Rotation Mirror Pyramid Layout for Distortion-Free Light Scanning

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Solution Overview

Problem

Existing light reflection devices in laser processing systems suffer from scanning distortion due to fluctuations in the reflection position of light, which reduces the processable range of the irradiated object, and existing solutions like mirror galvanometers require acceleration and deceleration, narrowing the scanning area.

Innovation Solution

An optical scanning device with a rotation mirror comprising a first and second regular polygon pyramid, where the pyramids are rotated integrally with each other, and the reflection surfaces are arranged to maintain a constant reflection position of light, preventing fluctuations and distortion during scanning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a polygon mirror rotation device is used to scan light, then the light can be radiated while moving angularly at a constant angular velocity, but scanning distortion occurs due to fluctuations in the reflection position of the light at each side reflection surface

Engineering Contradiction:
Improveangular velocity of light radiationVSAvoidreflection position stability
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The polygon mirror is segmented into multiple planar mirrors arranged in a regular polygonal configuration. Each planar mirror independently reflects light, and by optimizing the number of mirrors and their angular positions, the system achieves both constant angular velocity radiation and stable reflection positions, eliminating scanning distortion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention optimizes specific parameters including the number of planar mirrors, the base angle of the pyramid structure, and the distance between the light source and the polygon mirror. These parameter adjustments ensure that the reflection position remains stable while maintaining constant angular velocity operation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a mirror galvanometer is used to prevent reflection position fluctuation, then the reflection position can be stabilized, but the scanning area becomes narrower and the processable range decreases due to acceleration and deceleration requirements

Engineering Contradiction:
Improvereflection position stabilityVSAvoidprocessable range of irradiated object
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The polygon mirror rotates continuously at a constant angular velocity, creating a periodic scanning pattern that covers a wide area. This periodic rotation eliminates the need for acceleration and deceleration phases required by mirror galvanometers, thereby maintaining both reflection position stability and a large processable range.

Inventive Principle:
Principle #19Periodic action

3Productivity

If planar mirrors are arranged in a regular polygonal shape and rotated, then light can be deflected efficiently, but scanning distortion occurs due to fluctuation in reflection position

Engineering Contradiction:
Improvelight deflection efficiencyVSAvoidscanning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention introduces asymmetric elements into the otherwise symmetric regular polygonal configuration by optimizing the base angle of the pyramid structure and the positioning of planar mirrors. This asymmetric optimization compensates for the inherent symmetry-induced fluctuations, maintaining both high deflection efficiency and scanning accuracy.

Inventive Principle:
Principle #4Asymmetry

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 allows for stable and efficient scanning without reducing the processable range, maintaining a constant reflection position and preventing distortion, similar to the advantages of both polygon mirrors and mirror galvanometers.

Implementation Method 1

a light reflection device that reflects incident light so as to deflect it

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4295987B1Light reflection device, light guiding device, and light scanning device
Publication Date: 2024.11.27 KAWASAKI JUKOGYO KK
  • EP4295987B1 patent drawingFigure 1
  • EP4295987B1 patent drawingFigure 2
  • EP4295987B1 patent drawingFigure 3

AI summary

A light reflection device comprises a motor and a reflection member having a reflection surface that is formed in a planar shape. The reflection surface reflects incident light. The reflection member performs a revolution and a rotation simultaneously. A direction of the revolution of the reflection member and a direction of the rotation of the reflection member are the same. The motor drives the reflection member so that the angular velocity of the revolution of the reflection member is equal to twice angular velocity of the rotation of the reflection member.