GB935587A - Improvements relating to electronic marking processes - Google Patents

Abstract

935,587. Cathode-ray oscilloscopes. SOC. NOUVELLE D'ELECTRONIQUE S.a.r.L. Dec. 18, 1959 [Dec. 29, 1958], No. 43152/59. Class 40 (7). In apparatus providing a cathode-ray tube display of a set of parallel marker lines P1 . . . Pn, the lines are produced by a " staircase " waveform 2e applied to the X deflect,on members and a saw-tooth waveform 2f applied to the Y deflection members, and the line intervals IN, their inclination a and the drift speed of the set, are adjustable. The markers are produced in the intervals between the scans of an unspecified picture display. At the beginning of each inter-scan period, a pulse is initiated by unit 1 and an ensuing saw-tooth pulse 2b from unit 2 is compared in unit 3 with a saw-tooth of very long duration from unit 5 to form a pulse c<SP>1</SP>, Fig. 2 (c), which triggers bi-stable multivibrator 6 to actuate a high-frequency saw-tooth generator 7, Fig. 2 (d), applied to the Y plates or deflection coils. The pulse from unit 1 triggers bi-stable multivibrator 8 to actuate saw-tooth generator 9, Fig. 2 (a), the output from which is fed, together with sawtooth waveform Fig. 2 (d), to form staircase waveform, Fig. 2 (e). The latter is fed through an adjustable-gain amplifier 11 to a unit 15 wherein mixing with an adjustable output from unit 14 produces the input of the X plates or coil. The drift speed is controlled by unit 5, which determines the delay of pulse c<SP>1</SP> relative to the start of the inter-scan period, Figs. 2 (g), (h), (i) (none shown), the marker line tilt by unit 14, and the inter-line spacing by the gain of amplifier 11. Multivibrators 6, 8 are re-set by the output of a comparator 12 wherein an adjustable D.C. voltage determines the number of lines displayed.