Master/slave control of touch sensing

摘要

Touch sensing can be accomplished using master/slave touch controllers that transmit drive signals to a touch surface and process sense signals including superpositions resulting from master/slave drive signals. The master/slave can drive and sense different sets of lines, respectively, of the touch surface. A communication link between master/slave can be established by transmitting a clock signal between master/slave, transmitting a command including sequence information to the slave, and initiating a communication sequence from the clock signal and sequence information. The slave can receive/transmit communications from/to the master during first/second portions of the communication sequence, respectively. Touch sensing operations can be synchronized between master/slave by transmitting a command including phase alignment information from master to slave, and generating slave clock signals based on the clock signal and the phase alignment information, such that sense signal processing by master clock signals are in-phase with sense signal processing by slave clock signals.

主权项

1. A method of synchronizing touch sensing operations of a master controller and a slave controller for joint operation of a touch sensing panel, the method comprising:
transmitting a first clock signal from the master controller to the slave controller; transmitting a first command from the master controller to the slave controller, the first command including phase alignment information; generating a slave clock signal in the slave controller based on the first clock signal and the phase alignment information, wherein the slave clock signal is generated in a known phase relationship with a master clock signal of the master controller; and performing touch sensing to detect touch on or near the touch sensing panel based on the master and slave clock signals, wherein the master controller operates a first portion of the touch sensing panel including one or more first drive lines and one or more first sense lines, and the slave controller operates a second portion of the touch sensing panel including one or more second drive lines and one or more second sense lines, wherein performing the touch sensing includes the master controller and the slave controller applying drive signals simultaneously during at least part of the touch sensing to the first and second drive lines such that the drive signals on both the first and second drive lines simultaneously interact with at least one sense line of the first and second sense lines resulting in a superposition sense signal based on an interaction of the drive signals with the at least one sense line, wherein the superposition sense signal comprises composite information associated with an amount of touch at one or more sensing nodes on the at least one sense line.