METHOD AND APPARATUS FOR SCANNING A BEAM OF LIGHT

摘要

A resonant MEMS scanning system operates a MEMS scanner at its resonant frequency to maximize scan angle and minimize power consumption. A controller includes a phase locked loop, an amplitude servo control loop, and a resonant frequency servo control loop. A microprocessor controls the loops and provides override during conditions such as start-up. Resonant frequency is dynamically thermally trimmed, allowing the device to be operated at higher Q. The phase lock loop operates in a pre-lock condition to allow faster start-up. Resonant frequency is controlled open loop during idle and start-up. Drive voltage is set high during start-up to achieve a rapid rise in scan angle.