| 摘要 |
An illumination device for illuminating a surface with a radiation beam of arcuate cross-section is disclosed. The device includes a radiation source for producing a radiation beam having a uniform intensity; an optical system including a stop with an arcuate opening to be irradiated with the radiation beam from the source, an image of the arcuate opening irradiated being projected on the surface for illumination of the same; and a light pipe assembly for directing the radiation beam from the source to the optical system while maintaining a substantially constant angle of opening of the same, the light pipe assembly including a plurality of subassemblies each having an array of light pipes of polygonal cross-section; wherein those light pipes in the subassemblies close to the source are combined to define an entrance surface of the light pipe assembly while those light pipes of the subassemblies close to the optical system are so disposed that their exit surfaces are arrayed along an arcuate line similar to the shape of the opening of the stop; and wherein the light pipe assembly is adapted to receive the radiation beam from the source to divide the received radiation beam into portions for the subassemblies, respectively; whereby the light portions emanating from the exit surfaces of the subassemblies illuminate the surface to be illuminated.
|
