A system for directing light in an interactive display system so as to
perform multiple functions. In addition to projecting images on the
interactive display system, the system is used to distribute infrared
(IR) light onto the display surface, and/or to receive and focus received
IR light reflected from a physical object on the display surface. A light
separating system separates a multi-waveband light from a source into a
predominantly visible light and a predominantly non-visible light, the
latter being redirected around visible light modulators and recombined
with the modulated visible light for projection onto the display surface
by a lensing system. In addition, or in the alternative, the light
separating system separates predominantly non-visible light reflected
from an object adjacent to the surface, from light produced by the
source, directing only the non-visible light received to the light sensor
used to image the display surface.