Optical sheet and display device having the optical sheet

摘要

An optical sheet has a transparent base material; a fine lens array constituted by a plurality of fine unit lenses formed on a front surface of the transparent base material; a diffusing layer formed on a rear surface of the transparent base material opposite to the surface on which the fine lens array is formed; and a light absorbing layer formed on the diffusing layer and including fine opening portions substantially located at focal points of the unit lenses; wherein: the diffusing layer is made of a transparent medium containing transparent fine particles different in refractive index from the transparent medium; and the transparent fine particles have a mean particle size in a particle size range for maximizing a value of Q/R at each of wavelengths in a visible region when Q is a scattering sectional area per transparent fine particle, and R is a radius of each of the transparent fine particles. <IMAGE>