Light-emitting device
US7253450B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2004 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Aug 26, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/882
Abstract
A foam-holding body 52 having a large difference in refractive index between foams 521 and the surrounding material is disposed on the major light extraction surface of the sapphire substrate 50. The foam-holding body 52 has translucency to light of a light-emitting wavelength and is formed of a material such as a silicone or the like, having a refractive index equal to or more than 1.77, and includes a foam-holding layer holding a plurality of foams made of an air or an inactive gas having a refractive index of about one. Therefore, when the light emitted in the light-emitting portion scatters in the foam-holding body 52, the spread of the scattered light becomes wide, which restricts repetition of the total reflection in the light-emitting device to improve an efficiency of the light extraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.