LED light source for backlighting with integrated electronics
US7317403B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2005 |
| Grant date | Jan 8, 2008 |
| Priority date | — |
| Expiry date | Jun 24, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S362/80
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED backlight structure for setting voltages and currents for LEDs. Red LEDs are connected in series between a first voltage regulator and a first controllable current source, green LEDs are connected in series between a second voltage regulator and a second controllable current source, blue LEDs are connected in series between a third voltage regulator and a third controllable current source. The current sources may be linear current regulators controlled to balance the three colors to achieve a target light output of the board using a light detection chamber. PWM controllers control transistor switches connected in parallel across groups of LEDs, where the duty cycles set the average current through each group of LEDs. The control values used to achieve target light characteristics are stored in memory. The PWM controller may control brightness levels of the LEDs. The backlight may be for an LCD television.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.