Light-guiding device, optical module, and head-mounted display device

Abstract

The disclosed subject matter provides a light-guiding device, an optical module, and a head-mounted display device. The light-guiding device includes a light-guiding substrate and an in-coupling area and an out-coupling area provided on the light-guiding substrate; the out-coupling area is configured to perform pupil expansion on light from the in-coupling area and couple the light out; the out-coupling area includes one or more first strip gratings with at least two grooves disposed on opposite sides of the first strip grating, the grooves being configured to induce additional diffraction orders from the first strip grating and form a target diffraction efficiency corresponding to the diffraction orders, so that light propagating to the first strip grating is change from originally diffracting on a first side of the first strip grating to additional diffracting on a second side of the first strip grating.

Dependencies are inferred from the claim text.