| 摘要 |
<p>The main lamp body (10) has a silvered concave surface (12), acting as a reflector, with centrally mounted light source (20). The front-glass (30) embodies on its inner surface, an array of parallel e.g. horizontally aligned convex ridges (31). Immediately behind is fitted a transparent screen (40) whose inner surface is provided with a ridged array, similar but e.g. vertically aligned. Both optical surfaces may extend (31',41') over areas (10') of the main body outside the emitting cavity (11). The striated surfaces may face each other and form a dust and dirt-proof enclosure. One surface may also include prismatic striations triangular in cross-section, or be modified in other optically significant ways.</p> |
