Compact Zoom Lens Optical System Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zoom lens optical systems for cameras with solid state imaging devices face challenges in being compact, correcting color aberration, and maintaining low manufacturing costs, often due to increased complexity and number of lenses which affect production costs and size.
Innovation Solution
A zoom lens optical system comprising a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power, where the lens groups are arranged sequentially and move to adjust distances between them to achieve zooming, with specific constraints on focal lengths and Abbe numbers to minimize size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the first lens group has a single lens, then the device complexity is reduced, but color aberration compensation becomes difficult
Solution Approach 1:
The patent applies parameter changes by carefully selecting the refractive index and Abbe number of the single lens in the first lens group. Specifically, it uses a lens with refractive index 1.50 < Nd < 1.70 and Abbe number 30 < Vd < 50, which optimizes the balance between device simplicity and color aberration compensation capability.
2Manufacturing precision
If the third lens group has four or more lenses, then color aberration is corrected, but production costs increase
Solution Approach 1:
The patent extracts the color aberration correction function from the third lens group and relocates it to the first lens group. By placing a specifically designed lens with appropriate refractive index and Abbe number in the first lens group, the system achieves color aberration correction without requiring multiple lenses in the third group, thereby reducing production costs.
Solution Approach 2:
The patent uses parameter changes by specifying particular ranges for refractive index (1.50 < Nd < 1.70) and Abbe number (30 < Vd < 50) of the lens in the first lens group, enabling effective color aberration correction with a single lens rather than requiring multiple lenses in other groups.
3Manufacturing precision
If the fourth lens group has two or more lenses, then aberration is reduced, but the number of lenses increases thereby increasing production costs and requiring larger receiving space
Solution Approach 1:
The patent extracts the aberration reduction function from the fourth lens group and consolidates it into a single lens configuration. By redesigning the fourth lens group to use only one lens with optimized parameters, the system maintains aberration reduction capability while reducing the total number of lenses, production costs, and receiving space requirements.
4Manufacturing precision
If more lenses are used in each lens group, then aberration is reduced, but the size and costs of the zoom lens optical system increase
Solution Approach 1:
The patent applies parameter changes by defining specific ranges for focal lengths of each lens group (first: 10-30mm, second: -20 to -5mm, third: 20-50mm, fourth: 5-15mm) and for the refractive index and Abbe number of the first lens group's lens. These parameter optimizations enable effective aberration reduction while maintaining a compact overall system size.
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 system effectively corrects color aberration, maintains a high zooming ratio, and reduces manufacturing costs by optimizing lens group movements and using aspherical surfaces, allowing for a compact and cost-effective design.
Implementation Method 1
a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, arranged sequentially from an object
Data Source
AI summary
A compact zoom lens optical system that includes: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power, wherein the first through fourth lens groups are arranged sequentially from an object, zooming is performed from a wide angle position to a telephoto position so that the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group increases, and the first through fourth lens groups satisfy:6≤LWFW+LtFt≤8where Lw denotes a distance between a first surface of an object-side lens of the first lens group and an image surface when in the wide angle position, Lt denotes a distance between the first surface of the object-side lens of the first lens group and the image surface when in the telephoto position, Fw denotes an overall focal length when in the wide angle position, and the Ft denotes an overall focal length when in the telephoto position.