PROBLEM TO BE SOLVED: To provide a luminaire capable of making distribution of light intensity in an illumination area uniform.SOLUTION: The luminaire comprises: a light source for irradiating an illumination area with light and a diffraction optical element disposed between the illumination area and the light source, and in which plural diffraction gratings are disposed in a two-dimensional state, in which distribution of a grating interval of the plural diffraction gratings along a predetermined line in the two-dimensional arrangement plane on the diffraction optical element, is configured so that the grating interval is wider on a center side than on an end side.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2016,JPO&INPIT【課題】照明領域における光強度の分布の均一化を図ることができる照明装置等の提供。【解決手段】 照明装置は、照明領域に光を照射する光源と、前記照明領域と前記光源との間に設けられ、複数の回折格子が2次元配置された回折光学素子とを含み、前記回折光学素子における2次元配置面内の所定ラインに沿った前記複数の回折格子の格子間隔の分布は、中心側の方が端側よりも格子間隔が広い特性を有する。【選択図】 図5
