Optical member and display device

Abstract

An optical member includes a plate like light diffusion member having a light incidence surface and a light emitting surface opposed each other, a phosphor layer provided directly on the light emitting surface of the light diffusion member and containing a phosphor that converts a color light to another color light, and a protection layer formed on a surface on the side opposite to the light diffusion member, of the phosphor layer. A moisture vapor transmission rate of the light diffusion member is 2 g/m 2 /day or less.

What is claimed is: 
     
         1 . An optical member comprising:
 a plate like light diffusion member having a light incidence surface and a light emitting surface opposed each other,   a phosphor layer provided directly on the light emitting surface of the light diffusion member and containing a phosphor that converts a color light to another color light, and   a protection layer formed on a surface on the side opposite to the light diffusion member, of the phosphor layer,   wherein a moisture vapor transmission rate of the light diffusion member is 2 g/m 2 /day or less.   
     
     
         2 . The optical member according to  claim 1 , wherein a thickness of the light diffusion member is 1 mm to 3 mm. 
     
     
         3 . A display device comprising:
 a light source;   an optical member transmitting light emitted from the light source; and   a display panel displaying an image by using the light passed through the optical member,   wherein the optical member comprises:
 a plate like light diffusion member having a light incidence surface and a light emitting surface opposed each other, 
 a phosphor layer provided directly on the light emitting surface of the light diffusion member and containing a phosphor that converts a color light to another color light, and 
 a protection layer formed on a surface on the side opposite to the light diffusion member, of the phosphor layer, 
 wherein a moisture vapor transmission rate of the light diffusion member is 2 g/m 2 /day or less and the light source is disposed opposite to the light incidence surface of the light diffusion member.