Two-Element Plastic Lens Assembly for Compact Image Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical lens assemblies for portable electronic devices face challenges in achieving compact size and low manufacturing cost while maintaining image quality, particularly in correcting chromatic polarization and reducing aberrations.
Innovation Solution
An optical lens assembly comprising a first lens element with positive refractive power and a second lens element with negative refractive power, both made of plastic or glass materials, with specific surface curvatures and thickness ratios to correct aberrations and reduce chromatic polarization, allowing for a compact design with improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If at least three lens elements with refractive power are adopted, then image quality can be maintained, but manufacturing cost and complexity increase
Solution Approach 1:
The patent extracts and eliminates unnecessary lens elements from the optical system. By carefully designing a two-element assembly with specific refractive power distributions and surface curvatures, the patent achieves adequate image quality without requiring three or more elements, thereby reducing manufacturing complexity and cost while maintaining essential optical performance
Solution Approach 2:
The patent applies parameter changes by optimizing the refractive powers, Abbe numbers, and surface curvature radii of the two lens elements. Specific mathematical relationships between these parameters are established to correct chromatic aberration and spherical aberration, enabling a two-element design to achieve image quality comparable to or exceeding three-element designs
2Reliability
If at least three lens elements with refractive power are adopted, then image quality can be maintained, but manufacturing cost increases
Solution Approach 1:
The patent removes the third lens element from the optical system, demonstrating that a two-element design can achieve sufficient image quality for portable devices. This extraction directly reduces the number of components that need to be manufactured, assembled, and aligned, thereby lowering manufacturing cost while maintaining acceptable optical performance
Solution Approach 2:
The patent employs plastic lens elements that can be manufactured cost-effectively through injection molding. By using molded plastic elements with aspheric surfaces rather than precision-ground glass elements, the patent reduces manufacturing cost while achieving the required optical quality for consumer portable devices
3Ease of manufacture
If two lens elements are used, then manufacturing cost is reduced, but chromatic polarization cannot be corrected
Solution Approach 1:
The patent corrects chromatic polarization by carefully selecting and coordinating the refractive powers and Abbe numbers of the two lens elements. The first element has positive refractive power with a specific Abbe number range, while the second element has negative refractive power with a complementary Abbe number, creating a chromatic correction effect that would normally require more elements
Solution Approach 2:
The patent uses lens elements made from materials with specifically selected optical properties, including different Abbe numbers and refractive indices. This material selection strategy enables the two-element assembly to achieve chromatic aberration correction through the composite optical effect of the paired elements
4Volume of moving object
If two lens elements are used, then device size is reduced, but aberrations cannot be corrected
Solution Approach 1:
The patent employs aspheric surfaces on one or both lens elements to correct spherical aberration and other monochromatic aberrations. The aspheric profiles are mathematically optimized to provide aberration correction that would otherwise require additional lens elements, enabling compact two-element design with adequate image quality
Solution Approach 2:
The patent optimizes multiple parameters including the curvature radii of the lens surfaces, the thickness of each element, and the spacing between elements. By establishing specific mathematical relationships between these parameters, the patent achieves effective aberration correction in a compact two-element configuration
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 proposed lens assembly achieves reduced chromatic polarization, enhanced image quality, and lower manufacturing costs by optimizing the refractive powers and surface shapes of the lens elements, enabling a more compact and efficient optical design for portable devices.
Implementation Method 1
a first lens element (110), which has positive refractive power
Implementation Method 2
a second lens element (120), which has negative refractive power
Implementation Method 3
correct chromatic polarization and reducing aberrations
Implementation Method 4
correct chromatic polarization and reducing aberrations
Data Source
AI summary
An optical lens assembly includes, in order from an object side to an image side, a first lens element and a second lens element. The first lens element with positive refractive power has an object-side surface being convex at a paraxial region and an image-side surface being concave at a paraxial region. The second lens element with negative refractive power is made of plastic material and has an image-side surface being concave at a paraxial region and being convex at a peripheral region, wherein an object-side surface and the image-side surface of the second lens element are aspheric.