Method and device for sensing control point on capacitive-type panel

A device for sensing a control point on a capacitive-type panel, where a conductive object approaches or contacts, the capacitive-type panel including M signal transmitting lines and N signal receiving lines defining M*N neighboring regions, the device comprising:

• a charge/discharge signal generator electrically connected to the M signal transmitting lines, the charge/discharge signal generator inputting a first charge/discharge signal and a second charge/discharge signal respectively to two sets of signal transmitting lines selected from the M signal transmitting lines during a first time period, and inputting a third charge/discharge signal and a fourth charge/discharge signal respectively to the two sets of signal transmitting lines during a second time period, wherein the first charge/discharge signal and the second charge/discharge signal are out of phase;
• and
• a voltage signal processor electrically connected to the N signal receiving lines, the voltage signal processor receiving a first voltage signal and a second voltage signal respectively from two sets of signal receiving lines selected from the N signal receiving lines during the first time period, receiving a third voltage signal and a fourth voltage signal respectively from two sets of signal receiving lines selected from the N signal receiving lines during the second time period, generating a characteristic value for a neighboring region defined by the two sets of signal transmitting lines and the two sets of signal receiving lines according to the first voltage signal, the second voltage signal, the third voltage signal and the fourth voltage signal, wherein
• the above three steps are repetitively performed so as to generate a plurality of characteristic values for a plurality of neighboring regions defined by different combinations of signal transmitting lines and signal receiving lines, and position information of at least one control point on the capacitive-type panel is estimated according to the characteristic values,
• wherein the first charge/discharge signal is a charge signal rising from a low voltage to a high voltage, the second charge/discharge signal is a discharge signal falling from a high voltage to a low voltage, the third charge/discharge signal is a discharge signal falling from a high voltage to a low voltage, and the fourth charge/discharge signal is a charge signal rising from a low voltage to a high voltage;
• and the voltage signal processor generates the characteristic value for the neighboring region defined by the two sets of signal transmitting lines and the two sets of signal receiving lines according to the first voltage signal, the second voltage signal, the third voltage signal and the fourth voltage signal by executing the steps of:
• the voltage signal processor generating a first voltage difference value or a function value equivalent to the first voltage difference value by comparing the first voltage signal and the second voltage signal;
• the voltage signal processor generating a second voltage difference value or a function value equivalent to the second voltage difference value by comparing the third voltage signal and the fourth voltage signal;
• and
• the voltage signal processor generating the characteristic value by subtracting the second voltage difference value or the function value equivalent to the second voltage difference from the first voltage difference value or the function value equivalent to the first voltage difference.