Common pixel correction for sensor panels
First Claim
1. An apparatus comprising:
- a plurality of transmit channels configured to stimulate a touch or force sensor panel;
a plurality of receive channels configured to receive sense signals from the touch or force sensor panel; and
processing circuitry capable of;
sensing a plurality of sensor nodes of the touch or force sensor panel, each sensor node coupled to one of the plurality of transmit channels and coupled to one of the plurality of receive channels;
sensing a plurality of reference nodes, each of the plurality of reference nodes coupled between one of the plurality of transmit channels and one of the plurality of receive channels; and
subtracting, for each sensor node coupled to a corresponding receive channel, a measurement from sensing the reference node coupled to the corresponding receive channel from a measurement of each of the plurality of sensor nodes.
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Accused Products
Abstract
Noise in sensor panel measurements can be reduced using a common pixel correction algorithm. Noise can be introduced into touch or force sensor panel measurements, for example, by circuitry of a transmit (Tx) section or a receive (Rx) section coupled to one or more sensing nodes of a sensor panel. For example, a digital-to-analog converter in the transmit section or an analog-to-digital converter in the receive section can introduce low-frequency correlated noise. Additionally, transmit and receive sections can introduce uncorrelated noise into the system. Reference nodes, coupled between Tx and Rx sections, can sense correlated and uncorrelated noise from the Tx and Rx sections. The noise measured at reference nodes can be subtract from signals measured at other sensing nodes coupled to the same Rx channel. The measurement at the reference node can be scaled using a scaling parameter to account for differences between reference nodes and sensing nodes.
22 Citations
25 Claims
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1. An apparatus comprising:
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a plurality of transmit channels configured to stimulate a touch or force sensor panel; a plurality of receive channels configured to receive sense signals from the touch or force sensor panel; and processing circuitry capable of; sensing a plurality of sensor nodes of the touch or force sensor panel, each sensor node coupled to one of the plurality of transmit channels and coupled to one of the plurality of receive channels; sensing a plurality of reference nodes, each of the plurality of reference nodes coupled between one of the plurality of transmit channels and one of the plurality of receive channels; and subtracting, for each sensor node coupled to a corresponding receive channel, a measurement from sensing the reference node coupled to the corresponding receive channel from a measurement of each of the plurality of sensor nodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for reducing noise in measurements of a touch or force sensor panel, comprising:
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sensing a plurality of sensor nodes of the touch or force sensor panel, each sensor node coupled to one of a plurality of transmit channels and coupled to one of a plurality of receive channels; sensing a plurality of reference nodes, each of the plurality of reference nodes coupled between a transmit channel and a receive channel; and subtracting, for each sensor node coupled to a corresponding receive channel, a measurement from sensing a reference node coupled to the corresponding receive channel from a measurement of each of the plurality of sensor nodes. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A non-transitory computer readable storage medium, the computer readable medium containing instructions that, when executed by a device including a processor, can perform a method for reducing noise in measurements of a touch or force sensor panel, the method comprising:
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sensing a plurality of sensor nodes of the touch or force sensor panel, each sensor node coupled to one of a plurality of transmit channels and coupled to one of a plurality of receive channels; sensing a plurality of reference nodes, each of the plurality of reference nodes coupled between a transmit channel and a receive channel; and subtracting, for each sensor node coupled to a corresponding receive channel, a measurement from sensing a reference node coupled to the corresponding receive channel from a measurement of each of the plurality of sensor nodes. - View Dependent Claims (22, 23, 24, 25)
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Specification