Variable-Zoom Imaging with Adjustable Aperture and Stable Focus
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Solution Overview
Problem
Existing optical zoom systems require moving parts, leading to reduced robustness and increased likelihood of vibrations and focus shift, while digital zoom systems suffer from a mismatch between optical imaging system and detector element sampling, resulting in high complexity and cost.
Innovation Solution
A variable-zoom imaging apparatus that combines digital zoom with a simpler optical system using an adjustable aperture stop to adjust the image-side numerical aperture in accordance with the resolution required by the digital zoom setting, allowing for different magnifications without moving optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional optical zoom systems are used, then variable magnification is achieved, but the system requires moving parts which reduce robustness and increase vibrations and focus shift
Solution Approach 1:
The patent replaces the mechanical zoom system with a digital zoom system that uses electronic detector element selection instead of moving optical elements. The imaging optics remain fixed, and magnification is achieved by selecting and processing signals from different subsets of detector elements, eliminating mechanical components entirely.
Solution Approach 2:
The patent changes the sampling parameters of the detector elements to achieve variable magnification. By selecting different subsets of detector elements and adjusting the sampling pattern, the system achieves different magnification levels without any mechanical movement, maintaining robustness while providing adaptability.
2Reliability
If digital zoom systems are used, then robustness is improved by eliminating moving parts, but mismatch between optical imaging system and detector element sampling increases complexity and cost
Solution Approach 1:
The patent introduces dynamic adaptability by allowing the imaging system to adjust its sampling pattern and numerical aperture based on the selected magnification level. The system dynamically reconfigures which detector elements are active and how they are sampled, optimizing the match between optical capabilities and digital zoom requirements for each magnification level.
Solution Approach 2:
The patent segments the detector element array into different subsets that can be independently activated based on the required magnification level. This segmentation allows the system to use only the necessary portion of the detector array for each zoom level, reducing the effective complexity and improving the match between optical and digital components.
3Reliability
If digital zoom with fixed optical system is used, then robustness is improved, but image quality may deteriorate due to mismatch between optical resolution and detector sampling
Solution Approach 1:
The patent makes the numerical aperture dynamic by adjusting it according to the selected magnification level. At higher digital zoom levels, the system reduces the numerical aperture to match the reduced field of view, ensuring that the optical resolution is optimally matched to the detector sampling density. This dynamic adjustment maintains image quality across all zoom levels while keeping the optical system fixed.
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 reduces design complexity and cost by maintaining high-quality digital images over the entire zoom range while avoiding image wander and focus shift, with a stable and robust system that maintains focus and avoids complex mechanical adjustments.
Implementation Method 1
The degree to which the optical imaging system can reproduce a small feature in the image field depends on the image-side numerical aperture NA of the optical imaging system, which corresponds to the range of angles at the imaging area for the light rays recombined by the optical imaging system at each point in the image area.
Implementation Method 2
the properties of each optical imaging element and their positionings relative to each other and each of the object and image areas collectively cause light rays emerging from each point of the object area to recombine at a corresponding point in the image area to thereby form the image
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
Disclosed is a variable-zoom imaging apparatus that includes: i) imaging optics configured to form an image in an imaging area of an object positioned in an object area; ii) an adjustable aperture stop to adjustably set a numerical aperture NA for the image formed by the imaging optics; iii) an electronic detector comprising an array of detector elements positioned in the imaging area to detect the image; and iv) image processing circuitry coupled to the electronic detector to produce a digital representation of the image based on signals from at least some of the detector elements. The image processing circuitry produces the digital representation with a different magnification of the object m for each of a plurality of different numerical apertures for the image set by the adjustable aperture stop.