| 摘要 |
Projection television screens suffer from lack of brightness, contrast, and uniformity at different viewing positions. To remedy these problems, a transparent film (14) is employed that is configured on its back surface (16) with a random pattern of generally parallel elongated microscopic recesses (17') or projections (17''). Its back surface is reflectively coated (18) and its front surface (15) is configured with lenticular light-refracting recesses (17') and projections (17'') that spread light entering and leaving that surface. At least the recesses or projections on the back surface (16) are convex or concave in both their longitudinal and transverse directions. The screen is generally oriented during use so that the elongated recesses or projections in the back surface are arranged vertically. Light (20, 21, 22) projected at the screen enters and is refracted at the front surface, is reflected by the back surface, and is refracted again at the front surface, providing bright images visible with good uniformity to a widely distributed audience. |
