Relay Optical System Lens Fixing Frame Autoclave Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rigid endoscopes face optical misalignment and decreased optical properties when sterilized using the autoclave method due to high temperature and pressure, which can cause lens displacement and contraction.
Innovation Solution
A relay optical system with a lens fixing frame comprising coaxially joined tubular bodies and lenses with specific refractive power configurations, an adhesive body, and an aperture stop, designed to maintain alignment and optical integrity by minimizing thermal expansion differences and eliminating the need for cemented lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If autoclave sterilization method is used to reduce sterilization cost, then sterilization cost is reduced, but lens alignment accuracy deteriorates due to thermal expansion and contraction at high temperature and pressure
Solution Approach 1:
The patent changes the material parameters of the lens barrel from conventional materials to specific resin materials with controlled thermal expansion coefficients. This parameter change allows the lens barrel to maintain dimensional stability during autoclave sterilization, preventing lens misalignment while enabling cost-effective autoclave sterilization method
Solution Approach 2:
The patent directly addresses thermal expansion effects by selecting resin materials for the lens barrel whose thermal expansion characteristics are matched to minimize relative displacement between lenses and the barrel during temperature cycling. This allows the system to withstand autoclave sterilization temperatures without compromising alignment accuracy
2Manufacturing precision
If multiple lenses are fixed with high-accuracy alignment using conventional methods (cemented lenses or lens pressing tubes), then optical alignment is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the need for complex lens fixing structures such as cemented lenses and lens pressing tubes. By redesigning the lens barrel as a precision-resin housing with integrated positioning features, the system achieves high alignment accuracy without requiring additional complex fixing components
Solution Approach 2:
The patent merges the functions of the lens barrel and the lens positioning structure into a single integrated resin component. The lens barrel itself incorporates the alignment and fixing functions, eliminating the need for separate fixing mechanisms and simplifying the overall device structure
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 maintains optical properties within tolerance even under high temperature and pressure conditions, reducing misalignment and optical degradation, and allows for high-accuracy alignment without relying on cemented lenses or excessive gap rings.
Implementation Method 1
an adhesive body extending from a through hole formed in each of at least three locations along a circumferential direction of the lens fixing frame to an outer edge of at least part of the plurality of lenses, and fixing the at least part of the plurality of lenses to the lens fixing frame
Implementation Method 2
a plurality of lenses located in the lens fixing frame so as to have a coincident optical axis
Data Source
AI summary
A relay optical system 20 for a rigid endoscope includes a lens fixing frame 21 and a plurality of lenses 22. The lens fixing frame 21 has a plurality of tubular bodies 26. The plurality of tubular bodies 26 are joined coaxially to each other. The plurality of lenses 22 are located at positions other than a joint position jp of the tubular bodies 26 in an axis direction of the lens fixing frame 21. The plurality of lenses 22 are located in the lens fixing frame 21 so as to have a coincident optical axis. The plurality of lenses 22 do not include a cemented lens.