Method for displaying signal characteristics

• US 5,241,302 A
• Filed: 09/13/1991
• Issued: 08/31/1993
• Est. Priority Date: 09/13/1991
• Status: Expired due to Fees

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Thong, Tran
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US07/759,352
• Time in Patent Office: 718 Days
• Field of Search: 340/701, 340/703, 340/722, 324/77 B, 324/78 D, 324/78 T, 324/78 Q
• US Class Current: 345/589
• CPC Class Codes: G01R 13/00 Arrangements for displaying electric variables or waveforms
• 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

Abstract

The present invention provides a method of displaying characteristics of a signal, where minimum amplitude of the signal during an interval is graphed versus time, maximum amplitude of the signal during the interval is graphed versus time, and the color or greyness of the area between the minimum amplitude graph and the maximum amplitude graph represents the average frequency during the interval of the amplitude measurements.

Claims

1. A method of processing a history of data values, each data value having a time value, a frequency value and an amplitude value for an input signal, comprising the steps of:

formatting the data values for display to produce for each of a plurality of time intervals of the history, each time interval defining a range of the time values, minimum and maximum amplitude values and an average frequency value; and

displaying the formatted data such that the minimum and maximum amplitude values are represented by distances above a time axis with a length equal to the time interval to form a box, and the average frequency value is represented by one of a plurality of intensity data values that fills the box, each intensity data value representing a specified range of frequencies.

2. The method of claim 1 wherein the formatting step for each time interval comprises the steps of:

determining a range of rows in a frame buffer to represent the minimum amplitude to maximum amplitude values;

determining a range of columns in the frame buffer to represent the time interval;

determining an intensity value to represent the average frequency; and

storing the intensity value at the locations in the frame buffer addressed by the range of columns and rows.

3. The method of claim 2 wherein the intensity data value represents a displayable color.

4. The method of claim 2 wherein the intensity data value represents a displayable grey tone.