4-Sensor Camera with Polarizing Beam Splitter for Fiber Inspection

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Solution Overview

Problem

Existing optical inspection systems face challenges in differentiating good fiber material from foreign bodies or imperfections of the same color or light, requiring complex lighting setups to capture color and polarization information effectively.

Innovation Solution

A 4-sensor camera device with a polarizing beam splitter that simultaneously detects color information and linear polarization state in the same wavelength range, using a beam splitter with angles of incidence greater than 45° and symmetrical prism wedges, combined with an evaluation device and a light source that emits polarized light, to enhance detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional optical inspection systems use complex lighting setups (infrared light, UV light, polarized transmitted light) to detect foreign bodies, then the detection capability is improved, but the device complexity increases

Engineering Contradiction:
Improvedetection capabilityVSAvoidlighting setup complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple detection functions (color detection and polarization state detection) into a single camera system by integrating a polarizing beam splitter and multiple sensors. This merging approach eliminates the need for separate infrared cameras, UV cameras, and polarized light cameras, thereby reducing device complexity while maintaining enhanced detection capability for foreign bodies in fiber materials

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inspection system is designed to perform multiple detection functions simultaneously using a single camera platform. By incorporating a polarizing beam splitter and multiple sensors, the system can detect color information, polarization states, and foreign bodies across different wavelength ranges (visible, infrared, UV) through one universal device, avoiding the need for multiple specialized cameras

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If multiple sensors and beam splitters are integrated into a single camera system, then the device structure is simplified, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvestructural simplicityVSAvoidalignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The camera system is segmented into distinct functional modules: a polarizing beam splitter layer that separates light paths, multiple sensors positioned at specific angles, and a lens system. This segmentation allows each component to be optimized and manufactured separately with precise specifications, then assembled with controlled tolerances, making the complex alignment requirements manageable through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent specifies particular geometric configurations for different parts of the system, such as prism wedges with specific angles and sensors positioned at precise angular orientations relative to the beam splitter. This local quality approach ensures that each component has optimized properties for its specific function, and the precise local specifications facilitate manufacturing by providing clear, localized tolerance requirements rather than requiring precision throughout the entire system

Inventive Principle:
Principle #3Local quality

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

Enables reliable detection of color and polarization state in a structurally simple manner, allowing for effective differentiation between fiber material and foreign parts, even in complex fiber streams, with improved resolution and reduced installation space.

Implementation Method 1

a polarizing beam splitter layer (24), in each case at an angle of incidence > 45°

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

beam splitter prism (4)... polarizing beam splitter layer (24)... split the light into its two polarization directions s and p

Methodology Applied
Scientific EffectBeam splitting: Reflection

Implementation Method 3

a light source that emits polarized light... source of polarized light that interacts with a detector device

Methodology Applied
Scientific EffectPolarized light emission: Polarisation

Implementation Method 4

detector device (camera)... with the aid of a source of polarized light that interacts with a detector device (camera), foreign parts in or between the fiber material can be illuminated

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 5

beam splitter prism (4)... prism wedges... angles of incidence > 45°

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3014252B1Device in spinning preparation, ginning or the like for identifying foreign bodies of the same colour or the same brightness or imperfections
Publication Date: 2021.01.13 TRUETZSCHLER GMBH & CO KG
  • EP3014252B1 patent drawingFigure 1~2
  • EP3014252B1 patent drawingFigure 3
  • EP3014252B1 patent drawingFigure 4

AI summary

In a device in spinning preparation, ginning or the like for identifying foreign bodies or imperfections in or among a stream of fibre material (fibre flocks), for example made of cotton, foreign bodies in or among the fibre material are illuminable with the aid of a source of polarized light which cooperates with a detector appliance (camera). In order to allow the colour and polarization state to be detected reliably in a structurally simple manner, provision is made of a beam splitter device made of prism wedges for use in a camera system for detecting the colour and polarization state, wherein a part of the colour information is splittable and is detectable using image sensors of at least one wavelength range and the remaining wavelength range is divisible into two or more polarization states by at least one polarizing beam splitter layer and detectable by image sensors.