Patent ID: 8143561

Claim:
A Micro-electronic-mechanical System (MEMS) scan controller generating clock frequency applied to a laser scanning unit (LSU) included a laser source emitting laser light, a MEMS mirror driving the laser light scanning an object forwardly or reversely in resonant way, a photoelectric detector (PD detector) receiving scanning beam and turning the light into PD signals, a bridge circuit for control of the MEMS mirror, and a laser controller that controls the laser source to emit laser light; comprising: a control logic, at least one D inverter, a phase locked loop and a counter comparator, the MEMS scan controller detecting resonant frequency of the MEMS mirror and generating a clock signal that drives the laser controller for emitting laser light and scanning by the MEMS mirror; wherein, the control logic receiving a PD signal from the PD detector and calculating the time interval of each PD signal so as to generate frequency modulation signals, amplitude modulation signals, and stable signals of the MEMS mirror; wherein, the D inverter receiving the frequency modulation signals as well as amplitude modulation signals from the control logic and generating resonant frequency signals as well as feedback signals; wherein, the phase locked loop receiving the resonant frequency signals from the D inverter and generating clock signals; wherein, the counter comparator receiving the clock signals from the phase locked loop and accumulating pulses of the clock signals; said MEMS scan controller being configured so that the clock signals are provided to laser controller to scan data within an effective scanning window.