Touch detection using multiple simultaneous frequencies
First Claim
1. A system for determining an amount of touch at each of a plurality of locations of touch sensor circuitry, the system comprising:
- touch sensor circuitry having a plurality of drive lines and a plurality of sense lines; and
an integrated circuit coupled to the touch sensor circuitry, includingdriver logic that generates a plurality of different sets of stimulation signals and applies the sets sequentially to the plurality of drive lines such that the stimulation signals in each set are applied simultaneously to the plurality of drive lines, the stimulation signals in each set including stimulation signals of different frequencies;
a plurality of sense channels, each sense channel receiving a sense signal from a different sense line of the touch sensor circuitry during application of each set of stimulation signals to the drive lines, wherein each sense signal includes a composite signal based on a plurality of stimulation signals in the applied set;
a demodulation section that demodulates each sense signal with demodulation signals at demodulation frequencies corresponding to the stimulation frequencies in the corresponding applied set, wherein each sense signal is demodulated with multiple demodulation signals to produce multiple demodulated values, each demodulated value including a composite value based on touch information of a plurality of locations of the touch sensor circuitry; and
a calculation section that calculates, based on a plurality of the demodulated values produced over a plurality of sequential applications of sets of stimulation signals, an amount of touch at each of the plurality of locations of the touch sensor circuitry.
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Accused Products
Abstract
The use of multiple stimulation frequencies and phases to generate an image of touch on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a column in a touch sensor panel and can have multiple mixers. Each mixer in the sense channel can utilize a circuit capable generating a demodulation frequency of a particular frequency. At each of multiple steps, various phases of selected frequencies can be used to simultaneously stimulate the rows of the touch sensor panel, and the multiple mixers in each sense channel can be configured to demodulate the signal received from the column connected to each sense channel using the selected frequencies. After all steps have been completed, the demodulated signals from the multiple mixers can be used in calculations to determine an image of touch for the touch sensor panel at each frequency.
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Citations
31 Claims
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1. A system for determining an amount of touch at each of a plurality of locations of touch sensor circuitry, the system comprising:
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touch sensor circuitry having a plurality of drive lines and a plurality of sense lines; and an integrated circuit coupled to the touch sensor circuitry, including driver logic that generates a plurality of different sets of stimulation signals and applies the sets sequentially to the plurality of drive lines such that the stimulation signals in each set are applied simultaneously to the plurality of drive lines, the stimulation signals in each set including stimulation signals of different frequencies; a plurality of sense channels, each sense channel receiving a sense signal from a different sense line of the touch sensor circuitry during application of each set of stimulation signals to the drive lines, wherein each sense signal includes a composite signal based on a plurality of stimulation signals in the applied set; a demodulation section that demodulates each sense signal with demodulation signals at demodulation frequencies corresponding to the stimulation frequencies in the corresponding applied set, wherein each sense signal is demodulated with multiple demodulation signals to produce multiple demodulated values, each demodulated value including a composite value based on touch information of a plurality of locations of the touch sensor circuitry; and a calculation section that calculates, based on a plurality of the demodulated values produced over a plurality of sequential applications of sets of stimulation signals, an amount of touch at each of the plurality of locations of the touch sensor circuitry. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for determining an amount of touch at each of a plurality of locations of touch sensor circuitry, the method comprising:
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generating a plurality of different sets of stimulation signals and applying the sets sequentially to a plurality of drive lines of the touch sensor circuitry such that the stimulation signals in each set are applied simultaneously to the plurality of drive lines, the stimulation signals in each set including stimulation signals of different frequencies; receiving a sense signal from each of a plurality of sense lines in the touch sensor circuitry into a corresponding one of a plurality of sense channels during application of each set of stimulation signals to the drive lines, wherein each sense signal includes a composite signal based on a plurality of stimulation signals in the applied set; demodulating each sense signal with demodulation signals at a plurality of demodulation frequencies corresponding to the stimulation frequencies in the corresponding applied set, wherein each sense signal is demodulated with multiple demodulation frequencies to produce multiple demodulated values, each demodulated value including a composite value based on touch information of a plurality of locations of the touch sensor circuitry; and calculating, based on a plurality of the demodulated values produced over a plurality of sequential applications of sets of stimulation signals, an amount of touch at each of the plurality of locations of the touch sensor circuitry. - View Dependent Claims (10, 11, 12)
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13. A method for obtaining a plurality of values used to generate an image of touch from touch sensor circuitry, the touch sensor circuitry including a plurality of drive lines and sense lines, the method comprising:
