Method and device for monitoring movement of mirrors in a MEMS device

A MEMS device comprising:

• at least one moveable in-plane mirror;
• and
• a circuit adapted to monitor movement of said in-plane mirror based upon capacitance changes in said MEMS device over time,
• said circuit comprising:
• a voltage supply operative to provide to said MEMS device a periodic pulsed driving voltage required for oscillation the movement of said in-plane mirror and a DC voltage;
• a current measuring circuit operative to measure over an entire oscillation cycle of the in-plane mirror a current proportional to a capacitance change involved with the oscillation movement of said in-plane mirror and associated with said DC voltage;
• a processor operative to monitor the movement of said in-plane mirror based on said current measurement;
• and
• wherein said current measuring circuit is adapted to measure current during a time segment of an omitted pulse in the periodic pulsed driving voltage.

A method for monitoring movement of at least one moving staggered mirror in a MEMS device, comprising:

• a. measuring a current associated with a movement of said at least one moving staggered mirror at a deflected position;
• b. identifying from said measured current a decaying resonance ripple associated with capacitance change oscillations in said MEMS device at the deflected position;
• and
• c. applying a counter-acting signal to said MEMS device during a fly-back period to suppress said decaying resonance ripple at the deflected position.

A MEMS device comprising:

• at least one moveable staggered mirror;
• and
• a circuit adapted to monitor movement of said at least one moveable mirror based upon capacitance changes in said MEMS device over time,
• said circuit comprising:
• a voltage supply operative to provide a driving voltage to said MEMS device required for movement of staggered mirror to a deflected position;
• a current measuring circuit operative to measure current associated with movement of said staggered mirror at the deflected position;
• a processor operative to identify from said measured current a decaying resonance ripple associated with capacitance change oscillations in said MEMS device at the deflected position and apply a counter-acting signal to said MEMS device during a fly-back period to suppress said decaying resonance ripple at the deflected position.