Progressive Power Lens Profile Shaping With Continuous Weight Maps
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Solution Overview
Problem
The shape of the addition profile in progressive power lenses is not easily changed without causing design failures in astigmatism and power distribution, necessitating thorough checks each time the profile is altered.
Innovation Solution
A method involving a weight map on an xy plane coordinate system is used to multiply approximate curvatures by weights, adjusting the addition profile smoothly while maintaining continuity, and incorporating judgment steps to ensure design integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the shape of the addition profile is changed, then the progressive mode can be adjusted to suit different wearers, but design failures may occur in astigmatism and power distribution
Solution Approach 1:
The patent implements a feedback mechanism where the calculation unit computes astigmatism and power distribution after modifying the addition profile, and the determination unit checks whether these values remain within predetermined ranges. This feedback loop ensures that profile adjustments do not cause design failures, resolving the contradiction between adaptability and reliability.
Solution Approach 2:
The patent applies preliminary anti-action by pre-establishing predetermined ranges for astigmatism and power distribution before making profile changes. The system proactively prevents design failures by checking whether modified profiles fall within these safe boundaries, countering the potential harmful effect of profile changes before they can cause problems.
2Adaptability or versatility
If the addition profile is modified to personalize power changes, then wearer preferences can be accommodated, but thorough checks are required each time
Solution Approach 1:
The patent implements self-service through automation where the calculation unit automatically computes astigmatism and power distribution, and the determination unit automatically checks whether these values are within acceptable ranges. This automated self-checking process eliminates manual verification time while enabling personalized profile adjustments, resolving the contradiction between adaptability and time loss.
3Adaptability or versatility
If the addition profile shape is altered, then different intermediate power distributions can be achieved, but the entire spectacle lens must be checked for design failures
Solution Approach 1:
The patent applies segmentation by dividing the verification process into distinct functional units: the calculation unit that computes astigmatism and power distribution separately, and the determination unit that checks each parameter against predetermined ranges. This segmented approach simplifies the overall verification process while maintaining comprehensive checking, resolving the contradiction between adaptability and device complexity.
Data Source
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AI summary
There is provided a method for changing a progressive mode of a progressive power lens and related techniques thereof, the method including: obtaining a weight map on an xy plane coordinate system for changing from progressive mode 1 to progressive mode 2, the weight map having continuity in all directions on the xy plane coordinate system; obtaining a z-coordinate value zadd by multiplying an approximate curvature Cp on the xy plane coordinate system at each point on a surface α, which is a design surface by weights wp corresponding to each point on the weight map; and designing a new surface α' based on the z-coordinate value zaddp obtained in the obtaining the z-coordinate value.