Patent ID: 8899813
Filing Date: 2014-12-02
Classification: F21S,F21Y,G02B,G09F

Abstract:
1. A lighting assembly to illuminate a target surface with a defined illumination profile, the lighting assembly comprising: a light source; a light guide edge lit by the light source, the light guide having a light input edge and a light output surface, and comprising light extracting elements to extract light from the light guide through the light output surface as intermediate light, the intermediate light directed away from the light input edge and the light output surface and having a maximum intensity at low ray angles relative to the light output surface; a light redirecting member positioned to receive the intermediate light, the light redirecting member having opposed major surfaces and comprising light redirecting zones comprising light redirecting elements at at least one of the major surfaces, in which: the light redirecting elements within each light redirecting zone are collectively configured to redirect a respective portion of the intermediate light incident thereon through a respective turning angle to produce a respective portion of output light having a defined angular spread and directed at a nominal output angle away from the light input edge and the light output surface of the light guide and towards a respective spatial region of the target surface such that the illumination profile on the target surface is the result of superposing the portions of the output light from all the light redirecting zones; and the portion of the intermediate light directed into each spatial region by the respective light redirecting zone depends on the illuminance within the region, as defined by the illumination profile, and at least one of the output angle and the angular spread of the respective portion of the output light.