Image Number 6 for United States Patent #8118468.
Disclosed are apparatus and methods for illuminating a display. In certain embodiments, the illumination apparatus includes a light guide that receives light from a light generator along an edge of the light guide and directs the received light via light extractor features (e.g., grooves) towards a display. The light guide includes at least two sets of light extractor features that are rotated with respect to each other so as to reduce a shadowing effect on the display when the display is viewed from within a specific range of viewing angles. In further embodiments, the spacing or orientation of each or one of the extractor feature sets may also be adjusted so that other visual artifacts, such as a Moire effect, are reduced.