| 摘要 |
PURPOSE:To perform highly accurate scale printing by providing two pieces of the same negative patterns at appropriate intervals. CONSTITUTION:A superhigh-pressure mercury arc lamp 2 and a reflecting plate 3, which reflects the rays emitted from said mercury arc lamp 2, are fixed on a rotary base 1 while setting them up inside the cathode-ray tube proper 4. Further on its upper part, a negative pattern 5 and the negative pattern 6 are mounted at proper intervals while placing thereon a cathode-ray tube bulb 8, in which sensitive liquid is injected on its screen surface 7. The rays inciding orthogonally to the negative pattern 5 pass through the negative pattern 6, while the rays not orthogonal to the negative pattern 5 are intercepted by the negative pattern 6 so that only the parallel rays 10, which passed through the negative patterns 5 and 6 reach the screen surface 7 of the cathode-ray tube 8. Further, the mercury arc lamp 2 and the reflecting plate 3 are rotated by the rotary base 1 so as to unify the ultraviolet ray illumination on the screen surface of the cathode-ray tube 8. |
