| 摘要 |
PURPOSE:To cheaply produce an illuminator having a golden specular surface by vacuum depositing an Al-Cu alloy on a surface of a specified temp. in a high vauum. CONSTITUTION:An alloy consisting of, by wt., Al 7.0-10.5% and Cu 93.0- 89.5% is put into the coil of tungsten filament 6, and glass bulb 2 is covered. The interior of bulb 2 is held at a high vacuum degree of 3X10<-3>mmHg or more, and the temp. of bulb 2 is maintained at 200-400 deg.C. By supplying an electric current to filament 6 the alloy is heat evaporated to deposit a 0.05-0.20mu thick film on the whole inside of bulb 2. An unnecessary portion of the film is then removed with an aq. sodium nitrate soln. or the like to form a bulb for a specular type electric bulb, and sealing, evaporation, etc. are carried out to produce specular type electric bulb 1. |
