System and method of sensing actuation and release voltages of an interferometric modulator
AssigneeQUALCOMM MEMS Technologies, Inc.
InventorsMarc Mignard, Clarence Chui, Mithran C. Mathew, Jeffrey B. Sampsell
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Abstract
A method for sensing the actuation and/or release voltages of a electromechanical system or a microelectromechanical device include applying a varying voltage to the device and sensing its state and different voltage levels. In one embodiment, the device is part of a system comprising an array of interferometric modulators suitable for a display. The method can be used to compensate for temperature dependent changes in display pixel characteristics.
Claims11
A mirror system comprising:
- an interferometric modulator array of mirrors;
- a timing control circuit for activating each of the mirrors;
- a drive circuit configured to apply one or more test voltages or currents;
- and
- a sensing circuit configured to sense a state of at least one of the mirrors and determine one or both of an actuation voltage and a release voltage based at least in part on the sensed state of the mirrors, wherein the sensing circuit comprises test circuitry configured to compare a sensed voltage of said at least one of the mirrors to a threshold voltage.
A method of pixel state sensing for modifying a drive voltage of an array of mirrors and a timing control circuit for controlling each of the mirrors, the method comprising:
- applying a first test voltage or current to charge a mirror for a predetermined amount of time;
- sensing a first state of the mirror to determine a first actuation or release voltage;
- applying a second test voltage or current to charge the mirror for the predetermined amount of time;
- sensing a second state of the mirror to determine a second actuation or release voltage;
- and
- modifying the drive voltage based on the determined first and second actuation or release voltages to control a voltage at which the mirror is actuated or released.
A system for calibrating a drive voltage for an array of mirrors and a timing control circuit for controlling each of the mirrors, the system comprising:
- means for applying a first test voltage or current to charge a mirror for a predetermined amount of time;
- means for sensing a first state of the mirror to determine a first actuation or release voltage;
- means for applying a second test voltage or current to charge the mirror for the predetermined amount of time;
- means for sensing a second state of the mirror to determine a second actuation or release voltage;
- and
- means for modifying the drive voltage based on the determined first and second actuation or release voltages to control a voltage at which the mirror is actuated or released.
Dependencies are inferred from the claim text.