USER -INPUT INTERFACE WITH A LIGHT GUIDE

摘要

A user-input interface comprises a light guide having first and second surfaces and at least one edge extending between the first and second surfaces, a photodetector provided at the at least one edge and operable to output a signal indicative of an amount of light arriving at the photodetector from within the light guide, and electronic circuitry configured to detect an object in physical contact with one of the first and second surfaces of the light guide in response to receipt of a signal from the photodetector that is indicative of a reduction in the amount of light arriving at the photodetector. The user-input interface may be of single-layered construction and may be particularly suitable for controlling an emissive window.