions different correspondingly with the exposure values; and   (c) heating the substrate to a temperature equal to or higher than a phase transition temperature at which the liquid crystalline compounds changes to an isotropic phase and high enough for polymerization and/or crosslinking to occur so as to form a solidified liquid crystal layer including a region in a low orientation state and a region in a high orientation state.   
   
   
       46 . The method according to  claim 45 , wherein a thin film transistor (TFT) is formed above the substrate before performing the step (a). 
   
   
       47 . The method according to  claim 45 , wherein a thin film transistor (TFT) is formed above the substrate after performing the step (d). 
   
   
       48 . A method of manufacturing a retardation substrate including a substrate and a solidified liquid crystal layer placed on the substrate, comprising the steps of:
 (a) applying on the substrate a solution containing a compound that exhibits properties of thermotropic liquid crystal and is polymerizable and/or crosslinkable in a photo-induced manner so as to form a film in which the liquid crystalline compound is oriented in a predetermined direction;   (b) irradiating the liquid crystalline compound with light such that regions having different exposure values are produced so as to make uncured-residue contents of the regions different correspondingly with the exposure values;   (c) heating the substrate at or higher than a phase transition temperature at which the liquid crystalline compounds changes to an isotropic phase; and   (d) irradiating a portion other than a region irradiated with light at a maximum exposure value in step (b) with light while keeping a temperature high enough for the liquid crystal compound to be maintained in the isotropic phase so as to form a solidified liquid crystal layer including a region in a low orientation state, a region in a high orientation state, and a region in a non-orientation state.   
   
   
       49 . The method according to  claim 48 , wherein an exposure value of each of the regions in step (d) is set such that a sum of the exposure values in steps (d) and (b) is equal to that of the region to which the light exposure is performed at the maximum exposure value in the step (b). 
   
   
       50 . The method according to  claim 48 , wherein a thin film transistor (TFT) is formed above the substrate before performing the step (a). 
   
   
       51 . The method according to  claim 48 , wherein a thin film transistor (TFT) is formed above the substrate after performing the step (d).