Patent attributes
There is provided a Fresnel lens sheet for converging light rays fallen thereon from oblique directions, and capable of reducing the reflection of external light, of enabling displaying images in satisfactory contrast, of suppressing the occurrence of moiré and of being easily manufactured. The Fresnel lens sheet 10 includes: a flat base part 11; a plurality of prisms 12 formed on the entrance surface of the base part 11, a plurality of V grooves 13 formed in the exit surface of the base part 11, and a plurality of wedge-shaped light absorbing parts 14 embedded in the V grooves 13, respectively. Each prism 12 has a refraction facet 12a that refracts light rays fallen thereon and a total-reflection facet 12b that totally reflects light rays fallen thereon. The prisms 12 refract and reflect light rays L1 incident thereon at large incident angles to deflect the light rays L1 for travel in a direction substantially perpendicular to the base part 11. The light absorbing parts 14 have a refractive index lower than that of the base part 11. The inclined surfaces 15a, contiguous with the base part 11, of the light absorbing parts 14 embedded in the grooves 13 of the base part 11 reflect the light rays L1 traveling through the base part 11.
