Lightguide with a light input edge between lateral edges of a folded strip

A lightguide formed from a film comprises a light mixing region between a light emitting region and an array of coupling lightguides. The first coupling lightguide of the array of coupling lightguides comprises a first light input edge between an inner lateral edge of the first coupling lightguide and an outer lateral edge of the first coupling lightguide opposite the inner lateral edge, wherein a width of the first light input edge is less than a width of the first coupling lightguide at the light mixing region and the first coupling lightguide is folded toward the outer lateral edge such that the first light input edge is between the outer lateral edge and the inner lateral edge along the array direction. In one embodiment, the first light input edge is offset from the outer lateral edge and positioned above the first coupling lightguide.