FRESNEL LENS SHEET, TRANSMISSION SCREEN AND BACK PROJECTION DISPLAY

摘要

An easy-to-produce Fresnel lens sheet for codensing lights projected obliquely in which reflection of external light is reduced, a good contrast of image is ensured and moiré is suppressed. The Fresnel lens sheet (10) comprises a plurality of prism elements (12) formed on the incident side of a planar base section (11), a plurality of V-grooves (13) formed on the exit side of the base section (11), and a plurality of wedge-type light absorbing parts (14) buried in respective grooves (13). Each prism element (12) has a refractive plane (12a) and a total reflection plane (12b), wherein a light L1 incident obliquely at a large angle is refracted and totally reflected to allow it to travel in a direction substantially perpendicular to the base section (11). Each light absorbing part (14) has a refractive index smaller than that of the base section (11) and an inclining interface (15a) between the base section (11) and each light absorbing part (14) buried in each groove (13) thereof reflects the light L1 traveling through the base section (11).