From the earlier resistive touch screen to the popular capacitive touch screen, touch screen is advancing by leaps and bounds in the development of mobile phones. What is the principle that enables the capacitive touch screens to sense our touch and react
Details
From the earlier resistive touch screen to the popular capacitive touch screen, touch screen is advancing by leaps and bounds in the development of mobile phones. What is the principle that enables the capacitive touch screens to sense our touch and react accordingly?
The structure of the capacitive touchscreen is mainly coated with a transparent thin film conductor layer on the glass screen, and a protective glass is added to the conductor layer. the double glass design can completely protect the conductor layer and the inductor.
When the finger touches the metal layer, due to the human electric field, the user and the surface of the capacitive touch screen form a low voltage. For high-frequency current, the capacitance is a direct conductor, so the finger absorbs a small current from the contact point. The current flows from the electrodes on the four corners of the touch screen, and the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position of the touch point by accurately calculating the proportion of the four currents.
