| 摘要 |
<p>A transparent rear-projection screen (4b) having a rear side to which red, green and blue pictures are projected from projectors (1, 2, 3). The rear side has parallel convex lenses (31) the focal points (36) of which are located in the front side of the screen. The front side is composed of parallel ridges (32) separated by deep recesses (34) of triangular cross section so that the thickness of each ridge (32) gradually decreases towards its top (33). The flanks of each ridge (32) are covered with a light-impenetrable material (35) while the top (33) of the ridge is not covered to allow light to pass therethrough. The dimensions of the ridges (32), the recesses (34) and so on are determined relative to each other so as to prevent decrease of contrast due to light rays which are transmitted through the front side into the screen and reflected back to the outside after internal reflection.</p> |
