Diffractive light guide plate and display device comprising same

A diffractive light guide plate comprising:

• a light guide unit configured to guide lights;
• a first diffractive optical element including a linear grating repeatedly formed at a predetermined pitch such that lights output from a light source are received and guided on the light guide unit, and configured to diffract the received lights;
• and
• a second diffractive optical element disposed in a region distinct from a region where the first diffractive optical element is disposed on one surface of the light guide unit, and including a two-dimensional pattern provided in a region where a virtual first linear pattern repeatedly arranged at a predetermined pitch along a first direction and a virtual second linear pattern repeatedly arranged at a predetermined pitch along a second direction different from the first direction intersect each other,
• wherein a horizontal section of the two-dimensional pattern has an elliptical shape and an angle formed between the long axis of the elliptical shape and a direction perpendicular to an extension direction of the linear grating included in the first diffractive optical element is 10° or more but less than 18°,
• wherein the two-dimensional pattern protrudes from the one surface of the light guide unit, and
• wherein a protruding height of the two-dimensional pattern is 0.084 times to 0.113 times a wavelength of the light output from the light source.