The present invention provides a Fresnel lens sheet capable of effectively
preventing such troubles as the production of double images that occurs
due to stray light. A Fresnel lens sheet (1) comprises a base (1a) in
sheet form, and a plurality of prisms (2) formed on the incident side of
the base (1a). Each prism (2) has a plane of refraction (3) that refracts
imaging light (LS) projected from a projector (5), and a plane of total
reflection (4) that totally reflects, toward the viewer's side, at least
a part of the light that has been refracted at this plane of refraction
(3). At least some of a plurality of the prisms (2) are so made that the
imaging light (LS) that has passed through these prisms (2) emerges in
the direction inclined toward the projector (5) side at predetermined
angles (.gamma.b, .gamma.c) with respect to the normal perpendicular to
the sheet plane of the base (1a).