TOUCH SCREEN

摘要

A display screen for projected images can act as a touch screen through use of IR sources with homogenizers to create an area of illumination in a plane parallel to and adjacent the screen surface. The presence of a finger or pointer reflects a portion of the illumination to a detector remote from the screen. The detector is capable of identifying the x-y location on the screen of the light spot being detected. In an alternative embodiment in which the use of a finger or other pointing device is impractical, a laser pointer, equipped with an IR source, projects a light spot on the screen whose x-y location can uniquely be determined by the detector device.