Augmented reality display device and near-eye display device

An augmented reality (AR) display device, comprising:

• a waveguide substrate;
• an in-coupling grating disposed on the waveguide substrate and configured to couple light into the waveguide substrate, wherein a grating vector of the in-coupling grating is a first vector K1;
• and
• an out-coupling grating disposed on the waveguide substrate and configured to couple the light in the waveguide substrate out of the waveguide substrate, wherein the out-coupling grating has a second vector k2 and a third vector k3, the first vector K1, the second vector k2, and the third vector k3 form a closed vector triangle, and when the AR display device is used, an angle between the second vector k2 and a horizontal direction X is less than or equal to 45°, and an angle between the third vector k3 and the horizontal direction X is less than or equal to 45°.

A near-eye display device, comprising an augmented reality (AR) display device, wherein the AR display device comprises:

• a waveguide substrate;
• an in-coupling grating disposed on the waveguide substrate and configured to couple light into the waveguide substrate, wherein a grating vector of the in-coupling grating is a first vector K1;
• a turn grating disposed on the waveguide substrate and configured to perform pupil expansion on the light coupled into the waveguide substrate by the in-coupling grating, wherein a grating vector of the turn grating serves is a second vector K2;
• and
• an out-coupling grating disposed on the waveguide substrate, wherein the out-coupling grating is configured to receive the light that is subject to the pupil expansion by the turn grating and couple the light out of the waveguide substrate, a grating vector of the out-coupling grating is a third vector K3, the first vector K1, the second vector K2, and the third vector K3 form a closed vector triangle, and an angle A between a direction of the third vector K3 and a horizontal direction X satisfies:
• −45°≤A≤45° when the AR display device is used;
• wherein a region of the out-coupling grating is in a shape of rectangle, and a length of a side of the rectangle satisfies:
• d=m+l*tan(FOV/2)*2,
• wherein d represents the length of the side of the rectangle, m represents an eye movement range of a user, l represents a distance from eyes of the user to a waveguide plate, and FOV represents a field of vision of an AR display system.