An optical plate includes a main body plate, and a plurality of lens patterns formed on a first surface of the main body plate, wherein the lens patterns are elongated in a first direction and arranged in parallel with each other in a second direction crossing the first direction, wherein a cross section of the lens patterns form a part of an ellipse shape, the ratio of a semi-major axis to a semi-minor axis of the ellipse shape ranging from about 1.65 to about 1.75.