| 摘要 |
There is described a retro-reflecting element of generally globular configuration adapted to retro-reflect a ray of light back along its own incident path, when impinged by grazing light on a part-spherical portion of its surface, bulging above the surface of a support layer wherein such element is partially embedded. The new element comprises an essentially optically homogeneous body forming said part-spherical portion and provided, on its remaining surface, with a plurality of closely spaced inwardly concave and reflective part-spherical small bowls capable of sending back, by multiple reflections totalling 180 DEG , light rays impinging on said bulging part-spherical portion and refracted therethrough within said body towards any of said bowls. There is also described a method for making said element. |
