Method and system for generating oscillographic displays of analog signals upon a TV

• US 4,058,826 A
• Filed: 04/15/1976
• Issued: 11/15/1977
• Est. Priority Date: 04/15/1976
• Status: Expired due to Term

• Current Assignee: Seymour Schneider
• Original Assignee: Seymour Schneider
• Inventors: Schneider, Seymour
• Primary Examiner(s): Richardson, Robert L.
• Application Number:
  US05/677,432
• Time in Patent Office: 579 Days
• Field of Search: 178/DIG. 4, 358/10, 358/139, 324/88
• US Class Current: 348/184
• CPC Class Codes: G01R 13/22 Circuits therefor
• CPC Class Codes: G09G 1/162 for displaying digital inputs as analog magnitudes, e.g. curves, bar graphs, coordinate axes, singly or in combination with alpha-numeric characters cathode-ray oscilloscopes for displaying analog inputs, singly or in combination with alpha-numeric characters G01R13/20; television receiver circuitry for displaying supplementary, e.g. alpha-numeric, information H04N5/445
• CPC Class Codes: H04N 17/02 for colour television signals

Abstract

An oscillographic display of at least one input signal which is of arbitrary period or is aperiodic may be generated upon a standard television receiver by storing the input signal in a storage medium containing a multiplicity of storage elements and triggering the storage in synchronism with the input signal. The rate of storage of the input signal is controlled independent of the input signal rate. The stored input signal is thereafter read out at a time rate synchronized to the horizontal synchronization frequency of the television receiver and converted into compatible video signals for display. Adjustment of the rate of storage of the input signal provides a corresponding change in time scale in the displayed input signal. Color labeling and a background color is provided as well as a graticule.

Claims

1. A method for generating an oscillographic display of at least one periodic or aperiodic input signal upon a standard television receiver with said input signal being generated external of said receiver and being independent of the television receiver raster frequency, comprising the steps of:

storing said input signal in a multiplicity of storage elements with each element being responsive to said input signal at a different moment in time;

initiating said storage in synchronism with said input signal;

controlling the rate at which said input signal is stored in said storage elements independent of the input signal rate;

reading the signals stored in said storage elements at a rate in synchronism with the horizontal synchronization frequency of said television receiver;

converting the read signals into corresponding video signals compatible with said television receiver; and

displaying said video signals.

2. A method as defined in claim 1 wherein said controlled rate is variable for adjusting the time scale of the input signal display upon the television receiver.

3. A method as defined in claim 2 further comprising the steps of generating a video color signal simultaneously with each video signal and generating a background color signal during the absence of each video color signal.

4. A method as defined in claim 3 further comprising the steps of generating a first plurality of video signals at a first fixed frequency proportional to a multiple of the horizontal synchronization rate for said standard television receiver and generating a second plurality of video signals at a second fixed frequency proportional to a fraction of the horizontal synchronization rate whereby said first and second plurality of video signals form a display graticule.

5. A method as defined in claim 4 further comprising generating graticule video color signals corresponding to said first and second plurality of video signals and displaying said graticule color signals during the time interval when said first and second plurality of video signals are being displayed.

6. A method as defined in claim 4 wherein said conversion of signals to corresponding video signals comprises the steps of:

generating a ramp signal having a period equal to the horizontal synchronization period for said standard television receiver;

sequentially comparing each read signal with each ramp signal; and

generating a video signal during each comparison at an instant in time when the magnitude of the signal equals the magnitude of said ramp signal.

7. A method as defined in claim 4 wherein said conversion of read signals to corresponding video signals comprises the steps of:

generating a ramp signal in synchronism with the horizontal synchronization pulse of said standard television receiver;

comparing the magnitude of two successive read signals with said ramp signal;

generating a first output signal when the magnitude of one of said two successive read signals equals the magnitude of said ramp signal;

generating a second output signal when the magnitude of the other said read signals equals the magnitude of said ramp signal;

generating a pulse of predetermined duration at the earliest inception of said first and second read signal

generating a video signal coincident in time with said pulse and of a duration equal to the greater of said predetermined pulse duration and the time difference between said first and second read signals.

8. A system for generating an oscillographic display of at least one period of aperiodic input signal upon a standard television receiver with said input signal being generated external of said receiver and being independent of the television receiver raster frequency comprising:

a storage medium containing a multiplicity of storage elements;

means for storing said input signal in said storage elements with each element being responsive to said input signal at a different moment in time;

means for controlling the rate of storage of said input signal in said storage elements;

means for triggering the initiation of said storage in synchronism with said input signal;

means for consecutively reading the signals stored in said storage elements at a rate in synchronism with the horizontal synchronization frequency of said television receiver;

means for converting the read signals into corresponding video signals compatible with said television receiver; and

means for displaying said video signals.

9. A system as defined in claim 8 further comprising clock means responsive to the triggering of said storage for generating clock pulses at a given rate and wherein said means for controlling said storage rate includes means for varying said clock pulse rate.

10. A system as defined in claim 9 wherein said means for storing said input signal is a sample and hold circuit including a multiplicity of switch means and storage capacitors and further comprising write commutator means for sequentially controlling each of said switch means in response to said clock pulses over a predetermined commutation period.

11. A system as defined in claim 10 further comprising means for converting said stored input signals into corresponding digital signals;

memory means;

means for storing said digital signals into said memory means;

means for retrieving the digital signals from said memory means and means for converting said digital signals to analog signals.

12. A system as defined in claim 10 further comprising:

means for receiving a multiple number of separate input signals;

means for converting each of said separate input signals into corresponding video signals;

means for generating a corresponding video color signal simultaneously with each video signal; and

means for generating a background color signal during the absence of each video color signal.

13. A system as defined in claim 12 further comprising means for adjusting the hue and saturation of each of said video color signals and of said background color signal.

14. A system as defined in claim 13 further comprising means for generating a master clock signal,

means for dividing the master clock signal into a first plurality of video signals at a rate proportional to a multiple of the horizontal synchronization rate;

means for further dividing the master clock signal into a second plurality of video signals at a rate proportional to a fraction of the horizontal synchronization rate; and

means for generating corresponding video color signals for said first and second plurality of video signals.

15. A television oscilloscope as defined in claim 14 further comprising digital memory means and

means for transferring each of the stored sampled signals to said digital memory means;

said digital memory means including means for converting the stored analog signals to digital signals and means responsive to a command instruction for reconverting said digital signals back to analog signals.

16. A television oscilloscope for examining at least one periodic or aperiodic input signal generated from a source external thereof, comprising;

in combination, within a single housing, a standard TV receiver including color demodulation means and vertical and horizontal deflection means, and means for generating an oscillographic display of said input signals upon said receiver, said generating means comprising;

a storage medium containing a multiplicity of storage elements;

means for storing said input signal in said storage elements with each element being responsive to said input signal at a different moment in time;

means for adjustably controlling the rate of storage of said input signal in said storage elements;

means for triggering the initiation of said storage in synchronism with said input signal;

means for consecutively reading the signals stored in said storage elements at a rate in synchronism with the horizontal synchronization frequency of a standard TV receiver;

means for converting the read signals into TV video signals;

means for generating pulses at the horizontal synchronization frequency of a standard TV receiver;

means for generating pulses at the vertical synchronization frequency of a standard TV receiver;

means for applying said video signals to said color demodulation means; and

means for applying said horizontal and vertical synchronization pulses to said horizontal and vertical deflection means respectively.