Micro-lens sheet and projection screen

Abstract

In order to provide a dual-surface lens sheet in which a color shift is reduced and positions of unit lenses on a front surface and a back surface are easily aligned even if the unit lenses are disposed in fine pitch when used for a rear projection screen which is used for a display device using a plurality of projector as light sources, a half-column-cylindrical-convex-lens is used in a lens sheet having lens sections on front surface and a back surface such that pitch ratio for disposing the unit lenses on the front surface and a back surface such that pitch ratio of 1:2 to 1:30 and disposition directions of the lens sections are uniform.

1 . A projection screen having a micro-lens sheet having a micro-lens array section in which a plurality of unit lenses are disposed in an approximate matrix in a second-dimensional manner, comprising: 
 a surface of a unit lens of the plurality of unit lenses formed in toric shape as a continuous surface, wherein a curvature of a cross sectional shape of the unit lens in one direction is smaller than a curvature in an orthogonal direction to the one direction;    the micro-lens array section, wherein the plurality of unit lenses are disposed in the approximate matrix in the second-dimension manner, and the micro-lens array is formed on one surface of a transparent sheet; and    a shading layer having an aperture section, wherein an optical axis of the aperture section is aligned with an optical axis of plurality of unit lenses on a surface of a sheet which is disposed opposite to the micro-lens array section.    
   
   
       2 . A projection screen according to  claim 1 , wherein directions of the curvature of each unit lens are uniformly disposed when the micro-lens array section in which the unit lens is disposed in the approximate matrix in the second-dimension manner is formed on one surface of the transparent sheet.  
   
   
       3 . A projection screen according to  claim 1 , wherein a lens thug of the toric surface which is a ratio between a thickness of a curvature section in a one direction and a thickness of a curvature section in a cross sectional surface in an orthogonal direction is ⅔ or smaller.  
     which is a ratio between a thickness of a curvature section in a horizontal direction and a thickness of a curvature section in a cross sectional surface in a vertical direction is ⅔ or smaller.  
   
   
       5 . A projection screen according to  claim 1 , wherein the micro-lens array section is formed on the one surface of the transparent sheet which is disposed in an area from which a light is incident, proximate to a projector, when the micro-lens array section is used for a transparent projection screen.  
   
   
       6 . A projection screen according to  claim 1 , wherein 
 the shading layer is formed in a non-light-condensing area on a surface of a base board opposite to a lens section, wherein a light does not condense by exposing a light through the micro-lens array section;    a photosensitive resin layer or a layer which is formed on a surface of the photosensitive resin layer is a base board for a lens, wherein a refractive index of the layer is lower than a refractive index of the transparent sheet.    
   
   
       7 . A projection screen, comprising: 
 a Fresnel lens having a concentric ring band proximate to a light incident region, the Fresnel lens being proximate to a projector, wherein the projection screen is a transparent projection screen according to the projection screen of  claim 1 .    
   
   
       8 . A projection screen according to  claim 7 , wherein a shape of a unit lens area is triangular, hexagonal, or rectangular.