Optical Fiber Inspection With Angled Scattered-Light Detection
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Solution Overview
Problem
Existing optical fiber manufacturing methods struggle to accurately detect air bubbles or voids in the glass fiber or coating resin, which affect optical transmission properties, due to inconsiderable light scattering by these defects.
Innovation Solution
An optical fiber inspecting device using multiple light-emitting and light-receiving units with diagonally intersecting optical axes and non-visible light wavelengths to enhance scattered light detection, combined with signal synthesis to improve the signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light source irradiates the optical fiber along a direction perpendicular to the axial direction and a photosensor receives the luminous flux directly, then the measurement of coating layer diameter and eccentricity is achieved, but air bubbles and voids cannot be accurately detected due to inconsiderable light scattering
Solution Approach 1:
The patent divides the detection function into two separate systems: a transmission-type detection system for measuring coating layer diameter and eccentricity, and a scattered light detection system for detecting air bubbles and voids. Each system is optimized for its specific detection purpose, allowing both functions to perform reliably without interfering with each other.
Solution Approach 2:
The patent introduces scattered light as an intermediary to detect air bubbles and voids. By detecting the light scattered by these defects rather than attempting to detect the defects directly, the system achieves reliable detection of transparent or low-contrast defects that would otherwise be invisible in transmission mode.
2Measurement precision
If the light-receiving unit is positioned to receive scattered light by diagonal intersection with the light beam, then direct light entry is prevented and scattered light detection sensitivity is improved, but device complexity increases
Solution Approach 1:
The patent positions the light-receiving unit in a spatial arrangement where its optical axis diagonally intersects the light beam path, creating a three-dimensional geometric relationship. This angular positioning in a different spatial dimension allows the receiver to capture scattered light while avoiding direct light entry, effectively using spatial geometry to solve the detection problem.
3Reliability
If multiple light-emitting and light-receiving units are used to improve detection coverage, then detection reliability is improved, but crosstalk between units increases
Solution Approach 1:
The patent extracts and separately processes signals from individual light-receiving units, applying specific signal processing techniques to each channel. By treating each detection channel independently and then synthesizing the results, the system maintains high signal-to-noise ratio while achieving comprehensive detection coverage through multiple units.
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
Accurately detects air bubbles and voids in optical fibers by minimizing direct light entry into receiving units and reducing crosstalk, thereby improving detection sensitivity and reliability.
Implementation Method 1
a first light-emitting unit that irradiates an optical fiber with a first light beam... and a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber
Implementation Method 2
a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber, and converts the scattered light to an electrical signal
Data Source
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AI summary
An optical fiber inspecting device is disclosed. The optical fiber inspecting device includes a first light-emitting unit that irradiates an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction, and a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber, and converts the scattered light to an electrical signal. An optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit.