Patent ID: 7218450

Claim:
A light diffusing film having, on at least one surface of a base film, a light diffusing layer made of an inorganic light diffuser selected from the group consisting of silica, zirconia, calcium carbonate, barium sulfate, glass and titanium dioxide; or organic light diffuser selected from the group consisting of urethane based resins, acryl based resins and vinyl chloride based resins, and a binder resin, wherein a lamination ratio is represented by the Formula 1 and a size of flocculated particles in a laminated light diffuser is represented by the Formula 2, wherein the light diffuser is made of two or more kinds of monodisperse particles, the following Formula 3 is satisfied, wherein an average particle diameter of the light diffuser is in the range of 5 to 50 μm: Lamination ratio = π × S ⁡ ( µ ⁢ ⁢ m ) × Number ⁢ ⁢ of ⁢ ⁢ laminated ⁢ ⁢ particles in ⁢ ⁢ a ⁢ ⁢ tested ⁢ ⁢ portion ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ light ⁢ ⁢ diffuser 480 ⁢ ⁢ µ ⁢ ⁢ m × 480 ⁢ ⁢ µ ⁢ ⁢ m × 100 ⁢ ( % ) ≤ 10 ⁢ % , [ Formula ⁢ ⁢ 1 ] Diameter of flocculated particles= S (μm)×Number of flocculated particles in a tested floc and in a tested portion of the light diffuser≦50μm [Formula 2] wherein S denotes the average particle diameter of the light diffuser, Sa 1/2 <Sb<Sa [Formula 3] wherein Sa denotes an average particle diameter of a relatively larger light diffuser particle and Sb denotes an average particle diameter of a relatively smaller diffuser particle.