Transcapacitive sensor having gate lines used for both display updating and capacitive sensing

摘要

Capacitive sensing is performed in an input device having an input sensor and associated display device using gate lines of the display device. A transmitter signal having a negative pulse is used to safely transmit a transcapacitive transmitter signal while not opening any of the access transistors in the display device.

主权项

1. An input device comprising a display device comprising an integrated sensing device:
a plurality of transmitter electrodes including a first transmitter electrode, the plurality of transmitter electrodes operable to be driven for both capacitive sensing and display updating, wherein each transmitter electrode of the plurality of transmitter electrodes comprises one or more gate lines of the display device, wherein the gate lines are configured for display updating and capacitive sensing; a plurality of receiver electrodes; and a processing system coupled to the plurality of transmitter electrodes and to the plurality of receiver electrodes, and configured to:
drive a transmitter signal on the first transmitter electrode that capacitively couples with the receiver electrodes for capacitive sensing, wherein the transmitter signal comprises a maximum amplitude that is below a display update turn-on voltage for the plurality of gate lines, andreceive resulting signals with the plurality of receiver electrodes, the resulting signals comprising effects corresponding to the transmitter signal driven on the first transmitter electrode, the effects in the resulting signal indicative of presence of an input object in a sensing region of the input device.