LCD 3D Printer Meniscus Lens Uniform Light Distribution

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Solution Overview

Problem

Conventional LCD type 3D printers suffer from uneven light intensity distribution across the LCD panel, leading to inconsistent curing of the liquid molding material and potential damage from excessive ultraviolet exposure, which shortens the lifespan of the LCD panel.

Innovation Solution

Incorporating an upwardly-convex meniscus lens between the light source and the LCD panel, optionally combined with a Fresnel lens, to reduce light irradiation angles and ensure uniform light distribution without the need for a mask image, allowing for a shorter focal distance and reduced printer size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional Fresnel lens is used to focus light from the light source to the LCD panel, then the light can be concentrated, but the light intensity becomes uneven across the LCD panel with excessive exposure at the center

Engineering Contradiction:
Improvelight intensity distributionVSAvoidLCD panel lifespan
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

An optical diffuser is introduced as an intermediary component between the Fresnel lens and the LCD panel. The diffuser scatters the concentrated light from the lens, redistributing it uniformly across the LCD panel surface. This mediator prevents direct exposure of the LCD panel to intense concentrated light while still delivering sufficient illumination for curing the liquid molding material, thereby extending the LCD panel's operational lifespan.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the optical parameters of the system by introducing a diffuser that modifies the light distribution pattern. The diffuser transforms the concentrated, non-uniform light intensity profile from the Fresnel lens into a uniform distribution pattern across the LCD panel, controlling the illumination parameters to prevent overexposure while maintaining curing effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the focal distance between the light source and lens is reduced to make the printer more compact, then the printer size is reduced, but the light intensity becomes more concentrated and uneven

Engineering Contradiction:
Improveprinter sizeVSAvoidlight intensity uniformity
Core Design Contradiction:
Volume of moving objectVSIllumination intensity

Solution Approach 1:

The optical diffuser serves as a mediator that decouples the relationship between focal distance and light uniformity. By placing the diffuser between the lens and LCD panel, the system can maintain a short focal distance for compactness while the diffuser ensures uniform light distribution, effectively breaking the trade-off between size and uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The optical path is segmented into distinct functional zones: the Fresnel lens for light concentration, the diffuser for uniformity, and the LCD panel for imaging. This segmentation allows each component to perform its optimal function independently, enabling compact design without sacrificing light uniformity.

Inventive Principle:
Principle #1Segmentation

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 solution achieves uniform light intensity across the LCD panel, improving the quality of the molded product and extending the lifespan of the LCD panel by preventing overexposure, while also enabling a more compact printer design.

Implementation Method 1

an upwardly-convex meniscus lens provided between the light source and the LCD panel to reduce a light irradiation angle

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a combination of a meniscus lens and a Fresnel lens is disposed under an LCD panel so that the intensity of light reaching the LCD panel can be uniformly distributed

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

a light source provided at a lower portion of the 3D printer to irradiate light upward... an ultraviolet LED... the liquid molding material is composed of a photo-curable liquid resin

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3427929B1LCD type 3D printer
Publication Date: 2021.11.24 RAY CO LTD
  • EP3427929B1 patent drawingFigure 1
  • EP3427929B1 patent drawingFigure 2
  • EP3427929B1 patent drawingFigure 3

AI summary

An LCD type 3D printer includes a light source provided at a lower portion of the 3D printer to irradiate light upward, a lens disposed at a predetermined distance from an upper portion of the light source, an LCD panel provided above the lens, a storage container provided above the LCD panel to store a liquid molding material, a build plate provided above the storage container to hold a molded product, and an elevating member provided at an upper portion of the build plate to move up and down. The lens includes an upwardly-convex meniscus lens or a convex lens provided between the light source and the LCD panel to reduce a light irradiation angle.