Directional flat illuminators

摘要

Disclosed is an optical valve or light valve for providing large area collimated illumination from localized light sources, and system and method thereof for 2D, 3D, and/or autosteroscopic displays. An optical valve may include a stepped structure, in which the steps include separated extraction features which may be optically hidden to light propagating in a first direction. Light propagating in a second direction may be refracted, diffracted, or reflected by the features to provide illumination beams exiting from the top surface of the optical valve. Such controlled illumination may provide for efficient, multi-user autostereoscopic displays as well as improved 2D display functionality.

主权项

1. An optical display, comprising:
a light valve, comprising: a first end at which light may enter the light valve and propagate in a first direction; a second end that is a reflective surface arranged to redirect light propagating in said first direction to propagate in a second direction back toward the first end, wherein the second end is a concave, curved reflective surface, or a Fresnel equivalent of a concave, curved reflective surface; a first light guiding surface extending between the first and second ends, wherein the first light guiding surface is substantially planar; and a second light guiding surface, extending between the first and second ends opposite the first light guiding surface, further comprising a plurality of guiding features and a plurality of elongate extraction features that have a curved cross-sectional profile and are curved along the direction in which they are elongated, wherein the extraction features and the guiding features are connected to and alternate with one another respectively, further wherein the plurality of extraction features allow light to pass substantially without loss when the light is propagating in said first direction and further wherein the curved cross-sectional profile of the extraction features allow light to reflect and exit the light valve through the first guide surface towards a viewing plane when the light is propagating in said second direction and further wherein the curvature of the extraction features along the direction in which the extraction features are elongated causes the light from a plurality of illumination elements to be focused, whereby the curved cross-sectional profile and the curvature of the extraction features and the curvature of the reflective end cooperate to direct focused light into respective viewing windows in the viewing plane, and further wherein the plurality of illumination elements are configured to provide light into the light valve; a transmissive spatial light modulator arranged to be illuminated by the light valve; and an illuminator controller for controlling the illumination elements.