To obtain a light guiding plate which is high in surface luminance, is less in luminance spot and has transparency and mechanical strength in combination.
The light guiding plate 2 is constituted of an annular structure- contg. thermoplastic resin, has plural recessed parts formed on an optical reflection area 2C and projecting parts formed in the vicinity of edges of the recessed parts. It is desirable that the recessed parts are grooves, which are slender in the direction approximately perpendicular to the incident direction of light and that the projecting parts are protuberating parts, which are formed in the vicinity of one edge or in the vicinity of both edges of the gooves, and it is desirable that the annular structure-contg. thermoplastic resin is an alicyclic structure-contg. thermoplastic resin.
KONISHI YUICHIRO
ISHIMARU KAZUYO
Next Patent: OPTICAL FIBER GUIDING TOOL