Optical Sensor Analog Discriminator Interference Masking

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Solution Overview

Problem

Optical sensors used in distance measurement systems face interference from partial reflections on transparent or highly reflective objects, leading to error measurements due to superimposed interference signals.

Innovation Solution

Incorporation of electronic discriminator means to mask out interfering signal pulses in the analog received signal before digitization, allowing only useful signal pulses to be evaluated, thereby eliminating interference and ensuring accurate object detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electronic discrimination means are used to mask out interfering signal pulses, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The electronic discrimination means performs preliminary masking of interfering signal pulses in the analog received signal before digitization. By proactively suppressing interference signals in the analog domain, the system prevents these signals from being processed further, thereby improving measurement precision while managing complexity through early intervention in the signal chain.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The electronic discrimination means acts as an intermediary component between the receiver and the evaluation unit. It selectively masks interfering signal pulses in the analog received signal, allowing only valid distance measurement signals to pass through to the evaluation unit, thus improving measurement accuracy without requiring complex processing throughout the entire system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If multiple light pulses are registered and evaluated, then productivity is improved, but reliability deteriorates due to interference signals

Engineering Contradiction:
Improveobject detection speedVSAvoidsignal evaluation accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The electronic discrimination means extracts and removes interfering signal pulses from the sequence of received signal pulses in the analog domain. By selectively masking these interference signals before digitization, the system can process multiple light pulses rapidly (improving productivity) while ensuring that only valid object detection signals are evaluated (maintaining reliability).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary filtering of interference signals in the analog received signal before the pulses are digitized and processed. This early masking action allows multiple pulses to be registered and evaluated quickly while preventing interference from compromising the reliability of the evaluation process.

Inventive Principle:
Principle #10Preliminary 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 enhances the functional reliability of optical sensors by suppressing interference signals, ensuring accurate distance measurements and preventing incorrect readings, particularly in applications requiring precise object detection and safety functions.

Implementation Method 1

A transmitter 3 is provided, emitting transmitted light in the form of light pulses

Methodology Applied
Scientific EffectLight: Light

Implementation Method 2

a receiver 4 that receives the light pulses

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4306998A1Optical sensor
Publication Date: 2024.01.17 LEUZE ELECTRONIC GMBH & CO KG
  • EP4306998A1 patent drawingFigure 1a~1b
  • EP4306998A1 patent drawingFigure 2~3
  • EP4306998A1 patent drawingFigure 4

AI summary

The invention relates to an optical sensor (1) with a light pulse emitting transmitter (3), a light pulse receiving receiver (4), and an evaluation unit (5) in which an object distance is determined from the transit time of light pulses to an object (9) and back to the receiver (4). Electronic discriminators are provided by means of which a received signal pulse (E) from a sequence of received signal pulses (E) generated by a light pulse of the sensor (1) can be filtered out in an analog received signal at the output of the receiver (4).