Oscillating Scanning FPCB Micromirror Integrated with Angle Detecting*

摘要

Monitoring the rotation angle of oscillation mirrors is critical in providing feedback information to control the laser scanning's accuracy and fast response, as well as synchronize with other information such as the measurement result in mirror-based scanning LiDAR. A measuring model for wide range rotating angle scanning, using a single photodiode detector integrated with a FPCB micromirror is proposed. It measures only one discrete mirror rotation angle, as well as the time interval between twice the mirror's rotation passing this angle such as to obtain the mirror's oscillation angle at any time. A sine wave with amplitude of 0.5v is used as the driving signal at resonant frequency region from 90HZ to 103HZ. The results of the experiments indicate that the optical scanning angle of the micromirror can be well controlled and measured at the range of 60 degree, where the optical scanning angle is equal to 4 times of single side mechanical angle of micromirror.