Scanned DLP Pixel Drift for Sub-Pixel Resin Curing
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Solution Overview
Problem
Conventional additive fabrication systems using DLP projectors suffer from voxelization, resulting in stepped surfaces instead of smooth, curved surfaces due to pixelated arrays, limiting resolution and mechanical complexity.
Innovation Solution
A curing system that translates a pixelated array of light emitted by a DLP projector along a single axis during the curing process, allowing for improved resolution and simplified mechanical and software requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a DLP projector is used to illuminate photopolymer resin with a pixelated array, then the curing process can be automated and standardized, but the resolution is limited and stepped surfaces are produced instead of smooth curved surfaces
Solution Approach 1:
The patent applies the Dynamics principle by translating the pixelated array along a translation axis at an oblique angle relative to the first array axis during the curing process. This dynamic movement allows the pixelated array to scan across the photopolymer resin, effectively reducing the pixelation effect and achieving smoother surfaces with sub-pixel resolution. The translating device moves the pixelated array between a first position and a second position spaced from the first position, enabling continuous scanning exposure that eliminates the stepped surface artifact inherent in static DLP projection.
2Manufacturing precision
If the pixelated array is translated along a translation axis at an oblique angle, then resolution is improved by reducing pixelated edges to sub-pixel increments, but the device complexity increases due to the translating device
Solution Approach 1:
The patent applies the Mechanics substitution principle by replacing complex multi-axis mechanical positioning systems with a single translating device that moves the pixelated array along one translation axis at an oblique angle. This substitution reduces mechanical complexity while achieving sub-pixel resolution through the oblique scanning motion, which effectively distributes the pixelation error across multiple positions during translation.
3Manufacturing precision
If the pixelated array is translated during curing, then smoother surfaces and higher resolution are achieved, but the curing time may increase due to the additional translation movement
Solution Approach 1:
The patent applies the Continuity of useful action principle by implementing continuous scanning exposure where the pixelated array translates along the translation axis while continuously illuminating the photopolymer resin. The ultraviolet light source emits ultraviolet light continuously during the translation process, ensuring that every portion of the resin receives the required fluence without interruption. This continuous action approach maintains efficient curing while achieving smooth surfaces through the scanning motion.
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
Enhances the resolution of fabricated components by reducing pixelated array edges to sub-pixel increments, achieving smoother surfaces and faster curing with reduced mechanical complexity.
Implementation Method 1
The ultraviolet light source is configured to selectively emit ultraviolet light. The ultraviolet light defines a pixelated array that illuminates at least a portion of the photopolymer resin.
Implementation Method 2
The translating device is configured to translate the pixelated array along a translation axis at an oblique angle relative to the first array axis
Implementation Method 3
Exposure to actinic radiation cures a thin layer of liquid resin, which causes it to harden and adhere to previously cured layers on the bottom surface of the build surface.
Data Source
AI summary
A curing system includes a basin configured to receive a photopolymer resin, an ultraviolet light source, and a translating device. The ultraviolet light source is configured to selectively emit ultraviolet light. The ultraviolet light defines a pixelated array that illuminates at least a portion of the photopolymer resin. The pixelated array includes a first array axis and a second array axis oriented perpendicular to the first array axis. The translating device is configured to translate the pixelated array along a translation axis at an oblique angle relative to the first array axis.