TOUCH PANEL
First Claim
1. A touch panel, comprising:
- a plurality of panel capacitors, wherein a second terminal of each panel capacitor is electrically connected to one another and, when one of the panel capacitors is selected as an object capacitor, a first terminal of each panel capacitor other than the first terminal of the object capacitor is coupled to a ground terminal;
a first switching unit, switching the first terminal of the object capacitor to a first voltage, a floating state, and a second voltage during a first time interval, a second time interval, and a third time interval respectively;
a second switching unit, coupled to the second terminals of the panel capacitors, conducting the second terminals of the panel capacitors to a basic voltage during the first time interval, switching the second terminals of the panel capacitors from the floating state to a signal detecting terminal during the second time interval, and conducting the second terminals of the panel capacitors to the signal detecting terminal persistently during the third time interval;
a first charging unit, coupled to the signal detecting terminal and referring to a charging control signal to determine whether a first charging current is to be provided during the third time interval;
a control unit, coupled to the signal detecting terminal and integrating a signal from the signal detecting terminal to generate an integrated voltage, and comparing the integrated voltage and a reference voltage to output a comparison signal and the charging control signal when the control unit is triggered; and
a counter, counting the comparison signal to generate a count value, wherein the touch panel identifies a variation in a capacitance value of the object capacitor by using the count value.
1 Assignment
0 Petitions
Accused Products
Abstract
A touch panel including a plurality of panel capacitors, a first switching unit, a second switching unit, a first charging unit, a control unit and a counter is provided. Each of the panel capacitors is sequentially selected as an object capacitor. The first switching unit and the second switching unit switch the voltages received by the two terminals of the object capacitor. The control unit controls a first charging current provided by the first charging unit according to the variation in the terminal voltages of the object capacitor, and generates a comparison signal accordingly. The counter counts the comparison signal and the touch panel identifies the variation in the capacitance value of the object capacitor by using a count value generated by the counter.
14 Citations
10 Claims
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1. A touch panel, comprising:
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a plurality of panel capacitors, wherein a second terminal of each panel capacitor is electrically connected to one another and, when one of the panel capacitors is selected as an object capacitor, a first terminal of each panel capacitor other than the first terminal of the object capacitor is coupled to a ground terminal; a first switching unit, switching the first terminal of the object capacitor to a first voltage, a floating state, and a second voltage during a first time interval, a second time interval, and a third time interval respectively; a second switching unit, coupled to the second terminals of the panel capacitors, conducting the second terminals of the panel capacitors to a basic voltage during the first time interval, switching the second terminals of the panel capacitors from the floating state to a signal detecting terminal during the second time interval, and conducting the second terminals of the panel capacitors to the signal detecting terminal persistently during the third time interval; a first charging unit, coupled to the signal detecting terminal and referring to a charging control signal to determine whether a first charging current is to be provided during the third time interval; a control unit, coupled to the signal detecting terminal and integrating a signal from the signal detecting terminal to generate an integrated voltage, and comparing the integrated voltage and a reference voltage to output a comparison signal and the charging control signal when the control unit is triggered; and a counter, counting the comparison signal to generate a count value, wherein the touch panel identifies a variation in a capacitance value of the object capacitor by using the count value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification