ACTIVE STYLUS DIFFERENTIAL SYNCHRONIZATION

摘要

A touch-sensing system is disclosed. The system includes a display device having a touch sensor with a matrix of row electrodes and column electrodes. Drive logic drives the row electrodes in a plurality of stylus sync sub-frames. In each, some row electrodes, referred to for that stylus sync sub-frame as sync-driven row electrodes, are driven by the drive logic with synchronization waveforms to synchronize the display device with an active stylus. For each stylus sync sub-frame, the sync-driven row electrodes are differentially driven by the drive logic, in the sense that a synchronization waveform used to drive one of the sync-driven row electrodes is different than a synchronization waveform used to drive another of the sync-driven row electrodes.

主权项

1. A touch sensing system, comprising:
a display device including a touch sensor having a matrix of row electrodes and column electrodes; drive logic coupled to the row electrodes and configured to drive the row electrodes during a plurality of touch-sensing frames, each of which includes a stylus sync sub-frame during which the drive logic drives at least some of the row electrodes, referred to for that stylus sync sub-frame as sync-driven row electrodes, with synchronization waveforms that are communicated electrostatically to cause synchronization of the display device with an active stylus; and where for each of the stylus sync sub-frames, the drive logic is configured to differentially drive the sync-driven row electrodes of such stylus sync sub-frame, such that a first synchronization waveform used to drive one of the sync-driven row electrodes is different than a second synchronization waveform used to drive another of the sync-driven row electrodes.