Apparatus for estimating level of signal output from photo-detection device and method therefor

Abstract

An apparatus for estimating a level of a signal output from a photo-detection device and a method therefor are provided. The apparatus includes a photo-detection device that outputs an electrical signal corresponding to an optical signal, a comparison device that outputs a high signal, when the electrical signal is greater than a threshold voltage, and outputs a low signal, when the electrical signal is not greater than the threshold voltage, and a controller that sets the threshold voltage, estimates a level of the electrical signal based on an output signal of the comparison device, and varies the threshold voltage based on the output signal of the comparison device, thus estimating the level of the electrical signal to have higher accuracy without having an ADC.

Dependencies are inferred from the claim text.