Optical Surface Optimization via Global Cost Function

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Solution Overview

Problem

Existing optimization methods for optical lenses are inefficient in handling a large number of criteria, leading to increased resource and time requirements, and often result in curvature variations, especially on the periphery of optimized surfaces.

Innovation Solution

A computer-based method that defines optical surface parameters using a global surface cost function, which is a weighted sum of individual cost functions, including derivatives, to optimize optical surfaces, ensuring smoothness and focusing on specific evaluation zones rather than the entire surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If known optimization methods are used to determine optical surface shape, then the optical function is achieved, but curvature variations occur especially on the periphery of the optimized surface

Engineering Contradiction:
Improvesurface smoothnessVSAvoidperipheral curvature uniformity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The optical surface is divided into multiple evaluation zones (central zone, intermediate zone, peripheral zone) with different cost function weights. This segmentation allows different regions to be optimized with different priorities, ensuring smooth transitions and reducing curvature variations at zone boundaries while maintaining overall surface quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different cost functions are applied to different evaluation zones based on their specific requirements. The central zone prioritizes optical performance criteria, while peripheral zones emphasize surface smoothness and curvature continuity. This local quality approach ensures each region is optimized for its specific function while maintaining global coherence.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the number of criteria for personalized optical lenses is increased, then the optimization quality improves, but the resource and time requirements increase

Engineering Contradiction:
Improveoptimization qualityVSAvoidoptimization efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The set of optimization criteria is segmented and assigned to different evaluation zones based on their relevance. Not all criteria are applied uniformly across the entire surface, but rather selectively in zones where they are most important. This reduces the computational burden while maintaining optimization quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cost function weights are dynamically adjusted based on the evaluation zone and optimization stage. By changing the relative importance of different criteria in different regions, the method efficiently balances multiple objectives without requiring equal computational resources for all parameters throughout the entire optimization process.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10473952B2Method for optimizing an optical surface
Publication Date: 2019.11.12 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • US10473952B2 patent drawing
  • US10473952B2 patent drawing
  • US10473952B2 patent drawing

AI summary

Method for optimizing an optical surface comprising: an initial optical surface providing step, a working optical surface defining step, during which a working optical surface is defined to be equal to the initial optical surface, a first surface cost function providing step, during which a first surface cost function of the nth derivative of the surface is provided, a set of surface cost functions providing step, during which a set of surface cost functions function of at least one criterion over evaluation zones is provided, a global surface cost function evaluation step during which a global surface cost function equal to a weighted sum of the previous cost functions is evaluated, a modifying step, during which the working surface is modified, wherein the evaluation and modifying steps are repeated so as to minimize the global surface cost function.