Touch Sensing Having Increased Immunity to the Presence of a Fluid Layer

摘要

In certain embodiments, a touch sensitive device includes a cover panel, a plurality of drive electrodes positioned below the cover panel, a plurality of sense electrodes positioned below the cover panel, and a controller. The controller includes a signal generator operable to supply a drive signal to a particular drive electrode of the plurality of drive electrodes. The controller further includes measurement circuits associated with each of the plurality of sense electrodes, each measurement circuit being operable to generate a signal corresponding to the charge transfer between the particular drive electrode and a corresponding sense electrode. The drive signal supplied by the signal generator has a frequency that reduces the charge transfer caused by a fluid layer located on the cover panel to an amount falling below a threshold corresponding to the point at which the controller determines that a touch is present.

主权项

1. A touch sensitive device, comprising
a cover panel; a plurality of drive electrodes positioned below the cover panel; a plurality of sense electrodes positioned below the cover panel; and a controller comprising:
a signal generator operable to supply a drive signal to a particular drive electrode of the plurality of drive electrodes; andmeasurement circuits associated with each of the plurality of sense electrodes, each measurement circuit operable to generate a signal corresponding to the charge transfer between the particular drive electrode and a corresponding sense electrode; wherein the drive signal has a frequency that reduces the charge transfer caused by a fluid layer located on the cover panel to an amount falling below a threshold corresponding to the point at which the controller determines that a touch is present.