Reflection plate, manufacturing method thereof, liquid crystal display device, and manufacturing method thereof

Abstract

A reflection plate is formed so as to have a wavy surface, and to have uneven distribution of normal line directions of the surface in terms of a specific azimuth angle. The wavy surface is formed due to line-shaped protruding patterns and an insulation film layer. The protruding patterns intersect with one another to form concave portions each having a shape of a closed figure. The protruding patterns are formed by patterning, such that they have almost uniform thickness.

What is claimed is:  
     
         1 . A reflection plate having concave and protruding portions on a surface thereof, wherein: 
 distribution of normal line directions on said surface is uneven in terms of a specific azimuth angle; and    reflection light intensity is dependent upon azimuth angle.    
     
     
         2 . The reflection plate according to  claim 1 . wherein 
 distribution of reflection light intensity in relation to polar angle at said specific azimuth angle shows one or more local maximum values, other than a normal reflection component.    
     
     
         3 . The reflection plate according to  claim 1 , wherein: 
 closed figures are formed by said protruding portions of said concave and protruding portions; and    said concave portions of said concave and protruding portions are enclosed by said closed figures.    
     
     
         4 . The reflection plate according to  claim 3 , wherein 
 said closed figures are a polygon.    
     
     
         5 . The reflection plate according to  claim 4 , wherein 
 said polygon is approximately a triangle, or approximately a trapezoid.    
     
     
         6 . The reflection plate according to  claim 4 , wherein 
 said polygon is approximately a triangle having a flattening ratio of equal to or greater than 0.5 and equal to or smaller than 0.8.    
     
     
         7 . The reflection plate according to  claim 3 , wherein 
 in each of said closed figures, its length in a first direction in which reflection light intensity becomes the largest, is smaller than its length in a second direction which is perpendicular to said first direction.    
     
     
         8 . The reflection plate according to  claim 3 , wherein 
 line shapes formed by said protruding portions of said closed figures have almost uniform width.    
     
     
         9 . The reflection plate according to  claim 3 , wherein 
 line shapes formed by said protruding portions of said closed figures have almost uniform thickness.    
     
     
         10 . A liquid crystal display device having the reflection plate recited in any one of  claims 1  to  9 .  
     
     
         11 . The liquid crystal display device according to  claim 10 , wherein 
 when incident light is radiated to a display surface of said liquid crystal display device from a direction of −30-degree polar angle, the reflection light intensity reaches local maximum in a range of polar angle of 0 to 10 degrees.    
     
     
         12 . The liquid crystal display device according to  claim 10 , wherein 
 when incident light is radiated to a display surface of said liquid crystal display device from a direction of −30-degree polar angle, the reflection light intensity has a positive slope in relation to polar angle in a range of polar angle of 10 to 20 degrees, said slope becomes smaller as polar angle becomes larger in a range of polar angle of 10 to A degrees (10<A<20), and said slope becomes larger as polar angle becomes larger in a range of polar angle of A to 20 degrees.    
     
     
         13 . A method of manufacturing a reflection plate, comprising: 
 coating an organic resin on a substrate, patterning said organic resin with a line-shape mask, and thus forming a plurality of line-shaped protruding patterns such that said protruding patterns intersect with one another to form concave portions each having a shape of a closed figure; and    coating an interlayer film so as to cover said line-shaped protruding patterns.    
     
     
         14 . The method of manufacturing a reflection plate according to  claim 13 , wherein 
 said line-shape mask comprises mask lines whose width at and about intersection portions of said mask lines is narrower than that of portions other than said intersection portions.    
     
     
         15 . A method of manufacturing a reflection plate, comprising 
 forming a contact hole portion, and at a same time, concave and protruding portions including a plurality of line-shaped protruding portions which intersect with one another, and concave portions enclosed by said protruding portions, by coating an organic resin on a substrate, and exposing and developing said organic resin by changing luminous exposure.    
     
     
         16 . The method of manufacturing a reflection plate according to  claim 15 , wherein 
 said patterning of said contact hole portion and said concave and protruding portions includes exposing said organic resin using different masks and by different luminous exposures for the two different portions.    
     
     
         17 . The method of manufacturing a reflection plate according to  claim 16 , wherein 
 luminous exposure of said organic resin for patterning said concave and protruding portions is 10 to 50% of luminous exposure of said organic resin for patterning said contact hole portion.    
     
     
         18 . The method of manufacturing a reflection plate according to  claim 17 , wherein 
 said patterning of said contact hole portion and said concave and protruding portions includes exposing said organic resin by using a half tone mask having different light transmittance for said contact hole portion and said concave and protruding portions, respectively.    
     
     
         19 . The method of manufacturing a reflection plate according to  claim 15 , wherein 
 a mask for forming said line-shaped protruding portions comprises mask lines whose width at and about intersection portions of said mask lines is narrower than that of portions other than said intersection portions.    
     
     
         20 . A method of manufacturing a liquid crystal display device, comprising 
 forming a reflection plate in accordance with a manufacturing method recited in any one of  claims 13  to  19 .