Spread illuminating apparatus with multi-layer light conductive member

摘要

A spread illuminating apparatus provides uniform illumination and high brightness over a whole screen. A plurality of plate-like light conductive members form a multi-layer light conductive member. An optical path conversion means composed of grooves formed parallel to the thickness direction of each plate-like light conductive member and flat portions is provided on one surface of each of the plate-like light conductive members. Each groove of each plate-like light conductive member overlaps partly with each groove of adjacent plate-like light conductive members thereby constituting each multiple groove. A plurality of multiple grooves of the light conductive member are formed with inclination such that one multiple groove thereof overlaps partly with adjacent multiple grooves with the longitudinal direction of the light conductive member.