US 9,810,902 B1
Opening angle measurement of an oscillating MEMS mirror
Offir Duvdevany, Tel Aviv (IL)
Assigned to STMicroelectronics Ltd, Netanya (IL)
Filed by STMicroelectronics Ltd, Netanya (IL)
Filed on Jun. 24, 2016, as Appl. No. 15/192,718.
Int. Cl. G02B 26/08 (2006.01); G02B 26/10 (2006.01); G01D 5/24 (2006.01)
CPC G02B 26/0833 (2013.01) [G01D 5/24 (2013.01); G02B 26/105 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A device, comprising:
a feedback measuring circuit configured to measure a signal flowing through a movable MEMS mirror;
processing circuitry configured to:
determine a time at which the signal indicates that a capacitance of the movable MEMS mirror is substantially at a maximum capacitance;
determine, over a window of time extending from the time at which the signal indicates that the capacitance of the movable MEMS mirror is substantially at the maximum to a given time, a total change in capacitance of the movable MEMS mirror compared to the maximum capacitance;
determine the capacitance at the given time as a function of the total change in capacitance;
determine an opening angle of the movable MEMS mirror as a function of the capacitance at the given time.