LIGHT DIFFUSING SHEET AND BACKLIGHT USING SAME

摘要

Disclosed is a light diffusing sheet which is capable of achieving high front luminance, while maintaining adequate diffusibility. The light diffusing sheet comprises a diffusion layer. The diffusion layer has a surface profile that satisfies the following conditions 1 and 2 and/or the following condition 3. Condition 1 is a condition under which when the kurtosis (JIS B0601, 2001) of a roughness curve as determined by two-dimensional surface profile measurement is represented by Rku, Rku is not less than 3.0. Condition 2 is a condition under which when the arithmetic mean roughness (JIS B0601, 2001) as determined by two-dimensional surface profile measurement is represented by Ra, Ra is not more than 1.5 µm. Condition 3 is a condition under which when the mean height (JIS B0601, 2001) of roughness curve elements as determined by two-dimensional surface profile measurement is represented by Rc and the mean length (JIS B0601, 2001) of roughness curve elements as determined by two-dimensional surface profile measurement is represented by RSm, the ratio of RSm to Rc (RSm/Rc) is not less than 7.0.