Zoom Lens Second Group Segmentation for Image Stabilization
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Solution Overview
Problem
Existing zoom lenses for image-pickup apparatuses face challenges in miniaturization and weight reduction while maintaining image stabilization performance, as they often require large and heavy drive systems to correct camera shake, leading to increased size and potential delays in decentering the lens.
Innovation Solution
A zoom lens configuration with specific refractive power arrangements and group movements, including a first lens group with negative power, a second lens group with positive power, and additional groups, where the second lens group includes a single positive lens and a negative-positive lens component, allowing for reduced space between lens groups and optimized focal lengths to minimize the load of the driving device and correct image blur effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a two-group zoom lens with variable power given only to the second lens group is used, then the lens structure is simplified, but the variations in aberration due to zooming are difficult to suppress at high zoom ratios
Solution Approach 1:
The second lens group is divided into two separate lens groups: a first lens group with negative refractive power and a second lens group with positive refractive power. This segmentation allows independent control of aberrations by each group while maintaining the overall simplified structure, resolving the contradiction between structural simplicity and aberration control at high zoom ratios.
2Adaptability or versatility
If the second lens group is displaced during zooming to achieve high zoom ratio, then the zoom ratio is increased, but the entire lens system becomes difficult to miniaturize
Solution Approach 1:
By dividing the second lens group into two separate groups with opposite refractive powers, the patent enables compact arrangement of lens elements. The first lens group with negative power and the second lens group with positive power can be positioned closer together, reducing the overall lens system length and enabling miniaturization while maintaining high zoom ratio capability.
3Reliability
If multiple lenses are moved in a direction substantially perpendicular to the optical axis for vibration compensation, then the vibration compensation is achieved, but the weight of the moving part is increased and the lens frame size is increased
Solution Approach 1:
The patent segments the lens system into specific groups with designated functions. The first lens group with negative refractive power and the second lens group with positive refractive power are positioned and configured to enable vibration compensation through controlled displacement, while the segmentation allows for optimized weight distribution and reduced overall moving mass compared to moving multiple lenses.
4Device complexity
If decentering of lens groups is used for vibration compensation, then no additional optical system is needed, but the response time for decentering is delayed
Solution Approach 1:
The patent configures the first lens group with negative refractive power and the second lens group with positive refractive power in a dynamic arrangement that enables rapid response to vibration compensation. The segmented structure allows for faster decentering movement compared to traditional single-group designs, reducing response time while maintaining the simplicity of the optical system.
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 enables a compact, lightweight image-pickup apparatus with improved image stabilization sensitivity and reduced aberrations, effectively correcting image blur while minimizing the size and weight of the camera shake drive system.
Implementation Method 1
The second A lens component displaces images in a direction substantially perpendicular to an optical axis by having a component of it's displacement perpendicular to the optical axis
Data Source
AI summary
At least one exemplary embodiment is directed to a zoom lens which includes first to fourth lens groups, each moving and having negative, positive, negative, and positive refractive power, arranged from an object to an image in that order. The second lens group includes a second A lens component composed of a single positive lens, and a second B lens component composed of a negative lens and a positive lens with positive refractive power as a whole, arranged from the object to the image in that order. The second A lens component displaces images in a direction substantially perpendicular to an optical axis by having a component of it's displacement perpendicular to the optical axis, and the zoom lens satisfies the following condition: 0.2<f2/f2A<0.6, where f2A and f2 are focal lengths of the second A lens component and the second lens group, respectively.