Patent ID: 7284884

Claim:
A surface light source device, comprising: a light path control plate; and at least one point-like light source supplying primary light toward said light path control plate, wherein said light path control plate has an inner face to which said primary light is incident and an outer face which is opposite to said inner face, said inner face is provided with projection-like transmission-reflection portions, each of which is composed of a transmission face permitting primary light to transmit through the transmission face and a reflection face which reflects transmitted light to bring changed light paths directed to said outer face, and curved-for-refraction portions, each of which refracts primary light to bring changed light paths directed to said outer face, said transmission-reflection portions and curved-for-refraction portions being arranged alternatingly, wherein first light reaching the outer face via said transmission-reflection portions and second light reaching said outer face via said curved-for-refraction portions are generated from primary light so that said first light and second light are emitted from said outer face as a synthesized light.