Micro-lens sheet and projection screen

Abstract

In order to provide a micro-lens sheet in which unit lenses are disposed in highly accurate pitch so as to control the light diffusing characteristics of the light emission direction not only in a horizontal direction but also over 360 degrees by using the lens function of one piece of lens sheet, a micro-lens sheet has a micro-lens array section in which unit lenses are disposed in approximate matrix in a second dimensional manner on at least one surface of a base board, and the micro-lens array section is formed on only one surface of the base board, the micro-lens array section includes the unit lens having an aspherical shape, and disposition pitch of neighboring unit lenses is 200 μm or shorter.

1 . A micro-lens sheet having a micro-lens array section in which unit lenses are disposed in approximate matrix in a second dimensional manner on at least one surface of a base board comprising: 
 the micro-lens array section being formed on only one surface of the base board;    the micro-lens array section including the unit lens having an aspherical shape; and    disposition pitch of neighboring unit lenses being 200 μm or shorter.    
     
     
         2 . A micro-lens sheet having a micro-lens array section in which unit lenses are disposed in approximate matrix in a second dimensional manner on at least one surface of a base board comprising: 
 the micro-lens array section being formed such that a reacted product of a radioactive-ray-curable-resin is bonded on only one surface of the base board;    the micro-lens array section including the unit lens having an aspherical shape; and    disposition pitch of neighboring unit lenses being 100 μm or shorter.    
     
     
         3 . A micro-lens sheet according to  claim 1 , wherein the micro-lens array section has only the unit lens having aspherical shape.  
     
     
         4 . A micro-lens sheet according to  claim 1 , wherein optical diffusion by each unit lens in the micro-lens sheet differs between a horizontal direction and a vertical direction.  
     
     
         5 . A micro-lens sheet according to  claim 1 , wherein the unit lens is disposed in a rectangular grid.  
     
     
         6 . A micro-lens sheet according to  claim 1 , wherein the unit lens is disposed in a delta disposition or honeycomb disposition.  
     
     
         7 . A micro-lens sheet according to  claim 1 , wherein a shading layer is formed in a non-light-condensing section on which light is not condensed by the unit lens on an opposite surface of the base board to the micro-lens array section.  
     
     
         8 . A rear-projection screen comprising: a lens array section of the micro-lens sheet according to  claim 1  and a lens array section of a Fresnel lens sheet facing each other such that the Fresnel lens sheet is disposed nearer to the projector as a light source.  
     
     
         9 . A display device comprising: 
 a light source comprising a liquid crystal projector or a digital micro-mirror device; and    a rear projection screen according to  claim 8 .    
     
     
         10 . A rear-projection screen which size is 30 inches or larger using the micro-lens sheet according to  claim 9 .  
     
     
         11 . A projection screen according to  claim 10 , wherein the Fresnel-lens sheet is disposed on the projector as a projection light source.  
     
     
         12 . A projection screen according to  claim 10 , wherein the light-diffusion layer in which a light diffusion member is dispersed is disposed near either one of the Fresnel-lens sheet or the micro-lens sheet.