Zoom Lens System with Cemented Third Group for Blur Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zoom lens systems face challenges in achieving high optical performance across a wide range of focal lengths while maintaining a compact and lightweight design, particularly in correcting image blur and preventing distortion.
Innovation Solution
A zoom lens system comprising multiple lens groups with specific optical powers and configurations, including a third lens group with cemented lens elements and an aperture stop between the second and third lens groups, which moves to correct image blurring and adjusts focal lengths, satisfying conditions that balance lens movement and size constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple lens groups with image blur correcting function are configured to achieve high optical performance, then optical performance is improved, but device complexity and size increase
Solution Approach 1:
The lens system is divided into five distinct lens groups (G1-G5) with specific optical powers, where each group serves a particular function. The third lens group G3 is further segmented into multiple lens elements including cemented elements L3c and L3d, allowing independent optimization of each segment's contribution to overall optical performance while managing complexity through modular design.
Solution Approach 2:
The lens element L3b within the third lens group serves multiple functions: it contributes to the overall positive optical power of G3, participates in image blur correction when moved perpendicular to the optical axis, and helps maintain compact system design. This multi-functionality reduces the need for additional dedicated components.
2Reliability
If lens elements are added to correct image blur and distortion, then optical performance is improved, but weight and size increase
Solution Approach 1:
Lens elements L3c and L3d are cemented together to form an integrated unit within the third lens group, reducing the number of separate components and associated mounting structures. This merging achieves effective image blur correction through the coordinated action of cemented elements while minimizing the weight increase that would result from multiple separate elements.
3Reliability
If aperture stop is positioned between lens groups to control light, then optical performance is improved, but device complexity increases
Solution Approach 1:
The aperture stop is positioned between the second lens group G2 (negative optical power) and the third lens group G3 (positive optical power), serving as an intermediary element that controls light transmission while the cemented elements L3c and L3d mediate the correction of image blur and distortion. This positioning allows the aperture stop to function effectively without requiring complex positioning mechanisms.
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 a compact, lightweight zoom lens system with effective image blur correction and improved optical performance across the wide-angle to telephoto range, preventing distortion and maintaining high image quality without increasing the lens barrel size.
Implementation Method 1
The lens element L3b optically corrects image blurring by moving in a way so as to have a component perpendicular to an optical axis
Implementation Method 2
Respective optical surfaces of the lens element L3c and the lens element L3d are mutually cemented
Implementation Method 3
When focusing from an infinity focusing state to a proximity focusing state, the fourth lens group moves along the optical axis
Implementation Method 4
When zooming from a wide-angle end to a telephoto end, at least the first lens group, the second lens group, the third lens group, and the fourth lens group move in a direction of the optical-axis
Data Source
AI summary
The zoom lens system includes a first lens group with positive power, a second lens group with negative power, a third lens group with positive power, a fourth lens group with negative power, and a fifth lens group with positive power. An aperture stop is provided between the second and the third lens groups. The third lens group includes lens element L3a and L3b with positive power, lens element L3c with negative power, and lens element L3d with positive power. The lens elements L3c and L3d are cemented. The lens element L3b corrects image blurring. The fourth lens group moves when focusing. When zooming, the first to the fourth lens group move.Here, condition (1) below is satisfied.0.24<fL3b/fG3<3.0 (1)WherefL3b is a focal length of the lens element L3b, and fG3 is a focal length of the third lens group.