The application of microstructures which improve the quality of light available to the viewer of an optical display
system, or any display which works on the concept of moving one surface into direct contact or close proximity of a
light guide to extract light through frustrated
total internal reflection. Optical microstructures are introduced on one or both of the surfaces of the
active layer to enhance its performance. Since the
active layer has both an input and an output function, means for enhancing both are presented. The
input function to the
active layer occurs on the internal surface, so this is where the present invention adds a collector-coupler, a means for facilitating the migration of light from the
waveguide into the active layer. The output function occurs on the external surface, where the present invention adds a
collimator, a means for both increasing the probability that a
light wave will be released from the active layer, and improving the apparent intensity by redirecting light
waves so that more of them reach the viewer. Compound microlenses on the internal surface of the active layer can serve as both collector-couplers and collimators, substantially improving light extraction from the
light guide and light distribution to the viewer. Depositing a reflective or
colored material in the interstitial spaces between these compound microlenses improves the
contrast ratio and mitigate pixel cross-talk. The opaque material can be conductive for use in actuating the display.