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

In the phase-shift measurement method, the distance traveled by light can be obtained on the basis of the phase difference between the reference signal and the measured signal. When a different colored object is measured, the intensity of the measured signal varies greatly, even at the same distance, which causes a different phase delay owing to the wide dynamic range input into the signal processing circuit. In this study, an intensity control method is proposed to solve this phase delay problem.