Endoscope Light Guide Fiber Flat Surface Positioning
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Solution Overview
Problem
Existing endoscopes face challenges in reducing the diameter of the insertion portion while maintaining effective optical performance and preventing erroneous assembly, particularly in the alignment and positioning of light guide fibers within the distal end component.
Innovation Solution
The endoscope design incorporates a light guide fiber with a first flat surface inclined at an angle less than 90 degrees, fixed within a through hole of a pipe with a matching flat surface, and a distal end member featuring a bottomed hole and concave portion to form an irradiation lens system, ensuring precise positioning and reducing the diameter of the insertion portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the light guide fiber is inserted into the insertion portion without precise positioning structures, then the assembly process is simpler, but the alignment precision between the fiber and lens system deteriorates
Solution Approach 1:
The distal end of the light guide fiber is pre-formed with a flat surface at a predetermined angle (e.g., 45 degrees) before insertion. This preliminary preparation ensures that when the fiber is inserted into the insertion portion, the flat surface automatically aligns with the corresponding positioning structure, achieving precise optical alignment without complex assembly procedures. The flat surface is created in advance through cutting or grinding operations performed during fiber manufacturing.
Solution Approach 2:
The insertion portion is designed with a positioning structure that automatically guides and orients the light guide fiber during insertion. The flat surface on the fiber distal end interacts with the positioning structure (such as a V-groove or angled surface) to self-align the fiber axis with the lens system optical axis. This self-aligning mechanism eliminates the need for external alignment tools or complex adjustment procedures, allowing the assembly process to be simple while maintaining high precision.
2Volume of moving object
If the insertion portion diameter is reduced to minimize endoscope size, then the endoscope is more compact and easier to insert, but the space for positioning and aligning the light guide fiber becomes insufficient
Solution Approach 1:
Instead of attempting to provide extensive positioning structures in the radial direction (which would increase diameter), the invention utilizes the axial dimension by forming a flat surface on the distal end of the light guide fiber. This flat surface creates an additional degree of freedom for positioning, allowing precise alignment to be achieved along the optical axis without requiring large radial space. The positioning is accomplished through the interaction of this flat surface with the insertion portion's positioning structure in the axial direction.
Solution Approach 2:
The positioning function is localized to a specific region on the distal end of the light guide fiber where the flat surface is formed. Rather than requiring the entire fiber or a large portion of it to participate in positioning, only a small localized area with the flat surface is used. This localized positioning mechanism minimizes the space requirements within the insertion portion while maintaining accurate alignment, enabling compact endoscope design without sacrificing positioning precision.
3Ease of manufacture
If conventional light guide fiber positioning methods are used, then the assembly process is straightforward, but erroneous assembly cannot be prevented
Solution Approach 1:
A flat surface is formed on the distal end of the light guide fiber at a specific asymmetric orientation (e.g., 45 degrees relative to the fiber axis). This asymmetric flat surface creates a unique geometric feature that can only fit into the insertion portion in one correct orientation. The corresponding positioning structure in the insertion portion is designed to match this asymmetric geometry, making it impossible to insert the fiber in any orientation other than the correct one. This asymmetric design provides built-in error prevention while maintaining assembly simplicity.
Solution Approach 2:
The asymmetric flat surface and matching positioning structure create a self-checking mechanism during assembly. When the operator attempts to insert the light guide fiber, the geometry of the flat surface automatically prevents incorrect insertion attempts before they can result in erroneous assembly. The correct orientation is the only one that allows the flat surface to engage properly with the positioning structure, providing immediate feedback to the operator. This self-service error prevention mechanism works automatically during the assembly process without requiring additional verification steps.
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 configuration allows for a smaller insertion portion diameter, prevents erroneous assembly, and achieves intended optical performance by ensuring accurate alignment and light distribution, enhancing the endoscope's ability to illuminate observation targets effectively.
Implementation Method 1
The illuminating light emitted from the light emission source is transmitted by a light guide fiber provided in the endoscope
Implementation Method 2
a distal end member provided with a bottomed hole for an illumination optical system, the bottomed hole including a pipe disposing hole into which an end portion of the pipe on the distal end side is disposed and a concave portion constituting an irradiation lens system to obtain a predetermined light distribution
Data Source
AI summary
An endoscope includes: a first fiber provided with a first flat surface from which illuminating light is emitted; a pipe including a through hole to which a distal end portion of the first fiber is fixed and including a first surface that can be a flat surface identical to the first flat surface and a second surface which is a flat surface orthogonal to a central axis of the through hole; and a distal end component in which a stopper hole in which an end portion on the distal end side of the pipe is disposed is formed, the stopper hole including an abutting surface on which at least part of the second surface of the pipe abuts, on a bottom side, a concave portion which constitutes for obtaining a predetermined light distribution and is located closer to the front end side than the abutting surface.