LED control using modulation frequency detection techniques
US8258709B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 1, 2010 |
| Grant date | Sep 4, 2012 |
| Priority date | — |
| Expiry date | May 21, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In one embodiment, the present disclosure provides a method for controlling a plurality of LED channels. The method includes receiving an LED brightness signal having a plurality of superimposed pulse width modulated (PWM) brightness signals each having a duty cycle and amplitude at a unique modulation frequency, each PWM brightness signal being proportional to the brightness of a respective LED channel. The method also includes determining a pulse area of each PWM brightness signal at each respective unique frequency. The pulse area is proportional to the product of the amplitude and the duty cycle. The method also includes generating pulse area signals proportional to the respective pulse area and comparing the respective pulse area signals to user defined and/or preset photometric values to generate respective error signals proportional to the difference between the respective pulse area signals and the user defined and/or preset photometric values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.