Projected Capacitive (PCAP)
In PCAP technology, the conductive structures (ITO or metal grid) are located on a base substrate (PET film or glass). The electrodes are arranged in the form of a diamond matrix and generate a capacitive field. If, for example, a finger interrupts the field, this leads to a change in capacitance between the two electrodes. The touch controller can detect the point of contact in the capacitive field and evaluate it reliably.
Resistive Touch (RTP)
Resistive touchscreens consist of two conductive layers separated by spacers called spacer dots. As soon as a user touches the screen with a finger, the two layers come into contact and generate a current flow. Through the resulting electrical voltage difference, the touch controller recognises the position of the input.
Surface Acoustic Wave (SAW)
SAW technology uses sound waves for communication. With this technology, piezoelectric transmitters create a frequency change of surface waves on the sensor. When touched, these waves are partially interrupted and allow the position of the finger to be accurately determined.
Infrared
Infrared touch technology is based on the interruption of an infrared light grid. The IR sensor contains a number of infrared LEDs. Each of these infrared LEDs has a corresponding phototransistor on the opposite side, creating a grid of invisible infrared light beams. By interrupting the infrared light beams (e.g. by a finger or pen), the input can be precisely determined.
