Fresnel lens and display devices with such fresnel lens

A Fresnel lens comprising an entrance plane and an exit plane with multiple bump units thereon, wherein

• the multiple bump units comprise:
• a first bump unit comprising multiple first orthogonal sawteeth, wherein the multiple first orthogonal sawteeth have the same tooth-width and their tooth-depth gradually increases in a radial direction from a central axis of the Fresnel lens toward an edge of the Fresnel lens;
• a second bump unit comprising multiple second double-sided sawteeth, wherein the multiple second double-sided sawteeth have the same tooth-depth and their tooth-width gradually decreases in the radial direction from the central axis toward the lens edge;
• on one side of the central axis of the lens, the first bump unit and the second bump unit are placed successively in the radial direction from the central axis toward the lens edge;
• on the other side of the central axis of the lens, the first bump unit and the second bump unit are also placed successively in the radial direction from the central axis toward the lens edge, the bump units on both sides of the lens are symmetrical.