MULTICOLOR OSCILLOSCOPE

• US 3,577,031 A
• Filed: 07/07/1969
• Issued: 05/04/1971
• Est. Priority Date: 07/07/1969
• Status: Expired due to Term

• Current Assignee: Neil R. Welsh, Richard E. Mccormick
• Original Assignee: Neil R. Welsh, Richard E. Mccormick
• Inventors: Welsh, Neil R., Mccormick, Richard E.
• Application Number:
  US04/839,240
• Time in Patent Office: 666 Days
• US Class Current: 315/368.18
• CPC Class Codes: G01R 13/28 Circuits for simultaneous or sequential presentation of more than one variable
• CPC Class Codes: H04N 9/28 Arrangements for convergence or focusing

Abstract

An oscilloscope employing a multibeam, multicolor cathode-ray tube in which each of several input signals are displayed in a different color on the cathode-ray tube screen. The electron beams are rapidly scanned along the vertical axis to produce a vertical raster. Plural horizontal reference lines are displayed in discrete colors simultaneously with the signal traces by displaying the reference lines and input signals as colored dots by individually intensity modulating the plural electron beams during their alternate up and down scans. Plural vertical reference lines are displayed in discrete colors simultaneously with the signal traces and the horizontal reference lines by energizing each of the beams for a single vertical trace at a predetermined position along the horizontal screen axis. Convergence circuits correct for both vertical and horizontal convergence, the horizontal convergence circuit being adapted to correct for convergence for differing horizontal drive waveforms. A vertical scan oscillator including a resonant circuit incorporating the vertical deflection coil provides a high frequency, high voltage scan without requiring large voltages across the amplification stage.

Claims

1. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having plural electron guns for producing plural independent electron beams for exciting respectively different colored phosphors on the tube screen;

vertical deflection means for scanning said beams upwardly and downwardly across said screen;

means for generating plural horizontal reference signals each corresponding to a horizontal reference display of respectively different color;

plural comparator means each respectively responsive to one of said input signals and one of said plural horizontal reference voltages for (i) comparing the position of said beam with said input signal during the scan of said beam across said sCreen in a predetermined vertical direction and energizing the electron gun of said beam when the beam position corresponds to the magnitude of the input signal, and (ii) comparing the position of said beam with said horizontal reference signal during the scan of said beam across said screen in the opposite vertical direction and energizing the electron gun of said beam when the beam position corresponds to the magnitude of the horizontal reference signal.

2. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having plural electron guns for producing plural independent electron beams for exciting respectively different colored phosphors on the tube screen;

vertical deflection means for scanning said beams upwardly and downwardly across said screen;

means responsive to said vertical deflection means for producing a vertical position signal proportional to the position of said beam;

means responsive to said vertical deflection means for producing a switch control signal at the bottom and top of the scan of said beam across said tube screen;

a first comparator for comparing one of said plural input signals with said vertical position signal;

a second comparator for comparing said vertical position signal with a horizontal reference signal;

means responsive to said vertical switch signal for alternately gating the output of one of said comparators to energize said cathode-ray tube during a down scan of said beam and the other of said comparators to energize said cathode-ray tube during the up scan of said beam.

3. An oscilloscope for displaying each of plural input signals in a respectively different color as described in claim 2 wherein said means for producing said vertical position signal comprises:

means responsive to the current through the vertical yoke winding of said cathode-ray tube, said current being proportional to the vertical position of said beam.

4. An oscilloscope for displaying each of plural input signals in a respectively different color as described in claim 2 wherein said means for producing said vertical switch signal comprises:

means responsive to the voltage across the vertical yoke winding of said cathode-ray tube, said signal changing sign at the top and bottom of each scan of said beam across the screen.

5. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having plural electron guns for producing plural independent electron beams for exciting respectively different colored phosphors on the tube screen;

vertical deflection means for continuously scanning said beams upwardly and downwardly across said screen;

horizontal deflection means for deflecting said beams horizontally across said screen; and

means for producing a vertical reference display line during said continuous scanning comprising;

detector means responsive to said horizontal deflection means for detecting a predetermined position along the horizontal axis;

means responsive to said detector means for energizing one of said electron beams of said cathode-ray tube to produce said vertical reference line at said predetermined position along the horizontal axis;

said detector means being further responsive to said vertical deflection means so that said vertical reference line is initiated substantially coincident with the initiation of one excursion of said continuous vertical scan.

6. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having plural electron guns for producing plural independent electron beams for exciting respectively different colored phosphors on the tube screen;

deflection means for scanning said beams vertically and deflecting said beams horizontally across said screen, said vertical scanning being continuous; and

means for pRoducing a vertical reference display line comprising;

means responsive to said deflection means for detecting a predetermined position along the horizontal axis;

means responsive to said detector means for energizing an electron beam of said cathode-ray tube; and

means responsive to the output of said detector means for maintaining said beam energized for a predetermined time period.

7. An oscilloscope for displaying each of plural input signals in a respectively different color as described in claim 6 wherein:

said means for maintaining said beam energized for a predetermined time period includes a pulse generator responsive to said detector means for producing a pulse whose width is substantially coincident with the length of a single excursion of said continuous vertical scan of said beam across the face of said tube.

8. An oscilloscope for displaying each of plural input signals in a respectively different color as described in claim 6 wherein:

said means for maintaining said beam energized for a predetermined time period includes a gate means responsive to the output of said detector means and to said deflection means so that said vertical reference line is terminated substantially coincident with the termination of one excursion of said vertical scan.

