Zoom Optical System Lens Group Configuration for Compact Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zoom optical systems face challenges in achieving excellent optical performance while simultaneously reducing size and weight.
Innovation Solution
A zoom optical system comprising a specific configuration of lens groups with varying refractive powers, where the first, second, third, fourth, and fifth lens groups are aligned along the optical axis, and the fourth lens group acts as a focusing lens group that moves along the optical axis during focusing. The system satisfies specific conditional expressions regarding the focal lengths of the lens groups to optimize optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional zoom optical system configuration is used, then the system can achieve basic zooming function, but excellent optical performance cannot be obtained while realizing size reduction and weight reduction
Solution Approach 1:
The optical system is divided into five distinct lens groups with specific refractive power assignments. Each lens group (first with positive power, second with negative power, third with positive power, fourth with negative power as focusing group, and fifth with negative power) is segmented to perform specific optical functions, enabling optimized performance while controlling overall system size and weight
Solution Approach 2:
The patent applies specific conditional expressions that define precise relationships between focal lengths of different lens groups (f1, f2, f3, f4, f5) and their ratios. By changing and optimizing these parameters according to the conditional expressions, the system achieves excellent optical performance while maintaining reduced size and weight characteristics
2Ease of operation
If the fourth lens group is configured as a focusing lens group that moves along the optical axis, then focusing function is improved, but system complexity increases
Solution Approach 1:
The fourth lens group is configured as a focusing lens group capable of moving along the optical axis to achieve focusing function. This dynamic configuration allows the lens group to adjust its position for focusing while maintaining a compact structure, balancing operational ease with mechanism complexity
Solution Approach 2:
The fourth lens group serves multiple functions: it acts as a focusing element that moves along the optical axis for focusing, while also contributing to the overall zooming function through its negative refractive power. This multi-functionality reduces the need for separate dedicated components, thereby controlling system complexity
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 configuration enables the achievement of excellent optical performance, including improved correction of spherical aberration, coma aberration, and field curves, while simultaneously reducing the size and weight of the zoom optical system.
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; a fourth lens group having negative refractive power; and a fifth lens group having negative refractive power
Data Source
AI summary
This variable-magnification optical system (ZL) comprises, in order along an optical axis from the object side, a first lens group (G1) that has a positive refractive power, a second lens group (G2) that has a negative refractive power, a third lens group (G3) that has a positive refractive power, a fourth lens group (G4) that has a negative refractive power, and a fifth lens group (G5) that has a negative refractive power. The distances between adjacent lens groups change during magnification. The fourth lens group (G4) is a focusing lens group that moves along the optical axis during focusing. The following conditional expression is satisfied: 0.11<f4/f5<0.70, where f4 is the focal length of the fourth lens group (G4) and f5 is the focal length of the fifth lens group (G5).