Patent ID: 9541259
Date: 2017-01-10
CPC Classifications: F21V,F21Y,G02F,H04N

Claim:
1. An illumination device, comprising: a plurality of light sources arranged in a row; and a diffusion lens that is disposed on a light-emitting side of the light sources in order to diffuse light emitted therefrom, the diffusion lens being disposed so as to follow an arrangement direction of the light sources to cover the plurality of these light sources, wherein a degree of light diffusion of the diffusion lens at a right angle to the arrangement direction of the light sources is larger than a degree of light diffusion in the arrangement direction of the light sources, wherein the diffusion lens has a housing recess that covers and houses the light sources, and a curved surface that is across from the housing recess and substantially protrudes outwards along a light-emitting direction of the light sources, wherein, in a cross-section at a right angle to the arrangement direction of the light sources, the curved surface has substantially arced sections that protrude outwards, the substantially arced sections being respectively formed at two spots on the left and the right of a central axis line that extends in a direction normal to an emitting surface of the light sources, and wherein, in the cross-section at a right angle to the arrangement direction of the light sources, respective centers of curvature of the two substantially arced sections of the curved surface are at mutually different distances from the emitting surface of the light sources or at mutually different distances from the central axis extending in the direction normal to the emitting surface of the light sources.