9. In a multicolor oscilloscope for displaying each of plural input signals in a respectively different color:

a multielectron beam cathode-ray tube and means for continuously scanning said beams across the screen of said tube along a given axis;

color convergence means for deflecting said electron beams to change the distance between the source of said electron beams and the point of convergence of said electron beams, said convergence means including;

electromagnet means proximate said electron beams; and

means for energizing said electromagnet means at a frequency which is double the scanning frequency of said electron beams along said given axis.

10. The multicolor oscilloscope of claim 9 wherein said means for energizing said electromagnet means includes an oscillator which is synchronous with said scanning frequency, said oscillator generating an output which is double the frequency of said scanning frequency, the output of said oscillator being connected to said electromagnet means.

11. The multicolor oscilloscope of claim 10 wherein said oscillator output is a square wave, said color convergence means including filter means for filtering the square wave output of said oscillator so that an essentially sinusoidal current is coupled to drive said electromagnet means.

12. The multicolor oscilloscope of claim 11 wherein said filter means comprises an independently adjustable filter for each beam of said cathode-ray tube, each filter being adjustable for varying the phase shift of the resultant sinusoidal current and the amplitude of said current.

13. In a multicolor oscilloscope for displaying each of plural input signals in a respectively different color:

a cathode-ray tube having a screen, plural phosphors on said screen for displaying said different colors when energized by an electron beam, and a deflection coil for producing a magnetic field for deflecting said electron beam generating means for generating a wave shape at the frequency at which said beam is to be deflected along one axis of said tube, and a capacitor connected in series with said deflection coil, said series circuit coupled to said generating means, said capacitor having a capacitance which resonates with the inductance of said coil at said frequency so that the voltage across said coil is substantially higher than that of the generated wave shape.

14. The multicolor oscilloscope of claim 13 wherein said generating means comprises:

means for producing a voltage proportional to the current through said deflection coil; and

amplifier means for amplifying said proportional voltage to produce said wave shape so that the output of said amplifieR means is feed back coupled to its input causing the circuit to oscillate at said frequency.

15. The multicolor oscilloscope of claim 14 additionally including:

means for phase shifting said voltage proportional to the current through said deflection coil, said phase shift causing a change in said oscillation frequency.

16. The multicolor oscilloscope of claim 15 further including:

phase comparator means for comparing the phase of the voltage proportional to the current through said deflection coil with the phase of a constant frequency signal; and

means operatively coupling the output of said phase comparator means to said phase shifting means so that the oscillation frequency is changed to avoid drift of the signals displayed on the screen of said cathode-ray tube.

17. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having plural electron guns for producing plural independent electron beams for exciting respectively different colored phosphors on the tube screen;

vertical deflection means for scanning said beams upwardly and downwardly across said screen;

plural comparator means respectively responsive to said input signals for comparing the position of one of said beams with the respective one of said input signals and energizing the electron gun of said beam when the beam position corresponds to the magnitude of the input signal.

18. An oscilloscope for displaying each of plural input signals in a respectively different color comprising:

a cathode-ray tube having a screen which includes phosphors which emit light of a plurality of colors when energized;

means for scanning said screen for selectively energizing said phosphors;

plural comparator means responsive to said input signals for simultaneously comparing the position of said scanning means with said input signals for generating a plurality of phosphor illumination dots on said screen; and

dots of respectively different color being generated for each of said input signals.

19. An oscilloscope for simultaneously displaying first and second waveforms comprising:

a cathode-ray tube having a screen and means for producing an electron beam for exciting phosphor on said screen;

deflection means for repetitively and continuously scanning said beam across said screen along one axis;

means for comparing the position of said beam with said first and second waveforms to (i) generate a phosphor illumination dot on said screen during scan in a given direction along said one axis corresponding to the magnitude of said first signal and (ii) generate a phosphor illumination dot on said screen during scan in the opposite direction along said one axis corresponding to the magnitude of said second signal.

20. A device for simultaneously visually displaying a plurality of input signals comprising:

a cathode-ray tube having a screen which includes phosphors which emit light of a plurality of colors when energized;

plural means for respectively monitoring the changes in amplitude of said input signals with time;

each of said means capable of monitoring a randomly varying signal wave shape;

means for continuously scanning said cathode-ray tube along one axis;

means for deflecting said cathode-ray tube along a second axis; and

plural means responsive to said monitoring means and said scanning means for comparing the position of said continuous scanning with the amplitude of each of said input signals during any single deflection along said second axis to energize a different one of said phosphors for each of said input signals at spatial locations dependent upon the amplitudes of said respective input signals.

21. An oscilloscope comprising:

means for continuously scanning a cathode-ray tube along one axis;

means for deflecting said cathode-ray tube along a second axis;

means for comparing the amplitudes of a plurality oF input signals with the output of said scanning means during any single deflection along said second axis; and

means responsive to said comparing means for generating a plurality of phosphor illumination dots on the face of said oscilloscope, dots of different colors being generated for each of said input signals.

22. In a multielectron-gun cathode-ray tube display system in which the electron beams are deflected along one axis at a constant frequency and wherein an input signal is compared with the electron beam deflection along said one axis:

means for synchronizing said constant frequency to a reference frequency; and

means for deflecting said electron beams along an axis perpendicular to said one axis, said means for deflecting being synchronized to said reference frequency.

23. In a display device having a cathode-ray tube in which a deflection coil magnetically deflects the electron beam at a given frequency:

generating means for generating a wave shape at said frequency; and

a series resonant circuit comprising;

a capacitor connected in series with said deflection coil, said series resonant circuit coupled to said generating means, said capacitor having a capacitance which resonates with the inductance of said coil at said frequency so that the voltage across said coil is substantially higher than that of the generated wave shape.