Imaging Lens Compact Design via Moving Lens Groups
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a demand for an imaging lens that is compact in size while maintaining good optical performance, which existing imaging lenses have not adequately addressed.
Innovation Solution
The proposed imaging lens consists of a first lens group with positive refractive power, a stop, a second lens group with positive refractive power, and a third lens group that includes both positive and negative lenses. During focusing, the first lens group, the stop, and the second lens group move as a focus group, while the third lens group remains stationary. This configuration satisfies specific conditional expressions to achieve a balance between lens size and optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the lens system is reduced in size to meet compactness requirements, then the overall dimensions decrease, but optical performance deteriorates
Solution Approach 1:
The lens system is divided into three distinct lens groups (first, second, and third lens groups) with different refractive power configurations. The first and second lens groups have positive refractive power while the third has negative refractive power. This segmentation allows each group to contribute differently to the overall optical performance, enabling compact design while maintaining image quality through optimized light path control in each segment.
Solution Approach 2:
The patent applies specific conditional expressions that define precise parameter ranges for focal lengths (f1, f2, f3), back focal length (Bf), total track length (TTL), and F-number (FNo). By controlling these optical parameters within specified ranges and satisfying mathematical relationships between them, the system achieves optimal balance between compactness and optical performance. The conditional expressions ensure that reducing lens size does not compromise the quality of focus and image formation.
2Length of moving object
If the focal length is reduced to make the lens more compact, then the lens length decreases, but the F number increases making the lens less efficient
Solution Approach 1:
The patent establishes specific mathematical relationships between focal lengths of individual lens groups (f1, f2, f3) and the total focal length (f), along with constraints on back focal length (Bf) and total track length (TTL). These parameter relationships enable the system to maintain a short overall length while controlling the F-number to ensure efficient light transmission. The conditional expressions ensure that the optical parameters are balanced to achieve both compactness and lighting efficiency.
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 described configuration enables the creation of an imaging lens that is both compact and achieves excellent optical performance, effectively addressing the need for a small-sized lens with good image quality.
Implementation Method 1
a first lens group G1 having a positive refractive power, a stop St, a second lens group G2 having a positive refractive power, and a third lens group G3
Data Source
AI summary
The imaging lens consists of, in order from the object side, a first lens group having a positive refractive power, a stop, a second lens group having a positive refractive power, and a third lens group. The third lens group includes one or more positive lenses and one or more negative lenses. During focusing, an entirety of the first lens group, the stop, and the second lens group, or an entirety of the second lens group integrally moves as a focus group, and the third lens group remains stationary with respect to an image plane. The imaging lens satisfies predetermined conditional expressions.