Orientation stabilization for MEMS devices
First Claim
1. Apparatus, comprising:
- a MEMS device; and
a controller adapted to;
receive, from a position sensor corresponding to the MEMS device, a sensor signal indicative of a current position of a movable part of the MEMS device with respect to a stationary part of the MEMS device; and
generate a control signal as a function of the sensor signal, wherein an actuator of the MEMS device is adapted to achieve a desired position of the movable part with respect to the stationary part based on the control signal, wherein the control signal has a voltage profile, wherein a first portion of the voltage profile has voltage having an absolute value greater than a snap-down voltage for the MEMS device.
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Accused Products
Abstract
A control circuit designed to control driving voltages applied to the actuating electrodes of a MEMS mirror. The control circuit is interfaced with a mirror position sensor and includes a variable gain amplifier whose output depends on a desired mirror equilibrium angle and a current mirror tilt angle determined by the sensor. The desired equilibrium angle can be changed by varying a reference signal applied to the amplifier. The control circuit can stabilize the mirror at relatively large tilt angles and, as a result, extend the available angular range beyond the snap-down angle. Since the number of MEMS mirrors that can be arrayed in an optical cross-connect is a function of the available angular range, the number of channels in a cross-connect may be substantially increased.
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Citations
19 Claims
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1. Apparatus, comprising:
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a MEMS device; and
a controller adapted to;
receive, from a position sensor corresponding to the MEMS device, a sensor signal indicative of a current position of a movable part of the MEMS device with respect to a stationary part of the MEMS device; and
generate a control signal as a function of the sensor signal, wherein an actuator of the MEMS device is adapted to achieve a desired position of the movable part with respect to the stationary part based on the control signal, wherein the control signal has a voltage profile, wherein a first portion of the voltage profile has voltage having an absolute value greater than a snap-down voltage for the MEMS device. - View Dependent Claims (2, 3, 4)
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5. Apparatus, comprising
a MEMS device; - and
a controller adapted to;
receive, from a position sensor corresponding to the MEMS device, a sensor signal indicative of a current position of a movable part of the MEMS device with respect to a stationary part of the MEMS device; and
generate a control signal as a function of the sensor signal, wherein an actuator of the MEMS device is adapted to achieve a desired position of the movable part with respect to the stationary part based on the control signal, wherein;
the movable part is rotatably coupled to the stationary part;
the sensor signal is indicative of a current rotation angle between the movable and stationary parts;
the control signal is a function of the current rotation angle;
the desired position corresponds to an equilibrium rotation angle between the movable and stationary parts; and
the control circuit is adapted to generate the control signal based on the sensor signal and a reference signal corresponding to the equilibrium rotation angle. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
receive the reference signal and a fourth signal based on the sensor signal; and
generate a fifth signal, wherein the control signal is based on the fifth signal.
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10. The invention of claim 9, wherein the fourth signal is a substantially linear function of the current rotation angle.
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11. The invention of claim 9, wherein the control circuit further comprises a second amplifier adapted to amplify the fifth signal to generate the control signal.
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12. The invention of claim 9, wherein the first amplifier comprises:
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an operational amplifier adapted to operate as an inverting adder; and
a voltage regulator connected to an output of the operational amplifier, wherein;
the operational amplifier is adapted to receive the reference and fourth signals; and
the fifth signal is a regulated output signal of the operational amplifier.
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13. The invention of claim 12, wherein the voltage regulator is adapted to clip the output signal of the operational amplifier if the output signal is more negative than a base voltage of the voltage regulator.
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14. Apparatus, comprising:
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means for receiving, from a position sensor corresponding to a MEMS device, a sensor signal indicative of a current rotation anile between a movable part of the MEMS device and a stationary part of the MEMS device; and
means for generating a control signal based on the sensor signal and a reference signal, wherein;
the movable part is rotatably coupled to the stationary part;
the control signal is a function of the current rotation angle;
the reference signal corresponds to an equilibrium rotation angle between the movable and stationary parts;
an actuator of the MEMS device achieves the equilibrium rotation angle based on the control signal; and
the equilibrium rotation angle is greater than or substantially equal to a snap-down angle for the MEMS device.
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15. Apparatus, comprising:
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means for receiving, from a position sensor corresponding to a MEMS device, a sensor signal indicative of a current rotation angle between a movable part of the MEMS device and a stationary part of the MEMS device; and
means for generating a control signal based on the sensor signal and a reference signal, wherein;
the movable part is rotatably coupled to the stationary part;
the control signal is a function of the current rotation angle;
the reference signal corresponds to an equilibrium rotation angle between the movable and stationary parts;
an actuator of the MEMS device achieves the equilibrium rotation angle based on the control signal; and
means for adjusting the reference signal to change the equilibrium rotation angle.
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16. A method comprising:
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receiving, from a position sensor corresponding to a MEMS device, a sensor signal indicative of a current rotation angle between a movable part of the MEMS device and a stationary part of the MEMS device; and
generating a control signal based on the sensor signal and a reference signal, wherein;
the movable part is rotatably coupled to the stationary part;
the control signal is a function of the current rotation angle;
the reference signal corresponds to an equilibrium rotation angle between the movable and stationary parts; and
an actuator of the MEMS device achieves the equilibrium rotation angle based on the control signal; and
adjusting the reference signal to change the equilibrium rotation angle. - View Dependent Claims (17)
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18. A method comprising:
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receiving, from a position sensor corresponding to a MEMS device, a sensor signal indicative of a current rotation angle between a movable part of the MEMS device and a stationary part of the MEMS device; and
generating a control signal based on the sensor signal and a reference signal, wherein;
the movable part is rotatably coupled to the stationary part;
the control signal is a function of the current rotation angle;
the reference signal corresponds to an equilibrium rotation angle between the movable and stationary parts;
an actuator of the MEMS device achieves the equilibrium rotation angle based on the control signal; and
the equilibrium rotation angle is greater than or substantially equal to a snap-down angle for the MEMS device. - View Dependent Claims (19)
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Specification