Multi-Projector Mask Projection 3D Printing for Uniform Exposure
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Solution Overview
Problem
Current 3D printing technologies, particularly DLP, face limitations in achieving large printing areas with uniform energy distribution, leading to uneven illumination and reduced accuracy and speed due to the non-uniform energy radiated from projectors, which worsens with increased printing size.
Innovation Solution
A model-adaptive multiple-projector system that uses adjacent projectors to create overlapping areas with different colored images, analyzes the overlapped regions, and applies energy homogenization through gray level interpolation and curve fitting to optimize energy distribution across the printing area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple projectors are used to increase printing area, then the scale of exposure area is improved, but the energy distribution becomes non-uniform due to overlapping regions
Solution Approach 1:
The patent applies local quality by differentiating the treatment of overlapping and non-overlapping regions. The system identifies overlapping regions between multiple projectors and applies different energy compensation strategies: non-overlapping regions receive standard energy distribution, while overlapping regions receive adjusted energy levels to prevent over-exposure. This localized differentiation resolves the uniformity issue while maintaining large printing area capability.
Solution Approach 2:
The system changes the energy distribution parameters dynamically based on spatial position. By calculating the overlap degree between projector beams and adjusting the light intensity parameters accordingly, the system compensates for the non-uniform energy distribution. The mapping function transforms the non-uniform energy pattern into a uniform effective exposure across the entire printing area.
2Area of stationary object
If light intensity is increased to achieve high power density for large printing area, then the printing area scale is improved, but the DMD chip overheating problem worsens
Solution Approach 1:
The patent segments the printing area into multiple regions corresponding to different projectors and their overlapping zones. By dividing the large printing area into manageable segments, the system can control the light intensity for each segment independently, achieving high power density where needed without uniformly increasing intensity across the entire system, thus preventing DMD chip overheating.
Solution Approach 2:
The system employs periodic scanning and iterative optimization of the projection patterns. By repeatedly projecting with adjusted parameters and measuring the actual energy distribution, the system converges on optimal intensity settings that achieve high power density for large area printing while preventing thermal accumulation that would cause DMD chip overheating.
3Area of stationary object
If the printing area is enlarged beyond 300mm*300mm, then the scale of exposure area is improved, but the galvanometer system complexity and cost increase due to area dynamic focusing requirement
Solution Approach 1:
The patent merges multiple fixed-focus projectors to achieve a large effective printing area, eliminating the need for a complex area dynamic focusing system. By combining the projection areas of multiple projectors with controlled overlapping, the system achieves large-scale printing (beyond 300mm*300mm) using simpler fixed-focus components rather than complex variable-focus mechanisms.
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 enhances the scale of exposure areas, improves printing accuracy and speed, and ensures uniform energy distribution, making it suitable for larger printing sizes with high power density without overheating the DMD chips.
Implementation Method 1
using multiple projectors as a light-source for mask projection
Implementation Method 2
the energy radiated from each DLP projector is non-uniform light energy, using multiple projectors will inevitably cause uneven distribution of the illumination intensity on each projector and it will also affect the overlapped area on the printing area
Implementation Method 3
optimizing slices based on the number projectors, and then a mapping function is obtained by analyzing the measured data with discrete gray levels through curve fitting, and the generated pictures are optimized based on the mapping function
Implementation Method 4
3D printing based on DLP technology... by aggradation of the binder, each layer of printing material are bobbed to form the designed shape
Data Source
AI summary
A model-adaptive multi-source large-scale mask projection 3D printing system configured to conduct the following steps: projecting pure-color images of first and second colors having identical attributes, capturing an image of an overlapping portion and calculating height and width information of the overlapping portion; splitting a pre-processed slice and respectively recording width and height information of two slices resulting from the splitting and generating two gray scale images having identical attributes thereto; counting power values of identical positions of slices in different gray scale values, performing a further calculation to obtain a projection mapping function, using the projection mapping function as a basis for performing optimization on gray scale interpolation of the generated images; and fusing the processed gray scale images and the originally split two slices to obtain a mask projection 3D printing slice having a uniform shaping brightness, and forming a final product.