Adjustment of touch sensing stimulation voltage levels based on touch performance
AssigneeApple Inc.
InventorsJacob L. Matlick, Adam Geboff
Life of this patent
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Abstract
The adjustment of stimulation signal amplitudes in capacitive touch sensor panels and/or styli to reduce power consumption while preserving satisfactory touch performance is disclosed, in particular in situations where the noise level is not significant and there is excess SNR margin. To accomplish this, one or more metrics can be measured, calculated or otherwise determined to use as a predictor of touch performance, and these metrics can be processed to determine the minimum stimulation voltage required to maintain acceptable touch performance.
Claims27
A method of determining a stimulation voltage for a touch sensing system, comprising:
- capturing one or more touch sensor panel images over a particular time interval, each touch sensor panel image captured by stimulating electrodes of a touch sensor panel with a same first stimulation voltage, wherein the one or more touch sensor panel images indicate one or more detected touches;
- computing one or more metrics based on at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- determining a second stimulation voltage amplitude from the one or more metrics;
- dynamically adjusting the stimulation voltage such that an amplitude of the adjusted stimulation voltage is equal to the second stimulation voltage-amplitude determined from the one or more metrics computed based on the at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- and
- stimulating the touch sensor system with the adjusted stimulation voltage.
A non-transitory computer-readable storage medium having stored therein instructions, which when executed by a device, cause the device to perform a method comprising:
- capturing one or more touch sensor panel images over a particular time interval, each touch sensor panel image captured by stimulating electrodes of a touch sensor panel with a same first stimulation voltage, wherein the one or more touch sensor panel images indicate one or more detected touches;
- computing one or more metrics based on at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- determining second stimulation voltage amplitude from the one or more metrics;
- dynamically adjusting the stimulation voltage such that an amplitude of the adjusted stimulation voltage is equal to the second stimulation voltage-amplitude determined from the one or more metrics computed based on the at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- and
- stimulating the touch sensor system with the adjusted stimulation voltage.
A computing device for determining a stimulation voltage for a touch sensing system, comprising:
- a touch sensor panel;
- and
- a touch controller communicatively coupled to the touch sensor panel, the touch controller including
- circuitry configured to stimulate the touch sensor panel and receive sense signals from the touch sensor panel, and
- a processor capable of
- capturing one or more touch sensor panel images over a particular time interval, each touch sensor panel image captured by stimulating electrodes of the touch sensor panel with a same first stimulation voltage, wherein the one or more touch sensor panel images indicate one or more detected touches;
- computing one or more metrics based on at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- determining a second stimulation voltage amplitude from the one or more metrics;
- dynamically adjusting the stimulation voltage such that an amplitude of the adjusted stimulation voltage is equal to the second stimulation voltage-amplitude determined from the one or more metrics computed based on at least one touch sensor panel image that indicates at least one of the one or more detected touches;
- and
- stimulating the touch sensor system with the adjusted stimulation voltage.
Dependencies are inferred from the claim text.