Touch receiving channel re-use scheme with receiver signal coding
First Claim
1. A system comprising:
- a sense amplifier comprising a positive terminal and a negative terminal;
switching circuitry for receiving a plurality of touch signals from a plurality of sense electrodes of a touch sensor panel, wherein the switching circuitry is operable to selectively couple each of the plurality of sense electrodes to the positive terminal of the sense amplifier or the negative terminal of the sense amplifier based on a matrix;
an analog-to-digital converter coupled to receive an output of the sense amplifier; and
decoding circuitry coupled to receive an output of the analog-to-digital converter, wherein the decoding circuitry is operable to decode the output of the analog-to-digital converter using an inverse of the matrix to generate a plurality of output signals that are representative of the plurality of touch signals.
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Accused Products
Abstract
Systems and processes for encoding and decoding touch signals output by a touch sensor are provided. In one example system, switching circuitry can be used to selectively couple each of the sense lines of a touch sensor to a positive terminal or a negative terminal of a sense amplifier based on the values of the elements of a matrix. The touch signals can be amplified and converted into digital form using a single sense amplifier and an ADC before being decoded using decoding circuitry. The decoding circuitry can decode the digital encoded touch signals by multiplying the digital encoded touch signals by each column of an inverse of the matrix used to encode the touch signals. The result of the decoding can be a set of signals that are representative of the touch signals output by the touch sensor.
31 Citations
24 Claims
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1. A system comprising:
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a sense amplifier comprising a positive terminal and a negative terminal; switching circuitry for receiving a plurality of touch signals from a plurality of sense electrodes of a touch sensor panel, wherein the switching circuitry is operable to selectively couple each of the plurality of sense electrodes to the positive terminal of the sense amplifier or the negative terminal of the sense amplifier based on a matrix; an analog-to-digital converter coupled to receive an output of the sense amplifier; and decoding circuitry coupled to receive an output of the analog-to-digital converter, wherein the decoding circuitry is operable to decode the output of the analog-to-digital converter using an inverse of the matrix to generate a plurality of output signals that are representative of the plurality of touch signals. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system comprising:
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a touch sensor panel, the touch sensor panel comprising; a plurality of drive electrodes; and a plurality of sense electrodes capacitively coupled to the plurality of drive electrodes; a sense amplifier comprising a positive terminal and a negative terminal; a plurality of switches for receiving a plurality of touch signals from the plurality of sense electrodes, wherein the plurality of switches are operable to individually couple each of the plurality of touch signals to the positive terminal of the sense amplifier or the negative terminal of the sense amplifier based on a matrix; an analog-to-digital converter coupled to receive an output of the sense amplifier; and decoding circuitry coupled to receive an output of the analog-to-digital converter, wherein the decoding circuitry is operable to decode the output of the analog-to-digital converter using an inverse of the matrix to generate a plurality of output signals that are representative of the plurality of touch signals. - View Dependent Claims (9, 10, 11, 12)
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13. A system comprising:
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a receiving channel operable to receive a plurality of touch signals and apply a plurality of values to the plurality of touch signals to generate an encoded signal; an analog-to-digital converter coupled to receive the encoded signal; and decoding circuitry coupled to receive an output of the analog-to-digital converter, wherein the decoding circuitry is operable to decode the output of the analog-to-digital converter using an inverse of the plurality of values to generate a plurality of output signals that are representative of the plurality of touch signals. - View Dependent Claims (14, 15, 16)
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17. A method comprising:
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stimulating a plurality of drive electrodes with a plurality of stimulation signals; receiving a plurality of touch signals generated in response to the plurality of stimulation signals; encoding the plurality of touch signals using a plurality of values; amplifying the encoded plurality of touch signals; converting the encoded plurality of touch signals in to a digital signal; and decoding the plurality of touch signals from the digital signal using an inverse of the plurality of values. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification