Asymmetric Diffractive Ophthalmic Lens Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ophthalmic lenses with diffractive structures, such as sinusoidal profiles, face limitations in optimizing optical properties, particularly in achieving balanced diffraction efficiency across orders and improving imaging performance for distance vision and depth of focus.
Innovation Solution
The design of ophthalmic lenses with ring-shaped diffractive structuring that deviates from sinusoidal waveforms by introducing asymmetry and periodicity changes, allowing for enhanced diffraction efficiency and depth of focus through tailored refractive and diffractive effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sinusoidal diffractive structure is used, then the lens produces a mirror symmetric intensity distribution, but the diffraction efficiency of negative orders is insufficient and imaging performance for distance vision is limited
Solution Approach 1:
The patent applies asymmetry by deviating from a sinusoidal waveform and using a waveform with asymmetric periods in the radial direction. This asymmetric waveform design allows the lens to generate different diffraction efficiency for positive and negative orders, specifically enhancing the negative orders to improve distance vision imaging performance while maintaining manufacturability through a systematic design approach
2Reliability
If the diffractive structure follows a strict sinusoidal pattern, then manufacturing is simplified, but the depth of focus and polychromatic efficiency balance are suboptimal
Solution Approach 1:
The patent applies parameter changes by modifying the waveform parameters (amplitude, period, shape) in the radial direction to create a non-sinusoidal pattern. These parameter variations are designed to optimize the balance between different diffraction orders and enhance polychromatic efficiency, while the changes follow a systematic pattern that maintains manufacturability
3Measurement precision
If polychromatic effects and material dispersion are considered, then optical accuracy is improved, but the design and manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by allowing different waveform characteristics at different radial positions of the lens. The asymmetric waveform design creates locally optimized regions that account for polychromatic effects and material dispersion variations across the lens, improving overall optical accuracy while maintaining a systematic design approach
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach increases the diffraction efficiency of negative orders, matches polychromatic efficiency with positive orders, and enhances imaging performance for distance vision, while also improving the depth of focus and manufacturability of ophthalmic lenses.
Implementation Method 1
a ring-shaped, diffractive structuring (14) which, in the radial direction, has a waveform which deviates from a sinusoidal waveform of the square of the radius by an asymmetry and/or a flattening and/or the periodicity
Implementation Method 2
a lens body (12) with a predetermined refractive effect
Data Source
AI summary
An ophthalmic lens includes a lens body with a predetermined refractive effect and a ring-shaped, diffractive structuring. The ring-shaped, diffractive structuring (4-4) has a waveform in the radial direction which differs from a sinusoidal waveform by an asymmetry and/or a flattening and/or a periodicity, wherein the asymmetry and/or flattening and/or periodicity is constant or changes strictly monotonically over the entire radial curve of the waveform. Further, a method for designing an ophthalmic lens is disclosed.