Solid Imaging Pixel Exposure Control for 3D Print Resolution
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Solution Overview
Problem
Existing three-dimensional object manufacturing techniques using digital light projectors face limitations in achieving smooth edges and high feature accuracy due to the fixed number of pixels, leading to rough or uneven object surfaces and reduced resolution, especially in larger build platforms.
Innovation Solution
The method involves varying the gray scale exposure levels or illumination time of each pixel to control the polymerization boundary of the photopolymer build material, utilizing software to optimize light intensity distribution and focus, allowing for precise control of light energy delivery to achieve smooth edges and high resolution without additional mechanical hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If digital light projectors with fixed pixels are used for three-dimensional object manufacturing, then the device complexity is reduced and ease of manufacture is improved, but the manufacturing precision and surface smoothness deteriorate due to rough or uneven object surfaces
Solution Approach 1:
The patent applies parameter changes by varying the gray scale exposure levels or illumination time of each pixel dynamically during the projection process. This allows the light energy delivery to be modulated without changing the physical pixel structure, thereby achieving smooth edges and high resolution while maintaining the simplicity of digital light projector hardware.
Solution Approach 2:
The invention introduces dynamics by making the exposure parameters (gray scale levels or illumination time) variable for each pixel rather than static. This dynamic control enables precise adjustment of light energy delivery to achieve smooth object surfaces and accurate features, resolving the contradiction between simple hardware and high manufacturing precision.
2Adaptability or versatility
If the build platform size is increased to accommodate larger objects, then the adaptability and versatility are improved, but the resolution and feature accuracy deteriorate due to the fixed number of pixels
Solution Approach 1:
By changing the exposure parameters (gray scale or time) of existing pixels, the system achieves effective sub-pixel resolution control. This allows larger build platforms to accommodate bigger objects while maintaining high resolution through dynamic light energy modulation rather than increasing pixel count.
Solution Approach 2:
The patent replaces the mechanical approach of increasing pixel density or using multiple projectors with a software-based parameter modulation approach. By controlling gray scale levels or illumination time, the system achieves high resolution on large platforms without additional mechanical hardware.
3Manufacturing precision
If multiple exposures or pixel shifting techniques are used to improve resolution, then the manufacturing precision is improved, but the productivity decreases due to slower process speed and alignment issues
Solution Approach 1:
The patent performs preliminary action by pre-calculating and pre-distorting the projection image data to compensate for the fixed pixel grid limitations. This single-exposure approach with pre-modulated gray scale or time parameters achieves high precision without requiring multiple sequential exposures, thereby maintaining high productivity.
Solution Approach 2:
The invention replaces mechanical pixel shifting or multiple exposure systems with a software-based parameter control system. By modulating gray scale levels or illumination time in a single exposure, the system achieves high feature accuracy without the productivity loss associated with multiple exposures or complex mechanical alignment systems.
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 results in improved wall smoothness, feature accuracy, and resolution in three-dimensional objects, enabling the production of larger and more complex objects with smooth edges and fine features, while maintaining a low-cost and efficient process.
Implementation Method 1
solidify and adhere successive layers of the object (i.e. laminae) In stereolithography, data representing the three-dimensional object is input as, or converted into, two-dimensional layer data representing cross-sections of the object to be formed. Layers of photopolymer build material are successively formed and selectively transformed or solidified (i.e. cured) using a computer controlled laser beam of ultraviolet (UV) radiation into successive laminae
Data Source
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AI summary
A solid imaging apparatus and method employing levels of exposure varied with gray scale or time or both of digitally light projected image of a cross-section of a three-dimensional object on a solidifiable photopolymer build material. The gray scale levels of exposure of projected pixels permits the polymerization boundaries in projected boundary pixels to be controlled to achieve preserved image features in a three-dimensional object and smooth out rough or uneven edges that would otherwise occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Software is used to control intensity parameters applied to pixels to be illuminated in the image projected in the cross-section being exposed in the image plane.