Intensity control of a phase-shift based laser scanner for reducing distance errors caused by different surface reflectivity

In the phase-shift measurement method, the distance light travels can be obtained based on the phase difference between the reference signal and the measured signal. When the object having various colors is measured, the intensity of the measured signal much varies even at the same distance, and it causes different phase delay due to wide dynamic range input to a signal processing circuit. In this work, an intensity control method is proposed to solve this phase delay problem.