US Patent 11567255 Waveguide illuminator having slab waveguide portion

A waveguide illuminator includes adjacent linear and slab waveguide areas. An input light beam is guided in a linear waveguide, is split into a plurality of sub-beams to propagate in individual linear waveguides to a slab waveguide area and form an output light beam in the slab waveguide area. An array of out-couplers is disposed in the slab waveguide area. The array of out-couplers out-couples portions of the output light beam forms an array of out-coupled beam portions for illuminating a display panel. Locations of the array of out-couplers are coordinated with locations of individual pixels of the display panel, thereby improving efficiency of light utilization by the display panel.