| CPC G02B 6/0041 (2013.01) [G02B 6/0055 (2013.01); G02B 6/0065 (2013.01); G02B 6/0003 (2013.01); G02B 6/0056 (2013.01)] | 20 Claims |

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1. A wide-area waveguide illumination system, comprising:
an optical waveguide formed by a sheet of an optically transmissive material having a generally uniform thickness and comprising a first broad-area surface, an opposing second broad-area surface, and a first light input edge;
one or more solid-state light sources optically coupled to the first light input edge;
an image print comprising a viewable surface and disposed in an energy receiving relationship with respect to the optical waveguide; and
a two-dimensional pattern of light extraction features distributed over an area of the optical waveguide with variable areal density and defining a plurality of higher-density light extraction areas alternating with a plurality of lower-density light extraction areas,
wherein distances between the light extraction features in the higher-density light extraction areas are generally less than in the lower-density light extraction areas.
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