Touch screens can be divided into four types: resistive type, capacitive sensing type, infrared type and surface acoustic wave type according to the medium used and the working principle. The touch screen is gradually upgraded and developed from low-end to high-end: from resistive type and infrared type to capacitive sensing type and surface acoustic wave type.
Capacitive touch
The capacitive
touch screen coats a transparent metal layer on a glass plate as a conductor. There are long and narrow electrodes on the four sides of the touch screen to form a low-voltage AC electric field in the conductor. When a finger touches the metal layer, when a conductive object touches it, it will change the capacitance of the contact. The current from the four-side electrodes will flow to the contact. The controller can determine the position of the touch through the current. Since the capacitance changes with temperature, humidity or grounding conditions, its stability is poor and drift phenomenon tends to occur.
Resistive touch
The resistive
touch screen is basically a structure of thin film and glass. When touched, the ITO on the lower layer of the film will touch the ITO on the upper layer of the glass, and a message will be sent through the sensor, and then sent from the controller to the computer. Transform to the X and Y values on the screen, and complete the click action, and present it on the screen.