20100040377 | Optical sensing module based on pulse width modulation signal and method thereof - A optical sensing module based on signals having pulse width modulation and a method thereof are disclosed for sensing a light source and providing an output signal having pulse width modulation. The optical sensing module comprises an optical sensor, a signal processing unit, and a duty cycle modulation unit. The signal processing unit provides a modulation control signal based on a sensing signal generated by sensing the light source from the optical sensor in conjunction with a gain control signal. The duty cycle modulation unit modulates the duty cycle of the pulse width modulation input signal to generate the pulse width modulation output signal based on the modulation control signal. The duty cycle difference between the duty cycle of the input signal and the duty cycle of the output signal is proportional to the intensity difference between the light source and a reference light source. | 02-18-2010 |