Structure and Detection Mechanism of
Projected Capacitive Touch Screen
X-electrodes are coated on one glass plate while Y-electrodes are coated on the other glass plate. The electrodes on the two glass plates are facing each other.
Because the human body is conductive, when a finger comes close to the electrodes, a capacitive coupling will occur between the finger and electrodes.
The capacitance value will be higher at the touched point where the capacitive coupling occurred. The touch screen detects a touched point by recognizing the point of high capacitance value.
The X-electrodes and Y-electrodes are placed in matrix. If the point ● is touched, the capacitance value on (X3-X4、Y4-Y5) electrodes will change, then the touched point will be detected.