Display to touch crosstalk compensation
First Claim
1. A method of compensating for crosstalk in a touch sensitive display, the touch sensitive display having display pixels for displaying data and touch components for sensing a touch or hover event, the method comprising:
- during a touch sensing mode of operation, driving the touch components with a stimulation voltage, the touch components generating an output within a frequency band, the output indicative of the touch or hover event;
during the touch sensing mode of operation, driving the display pixels with the varying voltage at a modulation frequency, the display pixels causing the crosstalk;
wherein the modulation frequency is such as to push at least a portion of the crosstalk out of the frequency band of the output;
demodulating the output to isolate the crosstalk therefrom;
determining a crosstalk compensation factor based on the isolated crosstalk; and
applying the determined crosstalk compensation factor to the output to provide a crosstalk compensated output.
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Accused Products
Abstract
A touch sensitive display capable of compensating for crosstalk in the display is disclosed. Crosstalk in display components can be reduced, eliminated, or otherwise compensated for by reducing or eliminating parasitic capacitances that cause the crosstalk. To do so, gate voltages to the display components, such as thin film transistors (TFTs), that introduce the parasitic capacitances can be reduced or otherwise adjusted. In one approach, the gate voltage can be set at multiple different low levels to generate respective sets of touch signals having different amounts of crosstalk. The different crosstalk amounts can then be used to determine and compensate for the crosstalk in the touch signals. In another approach, gate voltage can be modulated between multiple different low levels to push crosstalk out of band with the generated touch signals. The out-of-band crosstalk can then be used to compensate for the crosstalk in the touch signals.
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Citations
12 Claims
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1. A method of compensating for crosstalk in a touch sensitive display, the touch sensitive display having display pixels for displaying data and touch components for sensing a touch or hover event, the method comprising:
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during a touch sensing mode of operation, driving the touch components with a stimulation voltage, the touch components generating an output within a frequency band, the output indicative of the touch or hover event; during the touch sensing mode of operation, driving the display pixels with the varying voltage at a modulation frequency, the display pixels causing the crosstalk; wherein the modulation frequency is such as to push at least a portion of the crosstalk out of the frequency band of the output; demodulating the output to isolate the crosstalk therefrom; determining a crosstalk compensation factor based on the isolated crosstalk; and applying the determined crosstalk compensation factor to the output to provide a crosstalk compensated output. - View Dependent Claims (2, 3, 4, 5)
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6. A touch sensitive display having a display mode of operation and a touch sensing mode of operation comprising:
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a stimulation voltage source configured to drive touch components with a stimulation voltage to generate a sensed signal output within a frequency band, the sensed signal output indicative of a touch or hover event; and a voltage source configured to drive display components during the touch sensing mode of operation with a voltage at a modulation frequency, the display components introducing crosstalk into the sensed signal output; the modulation frequency such as to push at least a portion of the crosstalk out of band with respect to the frequency band of the sensed signal output; and a demodulator configured to reject the crosstalk within the sensed signal output and provide a crosstalk a compensated output. - View Dependent Claims (7)
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8. An apparatus for compensating for crosstalk in a touch sensitive display comprising:
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a plurality of display pixels; a plurality of touch components; a modulator providing a modulating voltage; a demodulator; a control circuitry configured for; during a touch sensing mode of operation, driving the touch components with a stimulation voltage, the touch components generating an output within a frequency band, the output indicative of the touch or hover event; during the touch sensing mode of operation, driving the plurality of display pixels with the modulating voltage at a modulation frequency, the display pixels causing the crosstalk; wherein the modulation frequency is such as to push at least a portion of the crosstalk out of the frequency band of the output; demodulating the output using the demodulator to isolate the crosstalk therefrom; determining a crosstalk compensation factor based on the isolated crosstalk; and applying the determined crosstalk compensation factor to the output to provide a crosstalk compensated output. - View Dependent Claims (9, 10, 11, 12)
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Specification