Patent ID: 6641274
Filing Date: 2003-11-04
Classification: G02B

Abstract:
A surface light source device comprising:a plate-shaped optical member having an incidence surface and an emitting surface; a rod-shaped light source disposed near the incidence surface of said plate-shaped optical member; and a plate-shaped optical block, separate from the plate-shaped optical member, disposed along the emitting surface of said plate-shaped optical member, said optical block having inner and outer sides with a directivity modifying surface provided on at least one of the inner and outer sides for modifying directivity of illumination light emitted from said emitting surface of said plate-shaped optical member, said directivity modifying surface including a repetition of inclined surfaces formed thereon, the inclined surfaces not being formed on said at least one side of the optical block in the vicinity of said incidence surface of said plate-shaped optical member.