Waveform Processing Circuit Undershoot for Light Detection

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Solution Overview

Problem

Existing object detection systems face challenges in accurately detecting the timing of receiving light due to noise and signal fluctuations, leading to inaccuracies in distance measurement.

Innovation Solution

A circuit device comprising a waveform processing circuit and a binarizing circuit is used to generate undershoot in the voltage signal from a light-receiving element, allowing for precise detection of the timing of light reception by binarizing the signal based on threshold values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional light detection techniques are used, then the detection system is simple, but the accuracy of detecting the timing of receiving light is insufficient

Engineering Contradiction:
Improveaccuracy of detecting timing of receiving lightVSAvoidcomplexity of circuit device
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The waveform processing circuit performs preliminary processing on the voltage signal by generating undershoot before the binarizing circuit converts it to a binary signal. This preliminary action of creating undershoot in advance allows for more accurate timing detection by providing a clearer threshold crossing point, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The waveform processing circuit acts as an intermediary between the light-receiving element and the binarizing circuit. It processes the voltage signal by generating undershoot, which serves as a mediator to improve the accuracy of timing detection without requiring complex changes to the overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If no undershoot is generated in the voltage signal, then the circuit is simpler, but the accuracy of distance measurement deteriorates due to noise and signal fluctuations

Engineering Contradiction:
Improveaccuracy of distance measurementVSAvoidcomplexity of waveform processing
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The waveform processing circuit generates undershoot in advance as a preliminary action to counteract the effects of noise and signal fluctuations. This pre-processing step creates a more distinct signal characteristic that improves distance measurement accuracy by providing a clearer reference point for timing detection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The generation of undershoot serves as a preliminary anti-action against noise and signal fluctuations. By intentionally creating this signal feature in advance, the system preemptively counteracts the detrimental effects of noise on measurement accuracy, allowing for more reliable timing detection.

Inventive Principle:
Principle #9Preliminary anti-action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly improves the accuracy of pulsed light detection and reduces measurement errors, enabling stable and precise distance calculation to objects.

Implementation Method 1

a light-receiving element to receive light projected from the projection device to the object and reflected from the object

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3147690B1Circuit device, optical detector, object detector, sensor, and movable device
Publication Date: 2019.02.20 RICOH CO LTD
  • EP3147690B1 patent drawingFigure 1
  • EP3147690B1 patent drawingFigure 2A~2C
  • EP3147690B1 patent drawingFigure 3A~3B

AI summary

A circuit device (44) includes a waveform processing circuit (60) and a binarizing circuit (70). The waveform processing circuit (60) generates undershoot in a voltage signal according to an output voltage from a light-receiving element (42). The binarizing circuit (70) binarizes the voltage signal based on a threshold value.