GB1327695A - Pattern generating system - Google Patents

Abstract

1327695 Cathode-ray tube displays ISE ELECTRONICS CORP 6 Sept 1971 [7 Sept 1970] 41406/71 Heading H4T In a cathode-ray tube pattern (e.g., Alpha- Numeric) display system employing a tube of the kind having a "dot" apertured matrix electrode assembly positioned within the tube between the cathode and the screen the patterns being produced by selective energization of the X and Y axis electrodes of the assembly a plurality of pattern signal generators are operated independently to effect the energization required to produce respective different patterns and are operated simultaneously to display modified patterns synthesized from the different patterns. Figure 8 shows an example of this in which the character "E" is synthesized by the simultaneous over-lapping production of the characters "F" and "L". One of the pattern signal generators may produce only a partial pattern which may be combined with the pattern produced by another generator to produce a modified pattern. Figure 7 shows an example of this in which the character "F" is modified by the addition of a partial pattern comprising the elements 7a to 7e of Fig. 7(a) to produce the modified pattern comprising the character "E". The matrix electrode assembly comprises a shield plate 7 (see Figs. 1 and 2) disposed between X axis electrodes 5a to 5g and Y axis electrodes 6a to 6e the whole assembly being apertured at the crossing positions of the X and Y electrodes so that when clock pulses a to e (Fig. 3) are supplied to terminals 11 to 15 respectively the diode pattern-signal generating circuit controls, in known manner, the trans. mission of electrons such that a pattern, in this case the character "H" (Fig. 4, not shown) is produced on the tube screen 2. Fig. 5 shows a further known pattern-signal generator in which terminals 50 to 54 correspond to terminals 11 to 15 and conductors 86 to 92 correspond to conductors 38 to 44 in Fig. 2, the generator including AND gates 60 to 64 which, when conditioned by a select input on conductor 70, supply outputs via OR gates 72 to 78 for producing the character "E", additional AND gates 65 to 69, conditioned by a select input on conductor 71 and associated OR gates 79 to 85 serving for the production of the character "F" and this known type of generator is modified as shown in Fig. 6 to provide the operation required by the invention. Referring to Fig. 6, AND gates 65 to 69, operate via OR gates 93, 94 and 97 to 106 to produce the character F (Fig. 7b) when conditioned by an input on conductor 71. When the latter input is removed and a conditioning input supplied to conductor 70 AND gates 61 to 64 operate via the OR gates 93, 94 and 98 to 106 such that a modified character "F" without the element le (Fig. 7b) is produced, AND gate 60 operates via OR gates 95 and 96 to produce the elements 1e and 7e and AND gates 61 to 63 operate additionally via OR gate 96 to produce the elements 7d, 7c and 7b and thus synthesize the character "E" from the modified character "F" produced by the generator 107 and the partial character produced by the generator 108.