| 摘要 |
PURPOSE:To reduce the value of a spark current by forming a conductive inner film which is formed in the inner surface of a tube for connecting the portion between a high tension conductor and the contact of an electron gun in which the resistivity and the surface roughness of the film are limited over the characteristic value. CONSTITUTION:A high tension voltage is applied to an electron gun 7 mounted within the neck portion 1 of a cathode-ray tube from a high tension conductor 4 through a conductive film 5 which is provided in the inner surface of a cone portion 2. At this time, the resistivity of the film 5 is formed to be over 0.2OMEGA.cm, and the surface roughness of the film 5 is formed to be over 6mu, and the resistance value between the high tension conductor 4 and the electron gun 7 is formed to be 2-100KOMEGA. And by limiting the surface roughness, the evaporating film of metal barium such as barium getter and the like is made to have discontinuity property and thus to prevent the resistance of the film 5 from lowering, and further by limiting the resistivity, a spark current is restrained under about 200A. Accordingly, it is possible to prevent obstacles accompanied by the spark without making the film 5 high resistance. |
