PROBLEM TO BE SOLVED: To provide an illumination device for plant cultivation having high illumination efficiency.SOLUTION: An illumination device for plant cultivation has: a light source a light guide body which has a first main surface, a second main surface, and four side end surfaces, one of which is an incident surface to which light from the light source is made incident and a lens sheet. The first main surface of the light guide body includes concave or convex light deflection elements, the second main surface of the light guide body includes a lens array extending in a normal direction of the incident surface of the light guide body, and an angle created by the first main surface and the light deflection elements is within a range of 1° or more and 10° or less. The lens sheet is equipped with prism lenses extending in a direction parallel to the incident surface of the light guide body, on a surface opposing to the second main surface of the light guide body.COPYRIGHT: (C)2015,JPO&INPIT【課題】照明効率の高い植物栽培用照明装置を提供することを課題とする。【解決手段】光源と、第1主面と第2主面と4つの側端面を有し4つの側端面の1つは光源からの光が入射する入射面である導光体と、レンズシートを備える植物栽培用照明装置とする。導光体の第1主面には凹状または凸状の光偏向要素を備え、導光体の第2主面には前記導光体の入射面の法線方向に延在するレンズアレイを備え、前記第1主面と前記光偏向要素の角が1°以上10°以下の範囲内である。レンズシートは、前記導光体の第2主面と対向する面に、前記導光体の入射面と平行方向に延在するプリズムレンズを備える。【選択図】図2
