Light guide device, light transmission method, light guide assembly and display equipment

The embodiment of the invention discloses a light guide device, a light transmission method, a light guide assembly and display equipment. The light guide device comprises a substrate, a coupling-in part and a coupling-out part, wherein the coupling-in part and the coupling-out part are arranged on the substrate. The substrate is used for transmitting light from the coupling-in part to the coupling-out part; the coupling-in part comprises a first coupling-in region and a second coupling-in region, and the first coupling-in region and the second coupling-in region are diffraction gratings; the coupling-out part comprises a first coupling-out region and a second coupling-out region, and the first coupling-out region and the second coupling-out region are diffraction gratings; the included angle between the grating vector direction of the first coupling-out area and the grating vector direction of the second coupling-out area is theta 1, and theta 1 is larger than 30 degrees and smaller than 150 degrees, so that