Polygon Mirror Lightguide for Widthwise Laser Spot Distribution

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Solution Overview

Problem

Conventional light guide devices are unable to disperse the position of an irradiated area in the line width direction without moving the irradiation target, particularly when processing circular or point-shaped areas or reading information.

Innovation Solution

A light guide device comprising a first light guide part, a rotatable polygon mirror with multiple reflective surfaces forming a regular polygonal shape, and a second light guide part that reflects and guides the light to offset the optical axis in the rotation axis direction, allowing the irradiated area to be distributed in the width direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional light guide device is used to irradiate a target, then the light can be directed to a specific point, but the irradiated area cannot be dispersed in the line width direction without moving the target

Engineering Contradiction:
Improveability to disperse irradiated area positionVSAvoidstructural complexity of light guide device
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The polygon mirror is segmented into multiple reflective surfaces (first reflective surface, second reflective surface, third reflective surface) positioned at different locations in the rotation axis direction. Each reflective surface directs light to a different position in the line width direction, thereby dispersing the irradiated area without moving the target.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reflective surfaces are arranged in the rotation axis direction (a dimension perpendicular to the scanning direction), which allows the irradiated area to be dispersed in the line width direction. This dimensional arrangement enables position distribution without mechanical movement of the target.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the position of reflective parts in the rotation axis direction differs, then the irradiated area position can be distributed, but the optical path length may vary

Engineering Contradiction:
Improveposition distribution of irradiated areaVSAvoidoptical path length consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Each reflective surface is specifically positioned at a different location in the rotation axis direction to create local variations in the optical path. The first reflective surface, second reflective surface, and third reflective surface are arranged such that their respective optical paths are equalized, ensuring consistent optical path length despite different positions.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the optical axis is offset in the rotation axis direction, then the irradiated area can be dispersed in the width direction, but the focus point may shift relative to the workpiece

Engineering Contradiction:
Improvewidth direction dispersion of irradiated areaVSAvoidfocus point position accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The polygon mirror rotates to bring different reflective surfaces into the optical path dynamically. As the mirror rotates, the first reflective surface, second reflective surface, and third reflective surface sequentially direct light to different positions in the line width direction, achieving both dispersion and consistent focus.

Inventive Principle:
Principle #15Dynamics

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 the distribution of the irradiated area in the width direction without moving the irradiation target, enhancing processing efficiency and preventing process saturation by maintaining a consistent optical path length and adjusting the focus point relative to the workpiece.

Implementation Method 1

The first light guide part reflects and guides a light emitted from a light source

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

The reflective part of the polygon mirror is configured to reflect the incident light so that the optical axis of the incident light is offset in the rotation axis direction

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The second light guide part reflects the light reflected by the reflective part of the polygon mirror and guides the light so that the light is irradiated to an irradiation target

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3812826B1Lightguide device and laser processing device
Publication Date: 2023.07.26 KAWASAKI JUKOGYO KK
  • EP3812826B1 patent drawingFigure 1
  • EP3812826B1 patent drawingFigure 2
  • EP3812826B1 patent drawingFigure 3

AI summary

The light guide device (13) includes a first light guide part (20), a polygon mirror (30), and a second light guide part (40). The first light guide part (20) reflects and guides the laser light emitted from the laser generator (12). The polygon mirror (30) is configured to be rotatable and includes a plurality of reflective parts (33), the reflective parts (33) being arranged to form a regular polygonal reflective surface when viewed in a rotation axis (31) direction, the polygon mirror (30) reflecting the laser light guided by the first light guide part (20) by the reflective part while rotating. The second light guide part (40) reflects the laser light reflected at the reflective part (33) of the polygon mirror (30) and guides the laser light so that the laser light is irradiated to the workpiece (100) at each of the reflective parts (33). The reflective part (33) of the polygon mirror (30) is configured to reflect the incident laser light so that the optical axis of the incident light is offset in the rotation axis (31) direction. At least two reflective parts (33) differ from each other in position in the rotation axis (31) direction.