Laser Processing Head Layout for Wavelength-Specific Return Light Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In hybrid laser processing systems using two laser beams of different wavelengths, it is challenging to determine the processing state of a workpiece and the internal state of the laser processing head due to the difficulty in separating reflected return light from the workpiece and vignetting light in optical components, particularly with multiple optical components in the optical path.

Innovation Solution

A laser processing head with a housing containing separate optical paths for each laser beam, using a partition wall to separate the optical paths and photodetectors specific to each wavelength band to detect reflected light, allowing for the determination of processing states by analyzing output signals from these detectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple optical components are disposed in the optical path of each laser beam in a hybrid laser processing system, then the processing capability is enhanced, but the difficulty of detecting and measuring the internal state of the laser processing head increases

Engineering Contradiction:
Improveprocessing capabilityVSAvoidinternal state detection difficulty
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the optical path into separate first and second optical paths for different wavelength laser beams. Photodetectors are specifically assigned to detect light from each wavelength band separately, allowing the system to handle multiple laser beams while maintaining detectability of the internal state through segmented monitoring

Inventive Principle:
Principle #1Segmentation

2Device complexity

If reflected return light from the workpiece and vignetting light in optical components are mixed, then the system structure is simplified, but the measurement precision of the processing state determination deteriorates

Engineering Contradiction:
Improvesystem structureVSAvoidprocessing state determination precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the detection function by providing separate photodetectors for different wavelength bands. The first photodetector detects light in the first wavelength band while the second photodetector detects light in the second wavelength band, enabling precise determination of processing state by analyzing wavelength-specific reflected light separately

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses wavelength as an intermediary to separate and identify different light sources. By detecting the wavelength characteristics of reflected light, the system can distinguish between processing-related signals and interference from optical components, improving measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

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 accurate determination of the processing state of the workpiece and the internal state of the laser processing head, improving processing quality and defect detection by separating and evaluating the reflected light components effectively.

Implementation Method 1

a first photodetector provided around the optical path of the first laser beam entering through the first light entrance port, and a second photodetector provided around the optical path of the second laser beam entering through the second light entrance port

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4091758B1Laser processing head, laser processing system, and method of determining abnormality of laser processing system
Publication Date: 2024.03.06 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4091758B1 patent drawingFigure 1
  • EP4091758B1 patent drawingFigure 2
  • EP4091758B1 patent drawingFigure 3

AI summary

Laser processing head 10 includes housing 11 and a plurality of optical components. Housing 11 is provided with partition wall 11a, first and second light entrance ports 12a, 12b through which first and second laser beams A, B respectively enter, and light irradiation port 13. Laser processing head 10 includes first and second photodetectors 91b, 92a provided around first and second light entrance ports 12a, 12b, respectively. First photodetector 91b is disposed opposite to second photodetector 92a across partition wall 11a. First photodetector 91b receives light in the second wavelength band including the wavelength of second laser beam B, and second photodetector 92a receives light in the first wavelength band including the wavelength of first laser beam A.