Abstract: A planar illumination device of an embodiment includes a substrate, a first linear Fresnel lens, and a second linear Fresnel lens. The substrate includes a plurality of light sources disposed two-dimensionally in a grid pattern. The first linear Fresnel lens is disposed at an emission side of the plurality of light sources and formed with a groove constituting a concave-convex surface of the lens and extending in one direction. The second linear Fresnel lens is disposed at an emission side of the first linear Fresnel lens and formed with a groove constituting the concave-convex surface of the lens and extending in a direction orthogonal to the one direction.

Abstract: A planar illumination device of an embodiment includes a substrate, a first linear Fresnel lens, and a second linear Fresnel lens. The substrate includes a plurality of light sources disposed two-dimensionally in a grid pattern. The first linear Fresnel lens is disposed at an emission side of the plurality of light sources and formed with a groove constituting a concave-convex surface of the lens and extending in one direction. The second linear Fresnel lens is disposed at an emission side of the first linear Fresnel lens and formed with a groove constituting the concave-convex surface of the lens and extending in a direction orthogonal to the one direction.

Abstract: A planar illumination device includes a light source substrate, a lens, a diffuser, and a spacer. The light source substrate includes a plurality of light-emitting devices two-dimensionally arrayed thereon. The lens receives light emitted from the light source substrate. The diffuser receives light emitted from the lens. The spacer is integrated with the diffuser and disposed between the lens and the diffuser.

Abstract: A planar lighting device according to an embodiment includes a substrate and a lens. A plurality of light sources are arranged on the substrate. The lens is formed to have, on an incident surface opposing the plurality of light sources, an optical element having a plurality of first optical parts that include a part that tapers from a bottom face having a hexagonal shape toward a tip, the first optical parts being arranged in a staggered arrangement.

Abstract: A planar illumination device includes a light source substrate, a lens, a diffuser, and a spacer. The light source substrate includes a plurality of light-emitting devices two-dimensionally arrayed thereon. The lens receives light emitted from the light source substrate. The diffuser receives light emitted from the lens. The spacer is integrated with the diffuser and disposed between the lens and the diffuser.

Abstract: A planar lighting device according to an embodiment includes a substrate and a lens. A plurality of light sources are arranged on the substrate. The lens is formed to have, on an incident surface opposing the plurality of light sources, an optical element having a plurality of first optical parts that include a part that tapers from a bottom face having a hexagonal shape toward a tip, the first optical parts being arranged in a staggered arrangement.

Abstract: LEDs (21) that emit illumination light and a cover unit (30) that houses the LEDs are provided. The cover unit is composed of a front cover part (31) that transmits, diffuses and reflects the illumination light from the LEDs and a rear cover part (32) that reflects the illumination light reflected at the front cover part again toward the front cover part. The front cover part and the rear cover part are integrally molded without a gap and the loss of light fluxes is therefore eliminated. Moreover, the uniformity of luminance distribution of the light-emitting surface is improved to solve the problem in that the side surfaces of the lighting device and the attaching surface (ceiling surface) are dark.