US Patent 11619774 Talbot pattern illuminator and display based thereon

An illuminator for a display panel includes a light source for providing a light beam and a lightguide coupled to the light source for receiving and propagating the light beam along the substrate. The lightguide includes an array of out-coupling gratings that runs parallel to the array of pixels for out-coupling portions of the light beam from the lightguide such that the out-coupled light beam portions propagate through the substrate and produce an array of optical power density peaks at the array of pixels due to Talbot effect. A period of the array of peaks is an integer multiple of a pitch of the array of pixels.