Patent ID: 8123391

Claim:
A surface light emitter comprising a surface-emitting device and a light control sheet, wherein a repetitive concavo-convex pattern of trapezoidal form in section is formed at least on one side of the light control sheet and has planar portions at distal ends of projections thereof tightly bonded to an output surface of the surface-emitting device, and wherein the light control sheet satisfies a condition 0.75>D>4[(sin θ−1/n) 2 +0.034] where θ represents the apex angle formed by opposite slant sides defining the trapezoidal projection of the light control sheet, n represents the refractive index of the light control sheet, and D represents the ratio of a length of a zone to a one-cycle length of the repetitive concavo-convex pattern of the light control sheet as determined in one of the pattern arrangement directions, the zone tightly bonded to the output surface of the surface-emitting device.