3D Printed Corrective Layer for Low-Stress Optical Lenses
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Solution Overview
Problem
Mass-manufacturing of smaller optical lenses faces challenges in achieving accuracy without introducing material stress, leading to higher failure rates and image quality deterioration due to residual stresses trapped during production.
Innovation Solution
A 3D overprinting technique is employed to correct surface imperfections by scanning the inner layer of optical lenses and printing a thin outer layer using inkjet or digital light processing, reducing residual stresses and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional molding or casting methods are used to mass-manufacture smaller optical lenses, then productivity is improved, but manufacturing precision deteriorates due to residual stresses trapped during production
Solution Approach 1:
The lens manufacturing process is segmented into two distinct stages: first, mass-production of lens blanks using traditional molding or casting methods; second, individual precision correction of each lens using 3D scanning and additive manufacturing. This segmentation allows high-volume production while maintaining individual lens accuracy through subsequent corrective processing.
Solution Approach 2:
The base lens is pre-formed using efficient molding or casting methods to establish the basic optical form. Then, a corrective layer is added subsequently to compensate for stress-induced deformations. This preliminary action allows the bulk material to be prepared efficiently while the precision correction is applied afterward to eliminate stress effects.
2Manufacturing precision
If optical lenses are created with a focus on accuracy through traditional methods, then manufacturing precision is improved, but reliability deteriorates due to greater material stress causing higher failure rates
Solution Approach 1:
The lens structure is segmented into a base layer (from molding/casting) and a corrective outer layer (from additive manufacturing). The base layer carries the bulk of the mechanical load, while the thin corrective layer (typically less than 10 micrometers) provides optical precision without introducing significant stress, thereby improving reliability.
Solution Approach 2:
The thickness parameter of the corrective layer is optimized to be extremely thin (less than 10 micrometers, often 1-5 micrometers). This parameter change ensures that the corrective layer provides sufficient optical precision while minimizing the stress introduced during the additive manufacturing process, thus improving lens reliability.
3Manufacturing precision
If 3D overprinting technique is used to correct surface imperfections, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
Each lens undergoes individual 3D scanning to map its specific surface deviations, and the additive manufacturing process automatically generates and applies a custom corrective layer tailored to that lens's unique imperfections. This self-service approach enables high precision without requiring complex manual intervention or sophisticated real-time control systems.
Solution Approach 2:
The complex mechanical processes of traditional precision lens grinding and polishing are replaced with a combination of 3D optical scanning and additive manufacturing. Instead of using complex mechanical removal processes, the system uses digital scanning to identify imperfections and deposits material additively to correct them, simplifying the overall manufacturing complexity.
4Ease of manufacture
If traditional molding methods are used, then ease of manufacture is improved, but manufacturing precision deteriorates due to residual stresses
Solution Approach 1:
The manufacturing process is segmented into a simple mass-production stage (molding or casting of lens blanks) and a precision correction stage (3D scanning and additive manufacturing of corrective layers). This segmentation maintains the ease of mass production while achieving high precision through the subsequent corrective processing of individual lenses.
Solution Approach 2:
The final lens becomes a composite structure combining the base lens material (from molding or casting) with a corrective layer material (from additive manufacturing). This composite approach allows the use of simple, efficient manufacturing methods for the bulk material while applying precision-correcting material with different properties to achieve the required optical accuracy.
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 method enhances the production yield of optical lenses by reducing residual stresses and improving accuracy, achieving higher than 95% success rate in mass production while maintaining low stress levels.
Implementation Method 1
a 3D printer to overprint an outer layer that includes one or more corrective layers on the inner layer
Data Source
AI summary
A corrected optical lens includes an inner layer that includes a low stress optical lens and an outer layer that includes one or more corrective layers. The outer layer may be formed on at least a portion of an outer surface of the inner layer by scanning the outer surface of the inner layer, generating a surface characterization file based on the outer surface scan, and 3D printing the one or more corrective layers on the outer surface of the inner layer based on the surface characterization file as input to a 3D printer. The surface characterization file may be corrected based on a particular predetermined contour of the inner layer prior to being input to the 3D printer. The correction may include, for example, reduction of root mean square (RMS) values of deviations of detected peaks and valleys on the surface of the inner layer.