Method and device for sensing control point on capacitive-type panel
For sensing a control point on a capacitive-type panel, first and second voltage signals are respectively received through two sets of receiving lines selected from N receiving lines in response to first and second charge/discharge signals transmitted through two sets of transmitting lines selected from M transmitting lines, respectively, during a first time period. Third and fourth voltage signals are received through two sets of receiving lines selected from the N receiving lines in response to third and fourth charge/discharge signals respectively transmitted through the two sets of transmitting lines, respectively, during a second time period. A characteristic value is generated according to the first, second, third and fourth voltage signals. Repeat the steps to generate characteristic values for neighboring regions defined by different combinations of transmitting lines and receiving lines. Position information of control point(s) on the capacitive-type panel is estimated accordingly.
1. A method 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 method being executed by a sensing device and comprising steps of:
receiving a first voltage signal and a second voltage signal through two sets of signal receiving lines selected from the N signal receiving lines in response to a first charge/discharge signal and a second charge/discharge signal transmitted through two sets of signal transmitting lines selected from the M signal transmitting lines, respectively, during a first time period; receiving a third voltage signal and a fourth voltage signal through the two sets of signal receiving lines selected from the N signal receiving lines in response to a third charge/discharge signal and a fourth charge/discharge signal transmitted through the two sets of signal transmitting lines, respectively, during a second time period, wherein the first charge/discharge signal and the second charge/discharge signal are out of phase; and
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 step of generating 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 comprise:
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;
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
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.
2. The method for sensing a control point according to claim 1 , wherein the characteristic values include a combination of positive number, negative number and zero.
3. The method for sensing a control point according to claim 1 , wherein the characteristic values are configured as a characteristic value array, and the position information of the at least one control point on the capacitive-type panel is estimated according to a data pattern included in the characteristic value array.
4. The method for sensing a control point according to claim 3 , wherein the position information of the al least one control point is estimated by:
performing an operation on a 3*3 data array selected from the characteristic value array;
determining the position information of the control point and a first offset vector when the result of the operation meets a first condition;
determining the position information of the control point and a second offset vector when the result of the operation meets a second condition;
determining the position information of the control point and a third offset vector when the result of the operation meets a third condition; and
determining the position information of the control point and a fourth offset vector when the result of the operation meets a fourth condition.
5. 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.
6. The device for sensing a control point according to claim 5 , wherein the characteristic values include a combination of positive number, negative number and zero.
7. The device for sensing a control point according to claim 5 , wherein the voltage signal processor further executes the steps of:
configuring the characteristic values as a characteristic value array; and
estimating the position information of the at least one control point on the capacitive-type panel according to a data pattern included in the characteristic value array.
8. The device for sensing a control point according to claim 7 , wherein the voltage signal processor executes the steps of:
performing an operation on a 3*3 array selected from the characteristic value array;
determining the position information of the control point and a first offset vector when the result of the operation meets a first condition;
determining the position information of the control point and a second offset vector when the result of the operation meets a second condition;
determining the position information of the control point and a third offset vector when the result of the operation meets a third condition; and
determining the position information of the control point and a fourth offset vector when the result of the operation meets a fourth condition.