Patent ID: 8251561
Filing Date: 2012-08-28
Classification: G02B

Abstract:
1. A lightguide for providing light in a display device, comprising: a lightguide substrate comprising first and second major faces and an edge face there between into which light from a light source is injected, the lightguide substrate configured to transfer the light between the first and second major faces by total internal reflection, an optical axis generally parallel to the first and second major faces and defining a nominal illumination direction through the lightguide, and an extraction region for extracting light from the lightguide; and a plurality of features formed on at least one of the first and second major faces between the edge face and the extraction region, said plurality of features configured such that a majority of the light from the light source incident on the plurality of features is refracted back into the lightguide at a lower angle to the optical axis than light incident on a face of the lightguide to reduce an angular spread of light relative the optical axis.