Stereolithography Build Platform with Rear Exposure for Layer Adhesion
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Solution Overview
Problem
In stereolithography, the insufficient light output from mask projection often leads to inadequate adhesion of workpieces to the construction platform, causing unintentional detachment during separation.
Innovation Solution
A modular, autonomous construction platform with a rear-side exposure device, photosensor, and controller that activates the rear exposure when the front light intensity exceeds a predetermined limit, ensuring two-sided curing and increased adhesion, and includes features like a light-emitting diode matrix, adjustable light intensity, and an energy store for independent operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rear exposure device is integrated into construction platform, then adhesion of first layers to construction platform is improved, but device complexity increases
Solution Approach 1:
The rear exposure device is integrated directly into the construction platform, merging the exposure function with the platform structure. This eliminates the need for separate exposure equipment and reduces overall system complexity while improving adhesion of the first layers to the construction platform.
Solution Approach 2:
The patent introduces rear exposure from the opposite side of the construction platform, adding a dimensional aspect to the curing process. This dual-sided exposure approach ensures complete adhesion of the first layers to the platform by curing material from both front and rear directions simultaneously.
2Ease of operation
If construction platform is made autonomous with energy store, then ease of operation is improved, but weight of moving object increases
Solution Approach 1:
The construction platform is equipped with an integrated energy store (battery) that enables autonomous operation without external power connections. The platform can independently power the rear exposure device and control systems, allowing operators to move and use the platform freely in the water tank without being constrained by power cable limitations.
3Strength
If light intensity of front exposure device is increased, then adhesion of workpiece to construction platform is improved, but productivity deteriorates due to material absorption
Solution Approach 1:
The patent introduces rear exposure from the opposite side of the construction platform, adding a dimensional aspect to the curing process. This dual-sided exposure approach ensures complete adhesion of the first layers to the platform by curing material from both front and rear directions simultaneously.
Solution Approach 2:
The rear exposure device applies light specifically to the first layers in contact with the construction platform, concentrating the curing action where adhesion is most critical. This localized approach ensures strong bonding without requiring excessive light intensity that would be absorbed by subsequent layers, thus maintaining productivity.
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
Prevents unintentional detachment of built-up layers by ensuring two-sided curing and autonomous energy supply, allowing for precise control of adhesion and energy efficiency without external connection.
Implementation Method 1
a photosensor for detecting a light intensity of a light from a front exposure device through the layer and/or a material
Implementation Method 2
the rear exposure device is formed by a light-emitting diode matrix
Implementation Method 3
the photosensor is a photodiode which is tuned to the wavelength range of the exposure from the front. The photodiode is, for example, a silicon carbide photodiode or a silicon photodiode
Data Source
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AI summary
The present invention relates to a build platform (100) for layer-by-layer construction of a workpiece (200) in a stereolithography process, comprising a rear exposure unit (101-1) for exposing a layer (103-n) from a rear side; a photosensor (105) for detecting the light intensity of light from a front exposure unit (101-2) through the layer (103-n) and/or a material and/or via a deflecting mirror; and a control unit (107) for activating the rear exposure unit (101-1) when the detected light intensity of the front exposure unit (101-2) exceeds a predetermined limit value.