| 摘要 |
Capacitive touch screens are commonly used as pointing sensors to provide a man-machine interface for computer driven systems. These screens commonly suffer from a 'handshadow effect' error associated with the undesired proximity detection of a portion of a relatively large object (such as a hand) comprising or associated with a smaller pointing portion or object (such as finger tip), where the smaller pointing portion is closer to a touch sensing surface than is the rest of the object. This error can be removed from an indicated touch position by using a history profile of data derived from the screen both just prior to its being touched, and just after the touch is detected. The earlier data in the historical sequence provide a measure dominated by the handshadow, while the data taken at or after the time of touch are more strongly influenced by the position of the finger tip. Thus, a variety of predictive or extrapolation methods can be used to either correct the raw signals occurring during touch, or processed to determine a new final value of the touch. <IMAGE>
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