| 摘要 |
913,504. Apparatus for viewing incandescent spots and their surroundings. ZEISS-STIFTUNG, CARL, [trading as ZEISS, C., [Firm of]]. Feb. 6, 1961 [Feb. 6, 1960], No. 4313/61. Class 97 (1). [Also in Group XL (a)] Apparatus for simultaneous observation of an incandescent spot and its surroundings comprises a source of visible light of short wavelength, said wavelength being shorter than the wavelength of the principle emission from said incandescent spot, means to focus said light on the area under observation, said area including said incandescent spot, and means for observing said illuminated area, said observation means including a filter passing only light of said short wavelength, said filter being placed in the path of the observation rays. In the apparatus shown, workpieces 8 and 9 on movable guides 10, 11 are to be welded together using an electron beam produced by means comprising a cathode 1, a control electrode 2, an anode 3, a diaphragm 5 and an electromagnetic focusing lens 6. The apparatus for simultaneously observing the incandescent spot produced by the electron beam 4 and its surroundings comprises a source 16 (such as a mercury vapour lamp) of short wavelength visible light, a lens 17 for focusing this light on to the area surrounding said incandescent spot, and observation means comprising mirrors 18, 19, lenses 20, 21 and a filter 25 passing only light of said short wavelength, an image of the spot being focused, for example, on to the photo-cathode of a television camera 22. Preferably the filter 25 passes only a narrow band width and may comprise an interference-layer filter. The lens 20 and mirror 18 are movable vertically for focusing. The apparatus is sealed in an air-tight enclosure 7 which may be evacuated through a pipe 12. |
