A light guide unit includes: a light guide plate curved about a center of curvature, and including a first outer circumferential surface and a first inner circumferential surface disposed closer to the center of curvature than the first outer circumferential surface; and a restoring force-offset layer coupled to at least one of the first outer circumferential surface and the first inner circumferential surface. The light guide plate includes a first material having a first thermal expansion coefficient, and the restoring force-offset layer includes a material having a thermal expansion coefficient different from the first thermal expansion coefficient to offset a restoring force of the light guide plate.