Polygon Mirror Scanning Head for Precise High-Speed 3D Modeling

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Solution Overview

Problem

Existing 3D modeling technologies face issues with control precision, vibration, and modeling quality due to direct head movement and acceleration, especially at increased modeling speeds.

Innovation Solution

The use of two sets of rotating polygon mirrors arranged in space, with controlled angular displacement and speed, to radiate a modeling beam without direct head movement, minimizing vibration and ensuring uniform beam output power density across the modeling plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the head directly moves to a beam radiation point through a 2-3 axis moving rail, then the beam radiation location can be controlled, but the control precision deteriorates and vibration is generated due to acceleration and deceleration

Engineering Contradiction:
Improvecontrol precisionVSAvoidmodeling speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical moving head system with an optical scanning system using polygon mirrors. Instead of physically moving the heavy head assembly along rails, the invention uses rotating polygon mirrors to deflect the laser beam across the modeling plane. This substitution eliminates mechanical inertia and acceleration-related vibrations while maintaining precise beam positioning through optical control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces polygon mirrors as intermediary elements between the laser source and the modeling plane. These mirrors act as mediators that redirect the beam without requiring the source to move. The mirrors convert rotational motion into precise linear scanning patterns, enabling high-speed operation without the vibration problems associated with direct head movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the head directly moves to a beam radiation point, then the beam can be radiated at the target location, but vibration and noise are generated due to acceleration and deceleration

Engineering Contradiction:
Improvemodeling qualityVSAvoidvibration and noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical moving head system with an optical scanning system using polygon mirrors. Instead of physically moving the heavy head assembly along rails, the invention uses rotating polygon mirrors to deflect the laser beam across the modeling plane. This substitution eliminates mechanical inertia and acceleration-related vibrations while maintaining precise beam positioning through optical control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the polygon mirrors rotate in one direction only, then vibration possibility is minimized, but the complexity of controlling angular displacement and speed increases

Engineering Contradiction:
Improvemodeling speedVSAvoidcontrol complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements continuous unidirectional rotation of the polygon mirrors rather than repeated start-stop-reverse cycles. This continuous rotation eliminates the vibration and noise associated with acceleration and deceleration. The control system maintains precise beam positioning through synchronized control of the mirror rotation speed and the laser beam pulsing timing, ensuring that the beam is radiated only when the mirror is at the correct angular position.

Inventive Principle:
Principle #20Continuity of useful action

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 approach allows for high-speed modeling beam radiation with reduced vibration and noise, improving modeling quality and precision by controlling the beam's radiation location and output power density.

Implementation Method 1

two sets of optical elements called polygon mirrors are properly arranged in the space, and the angular displacement and angular speed of two polygon mirrors and a modeling beam source unit for generating a modeling beam are controlled so that they operate in conjunction with each other

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3217208B1Head device of three-dimensional modeling equipment having unidirectionally rotating polygon mirrors, scanning method for modeling plane using same, and three-dimensional modeling device using same
Publication Date: 2024.05.08 KOREA INSTITUTE OF INDUSTRIAL TECHNOLOGY
  • EP3217208B1 patent drawingFigure 1
  • EP3217208B1 patent drawingFigure 2
  • EP3217208B1 patent drawingFigure 3(a)~3(d)

AI summary

The present invention relates to: a head device of three-dimensional modeling equipment which has unidirectionally rotating polygon mirrors, can perform biaxial scanning at a high speed due to a combination of the mirrors, can easily control timing and a modeling ray irradiation position, and can enhance modeling precision; and a scanning method for a modeling plane (10) using the same. The present invention provides a head device of three-dimensional equipment which comprises: a modeling light source part (15); a first light guide part (20) which has the function of primarily reflecting modeling rays from the modeling light source part (15) and allowing the rays to be incident on a second light guide part (30); the second light guide part (30) which has the function of secondarily reflecting the modeling rays received from the first light guide part (20) and allowing the rays to be incident on a modeling plane (10); and a control part (40) which combines and controls the on-off and the output power of the modeling rays, and the operations of the first light guide part (20) and the second light guide part (30), wherein at least one of the first light guide part (20) and the second light guide part (30) comprises polygon mirrors which have a predetermined number of light reflecting surfaces at the sides thereof and unidirectionally rotate about a predetermined rotation axis.