Method and apparatus for scaling the average current supply to light-emitting elements
US7482760B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 2005 |
| Grant date | Jan 27, 2009 |
| Priority date | — |
| Expiry date | Jul 28, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2300/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method and apparatus for scaling the average drive current supplied to a light-emitting element or string thereof by coupling a scaling signal to an original control signal thereby generating an effective control signal for control of the light-emitting element(s). The scaling signal can be a modulated signal, for example a Pulse Width Modulation (PWM) signal, Pulse Code Modulation (PCM) signal, or other signal and modifies the original control signal to produce an effective control signal. The effective control signal is subsequently used to control the supply of power to the light-emitting element(s) from a power source via a switching device. The effective control signal essentially modifies the ON time of the light-emitting element(s), thereby modifying the average drive current passing through the light-emitting element(s). The scaling signal is coupled to the original control signal by a coupling mechanism, thereby enabling the modification of the original control signal by the scaling signal forming the effective control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.