Object detection in touch systems

摘要

A signal processor implements a technique for detecting objects on a panel which transmits signals inside the panel such that the objects are allowed to interact with (e.g. attenuate) the signals by contact with a touch surface of the panel. The signal processor operates to define cells that have a given location on the touch surface and are associated with a respective set of intersecting paths for the signals across the touch surface. The signal processor operates to obtain (70) an output signal from a signal detection arrangement that measures a signal property for each path; process (71) the output signal to obtain an interaction value for each path; and determine (73-75) a touch status of a selected cell among the cells by analyzing the distribution of interaction values for at least part of the intersecting paths. The touch status indicates presence or absence of one of the objects in the selected cell.

主权项

1. A method for detecting objects on a panel having a touch surface, said method comprising:
defining a plurality of reconstruction cells with respect to the touch surface, each of the plurality of reconstruction cells corresponding to a region on the touch surface, the region being intersected by a respective set of signal transmission paths, the signal transmission paths defined by signals transmitted across the touch surface from a plurality of emitters to a plurality of detectors, and the signal transmission paths extending across the touch surface of the panel between pairs of the plurality of emitters and the plurality of detectors; obtaining an output signal based on a signal property measurement for each signal transmission path; processing the output signal to obtain an interaction value for each signal transmission path; and determining a touch status of a selected reconstruction cell among the plurality of reconstruction cells by analyzing a distribution of interaction values for signal transmission paths intersecting the region on the touch surface corresponding to the selected reconstruction cell, the touch status indicating presence or absence of at least one of the objects in the region corresponding to the selected reconstruction cell; wherein the determining a touch status includes
identifying, based on the interaction values, at least one of interacting and non-interacting signal transmission paths among the signal transmission paths intersecting the region corresponding to the selected reconstruction cell; anddetermining the touch status based on a ratio given by a count of said at least one of interacting and non-interacting signal transmission paths.