LIGHT DIFFUSION FILM WITH UNIFORM SURFACE ROUGHNESS AND LOW RETARDATION VALUE AND METHOD FOR MANUFACTURING THE SAME

摘要

A light diffusion film having a uniform surface roughness and a low retardation value, and a manufacturing method thereof are provided to perform high haze, high total light transmittance, and improved luminance. A light diffusion film is made of thermoplastic resin. In the light diffusion film, illuminance is 0.5~3um and HDI(Height Distribution Index) is 3~8um. A retardation value of the light diffusion film is less than 25nm. Thickness of the light diffusion film is 60~450um. In the light diffusion film, haze is more than 70% and total light transmittance is more than 80%. An embossing pattern is formed in at least one surface of the light diffusion film. A sand blast process is performed by spraying a polishing agent having a particle diameter of 100~180um on a roll surface. The roll formed by the sand blast process is used as a cooling roll(11) of a pressing process of the thermoplastic resin.