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US 8,508,504 B2Granted
Methods of filtering noise in capacitive touch panel
AssigneeFocaltech Systems Co., Ltd.
InventorLiangHua Mo
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method of filtering noise in capacitive touch panel. By performing the correlation scan more than one time on the same channel, comparing the results of the correlation scans, and determining background noise by empty scans, the noise in capacitive touch panel can be filtered.
Claims15
A method comprising:
- (a) performing, while a touch panel is being touched, a series of scans of the touch panel at a single frequency, with each scan yielding a scan value;
- (b) comparing the scan values of the series to each other to find a set of scan values that are close to each other in that they differ from each other by less than a threshold;
- (c) if the set of close scan values are found, then setting a final scan value to an average of the close scan values;
- (d) repeating steps (a)-(c) at the same single frequency until
- (i) the set of close scan values are found within a single series, or
- (ii) steps (a)-(c) have been performed a predetermined number of times, whichever occurs first;
- and
- (e) if steps (a)-(d) have been performed the predetermined number times without the set of close scan values being found within a single series, then repeating steps (a)-(d) with a different frequency.
5 more elements
A touch panel configured to:
- (a) perform, while the touch panel is being touched, a series of scans of the touch panel at a single frequency, with each scan yielding a scan value;
- (b) compare the scan values of the series to each other to find a set of scan values that are close to each other in that they differ from each other by less than a threshold;
- (c) set a final scan value to an average of the close scan values if the set of close scan values are found;
- (d) repeat steps (a)-(c) at the same single frequency until
- (i) the set of close scan values are found within a single series, or
- (ii) steps (a)-(c) have been performed a predetermined number of times, whichever occurs first;
- and
- (e) if steps (a)-(d) have been performed the predetermined number times without the set of close scan values being found within a single series, then repeat steps (a)-(d) with a different frequency.
5 more elements
Dependencies are inferred from the claim text.