A bi-axial capacitive scanning mirror with closed-loop control

Closed-loop control of slow-axis trajectory for a bi-axial capacitive raster-scanning micro-mirror is studied in this work. To minimize the design area, the implementation features the use of shared electrodes for simultaneous driving and sensing. To ensure stable operation, the control system design with a phase-lead controller considers the effects of electronics noise and dc offset, and nonlinearity of the vertical comb electrodes. Stable closed-loop operation is demonstrated for triangular wave input at 60 Hz.