Patent GB-634567-A (GB)
Title: Improvements in and relating to cathode ray tube display systems
IPC: G01R13/20
Filed: 1946-03-30
Abstract: 634,567. Cathode-ray oscillographs. PARKER, E., WALLIS, P. R., WORONCOW, A., and BUCKINGHAM, J, March 30, 1946, No. 9942. [Class 37] [Also in Groups XL (a) and XL (c)] A cathode-ray is deflected to delineate a plane representation of three mutually perpendicular co-ordinates and is modulated in intensity by the instantaneous values of any of three variable quantities represented or measured along the co-ordinates. Sawtooth time-bases for the X, Y co-ordinates are applied at x, y, Fig. 2, to induce oscillations in coil 3 for application to the Y-plates of the cathode-ray tube and in coil 4; oscillations in coil 4 are fed to coil 5, while a sawtooth timebase for the Z co-ordinate is applied at z to induce oscillations in coil 6 for application to the X-plates and in coil 7 for application to the brilliance or, deflection sensitivity control. Coils 3, 4 and 6, 7 are rotatable relatively to coils 1, 2 and 5, 8 respectively, and it is shown that where coils 6, 7 are respectively parallel to coils 5, 8, the cathode-ray scans a square, Fig. 7 (a), which rotates about its centre, e.g., Fig. 7 (e), as coils 3, 4 are rotated. Rotation of coils 6, 7, relatively to coils 5, 8, causes the scan of Fig. 7 (a) to change to that of Figs. 7 (b), (c), (d), and the scan of Fig. 7 (e) to change to Figs. 7 (f), (g) and (h). By applying the oscillations in coil 7 to the brilliance control, the representation is modulated as shown in Fig. 9, where the intensity decreases as the lines of the drawing become thinner. If the output of coil 7 is applied to the deflection sensitivity control, perspective is introduced as shown in Fig. 10. In radar, the volume scanned by the aerial array can be delineated as in Fig. 11 (a) and rotated in accordance with the mean direction of the aerial array; a truncated section of the square cone can be brightened by the application of a short range time-base to enclose a selected echo, and by suitable switching, the display can be changed to the form shown in Fig. 11 (b). Where desired, the display may be in the form of a hemisphere, Fig. 12, not shown. The cathode-ray may be suitably modulated to produce reference spots, lines or surfaces; such modulation may be by way of brightening the ray or by way of suppressing it, Figs. 13, 14, not shown. By removal of the elevation co-ordinate, the cube becomes an oblique view, Fig. 15, in which, e.g. range is plotted against bearing and by alternating this view with the one in which the elevation scan is present and the bearing scan is an adjustable wall, the echoes appear on the base and the wall can be moved until they also appear on the wall. Stereoscopic effects can be obtained by the use of two tubes (or one multi-grid tube) each producing a different view of the volume scanned, Fig. 16, not shown. When a " petal scan is employed, the volume is projected as a cylinder, Figs. 17 and 18, not shown. In another radar display, the echo appears on two planes, bearing-range ABCD, Fig. 19, and elevation range EFGH; if the target is on the centre line of the radar beam it appears as a cross at the intersection of the planes; this display may cover a small area only and be adjustable in accordance with the elevation and bearing adjustments of the aerial array, Fig. 20 (not shown). The deflecting fields may be magnetic or electrostatic and three fields at 120 degrees may be employed, Fig. 8, not shown. A planetarium can be represented by, e.g., the hemispherical projection of Fig. 12, not shown.