White reflective film for edge-light type backlight, and liquid crystal display backlight using same

Abstract

A white reflective film for an edge light backlight improves the luminance and unevenness therein, voids uneven close contact with, and scraping of, the light guide plate, and minimizes the crushing of convexes formed on at least one side, even in cases where the reflective film is laid directly over a corrugated chassis designed to house circuitry or the reflective film is used in combination with LEDs. The film satisfies (i) to (iii): (i) a stiffness of 2 to 10 mN·m; (ii) convexes have been formed on at least one face (A), and their maximum height is 5 to 60 μm; (iii) the convexes contain an aromatic polyester.

1 . A white reflective film for an edge light backlight which satisfies (i) to (iii):
 (i) a stiffness of 2 to 10 mN·m;   (ii) convexes formed on at least one face (A) and having a maximum height of 5 to 60 μm;   (iii) the convexes contain polyethylene terephthalate.   
     
     
         2 . The white reflective film described in  claim 1 , wherein the convexes have been obtained through compression molding. 
     
     
         3 . The white reflective film described in  claim 1 , wherein the convexes have been obtained through compression molding and the polyethylene terephthalate contains a polyethylene terephthalate copolymer comprising an isophthalic acid component as a copolymerization component. 
     
     
         4 . The white reflective film described in  claim 1 , wherein the convexes have an area of 0.5 to 3 mm 2 . 
     
     
         5 . An LCD backlight comprising the white reflective film described in  claim 1  and a light source containing light emitting diodes and 76.2 cm (30 inches) or more in size. 
     
     
         6 . The LCD backlight described in  claim 5 , further comprising a light guide plate with surface concaves or convexes 5 μm or more in depth or height and in which the white reflective film is arranged such that the convexes on a surface (A) face the light guide plate.