Detecting multi-touch inputs

摘要

Determining a touch contact location is disclosed. A signal that has been disturbed by a touch input on a surface is received. The received signal is transformed to determine a spatial domain signal. The spatial domain signal is compared with an expected signal associated with a potential location of a source of a disturbance caused by the touch input. The touch contact location of the touch input is determined based at least in part on the comparison.

主权项

1. A system for determining a touch contact location, comprising:
a communication interface configured to receive a signal that has been disturbed by a touch input on a surface, wherein the signal was propagating in a medium of the surface prior to the touch input; and a processor coupled with the communication interface and configured to:
correlate the received signal to determine a time domain signal encoding a time delay represented in the received signal;transform the time domain signal to determine a spatial domain signal, wherein transforming the received signal includes translating the time delay represented in the received signal disturbed by the touch input to a physical distance encoded in the spatial domain signal;compare the spatial domain signal with an expected signal associated with a potential location of a source of a disturbance caused by the touch input, wherein the spatial domain signal encodes the physical distance traveled by the received signal due to the disturbance caused by the touch input and the expected signal encodes a variable with respect to a measure of distance; anddetermine the touch contact location of the touch input based at least in part on the comparison.