Light emitting device and driving method thereof
US8653747B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2011 |
| Grant date | Feb 18, 2014 |
| Priority date | — |
| Expiry date | Aug 8, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light emitting device includes a plurality of light emitting modules and a plurality of voltage controlling circuits capable of being independently controlled. Each voltage controlling circuit includes a dynamic voltage controlling module, a current controlling module, and a luminance controlling module. The dynamic voltage controlling module is used for comparing a voltage level at a second terminal of the light emitting module and a voltage level of a reference voltage source, so as to output a first voltage. The current controlling module is used for adjusting a bias current flowing through the light emitting module, according to the first voltage. The luminance controlling module is used for comparing the first voltage with a clock signal, and for generating a pulse width modulation signal according to a result of the comparison, so as to dynamically control a duty cycle of the light emitting module.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.