A biaxial piezoelectric MEMS scanning mirror and its application to pico-projectors

In this paper, we report a two-dimensional MEMS optical scanner that actuate and detect the angular motion through the piezoelectric effect of thin film PZT. Typical scan ranges were ±12° at 25 kHz for the horizontal resonance and ±8° at 60 Hz for the vertical non-resonance, and the overall power consumption was 100 mW or less. A newly designed mechanical rib structure on the backside of the mirror was found to suppress the dynamic deformation of the mirror to the level compatible with a high definition of 720 pixels or more. A scanning laser type pico-projector was developed for demonstration.