Stereolithography Machine Optical Unit Cost Reduction
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Solution Overview
Problem
Stereolithography machines with F-theta lenses are expensive, limiting their use to professional and industrial sectors due to high costs and restricted size options, which also affect the size and definition of the three-dimensional objects that can be produced.
Innovation Solution
A stereolithography machine design that replaces the F-theta lens with a more economical optical unit, comprising a common lens or set of lenses arranged upstream of the light reflecting device, allowing for flexible selection of the incidence area size and maintaining a Gaussian light beam with controlled spot size variation, reducing costs and increasing flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If an F-theta lens is used to focus the light beam on the incidence area, then the light beam can be focused independently of the incident direction, but the machine cost increases more than proportionally with the size of the incidence area
Solution Approach 1:
The patent extracts the F-theta lens from the optical system and replaces it with a simple collimated beam source combined with a galvanometric mirror system. This removes the expensive component while maintaining the core functionality of steering the light beam across the incidence area through angular deflection rather than focal length adjustment.
Solution Approach 2:
The patent substitutes the expensive, precision-crafted F-theta lens with inexpensive, easily replaceable components: a standard collimated beam source and off-the-shelf galvanometric mirrors. These cheaper components achieve the same operational goal without requiring complex optical design or expensive manufacturing.
2Volume of moving object
If the F-theta lens size is increased to obtain a larger incidence area, then the maximum size of the three-dimensional object increases, but the machine cost increases more than proportionally
Solution Approach 1:
The patent employs dynamic angular deflection of the light beam using galvanometric mirrors to scan across a large incidence area. Instead of relying on a large, static F-theta lens, the system dynamically steers a collimated beam to cover the required area, allowing large object production without proportional cost increases.
Solution Approach 2:
The patent transitions from scaling the optical component size (one-dimensional approach with F-theta lens diameter) to scaling the scan area through angular space (two-dimensional approach with mirror rotation angles). This allows the incidence area to be enlarged without increasing the physical size of expensive optical components.
3Manufacturing precision
If the F-theta lens focal length is increased to reduce the minimum cross section of the light beam, then the image definition improves, but the incidence area size must be reduced
Solution Approach 1:
The patent changes the controlling parameter from focal length (which couples beam size and incidence area) to angular deflection angle. By using a collimated beam with fixed small diameter and steering it through variable angles with galvanometric mirrors, the system independently controls both beam spot size (for definition) and scan area (for incidence area), breaking the coupling that existed with F-theta lenses.
4Ease of manufacture
If F-theta lenses with short focal length are used to limit machine cost, then the machine cost is reduced, but the incidence area size is correspondingly reduced
Solution Approach 1:
The patent replaces the optical focusing mechanism (F-theta lens) with a mechanical steering mechanism (galvanometric mirrors). This substitution allows the use of simple, inexpensive optical components while achieving large incidence areas through mechanical angular deflection, rather than relying on expensive, large-diameter lenses.
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 machine becomes more affordable and versatile, enabling larger three-dimensional object production with improved flexibility in size options, suitable for a broader range of applications beyond professional and industrial use, while maintaining acceptable object definition.
Implementation Method 1
a stereolithography machine suited to produce a three-dimensional object through the superimposition of a plurality of layers of a base material, in the liquid or paste state, that is solidified through selective exposure to a light beam
Implementation Method 2
The machine comprises also an optical unit configured so as to focus the light beam on a focal surface
Implementation Method 3
Said machine comprises also light reflecting means that deviate the light beam selectively towards any point of the incidence area
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention is a stereolithography machine (1) comprising: a container (2) containing a base material (3) that defines an outer surface (4) delimiting it; a light emitting unit (5) suited to emit a light beam (6); a light reflecting device (7) suited to deviate the light beam (6) towards an incidence area (8) belonging to the outer surface (4); a logic control unit (19) suited to control the light reflecting device (7) in such a way that the light beam (6) is selectively incident on an operating area (10) belonging to the incidence area (8); an optical unit (11) suited to focus the light beam (6) on a focal surface (12) where the light beam (6) has minimum cross section (15). The optical unit (11) is arranged between the light emitting unit (5) and the light reflecting device (7), the light emitting unit (5) and the optical unit (11) being configured in such a way that the ratio between the maximum diameter of the intersection area of the light beam (6) with the operating area (10) and the diameter (WF) of the minimum cross section (15) does not exceed 1.15.