How does a multitouch screen work

- Dec 20, 2018 -

20181218143319_9359

Operation steps of multi-point capacitive screen. During operation, the controller supplies power to the driving line successively, thus forming a specific electric field between each node and the conductor.Then the capacitance variation between the electrodes was measured by serial scanning of the sensing lines to achieve multi-point positioning.When the finger or the touch media are close together, the controller can quickly detect the change of capacitance between the touch node and the wire, and then confirm the position of the touch.The shaft is driven by a set of AC signals, and the response across the touch screen is measured by electrodes on other shafts.Users call this "crosscutting" or projective sensing.The sensor is coated with ITO patterns of X and Y axes. When the finger touches the surface of the touch screen, the capacitance value below the touch point increases according to the distance of the touch point. Continuous scanning on the sensor detects the change of the capacitance value, and the control chip calculates the contact point and returns it to the processor