Laser Head Protector Temperature Sensing for Contamination Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing dirt detecting means in laser processing heads, which is disposed on the rim of the protective glass, suffers from low intensity and accuracy in detecting contaminants due to diffusely reflected light, and is prone to interference from scattered light.

Innovation Solution

A laser processing head with a transparent protector that is detachably fixed to the housing, equipped with a temperature sensor to detect the temperature of the transparent protector, allowing for the detection of contaminant adhesion by measuring the temperature increase caused by absorbed laser light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the dirt detecting means is disposed on the rim of the protective glass to detect contaminants, then the detection structure is simple, but the detection accuracy is low due to low intensity of diffusely reflected light and interference from scattered light

Engineering Contradiction:

Improvedetection structureVSAvoidcontaminant detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the optical detection system (light sources, optical sensors, diffuse reflection detection) with a thermal detection system (temperature sensor). Instead of detecting light reflected from contaminants, the system measures temperature changes of the protective glass caused by heat from accumulated contaminants, thereby resolving the accuracy issues of optical detection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces temperature as an intermediary parameter to indirectly detect contaminant accumulation. Rather than directly detecting contaminants through light, the system uses temperature rise as a mediator that correlates with contaminant mass, enabling accurate detection without the limitations of direct optical methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the dirt detecting means detects diffusely reflected light from contaminants, then the detection method is straightforward, but the detection value is low making accurate detection difficult

Engineering Contradiction:

Improvedetection methodVSAvoiddetection value

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent substitutes the optical detection method (detecting diffuse reflected light) with a thermal detection method (measuring temperature). This replacement maintains operational simplicity while dramatically improving detection sensitivity, as temperature sensors can detect subtle thermal changes caused by contaminant heat absorption more effectively than optical sensors can detect weak reflected light.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from optical intensity (diffuse reflected light) to thermal parameter (temperature). This parameter transformation enables more sensitive detection of contaminant accumulation, as temperature rise provides a stronger and more reliable signal than the weak optical reflection from contaminated surfaces.

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

This method enables accurate detection of contaminant adhesion on the transparent protector, providing a reliable means to determine when the protector needs to be replaced, thus maintaining the integrity of the laser processing system.

Implementation Method 1

the intensity of the laser light to be radiated to the work material decreases. Therefore, the laser processing head includes a protective glass for protecting the collecting lens from contaminants such as the sputters or fumes

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

A laser processing head includes a housing, a transparent protector that is detachably fixed to the housing, and a temperature sensor that detects the temperature of the transparent protector

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentEP3685953B1Laser processing head and laser processing system using same

Publication Date: 2025.02.12 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

Figure 1
Figure 2
Figure 3

AI summary

Laser processing head (20) of the present disclosure includes housing (30), transparent protector (40), and temperature sensor (70). Housing (30) includes an optical path of processing laser light (LB). Transparent protector (40) is detachably fixed to housing (30), passes processing laser light (LB), and suppresses dust of work material (W) entering into housing (30). Here, the dust is generated from the work material (W) irradiated with processing laser light (LB). Temperature sensor (70) detects the temperature of transparent protector (40).