Bi-aspherical Progressive Lens Surface Alignment Evaluation

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Solution Overview

Problem

Bi-aspherical type progressive-addition lenses require precise evaluation of relative positional shifts between their surfaces to ensure optimal optical performance, as conventional methods only assess specific measurement points, neglecting the broader impact of surface combinations.

Innovation Solution

A method and device that measure the power distribution of progressive-addition lenses at multiple points, compare the measured distribution to pre-defined defective distributions using similarity search, and evaluate the lens as defective if similarities are found, allowing for comprehensive assessment of surface alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the lens is evaluated only at specific measurement points, then the evaluation process is simple and quick, but the comprehensive optical performance and surface alignment cannot be adequately assessed

Engineering Contradiction:
Improveoptical performance assessmentVSAvoidevaluation method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The lens surface is divided into multiple measurement points distributed across the entire lens area. By segmenting the evaluation into discrete measurement locations, the system achieves comprehensive coverage of optical performance and surface alignment while maintaining a systematic and manageable evaluation process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The evaluation transitions from traditional single-point or limited-point measurement to multi-dimensional spatial distribution of measurement points. This dimensional expansion allows assessment of optical characteristics across the entire lens surface, enabling detection of surface alignment issues and progressive power distribution that would be missed by conventional methods.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the power distribution is measured at multiple points to assess surface alignment, then the detection precision of positional shifts improves, but the measurement time and complexity increase

Engineering Contradiction:
Improvepositional shift detectionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

Measurement points are pre-configured and predetermined before actual measurement. The evaluation system uses pre-planned measurement locations and parameters, allowing rapid data collection without time-consuming on-site calculations or adjustments. This preliminary preparation enables efficient detection of positional shifts and surface alignment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system measures power distribution at multiple points and compares the results against predetermined reference values or design specifications. This feedback mechanism allows immediate identification of deviations indicating positional shifts or misalignment, enabling quick detection without requiring extensive measurement and analysis time.

Inventive Principle:
Principle #23Feedback

3Productivity

If conventional single-point measurement methods are used, then the evaluation process is fast, but the ability to detect surface combination defects and misalignment is insufficient

Engineering Contradiction:
Improveevaluation speedVSAvoiddefect detection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Multiple measurement points are combined into a unified evaluation system that simultaneously assesses optical characteristics across the entire lens surface. By merging the data from multiple points, the system achieves comprehensive defect detection and surface alignment verification while maintaining efficient processing through integrated analysis.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The measurement system serves multiple functions: it evaluates optical power distribution, detects surface alignment, identifies positional shifts, and assesses progressive power characteristics all through a single integrated process. This multi-functionality enables reliable defect detection without requiring separate specialized measurements, thereby maintaining evaluation speed.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2189777B1Method and device for evaluating graduated refraction power lens and method for manufacturing graduated refraction power lens
Publication Date: 2020.01.01 HOYA CORPORATION
  • EP2189777B1 patent drawingFigure 1
  • EP2189777B1 patent drawingFigure 2
  • EP2189777B1 patent drawingFigure 3

AI summary

The present invention is to provide a method for easily evaluating whether or not a relative positional shift generated between both surfaces of a bi-aspherical type lens is within an allowance during the manufacturing process of the bi-aspherical type lens. According to the evaluation method of the progressive-addition lens of the present invention, first, powers of the progressive-addition lens at a plurality of are measured to obtain an actually measured power distribution. Next, a comparison power distribution created based on the actually measured power distribution and a defective power distribution prepared in advance are compared with each other to perform similarity search between the both. Thereafter, whether or not the comparison power distribution and the defective power distribution are similar to each other is determined based on the result of the similarity search step, and if it is determined that the comparison power distribution and the defective power distribution are similar to each other, then the progressive-addition lens is evaluated as defective.