Achromatic Lens Structure with Aspherical Segments and Composite Materials
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Solution Overview
Problem
Conventional imaging devices suffer from chromatic and spherical aberrations due to the varying refractive indices of lenses for different wavelengths of light, leading to blurry images and color fringes, which existing technologies have not effectively addressed, especially in wafer-level fabrication processes.
Innovation Solution
The implementation of a lens structure that incorporates a transparent material with a different dispersion and refractive index than the lenses, allowing for the correction of chromatic and spherical aberrations by bonding substrates and lenses together without air gaps, and using aspherical lens profiles to enhance image focus across a larger field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional spherical lens structure is used, then the manufacturing process is simple, but chromatic and spherical aberrations occur causing blurry images
Solution Approach 1:
The lens is divided into multiple segments: a first aspherical lens portion, a second aspherical lens portion, and an intermediate portion between them. Each portion has different optical properties and curvatures, allowing independent optimization to correct both chromatic and spherical aberrations while maintaining manufacturing feasibility through wafer-level fabrication.
Solution Approach 2:
The patent employs aspherical lens portions with non-uniform curvatures instead of traditional spherical surfaces. The first and second aspherical lens portions have different aspherical coefficients and curvature distributions, enabling precise control of light ray paths to eliminate spherical and chromatic aberrations that cannot be corrected with symmetric spherical lenses.
2Manufacturing precision
If a single lens material is used, then the manufacturing process is simple, but chromatic aberration causes different wavelengths to focus at different positions
Solution Approach 1:
The lens combines multiple materials with different dispersion properties: a first lens material for the first aspherical lens portion, a second lens material for the second aspherical lens portion, and potentially a third material for the intermediate portion. This composite structure enables chromatic aberration correction by utilizing the different refractive indices and Abbe numbers of the materials, while wafer-level co-fabrication maintains manufacturing efficiency.
3Manufacturing precision
If air gaps are present between substrate and lens, then assembly is easier, but optical performance deteriorates due to additional refraction interfaces
Solution Approach 1:
The patent integrates the lens structure directly with the substrate without air gaps, merging the lens and substrate into a monolithic or closely coupled structure. This eliminates parasitic refraction at air-substrate interfaces, improves optical performance, and enables wafer-level co-fabrication where lenses are formed directly on or bonded to the substrate in a single manufacturing process.
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 solution effectively corrects chromatic and spherical aberrations, ensuring that different wavelengths of light are focused at a single point, resulting in sharper images and reduced color fringes, while allowing for efficient wafer-level fabrication and improved field performance.
Implementation Method 1
Chromatic aberration is caused by a lens having a different refractive index for different wavelengths of light, known as the dispersion of the lens. Since the focal length of a lens is dependent on the refractive index of the lens material, different wavelengths of light will be focused at different positions.
Implementation Method 2
Spherical aberration is an image imperfection that occurs due to the increased refraction of light rays 120 when the light rays 120 strike a lens 112, 114 near its edge, in comparison with light rays 120 that strike nearer the center of the lens 112, 114.
Implementation Method 3
The transparent material may also be used to bond components of the lens structure, such as substrates and lenses, to each other.
Data Source
AI summary
Lens structures, imaging devices, and methods of making the same that include a lens and a transparent material having different dispersions and used to correct chromatic and spherical aberrations. The transparent material may be a curable polymer used to join the lens to other elements of the lens structure.