Movable Light Source Stage for Additive Fabrication
Solution Overview
Problem
Conventional additive fabrication systems face limitations with laser light sources, including fixed spot sizes, varying optical path lengths, and reduced accuracy at greater distances, which restrict the size of build areas and precision in forming solid material, while digital light processing sources have accuracy issues due to fixed light source arrays and divergence over longer distances.
Innovation Solution
A moveable stage with offset light sources, such as LED arrays, that can adjust beam sizes and move across the build area to maintain consistent optical path lengths and precision, combined with leveling elements like rollers to counteract distortions in flexible container surfaces, allowing for larger build volumes and improved fabrication accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser light sources are used in conventional additive fabrication systems, then the fabrication process can be performed, but the fixed spot sizes and varying optical path lengths reduce accuracy at greater distances and restrict build area size
Solution Approach 1:
The patent employs a movable stage that carries the light source array, allowing the system to dynamically reposition itself across the build area. This dynamic repositioning enables the use of smaller, more accurate light sources while achieving large build areas through motion, resolving the contradiction between precision and build area size.
Solution Approach 2:
The light source is divided into multiple discrete LEDs arranged in an array on the movable stage. Each LED acts as an independent, precise light emitter that can be individually controlled, allowing high precision across the entire build area while maintaining compact source dimensions.
2Area of stationary object
If digital light processing sources are used, then larger build areas can be achieved, but fixed light source arrays cause divergence and accuracy issues over longer distances
Solution Approach 1:
Instead of using a fixed array of light sources, the patent employs a movable stage that carries a compact light source array. The stage moves dynamically across the build area, maintaining consistent optical path lengths and preventing light divergence, thereby preserving precision over large distances.
Solution Approach 2:
The movable stage acts as an intermediary mechanism that brings the light source close to the material surface at each position. This intermediary motion allows the system to achieve both large build areas and high precision by repeatedly positioning the source at optimal distances.
3Reliability
If flexible container surfaces are used to hold liquid photopolymer, then the container can be sealed and contained, but surface distortions occur that affect light delivery and fabrication precision
Solution Approach 1:
The patent incorporates movable rollers that dynamically adjust and press against the flexible container surface to maintain it in a substantially planar state during light exposure. This dynamic mechanical intervention compensates for inherent surface distortions, ensuring consistent light delivery and high fabrication precision while maintaining reliable sealing.
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 enables the fabrication of larger parts with improved precision and accuracy by allowing light to be directed to any position within the build area and maintaining consistent light intensity, reducing distortions and increasing the speed of the fabrication process.
Implementation Method 1
Exposure to actinic radiation cures a thin layer of liquid photopolymer, which causes it to harden and adhere to previously cured layers or the bottom surface of the build platform
Data Source
AI summary
Techniques for illuminating a photocurable material within a build area of an additive fabrication device are described. According to some aspects, a light source is provided that can be moved alongside a build area, allowing light to be directed to any desired position within the build area by moving the light source. This configuration may also allow the distance from the light source to the build area to be substantially the same for each position across the build area by moving the light source whilst maintaining a fixed distance from the light source to the build volume. The described approach may allow for fabrication of larger parts in an additive fabrication device by expanding or eliminating the practical upper limit on the area of the build volume that can be imposed by use of a laser light source in such a device.