Capacitive touch system and method of operating a capacitive touch system
First Claim
1. A capacitive touch system, comprising:
- a touch panel comprising a plurality of scan areas, wherein each scan area of the plurality of scan areas comprises a plurality of sensing units;
a detection circuit coupled to the touch panel for utilizing the Wheatstone bridge principle to transmit driving signals to the plurality of scan areas in turn to generate a detection result corresponding to each scan area of the plurality of scan areas according to a predetermined timing, the detection circuit comprising;
a first switch circuit for connecting a first sensing line corresponding to a scan area to a first terminal of a power source;
a comparator;
a second switch circuit for connecting two adjacent second sensing lines corresponding to the scan area to the comparator;
a variable capacitor having a first terminal coupled to a second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to a second terminal of the power source; and
a fixed capacitor having a first terminal coupled to another second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to the second terminal of the power source; and
a microprocessor for generating the predetermined timing to the detection circuit, and determining whether each scan area is touched according to a detection result corresponding to each scan area.
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Accused Products
Abstract
A capacitive touch system includes a touch panel, a detection circuit, and a microprocessor. The touch panel includes a plurality of scan areas. Each scan area of the plurality of scan areas includes a plurality of sensing units. The detection circuit is coupled to the touch panel for utilizing the Wheatstone bridge principle to transmit driving signals to the plurality of scan areas in turn to generate a detection result corresponding to each scan area of the plurality of scan areas according to a predetermined timing. The microprocessor is used for generating the predetermined timing to the detection circuit, and determining whether each area is touched according to a detection result corresponding to each scan area.
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Citations
15 Claims
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1. A capacitive touch system, comprising:
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a touch panel comprising a plurality of scan areas, wherein each scan area of the plurality of scan areas comprises a plurality of sensing units; a detection circuit coupled to the touch panel for utilizing the Wheatstone bridge principle to transmit driving signals to the plurality of scan areas in turn to generate a detection result corresponding to each scan area of the plurality of scan areas according to a predetermined timing, the detection circuit comprising; a first switch circuit for connecting a first sensing line corresponding to a scan area to a first terminal of a power source; a comparator; a second switch circuit for connecting two adjacent second sensing lines corresponding to the scan area to the comparator; a variable capacitor having a first terminal coupled to a second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to a second terminal of the power source; and a fixed capacitor having a first terminal coupled to another second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to the second terminal of the power source; and a microprocessor for generating the predetermined timing to the detection circuit, and determining whether each scan area is touched according to a detection result corresponding to each scan area. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of operating a capacitive touch system, the capacitive touch system comprising a touch panel, a detection circuit, and a microprocessor, the touch panel comprising a plurality of scan areas, and each scan area of the plurality of scan areas comprising a plurality of sensing units, the method comprising:
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the microprocessor generating a first predetermined timing; the detection circuit utilizing the Wheatstone bridge principle to transmit driving signals to the plurality of scan areas in turn to generate a detection result corresponding to each scan area of the plurality of scan areas according to the first predetermined timing, wherein the detection circuit comprises; a first switch circuit for connecting a first sensing line corresponding to a scan area to a first terminal of a power source; a comparator; a second switch circuit for connecting two adjacent second sensing lines corresponding to the scan area to the comparator; a variable capacitor having a first terminal coupled to a second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to a second terminal of the power source; and a fixed capacitor having a first terminal coupled to another second sensing line of the two adjacent second sensing lines and the comparator, and a second terminal coupled to the second terminal of the power source; and the microprocessor executing a corresponding operation according to a detection result corresponding to each scan area. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification