US Patent 11853006 Light engine

A light engine arranged to form an image visible from a viewing window. The light engine comprises: a display device arranged to display a hologram of the image and spatially modulate light in accordance with the hologram; a hologram replicator arranged to receive the spatially modulated light and provide a plurality of different light propagation paths for the spatially modulated light from the display device to the viewing window; and a control device disposed in an optical path between the first replicator and the second replicator. The control device is angled such that light from the first replicator is incident at an acute angle on the control device, and each cell of the array is switchable between a first state and a second state.