Patent attributes
The present disclosure provides a diffraction light guide plate including: a light guide unit; an input diffraction optical element configured to diffract light which is outputted from a light source and inputted to the input diffraction optical element, to guide the inputted light on the light guide unit; and two diffraction optical elements configured to receive the diffracted light from the input diffraction optical element and one-dimensionally expand the received light by diffraction, wherein each of the two diffraction optical elements receives the expanded light from the other of the diffraction optical elements and outputs the received light from the light guide unit by the diffraction, and there is no region where the two diffraction optical elements overlap each other on the light guide unit.