Methods for measurement and characterization of interferometric modulators
First Claim
1. A method of identifying a transition voltage in a microelectromechanical systems (MEMS) device, the method comprising:
- providing a circuit comprising the MEMS device, the circuit being configured to provide a substantially constant impedance for an applied voltage;
applying a constant voltage to the circuit for a period of time, wherein application of the constant voltage causes a change in the state of the MEMS device, and wherein the impedance of the circuit before the state change of the MEMS device is substantially equal to the impedance of the circuit after the state change;
measuring a voltage across the MEMS device as a function of time; and
identifying the transition voltage at which the state of the MEMS device changes based upon the measurement of the voltage as a function of time.
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Accused Products
Abstract
Various methods are described to characterize interferometric modulators or similar devices. Measured voltages across interferometric modulators may be used to characterize transition voltages of the interferometric modulators. Measured currents may be analyzed by integration of measured current to provide an indication of a dynamic response of the interferometric modulator. Frequency analysis may be used to provide an indication of a hysteresis window of the interferometric modulator or mechanical properties of the interferometric modulator. Capacitance may be determined through signal correlation, and spread-spectrum analysis may be used to minimize the effect of noise or interference on measurements of various interferometric modulator parameters.
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Citations
30 Claims
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1. A method of identifying a transition voltage in a microelectromechanical systems (MEMS) device, the method comprising:
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providing a circuit comprising the MEMS device, the circuit being configured to provide a substantially constant impedance for an applied voltage; applying a constant voltage to the circuit for a period of time, wherein application of the constant voltage causes a change in the state of the MEMS device, and wherein the impedance of the circuit before the state change of the MEMS device is substantially equal to the impedance of the circuit after the state change; measuring a voltage across the MEMS device as a function of time; and identifying the transition voltage at which the state of the MEMS device changes based upon the measurement of the voltage as a function of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of identifying a transition voltage in an array of electromechanical system (EMS) devices, the method comprising:
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applying a driving voltage which remains substantially constant for a period of time to the array of EMS devices arranged in parallel, wherein the driving voltage is applied via a circuit comprising a resistance in series with the array of EMS devices, wherein the resistance in series with the array of EMS devices is substantially larger than the resistance of the array of EMS devices, wherein applying a driving voltage causes a change in the states of the array of EMS devices, and wherein an impedance of the circuit remains substantially constant during application of the driving voltage; measuring a resultant voltage across the array of EMS devices as a function of time; and identifying the transition voltage at which the resultant voltage remains substantially constant for a period of time during transition of the EMS devices within the array from a first state to a second state. - View Dependent Claims (16, 17, 18, 19)
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20. A method of determining a transition voltage in a microelectromechanical system (MEMS) device, the method comprising:
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applying a driving voltage comprising a substantially square waveform to the MEMS device using a circuit configured to provide a substantially constant impedance for an applied voltage, wherein applying a driving voltage causes a change in the state of the MEMS device, and wherein the impedance of the circuit before the change in state of the MEMS device is substantially equal to the impedance of the circuit after the change in state of the MEMS device; measuring a voltage across the MEMS device as a function of time; and determining at least a first transition voltage wherein the voltage across the MEMS device remains substantially constant for a period of time. - View Dependent Claims (21, 22)
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23. A device, comprising:
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a circuit comprising a microelectromechanical system (MEMS) device, wherein the circuit is configured to provide a substantially constant impedance for an applied voltage; and circuitry configured to apply a constant voltage to the MEMS device for a period of time, measure a voltage across the MEMS device as a function of time, and identify a transition voltage based upon the measurement of the voltage as a function of time, wherein application of the constant voltage causes the MEMS device to change from a first state to a second state, and wherein the impedance of the circuit remains substantially constant regardless of the state of the MEMS device. - View Dependent Claims (24, 25, 26, 27)
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28. A device, comprising:
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means for maintaining a constant impedance for an applied voltage; means for applying a voltage to a microelectromechanical system (MEMS) device to induce a state change of the MEMS device, wherein the voltage remains substantially constant for a period of time, and wherein the impedance remains constant regardless of the state change of the MEMS device; means for measuring a voltage across the MEMS device; and means for identifying a transition voltage of the MEMS device based on the measured voltage. - View Dependent Claims (29, 30)
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Specification