Protective Glass Contamination Detection With Dynamic Laser Thresholds

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Solution Overview

Problem

Existing protective glass contamination detection systems fail to accurately assess contamination levels due to variations in laser processing conditions, leading to improper detection of contamination on protective glass surfaces in laser processing machines.

Innovation Solution

A protective glass contamination detection device that adjusts contamination thresholds based on real-time processing conditions, including laser beam parameters and sensor characteristics, to accurately determine the degree of contamination on the protective glass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed contamination threshold is used for detection, then the detection system is simple to operate, but the detection accuracy deteriorates when laser processing conditions change

Engineering Contradiction:
Improvedetection system operationVSAvoidcontamination detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The contamination threshold is changed from a fixed value to a dynamic value that automatically adjusts according to laser processing conditions. The threshold calculation unit computes the threshold based on real-time laser output, duty ratio, and pulse frequency parameters, enabling the detection system to adapt to varying processing conditions while maintaining accurate contamination detection

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The detection threshold parameter is modified as a function of laser processing parameters (output, duty ratio, pulse frequency). By establishing a mathematical relationship between the threshold and these parameters, the system dynamically adjusts the threshold to compensate for changes in scattered light intensity caused by varying laser conditions, thereby maintaining detection accuracy

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the laser output is doubled according to processing conditions, then the processing efficiency is improved, but the scattered light intensity doubles causing improper contamination detection

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidcontamination detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system incorporates feedback from laser processing parameters (output, duty ratio, pulse frequency) to dynamically adjust the contamination threshold. When laser output is increased to improve productivity, the threshold calculation unit receives this information and automatically adjusts the threshold accordingly, compensating for the doubled scattered light intensity and maintaining accurate contamination detection

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The contamination detection threshold is changed as a function of laser processing parameters. The threshold calculation unit computes the threshold based on the relationship between laser output, duty ratio, pulse frequency, and scattered light intensity, enabling the system to maintain detection accuracy even when laser output is doubled for improved processing efficiency

Inventive Principle:
Principle #35Parameter changes

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

Enables precise detection of contamination levels on protective glass, ensuring timely replacement and maintaining processing quality by accounting for variations in laser processing conditions.

Implementation Method 1

detect scattered light caused by the contamination adhered to the protective glass

Methodology Applied
Scientific EffectScattered light: Scattering

Data Source

PatentEP4417357B1Protective glass dirtiness detection device and protective glass dirtiness detection method
Publication Date: 2026.01.21 AMADA CO LTD
  • EP4417357B1 patent drawingFigure 1
  • EP4417357B1 patent drawingFigure 2~3
  • EP4417357B1 patent drawingFigure 4

AI summary

A protective glass contamination detection device that detects contamination on a protective glass 25 for protecting a focusing lens 19 for focusing a laser beam to irradiate the focused laser beam onto a workpiece W includes a scattered light detection unit 27, an information acquisition unit 35, a contamination threshold setting unit 37, and a contamination determination unit 39. The scattered light detection unit 27 detects scattered light SL generated by contamination 51 adhered to the protective glass 25. An information acquisition unit 35 acquires information on processing conditions of a laser processing machine. The contamination threshold setting unit 37 sets a contamination threshold for detecting contamination on the protective glass 25 from a detection value X detected by the scattered light detection unit based on processing conditions of the laser processing machine. The contamination determination unit 39 determines a degree of contamination on the protective glass 25 based on the detection value X and the contamination threshold.