| 摘要 |
PURPOSE:To enable the electric potential of a getter film to be reliably maintained at a constant level by forming an area of the inner surface of a vacuum encircling case, a conductive film electrically connecting an area of the inner surface of a vacuum encircling case which is brought into contact with a spring electrode and an area of said inner surface on which a getter vapordeposition film is to be formed. CONSTITUTION:Conductive films 2 consisting of thin Cr films which can be brought into good contact with glass, are formed by vapordeposition on an area of the inner surface of the spring electrode bulb 1 of an electron gun which is to be brought into contact with an electron gun, on an area of the inner surface of the bulb 1 to be coated with a vapordeposition film 7 formed by a flash getter and on a belt-like section connecting these areas in the tube axis direction. A spring electrode 8 supports an electron gun and conducts the electric potential of a third electrode to the conductive films 2. As a result, the electric potential of the barium getter film 7 is always reliably maintained the same as that of a third electrode, thereby preventing any possibility that the electron orbit might be varied by the electrification or the discharge of the barium getter film 7. |
