Variable Magnification Optical System for Endoscope Working Distance
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Solution Overview
Problem
Existing rigid endoscope systems face challenges in achieving variable magnification without changing the working distance, which limits their ability to perform precise observations, especially in confined spaces and when surgical instruments are present, and they often require complex structures that complicate disinfection and sterilization.
Innovation Solution
A variable magnification optical system with a first lens group and a final lens group fixed in the optical axis direction, and multiple movable lens groups between them, allowing for zooming and focusing without altering the overall optical length, enabling adjustable observation magnification and field of view without changing the working distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a focusing mechanism such as a cam is provided within the insertion section to enable enlarged observation, then the observation magnification can be increased, but the insertion section cannot be miniaturized
Solution Approach 1:
The optical system is divided into multiple lens groups (first through fourth lens groups) with different functions. The first and fourth lens groups remain fixed while the second and third lens groups move for zooming, and the second lens group moves additionally for focusing. This segmentation allows focusing functionality to be achieved without adding mechanisms to the insertion section, enabling miniaturization while maintaining high magnification capability.
Solution Approach 2:
The patent transitions from a single-dimension focusing mechanism (cam-based axial movement) to a multi-dimensional lens group movement system. By moving lens groups in different dimensions (second and third groups moving axially for zooming, second group moving additionally for focusing), the system achieves high magnification without increasing insertion section size.
2Measurement precision
If the distal end of the objective lens is brought closer to the affected site to perform enlarged observation, then the observation magnification is increased, but interference with surgical instruments occurs
Solution Approach 1:
The patent implements a dynamic zooming system where the second and third lens groups move relative to each other along the optical axis. This allows continuous adjustment of magnification from wide-angle to telephoto ends while maintaining a fixed working distance, providing adaptability to different surgical scenarios without instrument interference.
Solution Approach 2:
The system changes optical parameters (magnification, field of view) by moving lens groups rather than changing the physical position of the objective lens distal end. This parameter-based adjustment enables magnification changes without altering the working distance, avoiding interference with surgical instruments.
3Measurement precision
If the optical overall length fluctuates during focusing to achieve high magnification, then the observation capability is improved, but the lens barrel structure becomes complicated
Solution Approach 1:
The optical system is segmented into four lens groups with specific refractive power distributions. The first lens group (positive), second lens group (negative), third lens group (positive), and fourth lens group (negative) are arranged to achieve high magnification through coordinated movement, simplifying the overall barrel structure compared to traditional single-mechanism designs.
Solution Approach 2:
The second lens group serves dual functions: it moves with the third lens group for zooming and moves additionally for focusing. This multi-functionality reduces the need for separate focusing mechanisms, simplifying the lens barrel structure while maintaining high magnification capability.
4Adaptability or versatility
If the lens barrel length is made variable to accommodate optical length changes, then the focusing and zooming capability is improved, but the watertight structure for disinfection cannot be maintained
Solution Approach 1:
The optical system is divided into four fixed-length lens groups that move within a fixed-length barrel. The first, second, third, and fourth lens groups maintain constant individual lengths, and their coordinated movement within the fixed barrel achieves both zooming and focusing while preserving the watertight structure for easy disinfection.
Solution Approach 2:
The patent implements dynamic lens group movement within a static barrel structure. The second and third lens groups move for zooming, and the second lens group moves additionally for focusing, all within a fixed-length barrel that maintains watertight sealing, enabling disinfection while providing full optical adjustment capability.
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
This solution allows for high-resolution, adjustable observation without increasing the size of the endoscope, simplifying its construction, and maintaining a watertight structure for easy disinfection and sterilization, enhancing surgical precision and efficiency.
Implementation Method 1
a variable magnification optical system connected to an observation optical system and including a first lens group arranged closest to an observation optical system side, a final lens group arranged closest to an image side, and a plurality of movable lens groups arranged between the first lens group and the final lens group and movable in an optical axis direction
Data Source
AI summary
A variable magnification optical system capable of realizing a high-resolution observation image display system that can arbitrarily change an observation field of view without changing a working distance of an observation optical system while keeping the observation optical system small in size and an imaging apparatus including the variable magnification optical system.