In PCAP technology, the touchscreen has conductive structures (ITO or metal mesh), which are on a basic substrate (PET film or glass). The electrodes are arranged in a diamond matrix shape and generate a capacitive field as soon as voltage is applied. If a conductive object, such as a finger, interrupts the field, this causes a change in capacitance between the two electrodes. The touch controller used can detect and reliably evaluate the point of contact or the change in position in the capacitive field.

 

 

 

 

SAW technology uses sound waves for communication. Piezoelectric transmitters create a frequency change of surface waves on the sensor. By touching, these waves are partially interrupted and allow the position of the finger to be accurately determined.

 

 

Resistive touchscreens consist of two conductive layers separated by spacers called spacer dots. As soon as a user touches the screen, the two layers come into contact and cause a current flow. Through the resulting electrical voltage difference, the touch controller recognises the position of the input.

 

 

 

 

 

 

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.