Minimizing mismatch during compensation
First Claim
1. A touch surface device, comprising:
- a compensation circuit configured for receiving an output signal from a sense node on a touch-sensitive panel, generating a compensation signal, adjusting at least one parameter of the compensation signal based on a location of the sense node on the panel, and combining the compensation signal with the output signal to produce a compensated output signal; and
a demodulator coupled for receiving and demodulating the compensated output signal.
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Accused Products
Abstract
A method and apparatus for minimizing mismatch effects between a compensation signal and an output signal generated by a touch surface device is disclosed. In one embodiment the apparatus includes a touch-sensitive panel having a sense node for providing an output signal indicative of a touch or no-touch condition on the panel; a drive circuit for generating a sinusoidal drive signal provided to the sense node of the touch-sensitive panel; at least one non-touch-sensitive node within the touch-sensitive panel, for generating a sinusoidal compensation signal, wherein the sinusoidal compensation signal is summed with the output signal to provide a sinusoidal compensated output signal; and a sensing circuit for receiving the sinusoidal compensated output signal.
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Citations
34 Claims
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1. A touch surface device, comprising:
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a compensation circuit configured for receiving an output signal from a sense node on a touch-sensitive panel, generating a compensation signal, adjusting at least one parameter of the compensation signal based on a location of the sense node on the panel, and combining the compensation signal with the output signal to produce a compensated output signal; and a demodulator coupled for receiving and demodulating the compensated output signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A touch surface device, comprising:
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a touch-sensitive panel having a sense node for providing an output signal indicative of a touch or no-touch condition on the panel; a drive circuit for generating a sinusoidal drive signal provided to the sense node of the touch-sensitive panel; at least one non-touch-sensitive node within the touch-sensitive panel, for generating a sinusoidal compensation signal, wherein the sinusoidal compensation signal is summed with the output signal to provide a sinusoidal compensated output signal; and a sensing circuit for receiving the sinusoidal compensated output signal. - View Dependent Claims (8, 9, 10)
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11. A computer system incorporating a touch surface device, comprising:
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a compensation circuit configured for receiving an output signal from a sense node on a touch-sensitive panel, generating a compensation signal, adjusting at least one parameter of the compensation signal based on a location of the sense node on the panel, and combining the compensation signal with the output signal to produce a compensated output signal; a demodulator coupled for receiving and demodulating the compensated output signal; and a processor coupled to receive and process the demodulated compensated output signal and perform one or more functions based on data provided by the compensated output signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A computer system incorporating a touch surface device, comprising:
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a touch-sensitive panel having a sense node for providing an output signal indicative of a touch or no-touch condition on the panel; a drive circuit for generating a sinusoidal drive signal provided to the sense node of the touch-sensitive panel; and at least one non-touch-sensitive node within the touch-sensitive panel, for generating a sinusoidal compensation signal, wherein the sinusoidal compensation signal is summed with the output signal to provide a sinusoidal compensated output signal; a sensing circuit for receiving the sinusoidal compensated output signal and converting the sinusoidal compensated output signal into a digital signal; and a processor for receiving and processing the digital signal and perform one or more functions based on the data provided by the digital signal. - View Dependent Claims (20, 21, 22)
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23. A method of minimizing mismatch between an output signal of a touch surface device and a compensation signal, comprising:
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generating an output signal at a sense node of a touch-sensitive panel, wherein the output signal is indicative of a touch or no-touch condition on the panel; combining the output signal with a compensation signal to produce a compensated output signal, wherein at least one parameter of the compensation signal is adjusted based on a location of the sense node on the panel; and demodulating the compensated output signal. - View Dependent Claims (24, 25, 26, 27)
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28. A method of minimizing mismatch between an output signal of a touch surface device and a compensation signal, comprising:
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providing a sinusoidal drive signal to a sense node of a touch-sensitive panel so as to generate an output signal indicative of a touch or no-touch condition on the sense node; inverting the sinusoidal drive signal to provide a compensation drive signal; and providing the compensation drive signal to at least one non-touch-sensitive node within the touch-sensitive panel, for generating a sinusoidal compensation signal, wherein the sinusoidal compensation signal is summed with the output signal to provide a sinusoidal compensated output signal. - View Dependent Claims (29)
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30. A method of minimizing mismatch effects between a compensation signal and an output signal generated by a touch surface device, comprising:
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providing a sinusoidal drive signal to a first electrode of the touch surface device; providing a sinusoidal output signal from a second electrode of the touch surface device to a first input of a summing circuit, the sinusoidal output signal being generated due to a mutual capacitance between the first and second electrodes; providing a sinusoidal compensation signal to a second input of the summing circuit, wherein the sinusoidal compensation signal is substantially 180 degrees out of phase with the sinusoidal output signal; and providing a compensated output signal from an output of the summing circuit to an inverting input of an amplifier, wherein a non-inverting input of the amplifier is provided with a substantially constant voltage.
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31. An apparatus for minimizing mismatch between an output signal of a touch surface device and a compensation signal, comprising:
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means for generating an output signal at a sense node of a touch-sensitive panel, wherein the output signal is indicative of a touch or no-touch condition on the panel; means for combining the output signal with a compensation signal to produce a compensated output signal, wherein at least one parameter of the compensation signal is adjusted based on a location of the sense node on the panel; and means for demodulating the compensated output signal. - View Dependent Claims (32)
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33. An apparatus for minimizing mismatch between an output signal of a touch surface device and a compensation signal, comprising:
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means for providing a sinusoidal drive signal to a sense node of a touch-sensitive panel so as to generate an output signal indicative of a touch or no-touch condition on the sense node; means for inverting the sinusoidal drive signal to provide a compensation drive signal; and means for providing the compensation drive signal to at least one non-touch-sensitive node within the touch-sensitive panel, for generating a sinusoidal compensation signal, wherein the sinusoidal compensation signal is summed with the output signal to provide a sinusoidal compensated output signal.
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34. An apparatus for minimizing mismatch effects between a compensation signal and an output signal generated by a touch surface device, comprising:
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means for providing a sinusoidal drive signal to a first electrode of the touch surface device; means for providing a sinusoidal output signal from a second electrode of the touch surface device to a first input of a summing circuit, the sinusoidal output signal being generated due to a mutual capacitance between the first and second electrodes; means for providing a sinusoidal compensation signal to a second input of the summing circuit, wherein the sinusoidal compensation signal is substantially 180 degrees out of phase with the sinusoidal output signal; and means for providing a compensated output signal from an output of the summing circuit to an inverting input of an amplifier, wherein a non-inverting input of the amplifier is provided with a substantially constant voltage.
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Specification