Optical Imaging With Nested Lens Groups for Compact Focus Adjustment
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Solution Overview
Problem
Existing collapsible and curved optical imaging systems face challenges in reducing size due to the number of lenses and large lens displacement for focus adjustment, making them unsuitable for small-sized portable devices.
Innovation Solution
An optical imaging system comprising a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, utilizing aspherical lenses and a refractive prism, with lens groups moving in the optical direction to adjust focal length and focus, reducing displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a collapsible optical imaging system with multiple lenses is used, then the focal length can be adjusted, but the overall length increases making it difficult to reduce system size
Solution Approach 1:
The patent employs a nested lens group configuration where lens groups are arranged in a compact sequence along the optical axis. The first through seventh lens groups are positioned such that they can be closely spaced while maintaining optical functionality, effectively nesting multiple optical elements within a reduced overall length compared to traditional collapsible designs.
Solution Approach 2:
The patent implements dynamic focus adjustment by enabling the lens groups to move along the optical axis. Specifically, at least one lens group is configured to be movable, allowing real-time focal length adjustment without requiring the entire system to expand in length, thus maintaining compactness while providing adaptability.
2Length of moving object
If a curved optical imaging system with a prism is used, then the length from foremost lens to imaging plane is reduced, but the lens displacement for focus adjustment becomes large
Solution Approach 1:
The patent divides the optical system into multiple discrete lens groups (first through seventh lens groups) with different refractive powers. This segmentation allows individual groups to be optimized for specific functions: some groups contribute to compactness while others are designed for efficient focus adjustment with minimal displacement, resolving the contradiction between reduced length and ease of operation.
Solution Approach 2:
Different lens groups are assigned different local properties including varying refractive powers (positive and negative) and specific surface curvatures. This local differentiation enables certain groups to compensate for others, achieving both compact overall length and minimal lens displacement for focus adjustment by optimizing each group's contribution to the overall optical performance.
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 achieves a compact size with variable magnification and precise focus adjustment, minimizing lens displacement for improved performance in small devices.
Implementation Method 1
a curved optical imaging system may be configured such that an optical direction is curved using a prism
Implementation Method 2
at least one of the seven lenses includes an aspherical surface
Data Source
AI summary
An optical imaging system includes a first lens group that can move in an optical direction and has negative refractive power; a second lens group that can move in the optical direction and has positive refractive power; and a third lens group that can move in the optical direction and has negative refractive power. The first lens group, the second lens group, and the third lens group include seven lenses in total, and at least one of the seven lenses includes an aspherical surface.