| 摘要 |
A touch sensitive apparatus (10) includes a touch plate ( 12) to which several pickup sensors (16, 104) and at least one excitation transducer (18, 106) are coupled. Each of the sensors (16, 104) is configured to sense bending waves in the touch plate (12), and the excitation transducer (18, 108) is configured to induce bending wave in the touch plate ( 12).The apparatus (10) may further include active buffer circuits (30, 106), wherein each of the active buffer circuits (30, 106) is coupled to one of the sensors ( 16, 104). A controller (120) is coupled to the sensors (16, 104) via the active buffer circuits (30, 106) and to the excitation transducer (18, 108) via a non- actively buffered connection. The controller (120) is configured to compute a location of a contact on the touch plate (12) responsive to sense signals received from the sensors (16, 104). The apparatus (10) may be used to perform a variety of calibrations, including touch plate and sensor calibrations. Changes in touch sensing apparatus calibration and performance may be detected and tracked over time. |
