It is a method that utilizes the property of blocking infrared rays when they hit obstacles using the straightness of infrared rays.
It has a structure to make a matrix by arranging a large number of lights around the panel so that the light emitting element (LED) and the light receiving element (photo sensor) face each other. When a finger touches the screen and blocks the light, the output of the blocked part is lowered, and this is the principle of determining the input coordinates by obtaining the X and Y coordinates of the part. A finger-only pen can be used as the input device, and it has the advantage of high light transmittance and high durability, suitable for application to the large screen.
It has the disadvantages of high manufacturing cost, low slimming and resolution, so it is mainly used for large-inch kiosks.