Patent GB-643843-A (GB)
Title: Electron discharge device
IPC: H01J40/00
Filed: 1945-03-15
Abstract: 643,843. Electron beam apparatus. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. March 15, 1945, No. 6605. Convention date, April 24, 1942. [Class 39 (i)] An electric discharge tube comprises a plurality of successive pairs of oppositely disposed deflecting elements having an alternating control voltage of high-frequency applied thereto between which an electron beam is directed, the spacing between the centres of said elements being such as to cause successive and additive deflection of the electron beam, a plurality of secondary emitting electrodes upon which the beam is successively directed and an output electrode for receiving the electron multiplied beam from the last of the secondary emitting electrodes. Fig. 1 shows cathode 13, apertured focusing electrode 15 and conductive tubular member 16 divided into compartments by apertured transverse conducting elements 17, 18, 19, the compartment formed by the elements 18 and 19 containing the pairs of deflecting electrodes 30, 31, 32. The beam after passing between the deflecting electrodes passes through the apertured element 19, through earthed apertured electrode 20 and is directed by element 20<SP>11</SP> connected to electrode 20 against the element 22 of the electron multiplying system comprising electrodes 22, 23, 24, 25 and 26 and screen 27 positioned before the collector 14. The distance between the centres of the pairs of deflecting electrodes 30, 31 and 32 is equal to the distance travelled by an electron during a half period of the controlling voltage, and the elements preferably have a dimension in the direction of travel of the electron beam a little less than the distance travelled by an electron during a half period. The electrodes are cross-connected so that the phase relationship between the electron beam and the voltage applied to the electrode elements will produce deflection in the same direction. In an alternative construction the distance between the centres of successive pairs of electrodes is equal to the distance travelled by an electron during a whole period of the applied controlling voltage and all the elements on one side of the beam are connected together. The signal input circuit is connected by lines 34, 35 to the deflector electrodes 31. The Specification as open to inspection under Sect. 91 describes the electron discharge device shown in Figs. 3, 5 and 6 (Cancelled), in which the deflecting electrode system comprises an elongated rectangular shaped member 62 having between its ends inwardly extending sections 64 provided with slots 65 forming deflecting elements 64<SP>1</SP> between the slots. It is stated that the distance from the centre line extending across the slotted portion is equal to a quarter-wave of the received or controlling voltage so that each half acts like a Lecher wire system of quarter-wave length. The voltage is fed to this circuit arrangement by means of leads 66 which may be connected to a transmission line system of coaxial cable type. The distance between the centres of elements 64<SP>1</SP> is equal to the distance that an electron travels during one period of the controlling voltage, the elements having a width in the direction of travel of the electron beam substantially corresponding to a half period. A pair of beam-directing elements 67 centres the beam between the deflecting electrode elements. The member 59 positioned before the collector 55 is provided with an aperture 59<SP>1</SP> across which is centrally situated a wire or conductor. No secondary emitting electrodes are described. This subject-matter does not appear in the Specification as accepted.