| 摘要 |
1,145,960. Cathode ray tubes; travelling wave tubes. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 22 March, 1967 [25 March, 1966], No. 13389/67. Heading HID. A cathode-ray tube travelling-wave deflection system includes a slow wave structure having active parts extending along opposite sides of the beam path, the distance between the two parts increasing with distance along the path to avoid interception of the beam, the structure being supported by a plurality of insulating stay rods which extend parallel to the path, and at least one of the rods being provided with an electrical conductor which is so shaped as to maintain the impedance of the slow wave structure substantially constant along its length. As shown, the deflection system is formed by two flattened helices 1, Fig. 1, disposed on opposite sides of the beam path 2, each helix being supported from a corresponding grooved ceramic rod 5, Fig. 2, by rods 3 sealed into glass 4. To each ceramic rod 5 is secured a U-shaped metal member 6, the height of the sides 7 of which increase towards the output end of the system to counteract the decrease of capacitance arising from the increasing spacing between the two helices, and thereby ensure uniformity of impedance. Members 6 may be pressed on to their respective rods, or may be constituted of a metal or carbon layer. |
