OPTICAL SHEET STACK BODY, ILLUMINATING DEVICE, AND DISPLAY DEVICE

摘要

An optical sheet stack body includes two optical sheets disposed to overlap a plurality of point light sources arranged in a first direction and arranged in a second direction crossing the first direction. The optical sheets are disposed so that a long-side direction of the optical sheet crosses the first and second directions at an angle other than right angle. A first optical sheet disposed on the point light source side has a plurality of first three-dimensional structures extending in a direction parallel to or almost parallel to the first direction. A second optical sheet disposed on the side opposite to the point light source has a plurality of second three-dimensional structures extending in a direction parallel to or almost parallel to the second direction. The second three-dimensional structure has a shape by which return light is generated from normal incident light more than the first three-dimensional structure.