Detecting interference in an input device having electrodes
First Claim
1. A method for detecting interference in an input device, the method comprising:
- driving a transmitter signal onto a transmitter sensor electrode of the input device;
receiving a resulting signal from a receiver sensor electrode of the input device;
resetting accumulator circuitry associated with an amplifier at a start of a first half of a sensing cycle;
sampling a first value associated with the resulting signal during the first half of the sensing cycle,wherein the accumulator circuitry accumulates the first value during the first half of the sensing cycle;
resetting the accumulator circuitry at a start of a second half of the sensing cycle;
sampling a second value associated with the resulting signal during the second half of the sensing cycle,wherein the accumulator circuitry accumulates the second value during the second half of the sensing cycle, andwherein the first value and the second value are each a different single voltage level;
generating an interference value based on the first value and the second value;
determining, based on the first value and the second value, an input in a sensing region of the input device;
comparing the interference value to a noise threshold;
generating a comparison between a rail voltage range of the amplifier and at least one selected from a group consisting of the first value and the second value; and
issuing a first flag in response to the comparison.
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Accused Products
Abstract
A method for detecting interference in an input device, the method involving: driving a transmitter signal onto a transmitter sensor electrode of the input device; receiving a resulting signal from a receiver sensor electrode of the input device; sampling a first value associated with the resulting signal during a first half of a sensing cycle; sampling a second value associated with the resulting signal during a second half of the sensing cycle; generating an interference value based on the first value and the second value; determining, based on the first value and the second value, an input in a sensing region of the input device; and comparing the interference value to a noise threshold.
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Citations
17 Claims
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1. A method for detecting interference in an input device, the method comprising:
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driving a transmitter signal onto a transmitter sensor electrode of the input device; receiving a resulting signal from a receiver sensor electrode of the input device; resetting accumulator circuitry associated with an amplifier at a start of a first half of a sensing cycle; sampling a first value associated with the resulting signal during the first half of the sensing cycle, wherein the accumulator circuitry accumulates the first value during the first half of the sensing cycle; resetting the accumulator circuitry at a start of a second half of the sensing cycle; sampling a second value associated with the resulting signal during the second half of the sensing cycle, wherein the accumulator circuitry accumulates the second value during the second half of the sensing cycle, and wherein the first value and the second value are each a different single voltage level; generating an interference value based on the first value and the second value; determining, based on the first value and the second value, an input in a sensing region of the input device; comparing the interference value to a noise threshold; generating a comparison between a rail voltage range of the amplifier and at least one selected from a group consisting of the first value and the second value; and issuing a first flag in response to the comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An input device configured to sense input objects in a sensing region, the input device comprising:
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transmitter circuitry configured to drive a transmitter signal onto a transmitter sensor electrode of the input device, wherein the transmitter signal comprises a transmitter waveform with repeating cycles, and wherein each cycle comprises a transition; receiver circuitry configured to receive a resulting signal from a receiver sensor electrode of the input device, the receiver circuitry comprising; accumulator circuitry comprising an amplifier and configured to; accumulate a first value of the resulting signal during a first half of a sensing cycle; and accumulate a second value of the resulting signal during a second half of the sensing cycle, wherein the first value and the second value are each a different single voltage level; demodulator circuitry configured to; determine an input from the sensing region of the input device based on the first value and the second value; and generate an interference value based on the first value and the second value; and control circuitry comprising a first comparator and a second comparator, the control circuitry configured to; generate, using the first comparator, a first comparison of the interference value and a noise threshold; generate, using the second comparator, a second comparison between a rail voltage range of the amplifier and at least one of the first value and the second value; and issue a flag based on the second comparison. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification