Patent attributes
Techniques are disclosed for extracting light from within a lightguide by providing therein a plurality of internal light extraction features. A broad range of internal light extraction feature configurations (e.g., geometries/shapes, materials, refractive index changes, etc.) can be provided, and a variety of processes/techniques (e.g., 3-D printing, laser cutting/etching, injection molding, embossment, layer stacking, extrusion, etc.) can be used to do so. The features can be configured to achieve any desired set of photometric performance criteria (e.g., single/double-sided emission, optical efficiency, energy efficiency, spatial/angular luminance distribution, intensity gradients, etc.) for a given lightguide-based fixture/device. In some cases, internal and surficial light extraction features can be used together to extract light. Also, a wide variety of lighting fixtures/devices (e.g., panels, bulbs, tubes, rings, containers, three-dimensional structures/sculptures, multi-layered, multi-sectioned, etc.) can be produced using the disclosed techniques. In some cases, transparent/semi-transparent devices can be produced.