| 摘要 |
<p>A rear projection screen consists of a Fresnel lens (20) and a picture-forming screen (21) placed in front of it. The picture-forming screen (21) has vertical backward convex lenses (22) on its back and vertical masking strips (23) on its front and strip-shaped sections (26) situated between the masking strips (23) and opposite the backward convex lenses (22). Each of these is designed to refract light rays coming from behind so that they are directed towards the strip-shaped sections (26). In order to increase the picture resolution or definition capability of the screen and to avoid notch sensitivity between the backward convex lenses (22) an intermediate lens (28) is provided between every two of the backward convex lenses (22). Every intermediate lens (28) has two sides (29, 30) shaped in such a way that the rays which hit one side (29) of each intermediate lens (28a) are refracted so that they are directed towards the strip-shaped section (26a) which is situated opposite to the backward convex lens (22a) which is adjacent to the other side (30) of the intermediate lens (28a) concerned, and that the rays which hit the other side (30) of the intermediate lens (28a) concerned are refracted so that they are directed towards the strip-shaped section (26b) which is situated opposite to the backward convex lens (22b) which is adjacent to said one side (29) of the intermediate lens (28a) concerned.</p> |
