Stereolithography Illumination System With Multilens Projector Array
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Solution Overview
Problem
Manufacturing an economical illumination system for stereolithography that efficiently couples LED light into an optical system, overcoming the challenge of achieving high optical power transmission while accommodating the wide-angle nature of LEDs, is difficult due to the need for a system that allows faster production speeds with equivalent or higher accuracy compared to laser-based systems.
Innovation Solution
A stereolithography illumination system comprising a planar support and a multilens projector array with a two-dimensional array of individually controllable LEDs, where each LED is associated with a conjugate image spot, and a multilens projector array comprising a stack of optical elements, including lenslets, to project light onto the resin surface, allowing for precise control and high resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If LED light is coupled into an optical system with wide-angle emission, then the system can achieve lower cost and higher production speed, but optical power transmission is insufficient
Solution Approach 1:
A coupling lens is introduced as an intermediary optical element between the LED and the optical system. This coupling lens collects the wide-angle LED light and redirects it into the optical system, serving as a mediator that transforms the LED's emission pattern into a form suitable for efficient coupling, thereby improving optical power transmission while maintaining the use of LEDs
Solution Approach 2:
The optical system parameters are optimized to match the LED characteristics. The coupling lens focal length, position, and the numerical aperture of the optical system are adjusted to maximize light collection efficiency from the wide-angle LED source, transforming the system parameters to accommodate the LED's emission properties and improve power transmission
2Productivity
If LED light is coupled into an optical system with wide-angle emission, then the system can achieve lower cost and higher production speed, but coupling efficiency is poor
Solution Approach 1:
The coupling lens acts as an intermediary that bridges the mismatch between the wide-angle LED emission and the optical system's acceptance angle. By positioning the coupling lens at the appropriate location with suitable focal length, it effectively captures and redirects LED light into the optical system, significantly improving coupling efficiency and enabling faster production speeds
Solution Approach 2:
The illumination system is designed to be movable relative to the workpiece location, allowing dynamic adjustment of the system position to optimize coupling efficiency at different working positions. This dynamic capability ensures maintained coupling efficiency throughout the production process, supporting higher production speeds
3Adaptability or versatility
If the illumination system is moved relative to the workpiece, then production flexibility is improved, but mechanical stability decreases
Solution Approach 1:
The illumination system is segmented into a movable module that can be independently positioned relative to the workpiece. This modular design allows the illumination system to be moved to different positions for flexible production while the main system structure remains stable, separating the moving and stationary components to maintain both flexibility and stability
Solution Approach 2:
The patent replaces complex mechanical positioning mechanisms with a simplified movable illumination system design. Instead of moving the entire apparatus, only the essential illumination module is made movable, reducing mechanical complexity and improving stability while maintaining production flexibility through controlled movement
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
The system achieves efficient optical power transmission, enabling faster production speeds with high accuracy and structural stability, reducing transmission losses by approximately 20% and maintaining high resolution, while being cost-effective and easy to implement.
Implementation Method 1
a multilens projector array (40) mechanically supported on the planar support (31) over the array (32) on a plano side (46), and having a work surface (451) arranged to receive a resin layer (16), the projector array (40) comprising a stack of optical elements, including a plurality of lenslets (44) adapted to project the LEDs onto the work surface (451)
Implementation Method 2
the spot of the laser beam traces the respective cross-sectional pattern on the surface of the liquid resin. Exposure to the laser light cures or solidifies the traced pattern
Data Source
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AI summary
The invention concerns an illumination system (30) for use in a stereolithography apparatus (1), comprising: a planar support (31); a multilens projector array (40) mechanically supported on the planar support 31 over the array 32 on a piano side 46, and having a work surface (451) arranged to receive a resin applying device (60) for applying a resin layer 16, the projector array 40 comprising a stack of optical elements, including a plurality of lenslets (44) adapted to project the LEDs onto the work surface (451), and a two-dimensional array (32) of individually controllable light- emitting diodes (LEDs) (34) arranged between the planar support (31) and the multilens projector (40). According to an aspect, the planar support (31) and the piano side 46 are supported on contact zones (33, 400) arranged over substantially the entire piano side 46; the illumination system thus forming a rigid body 30.