| 摘要 |
<p>The invention relates to a tube emitting electromagnetic radiation which is made of glass or transparent non-fluorescent quartz and has an elongated boring able to house a radiation-emitting filament or bundle. The boring has a substantially square or rectangular cross-section at least two opposite sides of which form dioptric convex surfaces shaped to alter the direction of the radiation emitted by the filament or axis of the bundle so as to render them parallel or substantially parallel in the solid transparent glass medium.</p> |
