Imaging Lens Assembly Aberration Correction
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Solution Overview
Problem
Conventional optical systems in portable electronic devices, such as smartphones and PDAs, fail to meet the demands for high-end camera functionalities due to inadequate light gathering ability and excessive spherical aberration, particularly with five lens elements that do not effectively reduce the total track length and maintain image quality.
Innovation Solution
A miniaturized imaging lens assembly with five non-cemented lens elements, including a first lens with positive refractive power and convex object-side surface, a second lens with negative refractive power and concave image-side surface, a third lens with positive refractive power and convex image-side surface, a fourth lens with negative refractive power, and a fifth lens with positive refractive power and concave image-side surface at a paraxial region, along with a stop between the object and the first lens, optimizing refractive power distribution and surface shapes to correct aberrations and reduce the total track length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a conventional optical system with five lens elements is used, then the total track length can be reduced, but the light gathering ability is insufficient and spherical aberration is excessive
Solution Approach 1:
The patent applies local quality by designing different surface shapes (convex, concave, aspheric) for different lens elements at specific locations. The first lens element has a convex object-side surface and aspheric image-side surface, while the fifth lens element has a concave paraxial region and convex peripheral region. This localized optimization of surface geometry corrects spherical aberration and improves light gathering ability without increasing the total track length.
Solution Approach 2:
The patent employs parameter changes by precisely controlling the refractive power distribution among the five lens elements and optimizing the curvature radii of their surfaces. The refractive powers are distributed as: first lens element (positive), second lens element (negative), third lens element (positive), fourth lens element (negative), and fifth lens element (positive). This parameter optimization reduces spherical aberration and improves image quality while maintaining a compact total track length.
2Reliability
If the number of lens elements is increased to improve image quality, then spherical aberration decreases, but the total track length increases
Solution Approach 1:
The patent merges the functions of multiple lens elements into a compact five-element configuration where each element contributes specific aberration correction. The alternating positive and negative refractive power elements work together to correct spherical aberration and other optical defects, achieving high image quality in a compact total track length that would be impossible with more elements.
Solution Approach 2:
The patent utilizes spheroidality by designing lens surfaces with specific curvature characteristics - convex, concave, and aspheric surfaces - to correct spherical aberration. The aspheric surfaces of the first and fifth lens elements, along with the convex/concave combinations of intermediate elements, work together to eliminate spherical aberration while maintaining a compact overall length.
3Illumination intensity
If the focal length of the first lens element is increased to improve light gathering ability, then the aperture ratio increases, but the total track length increases
Solution Approach 1:
The patent applies dimensionality change by optimizing the axial and radial positions of lens elements and surfaces. The aspheric surfaces and convex/concave geometries are designed to achieve optimal light gathering in the paraxial and peripheral regions simultaneously. This spatial optimization allows high aperture ratio and effective light gathering without increasing the axial total track length.
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 solution provides improved light gathering ability, reduced spherical aberration, and a compact design, enabling high image quality suitable for 3D image capturing applications in digital cameras and mobile devices while maintaining a compact size.
Implementation Method 1
an imaging lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The imaging lens assembly has five non-cemented lens elements with refractive power.
Data Source
AI summary
An imaging lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The imaging lens assembly has five non-cemented lens elements with refractive power and further includes a stop located between an imaged object and the first lens element. The first lens element with positive refractive power has a convex object-side surface. The second through fifth lens elements all have refractive power. The third lens element has a convex image-side surface. The fifth lens element has a concave image-side surface at a paraxial region thereof, wherein the image-side surface of the fifth lens element has a convex shape at a peripheral region thereof, and both of an object-side surface and the image-side surface of the fifth lens element are aspheric.