Selective scanning for touch-sensitive display device

A touch-sensitive display device, comprising:

• a touch-sensitive display including a plurality of display electrodes;
• a logic machine;
• and
• a storage machine holding instructions executable by the logic machine to:
• over a series of touch-sensing time frames, interpret electrical conditions of display electrodes of a touch-sensitive display device to estimate frame-by-frame positions of two or more stylus electrodes of an active stylus relative to the touch-sensitive display device;
• based on the estimated frame-by-frame positions of the stylus electrodes, predict future positions of each of the two or more stylus electrodes during a future touch-sensing time frame;
• identify regions of interest on the touch-sensitive display device, each region of interest including a plurality of display electrodes surrounding the predicted future position of a stylus electrode of the two or more stylus electrodes;
• and
• during the future touch-sensing time frame, selectively scan display electrodes in the regions of interest.

A method for touch input detection, comprising:

• over a series of touch-sensing time frames, interpreting electrical conditions of display electrodes of a touch-sensitive display device to estimate frame-by-frame positions for each of a plurality of stylus electrodes of an active stylus;
• based on the estimated frame-by-frame positions of the stylus electrodes, predicting future positions of each stylus electrode during a future touch-sensing time frame;
• identifying regions of interest on the touch-sensitive display device based on a known physical structure of the active stylus, each region of interest including a plurality of display electrodes surrounding the predicted future position of a stylus electrode of the plurality, and each region of interest having a size proportional to an estimated speed of its corresponding stylus electrode;
• and
• during the future touch-sensing time frame, selectively scanning display electrodes in the regions of interest.