Patent ID: 7654681

Claim:
A surface light source device using light emitting diodes, the device comprising: a housing having a top opening to emit light; a light emitting diode board disposed on an inner bottom surface of the housing, the board on which a plurality of light emitting diodes are arranged; and a color conversion laminate formed by depositing a plurality of phosphor-mixed resin layers containing phosphors, the layers disposed above the plurality of light emitting diodes to be perpendicular to each other, the layers disposed at a top of the opening of the housing and providing light having different wavelength, wherein the plurality of phosphor-mixed resin layers are deposited in such a way that a first phosphor-mixed layer adjacent the plurality of light emitting diodes provides a relatively lower wavelength than a second phosphor-mixed layer adjacent the plurality of light emitting diodes, wherein the first phosphor mixed layer is closer to the plurality of light emitting diodes than the second phosphor-mixed layer.