| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diffusion sheet, a light source unit and a liquid crystal display device capable of suppressing frontal luminance unevenness and oblique luminance unevenness. <P>SOLUTION: In a diffusion sheet of the present invention, in a diffusion angle distribution diagram in which the abscissa represents relative positions in a sheet surface and the ordinate represents diffusion angles at the relative positions in the sheet surface, there are a plurality of peak points indicating peak values of the diffusion angle and bottom points indicating bottom values of the diffusion angle, the arithmetic average value of the diffusion angles between the adjacent peak points and bottom points is larger than the arithmetic average value of the diffusion angles at all points distributed between the adjacent peak points and bottom points, and if a point indicating a diffusion angle equal to the sum of the bottom values and three fifths of the value obtained subtracting the bottom values from the peak values is defined as b point, in an arbitrary cycle of the diffusion angle distribution diagram, the ratio d/c of the distance c of the cycle to the distance d between two adjacent b points across the bottom points satisfies 0.79≤d/c<0.90. <P>COPYRIGHT: (C)2012,JPO&INPIT |
