Patent ID: 7903086
Filing Date: 2011-03-08
Classification: G06F

Abstract:
1. An imaging device, comprising: a light source for illuminating an imaging surface; an oscillator configured to generate a first waveform of a first frequency; a light controller circuit configured to generate a light control pulse; a first multiplier configured to receive the first waveform and the light control pulse and modulate therefrom, a drive signal for driving the light source; a photodetector configured to receive reflected light from the imaging surface and generate therefrom, a first output signal, wherein the first output signal comprises a first signal component corresponding to reflected light from the imaging surface, and a second signal component corresponding to ambient light received in the imaging device; an amplifier configured to amplify the first output signal; and a circuit configured to remove the second signal component corresponding to ambient light, wherein the circuit comprises a second multiplier configured to demodulate the amplified first output signal with the first waveform.