Driver system resonant frequency determination

A method for use with a display device, the method comprising:

• scanning a display region with a slow-scan mirror driven by a slow-scan microelectromechanical systems (MEMS) driver;
• and
• in a fast-scan period of a fast-scan mirror driven by a nonlinear driver:
• at a signal generator, generating a periodic electrical signal, the periodic electrical signal having a first frequency;
• transmitting the periodic electrical signal to a signal detector and a nonlinear driver;
• amplifying the periodic electrical signal at the nonlinear driver to produce an amplified signal;
• driving the fast-scan mirror with the amplified electrical signal;
• at the signal detector:
• receiving the periodic electrical signal and a fast-scan MEMS sensor output signal;
• detecting an amplitude difference between the periodic electrical signal and the fast-scan MEMS sensor output signal;
• and
• transmitting the amplitude difference to a processor;
• and
• at the processor, determining, based on the amplitude difference, a driver system resonant frequency of a fast-scan driver system including the nonlinear driver.

A display device comprising:

• a laser beam emitter configured to emit a laser beam;
• a fast-scan driver system including a nonlinear driver and a fast-scan MEMS sensor;
• a slow-scan MEMS driver, wherein:
• the nonlinear driver and the slow-scan MEMS driver are respectively configured to drive a fast-scan mirror and a slow-scan mirror;
• and
• the slow-scan mirror and the fast-scan mirror are configured to reflect the laser beam onto a display region;
• a signal generator that includes a phase-locked loop and is configured to generate a periodic electrical signal having a first frequency, wherein the nonlinear driver is configured to:
• receive the periodic electrical signal from the signal generator;
• amplify the periodic electrical signal to produce an amplified signal;
• and
• drive the fast-scan mirror with the amplified electrical signal, wherein the fast-scan MEMS sensor is configured to detect a motion of the fast-scan mirror;
• a signal detector configured to:
• receive the periodic electrical signal from the signal generator and a fast-scan MEMS sensor output signal from the fast-scan MEMS sensor;
• detect an amplitude difference between the periodic electrical signal and the fast-scan MEMS sensor output signal;
• and
• a processor configured to:
• receive the amplitude difference from the signal detector;
• and
• determine, based on the amplitude difference, a gain of the signal generator;
• and
• generate, based on the gain, a modified periodic electrical signal with a second frequency different from the first frequency.