Coarse scan and targeted active mode scan for touch

摘要

Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected. 452 454 456 DETECT BANK 1 BANK2 BANK BANKN S T CTN-i SCAN SCAN SCAN SCAN PERFORM COARSE DETECTION SCAN + TOUCH NO DETECTED 510 PERFORM FINE SCAN ABORT FINE SCAN