Achromatic Doublet Prism Array for Wide-Angle Camera
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Solution Overview
Problem
Wide-angle camera systems using N×N lens arrays suffer from severe chromatic aberration due to the use of prisms, which significantly reduces the modulation transfer function (MTF) and image quality.
Innovation Solution
A novel achromatic doublet prism array is employed, comprising two asymmetric prisms made of different materials with specific refractive indices and Abbe numbers, formed using wafer-level fabrication to reduce chromatic aberration and improve optical resolution, while maintaining a compact camera format.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a prism is used in an N×N lens array system to achieve wide-angle viewing, then the viewing angle is increased, but severe chromatic aberration occurs that reduces MTF and image quality
Solution Approach 1:
The single prism is segmented into multiple prisms with different materials and optical properties. The patent uses a 3×3 array of prisms where each prism has slightly different refractive index and Abbe number, allowing chromatic aberration to be distributed and corrected across multiple elements while maintaining the wide-angle viewing capability
Solution Approach 2:
Each prism in the array has locally optimized optical properties (different refractive indices and Abbe numbers) to correct chromatic aberration in its specific region. The gradual variation of optical properties across the array allows for localized correction of color fringing while maintaining overall wide-angle performance
2Device complexity
If conventional single prisms are used in lens arrays, then device complexity is reduced, but chromatic aberration significantly degrades optical resolution
Solution Approach 1:
The patent employs composite material structures where multiple prisms with different glass types (different refractive indices and Abbe numbers) are arranged in an array. This composite approach allows chromatic aberration to be corrected through the combined optical effect of materials with complementary properties, improving optical resolution without excessive complexity
Solution Approach 2:
The patent systematically varies optical parameters (refractive index, Abbe number) across the prism array to correct chromatic aberration. By carefully selecting and arranging prisms with progressively changing parameters, the system achieves high optical resolution while maintaining a relatively simple overall structure
3Manufacturing precision
If achromatic doublet prisms are implemented to reduce chromatic aberration, then image quality improves, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple prism functions into a unified array structure where adjacent prisms work together as an integrated optical system. The achromatic doublet prisms are arranged in a compact grid pattern that combines correction functionality across the entire array, achieving high image quality without proportionally increasing overall device complexity
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 achromatic doublet prism array significantly enhances optical resolution and image quality by minimizing chromatic aberration, making it comparable to cameras without prisms, while maintaining a compact and efficient manufacturing process.
Implementation Method 1
an array of achromatic doublet prisms on a second side of the substrate, where each of the achromatic doublet prisms is aligned to provide a viewing angle
Data Source
AI summary
A wide-angle camera and fabrication method thereof includes a sensor with a plurality of pixel sub-arrays and an array of optical elements on a first side of a substrate. Each of the optical elements is capable of forming an image from a field of view onto a different one of the pixel sub-arrays. The wide-angle camera also includes an array of achromatic doublet prisms on a second side of the substrate, where each of the achromatic doublet prisms is aligned to provide a viewing angle with a different one of the optical elements. The sensor captures a wide-angle field of view while having a compact format.