Self capacitive touch screen

Self Capacitive Touch Screen,During the detection, the electrode matrix of x-axis and y-axis is detected by the self capacitive Touch screen in turn. According to the change of capacitance before and after the touch, the x-axis coordinates and y-axis coordinates are determined respectively, and the touch point coordinates of the capacitance screen are obtained.

The coordinates of a single touch point in the x-axis and Y-axis directions are unique. When there are two touch points and the two touch points are not in the same x-axis or the same y-axis, four coordinates are formed in the x-axis and y-axis, but only two of them are real, and the other two are commonly known as "ghost points". Therefore, the self capacitive touch screen cannot realize real multi touch.

Capacitance is formed at the intersection of x-axis and y-axis electrode matrix of the mutual capacitance Touch Screen, that is, the x-axis and y-axis electrodes form the two poles of the capacitance respectively. When the finger touch the capacitance screen, the coupling capacitance is generated with the two electrodes near the touch point, resulting in the change of capacitance between the two electrodes.

During the detection, the y-axis electrode matrix sends out signals in time and sequence, and the x-axis electrode matrix receives signals at the same time, so as to obtain the capacitance values of all the cross points of the x-axis and y-axis electrode matrix. According to the change of the capacitance, the coordinates of each touch point can be calculated. Currently, it can support the touch of 10 fingers.