Illumination device
US9217552B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 2, 2013 |
| Grant date | Dec 22, 2015 |
| Priority date | — |
| Expiry date | Jul 2, 2033 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21Y2115/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lighting device (100) includes: a surface light source (1); a first lens (L1) having a first focal point (F1), the first lens being provided on the light exit surface side of the surface light source; and a second lens (L2) having a second focal point (F2), 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 (I1) is formed by the first lens and a second virtual image (I2) is formed by the second lens, wherein the first virtual image (I1) is formed between the second focal point (F2) and the first lens, the second focal point (F2) is on a side opposite to the light source side relative to a predetermined focal position f′, 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 (SO) as a lens surface, and a plurality of boundary lines (B1-B4) whose curvatures vary discontinuously are provided in the non-revolution surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.