Dog Bone Fluidic Lens Minimizes Spherical Defocus
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Solution Overview
Problem
Cylindrical tunable fluidic lenses face challenges in minimizing spherical defocus and higher order aberrations, leading to bulky structures and the need for complex mechanical systems to correct refractive errors, while existing solutions fail to achieve pure cylindrical focusing without additional optical and mechanical components.
Innovation Solution
The use of a dog bone shaped opening for the flexible membrane of a fluidic lens, which allows deformation without significant spherical contribution to the wavefront, enabling tunable cylindrical focusing without spherical defocusing effects or non-cylindrical aberrations, and is designed to have a relatively low length-to-width ratio for compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a rectangular aperture is used to create a cylindrical fluidic lens, then the cylindrical optical power is achieved, but spherical defocus and higher order aberrations are introduced
Solution Approach 1:
The patent applies asymmetry by using a dog bone shaped aperture instead of a symmetric rectangular aperture. The dog bone shape has non-uniform width along its length, with narrower ends and a wider middle section. This asymmetric geometry creates a cylindrical optical power in one direction while minimizing the spherical defocus and higher order aberrations that plague rectangular apertures, as the varying width compensates for the spherical contribution across the aperture area
Solution Approach 2:
The patent applies local quality by varying the aperture width at different locations along the dog bone shape. The aperture has different effective widths at the ends versus the middle, creating localized optical effects that collectively produce pure cylindrical focusing. This local variation in aperture geometry allows different regions to contribute differently to the overall optical function, minimizing aberrations while maintaining cylindrical power
2Object-generated harmful factors
If a high aspect ratio is used to minimize spherical defocus in cylindrical lenses, then the spherical contribution is reduced, but the structure becomes bulky and impractical to fabricate
Solution Approach 1:
The patent applies parameter changes by optimizing the dog bone aperture dimensions to achieve a balanced aspect ratio that is much lower than traditional cylindrical lenses. By carefully selecting the length, width, and curvature parameters of the dog bone shape, the invention achieves minimal spherical defocus without requiring an excessively high aspect ratio, resulting in a compact, fabricable lens structure with practical dimensions
3Shape
If rigid cylindrical lenses with variable optical power are used, then cylindrical focusing is achieved, but complex mechanical systems are required to control rotation precisely
Solution Approach 1:
The patent applies mechanics substitution by replacing the mechanical rotation control system with a fluidic pressure control system. Instead of mechanically rotating rigid cylindrical lenses to change optical power, the invention uses a flexible membrane that deforms in response to fluid pressure changes. This substitutes complex mechanical rotation mechanisms with simpler fluid pressure actuation, enabling variable cylindrical optical power without precise mechanical control systems
4Adaptability or versatility
If a flexible membrane is deformed to change focal length in spherical fluidic lenses, then tunable optical power is achieved, but cylindrical counterparts introduce spherical defocus
Solution Approach 1:
The patent applies asymmetry by using a dog bone shaped aperture with the flexible membrane, rather than a symmetric circular or rectangular aperture. This asymmetric geometry enables the membrane deformation to produce purely cylindrical optical power tuning without introducing spherical defocus, as the varying width along the dog bone shape compensates for the spherical contribution during deformation
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
The dog bone shaped cylindrical fluidic lenses provide pure cylindrical focusing with minimal spherical defocus and higher order aberrations, maintaining simplicity and compactness similar to spherical fluidic lenses, thus overcoming the limitations of previous cylindrical lens designs.
Implementation Method 1
a deformation of the flexible transparent membrane, and the deformation and power are configured to change based on a pressure difference between the fluidic chamber and outside thereofto
Implementation Method 2
a flexible transparent membrane attached to the fluidic chamber and covering the opening
Implementation Method 3
The geometry of the lens' open face or faces determines the light refraction characteristics of the lens
Data Source
AI summary
The invention relates to cylindrical tunable fluidic lenses. The cylindrical optical power of the lenses may be continuously tuned within at least ±10 diopters, without inducing any significant spherical aberration, or any other significant aberrations. The lenses feature a geometry that produces minimal or no spherical defocus. These cylindrical tunable fluidic lenses could be used to induce and/or correct cylindrical optical aberrations in adaptive optical systems, particularly in ophthalmologic applications related to objective and automatic assessment of the refractive error of the eye, without the need of receiving feedback from the subjects.