US Patent 10185393 Waveguide display with spatially switchable grating

A near-eye-display (NED) includes an eye tracking system and a waveguide display. The eye tracking system tracks locations based on a location of the user's eyes. The waveguide display includes a light source, an output waveguide and a controller. The output waveguide includes a dynamic output grating that outputs an expanded image light to the tracked eyebox locations. The decoupling grating is a 2D array of spatially switchable liquid crystal (LC) pixels including an active subset of LC pixels emitting light to regions within the tracked eyebox locations. The decoupling grating dynamically out-couples the expanded image light to the tracked location based on switching instructions generated and provided by the controller.