US Patent 11656398 Illumination and display apparatus

An illumination apparatus comprises a first substrate, an optical structure, an array of light emitting elements disposed on the first substrate and between the first substrate and the optical structure, and a mask comprising a plurality of apertures therein. The optical structure is configured to receive light emitted by the array of light emitting elements, direct the received light into a direction away from the first substrate, direct at least some of the light which has been directed away from the first substrate back towards the first substrate, and direct at least some of the light which has been directed back towards the first substrate through the plurality of apertures of the mask.