Spectroscopic Imaging Device Using Phase-Shifted Optical Component

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Solution Overview

Problem

Current optical detection and surveillance systems face high false alarm probabilities due to insufficient characterization of objects, especially when objects are small compared to the spatial resolution limit, and existing multispectral or hyperspectral cameras are complex and expensive.

Innovation Solution

A spectroscopic imaging device with an optical component that modifies images based on spectral differentiation, providing spectroscopic information by altering the image pattern of light rays from a scene point for different colors, allowing for object identification without the need for additional imaging channels or complex calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multispectral or hyperspectral cameras are used to collect spectral information, then the false alarm probability is reduced and object characterization is improved, but the device complexity and cost increase significantly

Engineering Contradiction:
Improvefalse alarm probabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the optical component's cross-section into multiple zones, each zone introducing a different phase shift for specific wavelengths. This segmentation allows spectral differentiation without requiring multiple imaging channels, thus reducing device complexity while maintaining reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of adding spectral dimension through multiple cameras or interferometric paths, the patent embeds spectral information into the spatial dimension by modifying image patterns through phase shifts. This transforms spectral differentiation from a multi-channel problem into a single-channel spatial modulation problem

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If interferometric systems are used to produce spectral information, then spectroscopic data is obtained, but the implementation complexity and cost increase

Engineering Contradiction:
Improvespectroscopic information accuracyVSAvoidimplementation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential spectral differentiation function from complex interferometric systems by using simple phase-shifting zones in the optical path. This extracts the core spectral information capability while removing the complex interferometric machinery

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical interferometric systems with a static optical component containing phase-shifting zones. This substitutes dynamic mechanical interference patterns with static spatial phase modulation, eliminating mechanical complexity while preserving spectral measurement capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If filters are applied to reduce false alarm probability based on apparent contrast and trajectory, then some false alarms are reduced, but the false alarm probability remains too high

Engineering Contradiction:
Improvefalse alarm probabilityVSAvoidobject characterization information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent uses wavelength-dependent phase shifts that manifest as color-specific image pattern modifications. Different wavelengths (colors) produce distinct spatial patterns, enabling spectral identification without losing object characterization information

Inventive Principle:
Principle #32Color changes

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 approach reduces false alarm probabilities by providing accurate spectroscopic information directly in captured images, enabling better object characterization and identification while being simple, quick, and cost-effective to implement.

Implementation Method 1

it comprises an optical component with spectral differentiation function, arranged to phase-shift light rays which come from the same point of the scene but which cross two different parts of a cross-section of the device, in accordance with a first effective phase difference between these two parts for a first possible color for the light rays, and in accordance with a second effective phase difference also between the two same parts but for a second color also possible for the light rays

Methodology Applied
Scientific EffectPhase shift:

Data Source

PatentEP3756039B1Device for imaging and delivering spectroscopic information
Publication Date: 2022.03.30 OFFICE NAT DETUDES & DE RECH AEROSPATIALES
  • EP3756039B1 patent drawingFigure 1~2c
  • EP3756039B1 patent drawingFigure 3a~3b
  • EP3756039B1 patent drawingFigure 3c~3d

AI summary

A device for imaging and delivering spectroscopic information comprises an objective (1), an image sensor (2) and an optical component (3) having a spectral differentiation function. The optical component having a spectral differentiation function modifies the image of a point in different ways for at least two colours, so that a form of the image of the point delivers spectroscopic information that appears directly in the image such as captured by the image sensor. Such a device may be used in a detecting and/or surveilling system, which then possesses a lower probability of false alarm.