Laser processing head and laser processing device provided with same

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Solution Overview

Problem

Existing laser processing heads with low reflectance on the outer and inner peripheral surfaces of the protective glass and shield holder fail to detect fine contamination effectively, leading to delayed detection of contamination on the protective glass.

Innovation Solution

Incorporating a reflective coating film on the outer peripheral surface of the protective glass and the inner peripheral surface of the shield holder, except for the opposed region facing the optical sensor, increases reflectance and enhances the detection of scattered light by the optical sensor, allowing for earlier detection of contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the outer peripheral surface of the protective glass and the inner peripheral surface of the opening have low reflectance, then the structure is simple and manufacturing is easier, but fine contamination cannot be detected effectively

Engineering Contradiction:
Improvecontamination detection precisionVSAvoidstructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by forming a reflective coating film only on specific regions (the outer peripheral surface of the protective glass and the inner peripheral surface of the opening) rather than the entire structure. This localized coating increases reflectance precisely where needed for contamination detection, while maintaining simplicity in other areas. The coating is applied selectively to surfaces that will reflect scattered light to the optical sensor, thereby improving detection precision without unnecessarily complicating the overall device structure.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If a reflective coating film is formed on the outer peripheral surface of the protective glass and inner peripheral surface of the opening, then finer contamination can be detected, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvecontamination detection precisionVSAvoidmanufacturing ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The reflective coating film is applied locally to specific surfaces (outer peripheral surface of protective glass and inner peripheral surface of opening) rather than requiring coating of entire components. This localized approach improves contamination detection precision by enhancing scattered light reflection to the optical sensor, while minimizing the impact on manufacturing ease since only specific regions require the additional coating process.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the reflective coating film is formed on the opposed region facing the optical sensor, then the detection sensitivity increases, but the laser beam transmission is blocked

Engineering Contradiction:
Improvedetection sensitivityVSAvoidlaser beam transmission
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by strategically positioning the reflective coating film on regions that will not interfere with the laser beam path. Specifically, the coating is formed on the outer peripheral surface of the protective glass and the inner peripheral surface of the opening, but deliberately excluded from the opposed region that faces the optical sensor. This ensures that scattered light from contamination is reflected toward the sensor while the laser beam remains unobstructed, thereby maintaining both detection sensitivity and laser transmission reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The reflective coating film acts as an intermediary element that redirects scattered light from contamination particles toward the optical sensor without interfering with the primary laser beam. By positioning the coating on peripheral surfaces rather than on the opposed region, it mediates between the need for high detection sensitivity and the requirement for uninterrupted laser transmission, enabling both functions to coexist effectively.

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

This configuration enables finer contamination to be reflected in the detection value of the optical sensor, facilitating early detection and preventing processing quality deterioration by prompting timely cleaning or replacement of the protective glass.

Implementation Method 1

a reflective coating film formed in a region in the outer peripheral surface except an opposed region facing the light receiving surface of the at least one optical sensor, or the shield holder including the reflective coating film formed in a region in the inner peripheral surface of the opening except the light passing hole

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3978179B1Laser processing head and laser processing device provided with same
Publication Date: 2023.10.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3978179B1 patent drawingFigure 1
  • EP3978179B1 patent drawingFigure 2
  • EP3978179B1 patent drawingFigure 3A~3B

AI summary

Provided is a laser processing head including: shield holder (23) that has opening (23b) formed through shield holder (23) and optical sensor mounting hole (23c) formed in an inner peripheral surface of opening (23b); optical sensor (24) that has light receiving surface (24a) facing the inside of opening (23b) through optical sensor mounting hole (23c) and is attached to shield holder (23); and second protective glass (25) that has an outer peripheral surface facing light receiving surface (24a) of optical sensor (24) and is provided in opening (23b), second protective glass (25) transmitting a laser beam emitted by a laser oscillator to emit the laser beam toward a workpiece, and second protective glass (25) including reflective coating film (25a) formed in a region in the outer peripheral surface except an opposed region facing light receiving surface (24a) of optical sensor (24).