Prism array

Patent Pending PROBLEM TO BE SOLVED: To set the diffusion angle of light to up-and-down directions to a prescribed range. ; SOLUTION: When a screen is composed of a prism array in which many prisms each receiving projector light with a prescribed light incident angle at a light receiving face, thereafter totally reflecting the light at a reflecting face, and emitting the reflected light toward a screen face are formed, the part upon which the projector light is struck in the reflecting face of each prism has a curved face shape.