摘要 |
Disclosed is an imaging directional backlight apparatus comprising a waveguide, a light source array, and a further optical element for providing large area directed illumination from localized light sources. The imaging directional backlight may comprise a stepped waveguide that may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources. The further optical element may comprise a superlens comprising first and second aligned lens arrays that may be arranged to modify the output viewing windows to achieve enhanced window imaging from the directional backlight. |