Light emitting device and driving circuit thereof
US8513899B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2009 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Dec 3, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light emitting device comprises a first light emitting unit and a second light emitting unit connected in series with each other, and a PTF unit connected in parallel with the first light emitting unit and in series with the second light emitting unit. Each of the first light emitting unit and second light emitting unit comprises at least one LED. The PTF unit allows the second light emitting unit to be operated before operation of the first light emitting unit upon application of an AC voltage source. The light emitting device reduces total harmonic distortion and flickering, and improves power factor and optical efficiency. A driving circuit of the light emitting device is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.