GB1400422A - Data visual display apparatus - Google Patents

Abstract

1400422 Cathode-ray tube displays REDIFON Ltd 15 Aug 1972 [16 Aug 1971] 38357/71 Heading H4T An Alpha-Numeric display system employs a colour cathode-ray tube of the beam penetration type 2, (Figs. 2, 3 and 4) on which character data is produced by intensification of the beam at appropriate positions in a 7Î5 dot matrix as shown at 16 (Fig. 2) in respect of the character "A". The beam deflection between the matrix dots is effected under control of counters 17, 21 and D/A converters 18, 22 via gain setting amplifiers 19, 23, deflection amplifiers 20, 24 and deflection coils 10, 11, the gains of amplifiers 19, 23 being controlled by colour selection signals at terminal 28 such that the magnitubes through which the beam is deflected remains constant when the beam energy (EHT voltage) is varied to produce displays in different colours. Control of the amplitude and duration of the beam intensification pulses from amplifier 26 (Fig. 2) by colour selection signals is also effected to compensate for the different sensitivities and persistence of the (two) screen phosphors, Red and Green, which allows four colours Red, Orange, Yellow and Green to be produced. The display is produced on 32 lines each of 64 character position (Fig. 3) using circuitry similar to that employed for the matrix production but with separate deflection coils 12, 13 and with the addition of facilities for horizontal and vertical tabulation. Fig. 4 shows the general arrangement of the EHT voltage switching system for producing colour changes. The invention is described in association with a ground-based aircraft flight simulator (Fig. 1A, not shown) the flow of data within which is illustrated by Fig. 6 (not shown). Colour is employed to indicate the status of specific items of data; e.g. Yellow is employed for unchanging information such as titles and headings, Green is employed to display parameters which are normal and Red is employed to display parameters which are abnormal. Orange is employed to display a line-marker cursor.