GB739377A - Improvements in or relating to storing electrical signals and transferring the stored signals into a different circuit - Google Patents

Abstract

739,377. Electron beam apparatus. KRAWINKEL, G. H. . April 21, 1952 [April 21, 1951], No. 9921/52. Class 39 (1). A device for storing electric signals supplied by one circuit and for transferring the stored signals in their original or in a transformed form into a different output circuit comprises within an evacuated casing an electron gun, deflecting plates in front of the gun, a signal-storage electrode consisting of a system of strip-like electrodes which are mounted individually insulated in a plane and radially converging towards the deflecting plates and which have a secondary emission ratio greater than one, a control electrode to which the signal voltage is applied and which is associated with all the strip-like storage electrodes so that the secondary emission and therefore the potential of the strip-like electrodes, when energized by the electron beam (storage beam) of constant intensity from the gun, are charged in dependence on the signal voltage, a counter electrode common to and arranged in spaced relationship with respect to the storage electrodes, a second electron gun with deflecting plates which cause the electron beam (target beam) of the second gun to sweep the space between the strip-like electrodes and the counter-electrode, and a target electrode in the path of the target beam where it emerges from this space. In the arrangement shown in Figs. 1 and 2 the insulated electrodes 20-27 are arranged fan-wise, converging on the centre of deflection of the deflection plates 14 controlling the beam from the gun 1. The insulated electrodes may be charged by electrons from a gun 2 which impinge on their up-turned ends, as shown in Fig. 1, and cause secondary electron emission; the signals to be stored may be applied either to the grid 17 of the gun 2 or to the secondary electron collecting electrode 29. To read the signals, electrons from the gun 1 pass between the insulated electrodes and an electrode 31 and variably deflected across an aperture 33 in an electrode 32 according to the stored charges, the output being taken from an electrode 34. An electron multiplier may be provided between electrodes 32 and 34, Fig. 3 (not shown). The tube may be provided with a diaphragm 37 having apertures 38, 39 to define the two beams, the diaphragm preferably having a secondary emission ratio less than 1. To ensure that the beam from the gun 1 moves exactly parallel to the aperture 33 in electrode 32, a plurality of deflecting plates 46-53, Fig. 4, opposite a common electrode 54, may be provided adjacent the diaphragm 37 and connected to individual variable potentials. In a modification, the gun 2 in Fig. 1 may be omitted and the beam from the gun 1 may move alternately between electrode 31 and the insulated electrodes, and through the aperture 39 in diaphragm 37 and past deflection plates 36 to the upturned edges of the insulated electrodes. The beam may be deflected to these alternate paths by a square wave applied to deflection plates 15; deflection plates 36 serve to re-deflect the beam parallel to the axis of the tube. The tube may be used for signal expansion by applying the waveform shown in Fig. 5 to the scanning deflection plate 14 and the waveform shown in Fig. 6 to the deflection plates 15; signals are thus stored during the short falling portion of the saw-tooth waveform shown in Fig. 5 and read during the longer rising portion. By reversing the relative phase of the applied waveforms signals may be contracted.