Light directional angle control for light-emitting device and light-emitting apparatus
US9618697B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2015 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Feb 13, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/872
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light-emitting device includes a photoluminescent layer that emits light containing first light, a light-transmissive layer located on or near the photoluminescent layer, a low-refractive-index layer and a high-refractive-index layer. A submicron structure is defined on the photoluminescent layer and/or the light-transmissive layer. The low-refractive-index layer is located on or near the photoluminescent layer so that the photoluminescent layer is located between the low-refractive-index layer and light-transmissive layer. The high-refractive-index layer is located on or near the low-refractive-index layer so that the low-refractive-index layer is located between the high-refractive-index layer and the photoluminescent layer. The submicron structure includes at least projections or recesses and satisfies the following relationship:λa/nwav-a<Dint<λa where Dint is the center-to-center distance between adjacent projections or recesses, λa is the wavelength of the first light in air, and nwav-a is the refractive index of the photoluminescent layer for the first light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.