TOUCH SENSOR
First Claim
1. A touch sensor comprising:
- a substrate;
a plurality of touch keys disposed in a plurality of rows and columns on the substrate and each comprising a first electrode and a second electrode surrounding the first electrode;
a plurality of drive lines disposed on the substrate and each connecting the second electrodes of the plurality of touch keys disposed in a first direction corresponding to each of the plurality of rows;
a plurality of sensor lines disposed on the substrate and each connecting the first electrodes of the plurality of touch keys disposed in a second direction corresponding to each of the plurality of columns;
a clock source applying a clock signal to the plurality of drive lines in sequence;
a selection circuit selecting the plurality of sensor lines in sequence during the application of the clock signal to one of the plurality of drive lines from the clock source; and
a detection circuit detecting a change of a capacitance of an electrostatic capacitor formed between the first electrode and the second electrode of the touch key connected to the sensor line selected by the selection circuit.
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Accused Products
Abstract
The invention provides a touch sensor in which the numbers of channels and wires are decreased simultaneously and a simultaneous touch operation of a plurality of touch keys is realized. A keyboard includes 36 pieces of touch keys disposed in 6 rows and 6 columns, drive lines, and sensor lines on an insulation substrate. The touch key includes a center electrode disposed on the insulation substrate and an annular electrode disposed surrounding this center electrode. A sensor circuit includes a selection circuit and an electric charge amplifier. The electric charge amplifier detects the amount of change of a capacitance of an electrostatic capacitor formed between the center electrode and the annular electrode of the touch key connected to one sensor line selected by the selection circuit.
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Citations
5 Claims
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1. A touch sensor comprising:
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a substrate; a plurality of touch keys disposed in a plurality of rows and columns on the substrate and each comprising a first electrode and a second electrode surrounding the first electrode; a plurality of drive lines disposed on the substrate and each connecting the second electrodes of the plurality of touch keys disposed in a first direction corresponding to each of the plurality of rows; a plurality of sensor lines disposed on the substrate and each connecting the first electrodes of the plurality of touch keys disposed in a second direction corresponding to each of the plurality of columns; a clock source applying a clock signal to the plurality of drive lines in sequence; a selection circuit selecting the plurality of sensor lines in sequence during the application of the clock signal to one of the plurality of drive lines from the clock source; and a detection circuit detecting a change of a capacitance of an electrostatic capacitor formed between the first electrode and the second electrode of the touch key connected to the sensor line selected by the selection circuit. - View Dependent Claims (2, 3, 4, 5)
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Specification