Patent ID: 9217552
Filing Date: 2015-12-22
Classification: F21K,F21V,F21Y,G02B

Abstract:
1. A lighting device, comprising: a surface light source having a light exit surface; a first lens having a first focal point, the first lens being provided on the light exit surface side of the surface light source; and a second lens having a second focal point, the second lens being provided on a light exit surface side of the first lens, the surface light source, the first lens, and the second lens being configured such that a first virtual image is formed by the first lens and a second virtual image is formed by the second lens, wherein the first virtual image is formed between the second focal point and the first lens, the second focal point is on a side opposite to the surface light source relative to a position which is distant from a principal point of the second lens by a predetermined focal length f′, the predetermined focal length f′ satisfies where I′ is the distance between the principal point of the second lens and a position of the first virtual image, D is an effective diameter of the second lens, and ε is a light source size factor which is either one of a size of the light exit surface of the surface light source or an arrangement pitch of a plurality of light-emitting elements included in the surface light source, and at least either of a light entry surface or a light exit surface of the first lens or the second lens includes a non-revolution surface as a lens surface, and a plurality of non-concentric boundary lines whose curvatures vary discontinuously are provided in the non-revolution surface.