Ophthalmic Lens Bevel Step for High Wrap Frame Fit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ophthalmic lens edging technologies face difficulties in achieving a proper fit between lenses and frames, particularly in high wrap frames, due to interference between the lens bevel and frame groove, leading to a poor fit, especially with thicker lenses.
Innovation Solution
A computer-programmed edger device that forms a bevel with an apex and a step in the peripheral edge of the lens blank, controlled by a central processing unit, allows for precise shaping and fitting by forming a step intermediate the bevel apex and the lens surface, ensuring a snug fit within frames with high wrap curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional bevel is formed in the lens periphery, then the lens can be edged to fit the frame opening, but the bevel interferes with the frame groove in high wrap frames, resulting in poor fit
Solution Approach 1:
The bevel is segmented into two distinct features: a first bevel portion and a second bevel portion, with the second portion positioned closer to the lens periphery. This segmentation allows each portion to serve different functions - the first portion provides structural support while the second portion interfaces with the frame groove, eliminating interference issues in high wrap frames
Solution Approach 2:
The invention introduces a new dimensional aspect by adding a second bevel portion at a different radial position from the first bevel portion. This creates a stepped configuration where the bevels are arranged at different distances from the lens optical center, allowing the lens to properly engage with high wrap frame grooves without interference
2Strength
If the lens thickness is increased for stronger prescription, then the vision correction capability is improved, but the lens bevel interferes more with the frame groove, worsening the fit
Solution Approach 1:
By segmenting the bevel into two portions at different radial positions, the invention allows the first bevel portion to accommodate the increased lens thickness for strong prescriptions, while the second bevel portion maintains proper engagement with the frame groove, thus resolving the interference problem that worsens with thicker lenses
3Adaptability or versatility
If the frame wrap curvature is increased to better fit the wearer's face, then the cosmetic appearance and comfort are improved, but the frame groove interferes with the lens bevel, resulting in poor fit
Solution Approach 1:
The invention addresses high wrap frame compatibility by introducing a second bevel portion positioned closer to the lens periphery. This dimensional adjustment allows the lens edge profile to properly engage with the groove in high wrap frames, enabling the frame to achieve better face contour adaptation without compromising the lens-fit quality
Data Source
AI summary
The present invention is directed to a machine programmed to edge an ophthalmic lens blank. The machine includes an edger device for forming a bevel in a peripheral edge of the lens blank, a central processing unit operably associated with the edger device for controlling operation thereof, and a computer program stored on a medium in communication with the central processing unit. The computer program includes a first instruction set operably causing the edger device to form a bevel in a peripheral edge of a lens blank. A second instruction set operably causes the edger device to form a step in the peripheral edge intermediate an apex of the bevel and an interface between the peripheral edge and a major surface of the lens blank. A method of controlling an edger device for edging an ophthalmic lens blank and a computer program are also disclosed.