Waveguide design incorporating reflective optics

摘要

This invention relates to devices for coupling light between an optical waveguide and an optical element in a manner that is substantially independent of temperature, using reflective optics. Certain embodiments of the invention concern improved designs for the transmit and receive optics of a waveguide-based optical touch screen sensor, incorporating reflective optics. The improved designs have substantially temperature independent operation and reduced optical losses. In one preferred embodiment the improved design incorporates a parabolic or quasi-parabolic reflector. In another preferred embodiment the improved design incorporates an elliptical or quasi-elliptical reflector. The transmit and receive elements and associated waveguides preferably comprise photo-patternable polymers.