Reflection type screen for diagonal projection and its production and projection television constituted by using this screen

PURPOSE: To provide the screen with which the projected image having a uniform brightness distribution are obtainable with a small installation area by using diagonal projection optical system by forming reflection type linear Fresnel lenses having a specific angle of inclination of lens faces on the surface. CONSTITUTION: The many reflection type linear Fresnel lenses are formed in the direction perpendicular to the optical axis of the diagonal projection optical system 2 on the surface of the reflection type screen 1 for diagonal projection. The surfaces of the lens faces 12 are roughened in order to visualize projecting light to diffuse and reflect the projected light. The lens faces 12 are so constituted that the angle of inclination of these lens faces 12 are larger the furtherer from the diagonal projection optical system 2. Namely, angle 13 of inclination of the lens faces 12 in the parts 8 on the side near the diagonal projection optical system 2 of the screen 1 is so constituted that the main directional direction of the distributed light of the projected light 3 is in a desired direction 5. The angle 14 of inclination of the lens faces 12 in the part 9 further from the diagonal projection optical system 2 is so constituted that the main directional direction of the distributed light of the projected light 3 is in a desired direction 6. COPYRIGHT: (C)1993,JPO&Japio