Capacitive sensor coupling correction
First Claim
1. A method of normalizing the effects of parasitic coupling in a touch sensor panel, the method comprising:
- stimulating a drive structure with at least one drive signal, the drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements;
detecting at least one sense signal at one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines;
correcting the magnitude of the at least one sense signal by utilizing a set of correctional coefficients, wherein the set of correctional coefficients is based at least in part upon a set of previously detected sense signals to provide at least one corrected sense signal; and
determining a touch position based on the at least one drive signal and the at least one corrected sense signal; and
wherein the set of previously sensed signals is determined by;
positioning a conductive element upon the touch sensor panel;
stimulating a plurality of drive structures; and
sensing a signal for each drive structure stimulated.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus for normalizing the effects of the changes to the parasitic capacitive coupling that can occur in touch sensor panels so as to reduce or eliminate the appearance of erroneous touch events. In some embodiments, at some time prior to regular device use (e.g. during factory calibration), a conductive sheet is initially positioned so as to entirely cover a touch surface of a touch sensor panel. A set of sensed signals may be determined upon driving the drive lines and sensing the sense lines of the panel. Correctional coefficients may then be calculated based in part upon the difference between a sensed signal and an expected signal. The correctional coefficients may then be stored in the device and used to determine signal corrections for a set of measured signals during normal operation.
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Citations
42 Claims
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1. A method of normalizing the effects of parasitic coupling in a touch sensor panel, the method comprising:
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stimulating a drive structure with at least one drive signal, the drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements; detecting at least one sense signal at one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines; correcting the magnitude of the at least one sense signal by utilizing a set of correctional coefficients, wherein the set of correctional coefficients is based at least in part upon a set of previously detected sense signals to provide at least one corrected sense signal; and determining a touch position based on the at least one drive signal and the at least one corrected sense signal; and wherein the set of previously sensed signals is determined by; positioning a conductive element upon the touch sensor panel; stimulating a plurality of drive structures; and sensing a signal for each drive structure stimulated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 26, 27)
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14. A touch sensor apparatus having a touch sensor panel, the apparatus adapted to normalize the effects of parasitic coupling in the touch sensor panel, the apparatus comprising:
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a drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines; a first module adapted to stimulate a set of drive lines of the plurality of drive lines; a second module adapted to sense at least one sense signal on at least one of the plurality of sense lines for each drive line stimulated; and a third module adapted to correct the magnitude of the at least one sense signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signals; and wherein the set of sensed signals is determined after positioning a conductive element proximate to a sensing portion of the touch sensor panel. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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23. A mobile phone comprising a touch sensor panel, the mobile phone adapted to normalize the effects of parasitic coupling, the mobile phone comprising:
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a drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines; a first module adapted to stimulate a set of drive lines of the plurality of drive lines; a second module adapted to sense at least one sense signal on at least one of the plurality of sense lines for each drive lines stimulated; and a third module adapted to correct the magnitude of a signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signal; and wherein the set of sensed signals is determined after positioning a conductive element proximate to a sensing portion of the touch sensor panel.
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24. A digital media player comprising a touch sensor panel, the digital media player adapted to normalize the effects of parasitic coupling, the digital media player comprising:
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a drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines; a first module adapted to stimulate a set of drive lines of the plurality of drive lines; a second module adapted to sense at least one sense signal on at least one of the plurality of sense lines for each drive lines stimulated; and a third module adapted to correct the magnitude of a signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signals; and wherein the set of sensed signals is determined after positioning a conductive element proximate to a sensing portion of the touch sensor panel.
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25. A personal computer comprising a touch sensor panel, the personal computer adapted to normalize the effects of parasitic coupling, the personal computer comprising:
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a drive structure comprises one of a plurality of drive lines on the touch sensor panel, each drive line comprising a plurality of drive line conductive elements, the drive line conductive elements being coupled together by a plurality of connecting traces, the connecting traces extend parallel to a plurality of sense lines and disposed between the plurality of sense lines and the plurality of drive line conductive elements one or more of the plurality of sense lines on the touch sensor panel, each sense line comprising at least one sense line conductive element, the plurality of sense lines being disposed transverse to the plurality of drive lines; a first module adapted to stimulate a set of drive lines of the plurality of drive lines; a second module adapted to sense at least one sense signal on at least one of the plurality of sense lines for each drive structure stimulated; and a third module adapted to correct the magnitude of the at least one sense signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signals; and wherein the set of sensed signals is determined after positioning a conductive element proximate to a sensing portion of the touch sensor panel.
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28. A method of normalizing the effects of parasitic coupling in a touch sensor panel, the method comprising:
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stimulating a drive structure; detecting a signal at a sense structure in response to stimulating the drive structure; and correcting the signal by utilizing a set of correctional coefficients, wherein the set of correctional coefficients is based at least in part upon a set of previously sensed signals, wherein the set of previously sensed signals is determined by a process comprising; completely covering the touch sensor panel with a conductive element; stimulating a plurality of drive structures; and sensing a signal for each drive structure stimulated. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A method of normalizing the effects of parasitic coupling in a touch sensor panel, the method comprising:
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stimulating a drive structure; detecting a signal at a sense structure in response to stimulating the drive structure; and correcting the signal by utilizing a set of correctional coefficients, wherein the set of correctional coefficients is based at least in part upon a set of previously sensed signals wherein the set of previously sensed signals is determined by a process comprising; completely covering a conductive element upon the touch sensor panel; stimulating a plurality of drive structures; and sensing a signal for each drive structure stimulated.
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41. An apparatus adapted to normalize the effects of parasitic coupling, the apparatus comprising:
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a memory unit adapted to store data; a first module adapted to stimulate a set of drive structures; a second module adapted to sense a signal for each drive structure stimulated; and a third module adapted to correct a signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signals; wherein; the set of correctional coefficients is adapted to correct for changes to parasitic capacitive coupling associated with one or more connecting traces coupled to the set of drive structures; and the expected signal is set to be equal to a first sensed signal; and wherein the first sensed signal is obtained from a drive structure having a shorter connecting trace than any other drive structure of the set of drive structures.
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42. An apparatus adapted to normalize the effects of parasitic coupling, the apparatus comprising:
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a memory unit adapted to store data; a first module adapted to stimulate a set of drive structures; a second module adapted to sense a signal for each drive structure stimulated; and a third module adapted to correct a signal by utilizing a set of correctional coefficients, wherein at least one correctional coefficient depends upon an expected signal and a set of sensed signals; wherein; the set of correctional coefficients is adapted to correct for changes to parasitic capacitive coupling associated with one or more metal traces coupled to the set of drive structures; the expected signal is derived from a function adapted to fit a plurality of sensed signals from the set of sensed signals; and the function comprises a third-order fit polynomial function.
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Specification