BACKGROUND

Field

The disclosure herein is generally related to electronic devices, and more specifically, to reducing the effects of interference caused by a sensing device in a display device.

Description of the Related Art

Input devices including proximity sensor devices may be used in a variety of electronic systems. A proximity sensor device may include a sensing region, demarked by a surface, in which the proximity sensor device determines the presence, location, force and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices may be used as input devices for larger computing systems, such as touchpads integrated in, or peripheral to, notebook computers, desktop computers, automotive multimedia systems, or internet of things (IoT) devices. Proximity sensor devices may also often be used in smaller computing systems, such as touch screens integrated in cellular phones.

SUMMARY

In one example, a processing system for an input device comprises sensor circuitry. The sensor circuitry is configured to operate sensor electrodes for input sensing during a first sensing frame. During a first period of the first sensing frame the sensor circuitry is configured to drive a first portion of the sensor electrodes with a sensing signal, drive a second portion of the sensor electrodes with a guarding signal, and drive a third portion of the sensor electrodes with a reference signal. The guarding signal and the sensing signal have at least one characteristic in common selected from the group consisting of amplitude, phase and frequency. The third portion of the sensor electrodes overlaps a first gate line of a display panel selected for updating during the first period.

In one example, the input device comprises sensor electrodes, and a processing system. The processing system is coupled to the sensor electrodes and is configured to operate the sensor electrodes for input sensing during a first sensing frame. During a first period of the first sensing frame the processing system is configured to drive a first portion of the sensor electrodes with a sensing signal, drive a second portion of the sensor electrodes with a guarding signal, and drive a third portion of the sensor electrodes with a reference signal. The guarding signal and the sensing signal have at least one characteristic in common selected from the group consisting of amplitude, phase and frequency. The third portion of the sensor electrodes overlaps a first gate line of a display panel selected for updating during the first period.

In one example, a method comprises driving, during a first period of a first sensing frame, a first portion of sensor electrodes with a sensing signal, and driving, during the first period, a second portion of the sensor electrodes with a guarding signal. The guarding signal and the sensing signal have at least one characteristic in common selected from the group consisting of amplitude, phase and frequency. The method further comprises driving, during the first period, a third portion of the sensor electrodes with a reference signal. The third portion of the sensor electrodes overlaps a first gate line of a display panel selected for updating during the first period.

