Method and apparatus for illuminating light sources within an electronic device
US7439679B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 2006 |
| Grant date | Oct 21, 2008 |
| Priority date | — |
| Expiry date | Mar 16, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/38
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for controlling a plurality of light sources (102,103,104,105) in an electronic device (100) is provided. In one embodiment, the plurality of light sources (102,103,104,105) is used to backlight an illuminated display (101). As switching multiple light sources on simultaneously can cause output voltages of power sources (219) to drop, thereby potentially affecting the overall operation of the electronic device (100), an illumination controller (107) distributes actuation times associated with illumination control signals (204,205,206,207) such that each actuation time is unique. A control signal generator (201) produces a control signal (202) having light source actuation information stored therein. The illumination controller (107) then generates a plurality of illumination control signals (204,205,206,207) that are capable of actuating the plurality of light sources (102,103,104,105). Each illumination control signal (204,205,206,207) has a duty cycle and actuation time associated therewith. The illumination controller (107) distributes the actuation times across the control signal (202) so as to reduce the instantaneous current drawn by the plurality of li…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.