Apparatus for driving multi-color LED strings
US9258861B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 2013 |
| Grant date | Feb 9, 2016 |
| Priority date | — |
| Expiry date | Aug 1, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus comprises red, green and blue LED strings each having a corresponding switching circuit. Each LED string is divided into a plurality of LED segments. The three LED strings are connected in parallel or in series. Each LED string may be connected in series with a respective current source or share a common current source. A controller controls each switching circuit so that the number of LED segments connected in series in the red, green or blue LED string can be respectively controlled according to a color setting signal and the voltage level of an input voltage. A first control method is provided for controlling the apparatus having a constant input voltage and a second control method is provided for controlling the apparatus having a periodically time-varying input voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.