Abstract: A rear projection screen consists of a Fresnel lens and a picture-forming screen placed in front of it. The picture-forming screen has vertical backward convex lenses on its back and vertical masking strips on its front and strip-shaped sections situated between the masking strips and opposite the backward convex lenses. Each of these is designed to refract light rays coming from behind so that they are directed towards the strip-shaped sections. In order to increase the picture resolution or definition capability of the screen and to avoid notch sensitivity between the backward convex lenses an intermediate lens is provided between every two of the backward convex lenses.

Abstract: A transparent rear projection screen has a Fresnel lens for paralleling light arriving from behind. In the front surface the screen is provided with grooves which extend in the vertical direction in the position of use of the screen. Each of the side flanks of the grooves adjoins a side part of an adjacent, also vertically extending convex lens. The side flanks of the grooves are totally reflecting to parallelled light arriving from behind in order to increase the deflection in the lateral direction of a part of the light arriving from behind by means of reflection into the adjacent lens. The angle which a side flank forms together with the side part of the adjacent lens is so small that total reflection from the inner surface of the side part of the lense of light which is totally reflected of the side flank in question is avoided. Moreover, between the vertical lenses to which the side flanks adjoin, at least one further lens is arranged.

Abstract: A transparent rear projection screen has a lense system for paralleling light arriving from behind. On the front side of the screen rectilinear lenses extending in the vertical direction in the position of use of the screen are provided the sides of which form a small angle of inclination with respect to the normal to the screen. The sides are totally reflecting to light arriving from behind and between the reflecting lenses further lenses are arranged. In order to compensate for color shading by the projection of differently colored television images upon the rear side of the screen, the tops of the reflecting lenses are so shaped and their totally reflecting sides have such an inclination with respect to the normal to the screen, and moreover have such a width that at the most 80% of the light which from behind enters the reflecting lenses is emitted through the tops of the lenses, and that at least 20% of said entering light is emitted through the sides of the lenses.