PHASE-TAGGED CAPACITANCE SENSING CIRCUIT AND ELECTRONIC DEVICE USING THE SAME
First Claim
1. An electronic device comprising:
- a touch panel comprising a plurality of sensing conductors;
a driving circuit for sending a driving signal which is modulated with a predetermined period and superposing phase information on it; and
a sensing circuit for accepting sensing signal and determining a sensing value based on the phase information and the same period of the driving signal.
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Accused Products
Abstract
An electronic device includes a touch panel, a driving circuit, and a sensing circuit. The driving circuit generates a driving signal, and superposes phase information on the driving signal. The touch panel includes multiple crossing conductors, for providing a sensing signal in response to a contact of an object on one of the sensing conductors and to a driving signal applied on the sensing element. The sensing circuit includes a signal extractor and a tag detector. The signal extractor generates a demodulation signal based on the period of the driving signal, width of the phase information, and for demodulating the sensing signal by using the demodulation signal to determine a sensing value. The tag detector enables the signal extractor as soon as a magnitude of the sensing signal is over a predetermined threshold. The signal demodulates the sensing signal by using a demodulation signal whose period is the same as the driving signal to determine the sensing value. The present electronic device can determine a touch position by processing of analog signal using the demodulation signal without phase compensation.
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Citations
19 Claims
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1. An electronic device comprising:
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a touch panel comprising a plurality of sensing conductors; a driving circuit for sending a driving signal which is modulated with a predetermined period and superposing phase information on it; and a sensing circuit for accepting sensing signal and determining a sensing value based on the phase information and the same period of the driving signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of processing information on an electronic device, the electronic device comprising a touch panel comprising a plurality of sensing conductors, the method comprising:
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providing a driving signal with a period; superposing phase information on the driving signal, and driving the driving signal to the plurality of conductors of the touch panel; generating a sensing signal in response to a contact of an object on one of the sensing conductor; performing peak detection to detect the phase information tagging in the sensing signal, and generating the start point for demodulation; and generating a demodulation signal based on the phase information and the period of driving signal, and demodulating the sensing signal by using the demodulation signal to determine a touch position of the touch panel. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification