Optical waveguide device for image display and display device having the same

Abstract

The application discloses an optical waveguide device for image display and a display device. The optical waveguide device comprises a coupling-in grating and a coupling-out grating provided on a waveguide substrate. The coupling-out grating is used to couple, at least a portion of light propagating into it along an input direction, out of the waveguide substrate, and has a receiving end located upstream and a coupling-out end located downstream along the input direction. The receiving end is divided into a first grating area, a second grating area and a blank area between the first and second grating areas in a width direction perpendicular to the input direction. The blank area can prevent central light from being prematurely diffracted and splitted by the coupling-out grating, thereby reducing the loss of light energy while ensuring effective coupling-out into an eyebox range, maximizing coupling-out efficiency, and improving the optical effect.