Minimizing mismatch during compensation
First Claim
1. A touch surface device, comprising:
- a touch-sensitive panel having a sense node for providing an output signal indicative of a touch or no-touch condition on the panel; and
a compensation circuit, coupled to the sense node, for generating a compensation signal, wherein the compensation circuit further adjusts at least one parameter of the compensation signal based on a location of the sense node on the panel.
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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.
268 Citations
32 Claims
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1. 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; and a compensation circuit, coupled to the sense node, for generating a compensation signal, wherein the compensation circuit further adjusts at least one parameter of the compensation signal based on a location of the sense node on the panel. - 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 touch-sensitive panel comprising a sense node configured to generate an output signal indicative of touch or no-touch condition on the panel; a compensation circuit, coupled to the sense node, for generating a compensation signal to be summed with the output signal to provide a compensated output signal, wherein the compensation circuit further adjusts at least one parameter of the compensation signal based on the location of the sense node on the panel; and a processor coupled to the output of the compensation circuit and configured to receive and process the 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; and summing the output signal with a compensation signal so as to provide a compensated output signal, wherein at least one parameter of the compensation signal is adjusted based on the location of the sense node on the panel. - View Dependent Claims (24, 25, 26)
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27. 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 (28)
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29. 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 relatively constant voltage.
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30. 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; and means for summing the output signal with a compensation signal so as to provide a compensated output signal, wherein at least one parameter of the compensation signal is adjusted based on the location of the sense node on the panel.
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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 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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32. 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 relatively constant voltage.
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Specification