Abstract: A prism sheet prevents the occurrence of a moiré pattern and a wet-out phenomenon by increasing irregularity of prisms formed thereon, by configuring the prisms adjacent to each other to have different heights, and by differently forming widths of triangular sectional surfaces of one prism according to positions. As the height difference of the prisms adjacent to each other is set as 1.2-1.5 ?m, a pressure applied to the prism sheet is distributed to the prisms. This may prevent deformation of the prisms.