The present invention provides a Fresnel lens sheet that can, in production using
a mold, be easily released from the mold and that scarcely produces stray light
upon use, and others. Each prism 2 on the incident side of a Fresnel lens
sheet 1 is formed to have a nearly triangular cross section and has a plane
of refraction 3 that refracts projected light S incident on this plane and
a plane of total reflection 4 that totally reflects, toward the viewer's
side, at least part of the light refracted at the plane of refraction 3.
Each prism 2 is made so that a root 5 between a prism 2 and
a prism 3 situated next to the prism 2, on the plane of total reflection
side of the prism 2 (a root 5 defined by the plane of refraction
3 of one prism 2B and the plane of total reflection 4 of another
prism 2A situated next to the prism 2B, on the side of the plane
of refraction 3 of the prism 2B) is curved toward the prism 2A
side from the prism 2B side.