| 摘要 |
1,120,751. Cathode-ray tube displays. STANDARD TELEPHONES & CABLES Ltd. 11 Feb., 1966, No. 6092/66. Heading H4T. The occurrence of a predetermined amplitude relationship between each sample of a sequentially and cyclically sampled plurality of signal sources 1 and a sawtooth wave from generator 9 (recurrent at the sampling rate under control of generator 4) produces, via comparison means 8, a trigger pulse which is utilized to control the intensity or focus of the beam of a cathode-ray tube deflected vertically by the sawtooth from 9 and horizontally by a second saw-tooth wave generator 11 synchronized by one stage of a control arrangement 3 for the sampling switches 2. The trigger pulse from means 8 may operate to de-focus the beam, to switch it on or, to vary the brightness of the existing spot. Alternatively, the trigger pulse may be employed to trip a bi-stable device to its second state in which the beam is blanked, the device being returned to its first state on the occurrence of the fly-back of the sawtooth from generator 9 or, on the occurrence of a predetermined level in the trace portion of such sawtooth. The signal sources may be e.g. thermocouples attached to the heater tubes of a power station, pressure transducers or depth gauges and ready identification of a particular signal input corresponding to a particular (vertical) line scan may be realized by blanking one or more of the latter (not corresponding to a signal input) by means of pulses from outputs of device 3 (not employed for control of switches 2) so that the display lines are divided into groups. Deviation of the signal inputs from the norm. may be deduced by comparing the display with a master drawing or graticule or, in the case where the bi-stable device is returned to its first state by the occurrence of a predetermined level in the trace position of the sawtooth wave, from the display itself. E.H.T. is derived via a diode from the flyback scan energy in amplifier 10 which supplies the line sawtooth from generator 9 to the vertical deflection means. |
