| 摘要 |
755,189. Reflectors; filters. GRETENER, E. Oct. 7, 1954 [Oct. 8, 1953], No. 28948/54. Drawings to Specification. Class 97α1<SP>1</SP>. A reflector comprises a concave metal support coated with a layer of heat-absorbing material and on top an interference filter which reflects visible light but transmits heat radiations. The absorbing layer absorbs substantially all radiation in the infra-red range and is generally a black layer. If this black layer has a coarse surface it may be first coated with a lacquer to provide a smooth base for the interference layers. The metal support may be cooled by air or by passing a cooling liquid through a tube round its rim. |
