Liquid crystal display device

Abstract

In a liquid crystal display device, a transparent sheet TPS is provided to a surface of a diffusion plate SCT which faces a light source (cold cathode fluorescent lamps CFL). The whole or at least respective portions of four sides forming peripheries of the transparent sheet TPS and the diffusion plate SCT are adhered to each other using a pressure sensitive adhesive double-sided tape or the like thus sealing a gap defined between them in a complete state or in an incomplete state with respect to outside air so that the drying conditions at a liquid-crystal-display element side and a light-source side of the diffusing plate SCT become equal.

What is claimed is:  
     
         1 . A liquid crystal display device comprising a liquid crystal display element, a light source, a substantially rectangular diffusion plate which is interposed between the liquid crystal display element and the light source, and at least one optical sheet which is arranged between the diffusion plate and the liquid crystal display element, wherein 
 the liquid crystal display device includes a transparent sheet which is arranged between the diffusion plate and the light source and has a contour which is substantially equal to a contour of the diffusion plate, and    at least one optical sheet is brought into contact with the diffusion plate and respective major portions or respective whole portions of four sides of the transparent sheet are adhered to the diffusion plate.    
     
     
         2 . A liquid crystal display device according to  claim 1 , wherein the whole four sides of the transparent sheet are adhered to diffusion plate.  
     
     
         3 . A liquid crystal display device according to  claim 1  or  2 , wherein the transparent sheet is adhered to the diffusion plate using a pressure sensitive adhesive double-sided tape or a tacky adhesive agent.  
     
     
         4 . A liquid crystal display device according any one of  claims 1  to  3 , wherein at least one optical sheet is adhered to the diffusion plate.  
     
     
         5 . A liquid crystal display device according any one of  claims 1  to  3 , wherein the liquid crystal display device includes a spacer which restricts a warp quantity of the diffusion plate in the direction toward the light source.  
     
     
         6 . A liquid crystal display device according  claim 5 , wherein at least one optical sheet is adhered to the diffusion plate.  
     
     
         7 . A liquid crystal display device comprising a liquid crystal display element, a light source, a substantially rectangular diffusion plate which is interposed between the liquid crystal display element and the light source, and at least one optical sheet which is arranged between the diffusion plate and the liquid crystal display element, wherein 
 the liquid crystal display device includes a transparent sheet which is arranged between the diffusion plate and the light source and has a contour which is substantially equal to a contour of the diffusion plate and a spacer which restricts a warp quantity of the diffusion plate in the direction toward the light source, and    at least one optical sheet is brought into contact with the diffusion plate and at least respective portions of four sides of the transparent sheet are adhered to the diffusion plate.    
     
     
         8 . A liquid crystal display device according to  claim 7 , wherein the whole or major portions of four sides of the transparent sheet are adhered to diffusion plate.  
     
     
         9 . A liquid crystal display device according to  claim 7  or  8 , wherein the transparent sheet is adhered to the diffusion plate using a pressure sensitive adhesive double-sided tape or a tacky adhesive agent.  
     
     
         10 . A liquid crystal display device according any one of  claims 7  to  9 , wherein at least one optical sheet is adhered to the diffusion plate.  
     
     
         11 . A liquid crystal display device comprising a liquid crystal display element, a light source, a substantially rectangular diffusion plate which is interposed between the liquid crystal display element and the light source, and at least one optical sheet which is arranged between the diffusion plate and the liquid crystal display element, wherein 
 the liquid crystal display device includes a transparent sheet which is arranged between the diffusion plate and the light source and has a contour which is substantially equal to a contour of the diffusion plate and a spacer which restricts a warp quantity of the diffusion plate in the direction toward the light source, and    at least one optical sheet is brought into contact with the diffusion plate and the whole surface of the transparent sheet is adhered to the diffusion plate.