A light guide plate includes a main body having opposing side faces, and front and rear faces connected to the opposing side faces, the front face being adapted to output light incident on at least one of the side faces, a plurality of front prisms disposed at the front face of the main body, and a plurality of dot prisms disposed in an array at the rear face of the main body, the dot prisms being spaced apart from each other, each of the dot prisms including prism parts, sizes of the dot prisms increasing as a distance from the at least one side face increases.