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simultaneously driving one or more drive lines with a first stimulation signal of a first frequency and a first phase, one or more drive lines with a second stimulation signal of the first frequency and a second phase, one or more drive lines with a third stimulation signal of a second frequency and the first phase, and one or more drive lines with a fourth stimulation signal of the second frequency and the second phase, wherein one stimulation signal is applied to each drive line; receiving a sense signal from each of a plurality of the sense lines into a different sense channel of the touch sensor circuitry; demodulating the sense signal received into each sense channel with a first demodulation signal of the first frequency and one of the first and second phases and a second demodulation signal of the second frequency and one of the first and second phases; accumulating the sense signals demodulated with the first and second demodulation signals in each sense channel to generate a plurality of values representing the accumulated demodulated sense signals for each sense channel; and storing the plurality of values for all sense channels. - View Dependent Claims (14, 15, 16, 17)
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18. A non-transitory computer readable storage medium storing program code for determining an amount of touch at each of a plurality of locations of touch sensor circuitry, the program code for performing a method comprising:
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generating a plurality of different sets of stimulation signals and applying the sets sequentially to a plurality of drive lines of the touch sensor circuitry such that the stimulation signals in each set are applied simultaneously to the plurality of drive lines, the stimulation signals in each set including stimulation signals of different frequencies; receiving sense signals from a plurality of sense lines of the touch sensor circuitry during application of each set of stimulation signals to the drive lines, wherein each sense signal includes a composite signal based on a plurality of stimulation signals in the applied set; demodulating the sense signals with demodulation signals at a plurality of demodulation frequencies corresponding to the stimulation frequencies in the corresponding applied set, wherein each sense signal is demodulated with multiple demodulation signals to produce multiple demodulated values, each demodulated value including a composite value based on touch information of a plurality of locations of the touch sensor circuitry; and calculating, based on a plurality of the demodulated values produced over a plurality of sequential applications of sets of stimulation signals, an amount of touch at each of the plurality of locations of the touch sensor circuitry. - View Dependent Claims (19, 20, 21, 22)
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23. A non-transitory computer readable storage medium storing program code for determining an amount of touch at each of a plurality of locations of touch sensor circuitry, the program code for performing a method comprising:
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generating a plurality of different sets of stimulation signals and applying the sets sequentially to a plurality of drive lines of the touch sensor circuitry such that the stimulation signals in each set are applied simultaneously to the plurality of drive lines, the stimulation signals in each set including stimulation signals of different frequencies; receiving a sense signal from each of a plurality of sense lines in the touch sensor circuitry into a corresponding one of a plurality of sense channels during application of each set of stimulation signals to the drive lines, wherein each sense signal includes a composite signal based on a plurality of stimulation signals in the applied set; demodulating each sense signal with demodulation signals at a plurality of demodulation frequencies corresponding to the stimulation frequencies in the corresponding applied set, wherein each sense signal is demodulated with multiple demodulation frequencies to produce multiple demodulated values, each demodulated value including a composite value based on touch information of a plurality of locations of the touch sensor circuitry; and calculating, based on a plurality of the demodulated values produced over a plurality of sequential applications of sets of stimulation signals, an amount of touch at each of the plurality of locations of the touch sensor circuitry. - View Dependent Claims (24, 25, 26)
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27. A non-transitory computer readable storage medium storing program code for obtaining a plurality of values used to generate an image of touch from touch sensor circuitry, the touch sensor circuitry including a plurality of drive lines and sense lines, the program code for performing a method comprising:
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simultaneously driving one or more drive lines with a first stimulation signal of a first frequency and a first phase, one or more drive lines with a second stimulation signal of the first frequency and a second phase, one or more drive lines with a third stimulation signal of a second frequency and the first phase, and one or more drive lines with a fourth stimulation signal of the second frequency and the second phase, wherein one stimulation signal is applied to each drive line; receiving a sense signal from each of a plurality of the sense lines into a different sense channel of the touch sensor circuitry; demodulating the sense signal received into each sense channel with a first demodulation signal of the first frequency and one of the first and second phases and a second demodulation signal of the second frequency and one of the first and second phases; accumulating the sense signals demodulated with the first and second demodulation signals in each sense channel to generate a plurality of values representing the accumulated demodulated sense signals for each sense channel; and storing the plurality of values for all sense channels. - View Dependent Claims (28, 29, 30, 31)
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Specification