Patent ID: 8599168
Filing Date: 2013-12-03
Classification: G06F

Abstract:
1. A touch detection method for capacitive touch panels comprising the steps of: (a) scanning rows and columns of a capacitive matrix of a touch panel respectively, (b) obtaining a capacitance differential value by one of the steps of: synchronously scanning two rows of the capacitive matrix at the same time to obtain the capacitance differential value between the two rows; synchronously scanning two columns of the capacitive matrix at the same time to obtain the capacitance differential value between the two columns; scanning one row of the capacitive matrix to obtain the capacitance differential value between the row and a reference capacitance; and scanning one column of the capacitive matrix to obtain the capacitance differential value between the column and a reference capacitance; (c) processing the obtained capacitance differential value; and (d) determining whether there is a touch on the touch panel in response to the processed capacitance differential value; wherein the step (b) further comprises steps of charging, charge sharing, charge difference calculation, sampling and amplification, wherein in said charging step, a first and a second capacitors are charged by a power supply; in said charge sharing step, the charges charged to the first and the second capacitors are shared by two intermediate capacitors that are respectively connected with the first and the second capacitors in parallel; in said charge difference calculation step, the two intermediate capacitors, when disconnected with the first and the second capacitors, are reversely connected to reserve residual charges; and in said sampling and said amplification steps, the value of the residual charges is converted to a directly proportional voltage value and output, wherein the first capacitor is the touch capacitor of a row or column, and the second capacitor is the touch capacitor of another row or column or a reference capacitor with the defined value.