Monolithic Spectral Imaging Circuit with Fabry-Perot Filters

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Solution Overview

Problem

Current hyperspectral imaging systems are costly, complex, and lack flexibility due to the need for fast computers, sensitive detectors, and large data storage, while existing integrated circuits for hyperspectral imaging suffer from high manufacturing costs and reduced spectral resolution due to hybrid integration of optical filters and sensors.

Innovation Solution

A monolithically integrated circuit with a spectral unit and optical sensors, using semiconductor process technology to integrate Fabry-Perot filters directly on the image sensor array, reducing stray light and manufacturing complexity, and enabling higher spectral resolution and cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If hybrid integration of optical filters and sensors is used, then manufacturing flexibility is improved, but manufacturing costs increase and spectral resolution decreases

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the optical filter layer and sensor layer into a single monolithic integrated circuit structure. The optical filters are formed directly on the sensor array using semiconductor fabrication processes, eliminating the need for separate filter assemblies and hybrid integration. This consolidation reduces manufacturing steps, lowers costs, and improves spectral resolution by eliminating alignment tolerances between separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces mechanical hybrid integration of separate optical filter assemblies with sensors using semiconductor monolithic integration processes. Instead of mechanically assembling filters onto sensors, the filters are formed directly on the sensor substrate through deposition and patterning processes, substituting mechanical assembly with semiconductor manufacturing methods.

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

2Adaptability or versatility

If hybrid integration of optical filters and sensors is used, then manufacturing flexibility is improved, but spectral resolution decreases

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidspectral resolution
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent merges the optical filter layer and sensor layer into a single monolithic integrated circuit structure. The optical filters are formed directly on the sensor array using semiconductor fabrication processes, eliminating the need for separate filter assemblies and hybrid integration. This consolidation reduces manufacturing steps, lowers costs, and improves spectral resolution by eliminating alignment tolerances between separate components.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If conventional hyperspectral imaging systems are used, then imaging capability is achieved, but system cost and complexity increase

Engineering Contradiction:
Improveimaging capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple discrete components (optical filters, sensors, readout circuitry) into a single monolithic integrated circuit. This integration eliminates separate filter assemblies, alignment mechanisms, and complex optical paths, dramatically reducing system complexity while maintaining full hyperspectral imaging capability through the integrated filter-sensor structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The monolithic integrated circuit performs multiple functions within a single device: the optical filters provide spectral selection, the sensors detect the filtered light, and the integrated readout circuitry processes the signals. This multi-functionality eliminates the need for separate components and reduces overall system complexity.

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

4Reliability

If conventional hyperspectral imaging systems are used, then imaging capability is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveimaging capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple discrete components (optical filters, sensors, readout circuitry) into a single monolithic integrated circuit. This integration eliminates separate filter assemblies, alignment mechanisms, and complex optical paths, dramatically reducing system complexity while maintaining full hyperspectral imaging capability through the integrated filter-sensor structure.

Inventive Principle:
Principle #5Merging (Combining)

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 solution provides a compact, reconfigurable, and cost-effective hyperspectral imaging system with improved spectral precision and reduced manufacturing costs, eliminating the need for additional lenses and enhancing image quality by minimizing stray light and manufacturing tolerances.

Implementation Method 1

Different ones of the optical filters are configured to have a different thickness, to pass different bands of wavelengths by means of interference

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP4137790B1Integrated circuit for spectral imaging system
Publication Date: 2025.10.29 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP4137790B1 patent drawingFigure 1
  • EP4137790B1 patent drawingFigure 2
  • EP4137790B1 patent drawingFigure 3

AI summary

The invention refers to an integrated circuit for an imaging system having arrays of optical sensors (40) and of optical filters (10), integrated with each other, each configured to pass a band of wavelengths, and further having read out circuitry (30) to read out pixel values from the array of sensors (40) to represent an image. Different ones of the optical filters (10) have different thicknesses to pass different bands of wavelengths by means of interference, to allow detection of a spectrum of wavelengths. The read out circuitry (30) has a wavelength selector for selecting between or combining read out signals of corresponding pixels of different optical filters (10). The invention further refers to an imaging system comprising such an integrated circuit and to a method of operating the imaging system to produce an output image by performing hyperspectral imaging.