Imaging Lens with Segmented Groups for Wide-Angle Aberration Control
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Solution Overview
Problem
Existing imaging lenses for electronic cameras, such as cinema and digital cameras, have limited wide-angle views and insufficient correction of various aberrations, making them unsuitable for high-pixel formats like 4K and 8K.
Innovation Solution
The design of an imaging lens with a specific configuration including a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with adjustable refractive power, where the first lens group is fixed, and the second and third groups move to focus, satisfying certain conditional formulas for curvature and focal length ratios to achieve a wide angle of view and effective aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a three group configuration with small F numbers is used, then the lens achieves compact size and reasonable aberration control, but the angle of view is limited to approximately 64° and cannot be considered wide
Solution Approach 1:
The lens is divided into four distinct lens groups (G1, G2, G3, G4) with specific refractive power assignments. The first lens group G1 with negative refractive power is positioned at the object side to expand the angle of view, while the subsequent groups G2, G3, and G4 with positive refractive power focus the light rays. This segmentation allows independent optimization of each group's function, achieving both wide angle of view and acceptable aberration control.
Solution Approach 2:
Each lens group is assigned specific optical properties and positioned at particular locations along the optical axis. The negative refractive power of G1 is localized at the object side where it is most effective for angle of view expansion, while positive refractive power groups are positioned progressively toward the image side for focusing. This local optimization of optical qualities enables the system to achieve wide angle of view while maintaining image quality.
2Device complexity
If conventional lens designs are used to achieve small F numbers, then the lens structure is simplified, but various aberrations are not sufficiently corrected for high-pixel formats
Solution Approach 1:
The optical system is segmented into four lens groups with alternating refractive powers. This segmentation allows each group to be optimized for specific aberration corrections: G1 handles field curvature and distortion, while G2, G3, and G4 work together to correct spherical aberration, coma, and chromatic aberration. The segmented structure provides sufficient degrees of freedom to correct multiple aberration types simultaneously.
Solution Approach 2:
The lens system employs composite optical design combining elements with different refractive powers and dispersion characteristics. By compositeing positive and negative lens groups with carefully selected focal lengths and positions, the system achieves superior aberration correction performance that would be difficult to obtain with homogeneous lens designs.
3Area of moving object
If the angle of view is widened beyond conventional designs, then the lens captures more scene, but aberration correction becomes increasingly difficult and image quality deteriorates
Solution Approach 1:
The four-group configuration with negative-positive-positive-positive refractive power distribution provides optimal balance for wide-angle applications. The negative power G1 at the object side is specifically designed to handle the wide field of view requirements, while the subsequent positive power groups progressively converge the light rays and correct the aberrations introduced by the wide-angle design. This segmented approach distributes the optical correction tasks across multiple specialized groups.
Solution Approach 2:
Optical qualities are locally optimized for the wide-angle requirement: G1 is positioned and designed specifically for field expansion with appropriate negative refractive power, while G2, G3, and G4 are positioned to progressively correct the specific aberration patterns that arise from wide-angle light paths. This local quality assignment enables effective aberration control across the wide field of view.
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 configuration results in an imaging lens capable of providing wide-angle views with improved correction of aberrations, such as astigmatism, distortion, and chromatic aberrations, enhancing image quality for high-pixel formats.
Implementation Method 1
a first positive lens L11 from among the at least two positive lenses is positioned most toward the object side
Implementation Method 2
three negative lenses L12 through L14 are consecutively provided adjacent to the first positive lens L11 at the image side thereof
Implementation Method 3
the first lens group G1 is fixed with respect to an imaging surface during focusing operations, and the second lens group G2 and the third lens group G3 move
Data Source
AI summary
An imaging lens is constituted by, in order from the object side to the image side: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a stop; and a third lens group having a positive refractive power or a negative refractive power. The first lens group has at least two positive lenses, a first positive lens from among the at least two positive lenses being positioned most toward the object side, and three negative lenses being consecutively provided adjacent to the first positive lens at the image side thereof. The first lens group is fixed with respect to an imaging surface, and focusing operations are performed by moving the second lens group and the third lens group.