Optical Positioning Touch

A type of touch technology using infra-red LEDs.

Using optical sensors at the top of the screen to recognise touch, this optical position technology relies on infra-red LEDs placed on the remaining 3 sides of the display.

The light emitted from the LED is reflected back to the imaging sensors and when the light beam is broken by a touch, a shadow is cast and therefore registers a touch.

The principles of optical position sensing