# US 4,399,512 A · Waveform searching system

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- Number: US 4,399,512 A
- Document ID: US4399512A
- Status: Granted
- Kind: A
- Application number: 06/217,462
- Filed: 1980-12-17
- Granted: 1983-08-16
- Earliest claimed: 1979-12-27
- Assignees: Iwasaki Tsushinki Kabushiki Kaisha
- Inventors: Masafumi Soma; Yoshihiko Kohno
- Web page: https://patentgrep.com/patent/US4399512A

## CPC

- G01R 29/02: Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time or duration
- G01R 13/06: Modifications for recording transient disturbances, e.g. by starting or accelerating a recording medium
- G01R 13/34: Circuits for representing a single waveform by sampling, e.g. for very high frequencies
- G01R 15/09: Autoranging circuits
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time; the input analog signal is sampled by the sampling pulses to produce sampled pulses; and the sampled pulses are displayed by the X-axis sweep signal on a CRT. In accordance with the present invention, there are provided detecting means for detecting a predetermined condition where a waveform formed by respective peak values of the sampled pulses cross in a predetermined direction at a predetermined search level by a predetermined number; and control means for sequentially changing a time base range until the detecting means detects the predetermined condition, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.

## Claims

### Claim 1

In a waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time; the input analog signal is sampled by the sampling pulses to produce sampled pulses; and the sampled pulses are displayed by the X-axis sweep signal on a CRT, the improvement comprising detecting means for producing a coincidence signal if a predetermined condition is detected where a waveform formed by respective peak values of the sampled pulses crosses in a predetermined direction at a predetermined search level by a predetermined number; and control means operatively connected to the detection means for sequentially changing a time base range of the CRT until said detecting means produces the coincidence signal, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.

### Claim 2

In a waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time; the input analog signal is sampled by the sampling pulses to produce sampled pulses; and the sampled pulses are displayed by the X-axis sweep signal on a CRT, the improvement comprising detecting means for producing a coincidence signal if a predetermined condition is detected where a waveform formed by respective peak values of the sampled pulses cross in a predetermined direction at a predetermined search level by a predetermined number; and control means operatively connected to the detection means for sequentially changing a time base range of the CRT determined by the inclination of the high-speed saw-tooth signal and the amplitude of the X-axis sweep voltage wave until the detecting means produces the coincidence signal, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.