Wide-angle lens ghost reflection reduction
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Solution Overview
Problem
Wide-angle lenses suffer from significant ghost reflections due to double reflections within the imaging system, which degrade image quality, especially when bright objects are in the field of view, and current technologies fail to adequately address this issue while maintaining compact size and high performance.
Innovation Solution
A wide-angle lens design comprising three groups of lens elements (G1, G2, and G3) with specific configurations, including meniscus and doublet lens elements, and anti-reflection coatings to minimize ghost reflections, ensuring that secondary images are out of focus and reduced in intensity relative to the primary image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If wide-angle lens design is used to achieve wide field of view, then field of view is improved, but ghost reflections increase
Solution Approach 1:
The patent applies anti-reflection coatings to lens surfaces to convert the harmful effect of reflections into beneficial light transmission. The coatings are specifically designed to reduce ghost reflections while maintaining the wide-angle field of view, transforming the problematic reflections into acceptable levels that do not degrade image quality
Solution Approach 2:
The patent employs different anti-reflection coating configurations on different lens surfaces (object-side and image-side surfaces of various lens elements). Each surface receives tailored coating treatment based on its specific role in the optical path, allowing localized optimization to reduce ghost reflections at critical interfaces while preserving the overall wide-angle performance
2Object-generated harmful factors
If lens elements are added to reduce ghost reflections, then ghost image intensity is reduced, but device complexity increases
Solution Approach 1:
The patent introduces anti-reflection coatings as an intermediary layer between air and lens material at various interfaces. These coatings act as mediators that reduce the refractive index mismatch, thereby minimizing ghost reflections without requiring additional lens elements or complex structural modifications
Solution Approach 2:
The patent modifies the optical parameters at lens interfaces by applying anti-reflection coatings with specific refractive indices. This changes the reflection characteristics at each surface, reducing ghost image intensity through parameter optimization rather than through adding more optical elements
3Object-generated harmful factors
If anti-reflection coatings are applied to reduce reflections, then ghost reflections are reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies anti-reflection coatings selectively at specific critical interfaces where ghost reflections are most problematic, rather than uniformly across all surfaces. This partial application approach reduces the overall manufacturing precision burden while still achieving sufficient ghost reflection reduction at the most critical locations
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 design effectively reduces ghost image intensity to less than 10^-4 times that of the primary image, maintaining high image quality across a wide field of view and accommodating bright objects, while being compact enough for portable electronic devices.
Implementation Method 1
coatings that are applied to the lenses and other elements
Implementation Method 2
Every transition of light ray across a material boundary where the materials have different refractive indices can produce a partial reflection of the light
Data Source
AI summary
Low ghosting wide-angle lens designs are presented. The dimensions and materials are selected such that the lens has a field of view of at least 145 degrees, f# of 2.2-2.9 and all secondary images of an object imaged on the image plane are focused such that they fall either outside of the image plane thus having a relative intensity that is less than 10−4 times the intensity of the primary image.In one embodiment a set of conditional expressions are all met. In another embodiment the conditional expressions are all met and the conditional expressions related to the physical size of the lens is narrowed. In another embodiment five and seven element designs are produced.