Capacitive sensing device and method that reduces influence from transient environmental changes
First Claim
1. A sensing method for a capacitive sensing device, comprising:
- detecting present measured values of a plurality of reference points selected from a plurality of sensing points, wherein the sensing points are defined by electrodes intersected with one another and the sensing point are configured to form an array, wherein the sensing points correspond to a plurality of respective reference measured values which is currently used, and wherein the reference points are located at the periphery of the array;
generating a present difference value according to the present measured values of the reference points and the reference measured values which are currently used;
comparing the present difference value with a second threshold;
executing a procedure for refreshing background noise to refresh the reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold;
detecting a plurality of present measured values of the sensing points;
generating a plurality of position signals of the sensing points according to the present measured values of the sensing points and the reference measured values which are currently used; and
adjusting a detecting frequency of the present measured values of the reference points according to comparison of the present difference value and a first threshold.
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Abstract
A capacitive sensing method includes detecting present measured values of plural reference points from plural sensing points; generating a present difference value according to the present measured values of the reference points and current reference measured values; comparing the present difference value with a threshold; detecting present measured values of the sensing points; generating plural position signals of the sensing points according to the present measured values of the sensing points and the current reference measured values; and controlling the output of the position signals according to a reference signal. When the present difference value is greater than the threshold, executing a procedure for refreshing background noise to refresh the current reference measured values. The sensing points are defined by intersected electrodes, configured to form an array, and correspond to the current reference measured values. The reference points are located at the periphery of the array.
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Citations
19 Claims
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1. A sensing method for a capacitive sensing device, comprising:
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detecting present measured values of a plurality of reference points selected from a plurality of sensing points, wherein the sensing points are defined by electrodes intersected with one another and the sensing point are configured to form an array, wherein the sensing points correspond to a plurality of respective reference measured values which is currently used, and wherein the reference points are located at the periphery of the array; generating a present difference value according to the present measured values of the reference points and the reference measured values which are currently used; comparing the present difference value with a second threshold; executing a procedure for refreshing background noise to refresh the reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold; detecting a plurality of present measured values of the sensing points; generating a plurality of position signals of the sensing points according to the present measured values of the sensing points and the reference measured values which are currently used; and adjusting a detecting frequency of the present measured values of the reference points according to comparison of the present difference value and a first threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A capacitive sensing device, comprising:
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a storage unit, storing a reference signal and a plurality of sets of reference measured values corresponding to respective present measured values, wherein one set of reference measured values is set to be used currently; a signal sensor, comprising a plurality of first electrodes and a plurality of second electrodes, wherein the first electrodes are intersected with the second electrodes, and the first electrodes and the second electrodes define a plurality of sensing points configured as an array, and wherein a plurality of reference measured values selected from each set of reference measured values corresponds to the respective sensing points; a driving/sensing unit, connected to the first electrodes and the second electrodes for detecting present measured values of the sensing points; a position sensing unit, connected to the driving/sensing unit and the storage unit, generating a present difference value according to the reference measured values which are currently used and present measured values of a plurality of reference points selected from the sensing points, and generating a plurality of position signals according to the present measured values of the sensing points and the set of reference measured values which are currently used, wherein the reference points are located at the periphery of the array; and a control unit, connected to the storage unit, the driving/sensing unit and the position sensing unit, for comparing the present difference value with a second threshold, wherein the control unit executes a procedure for refreshing background noise to refresh the set of reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold, wherein the control unit adjusts a detecting frequency of the driving/sensing unit applied to the present measured values of the reference points according to comparison of the present difference value and a first threshold. - View Dependent Claims (13, 14, 15)
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16. A sensing method for a capacitive sensing device, comprising:
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detecting present measured values of a plurality of reference points selected from a plurality of sensing points, wherein the sensing points are defined by electrodes intersected with one another and the sensing point are configured to form an array, wherein the sensing points correspond to a plurality of respective reference measured values which is currently used, wherein the reference points are located at the periphery of the array, and wherein the step of detecting present measured values of a plurality of reference points selected from a plurality of sensing points comprises; driving at least one electrode located at a first side of the array and at least one electrode located at a second side of the array from the electrodes, wherein the first side is opposite to the second side; and measuring at least one electrode located at a third side of the array and at least one electrode located at a fourth side of the array from the electrodes to obtain the present measured values of the reference points, wherein the third side is opposite to the fourth side; generating a present difference value according to the present measured values of the reference points and the reference measured values which are currently used; comparing the present difference value with a second threshold; executing a procedure for refreshing background noise to refresh the reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold; detecting a plurality of present measured values of the sensing points; and
generating a plurality of position signals of the sensing points according to the present measured values of the sensing points and the reference measured values which are currently used.
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17. A sensing method for a capacitive sensing device, comprising:
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detecting present measured values of a plurality of reference points selected from a plurality of sensing points, wherein the sensing points are defined by electrodes intersected with one another and the sensing point are configured to form an array, wherein the sensing points correspond to a plurality of respective reference measured values which is currently used, wherein the reference points are located at the periphery of the array wherein the electrodes comprise a plurality of first electrodes and a plurality of second electrodes intersected with the first electrodes, and wherein the step of detecting present measured values of a plurality of reference points selected from a plurality of sensing points comprises; driving at least one of the first electrodes located at a first side of the array and at least one of the first electrodes located at a second side of the array, wherein the first side is opposite to the second side; and measuring a number of the second electrodes to obtain the present measured values of the reference points, wherein any two of the measured second electrodes are spaced by at least one unmeasured second electrode; generating a present difference value according to the present measured values of the reference points and the reference measured values which are currently used; comparing the present difference value with a second threshold; executing a procedure for refreshing background noise to refresh the reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold; detecting a plurality of present measured values of the sensing points; generating a plurality of position signals of the sensing points according to the present measured values of the sensing points and the reference measured values which are currently used.
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18. A sensing method for a capacitive sensing device, comprising:
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detecting present measured values of a plurality of reference points selected from a plurality of sensing points, wherein the sensing points are defined by electrodes intersected with one another and the sensing point are configured to form an array, wherein the sensing points correspond to a plurality of respective reference measured values which is currently used, wherein the reference points are located at the periphery of the array, wherein the electrodes comprise a plurality of first electrodes and a plurality of second electrodes intersected with the first electrodes, and wherein the step of detecting present measured values of a plurality of reference points selected from a plurality of sensing points comprises; driving at least one of the first electrodes located at a first side of the array and at least one of the first electrodes located at a second side of the array, wherein the first side is opposite to the second side; measuring at least one of the second electrodes to obtain present measured values of some of the reference points; driving at least one of the second electrodes located at a third side of the array and a least one of the second electrodes located at a fourth side, wherein the third side is opposite to the fourth side; and measuring at least one of the first electrodes to obtain present measured values of the rest reference points; generating a present difference value according to the present measured values of the reference points and the reference measured values which are currently used; comparing the present difference value with a second threshold; executing a procedure for refreshing background noise to refresh the reference measured values which are currently used based on the present difference value when the present difference value is greater than the second threshold; detecting a plurality of present measured values of the sensing points; and
generating a plurality of position signals of the sensing points according to the present measured values of the sensing points and the reference measured values which are currently used. - View Dependent Claims (19)
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Specification