US 12,072,484 B2
Power efficiency optimization method of LC resonant driver for MEMS mirrors
Chang Joon Park, Sunnyvale, CA (US); and Martin Francis Galinski, Santa Clara, CA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by MICROSOFT TECHNOLOGY LICENSING, LLC, Redmond, WA (US)
Filed on Jun. 21, 2021, as Appl. No. 17/353,724.
Prior Publication US 2022/0404611 A1, Dec. 22, 2022
Int. Cl. G02B 26/08 (2006.01); H03H 7/00 (2006.01); H03H 9/15 (2006.01)
CPC G02B 26/0833 (2013.01) [H03H 9/15 (2013.01); H03H 2007/006 (2013.01); H03H 2009/155 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system to efficiently drive a mirror device, the system comprising:
a driver circuit configured to generate an alternating drive signal;
a resonance circuit that is configured to receive the alternating drive signal from the driver circuit, wherein:
the resonance circuit is coupled to the mirror device and configured to drive the mirror device responsive to the alternating drive signal;
the resonance circuit includes a variable capacitance circuit that has a capacitance value that varies in response to a bias control input signal;
the resonance circuit has a resonant frequency that is determined at least in part by the capacitance value of the variable capacitance circuit; and
a sense circuit that is configured to generate a sense signal responsive to an output of the mirror device; and
a capacitance control circuit that is configured to receive the sense signal and adjust the bias control signal of the variable capacitance circuit until a peak signal level is observed in the sense signal, wherein the peak signal level indicates a matched resonant frequency of the mirror device and the resonance circuit.