| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light diffusion sheet free from the decrease of surface brightness or the deterioration of contrast due to a stray light, having less angle dependency and less scatter reflection of the external light and a liquid crystal display. <P>SOLUTION: In the light diffusion sheet arranged in observer side of the liquid crystal display and having a plurality of unit lenses formed into one- or two-dimensional direction, the unit lens is substantially trapezoidal in cross section, the lower bottom of the trapezoid is made to be a light incidence portion and the upper bottom thereof is made to be a light emission portion. The optical diffusion sheet is formed by a materials having a specific refractive index N1, a portion, the cross section of that is triangular and that is located between adjacent unit lenses, is formed by a material that has a refractive index N2 that is lower than the N1. When the angle defined by the slant of the trapezoid with respect to a normal line to the light emission portion is set to (θ), the relationship holds sin(90°-θ)>N2/N1 and N1<1/sin2θ. <P>COPYRIGHT: (C)2008,JPO&INPIT |
