Lens Blank Selection Method for Optical Lens Manufacturing
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Solution Overview
Problem
The increasing trend towards larger spectacle frames complicates the production of optical lenses, leading to wastage of material as larger lens blanks are required, which are not always optimally sized for the specific frame dimensions, resulting in inefficient use of material.
Innovation Solution
A method is developed to determine the most appropriate lens blank for manufacturing by using over-thickness data based on manufacturing and finished optical article data, which includes a virtual volume orientation step to select the suitable lens blank from a list differing in diameter and thickness, ensuring sufficient rigidity and outline over-thickness values for optimal machining and material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a lens blank with significantly larger diameter is required to accommodate dissymmetric frame dimensions, then the lens blank can be of sufficient size to enable an optical lens of the required size to be obtained, but this leads to wastage of the optical material of the optical lens blank
Solution Approach 1:
The patent applies preliminary action by determining the most appropriate lens blank before manufacturing begins. The system calculates required dimensions based on frame geometry and lens design parameters, then selects a lens blank that precisely matches these requirements. This pre-planning prevents over-selection of lens blank size, thereby minimizing material wastage while ensuring sufficient material is available for machining both surfaces.
2Ease of manufacture
If a lens blank is selected to accommodate large spectacle frames, then the lens can be manufactured for the frame, but the lens blank is not optimally sized for the specific frame dimensions, resulting in inefficient use of material
Solution Approach 1:
The patent applies parameter changes by dynamically calculating the optimal lens blank dimensions based on specific frame parameters (nasal and temporal distances, frame shape) and lens design requirements. The system adjusts the selected lens blank parameters (diameter, thickness) to precisely match the manufacturing needs, rather than using fixed or oversized blanks. This optimization improves both manufacturability and material usage efficiency.
3Manufacturing precision
If both surfaces of the lens blank are machined, then an optical lens with finished back and front surfaces is obtained, but this requires sufficient material thickness which increases lens blank size requirements
Solution Approach 1:
The patent applies preliminary action by calculating the minimum required lens blank thickness before manufacturing begins. The system considers the need to machine both surfaces and determines the precise thickness required to achieve the desired finished lens thickness plus machining allowances. This pre-calculation ensures the selected lens blank has exactly the right volume - sufficient for dual-surface machining while minimizing unnecessary material.
Data Source
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AI summary
A Method implemented by computer means for determining a lens blank intended to be used for the manufacturing of a finished optical article, the method comprises: - a virtual volume data determining step, during which virtual volume data are determined based at least on finished optical article data representative of the volume of the finished optical article and over-thickness data representative of over-thickness requirements, the virtual volume data are determined so that the virtual volume defined by the virtual volume data includes the volume of the finished optical article volume of the finished optical article and the over-thickness, - a lens blank determining step, during which a lens blank is determined based on said virtual volume data so as to include the virtual volume defined by the virtual volume data.