| 摘要 |
PURPOSE:To definitely identify an object without errors and accurately recognize an angle of the position of the object by providing a circular phosphor layer with a high persistence on which an angular scale is formed at the peripheral section of a phosphor screen on which the layer is displayed as a radar picture in multiple layers or in succession. CONSTITUTION:As shown in the figure, when pure water is injected toward the inner suface of panel from nozzle at a pressure of approximately 2kg/cm<2>, a slurry 34b flows and is removed and an illuminating phosphor layer 34c is formed circularly on its peripheral section. Then a cathode-ray tube for a radar is completed by sealing a film-type angular scale plate 37 with an angular scale 371 at the position in which the outer surface of the panel is opposed to the phosphor layer 34c. As described above, since the phosphor layer 34c with a long persistence is provided at the position in which the layer is opposed to the film-type angular scale plate 37 with the angular scale 371 and this angular scale plate 37 is sealed directly on a panel 31, an angle in which an object exists can known exceedingly definitely even when a number of persons observe it. |
