Multi-Wavelength Photodetector Row Selection for Faster Hyperspectral Imaging

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Solution Overview

Problem

Hyperspectral imaging requires high-speed processing to efficiently utilize spectral information for inspection tasks.

Innovation Solution

A photodetector and camera system with multiple photodetection substrates having different wavelength sensitivities, aligned in a specific configuration, and a circuit board with selective row reading capabilities to allow for targeted signal acquisition, reducing unnecessary data processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all pixel circuits in all rows are read in sequence, then complete spectral information is acquired, but processing speed is reduced

Engineering Contradiction:
Improvespectral information completenessVSAvoidprocessing speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the pixel circuits into multiple rows, each corresponding to different wavelength ranges. The row selection circuit enables independent selection and reading of specific rows, allowing the system to process only the spectral information needed for the current inspection task, thereby improving processing speed while maintaining measurement precision for relevant wavelengths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by reading only the necessary rows containing relevant spectral information rather than all rows. The row selection circuit allows the system to perform partial reading operations, acquiring sufficient spectral data for inspection without the overhead of reading unnecessary wavelength ranges, thus balancing measurement completeness with processing efficiency.

Inventive Principle:
Principle #16Partial or excessive action

2Adaptability or versatility

If multiple photodetection substrates are used to cover different wavelength ranges, then spectral coverage is improved, but device complexity increases

Engineering Contradiction:
Improvespectral coverageVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple photodetection substrates with different spectral sensitivities onto a single circuit board. Each substrate covers a different wavelength range, and they are integrated with a unified circuit board containing pixel circuits and row selection circuitry, achieving broad spectral coverage while managing device complexity through integrated design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The circuit board is designed with universal functionality to support multiple photodetection substrates with different spectral characteristics. The pixel circuits and row selection circuit can work with any of the mounted substrates, allowing the system to adapt to different spectral requirements without requiring separate dedicated circuits for each substrate type.

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

3Measurement precision

If photodetection substrates are aligned in column direction with dispersion element, then spectral direction alignment is achieved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvespectral direction alignmentVSAvoidalignment precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies local quality by aligning the column direction of photodetection substrates specifically with the spectral dispersion direction. This localized alignment approach ensures that spectral information is correctly mapped to the appropriate pixel rows, achieving measurement precision in the critical spectral direction while maintaining a manageable overall manufacturing precision requirement.

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

Enhances processing speed in hyperspectral imaging by selectively reading signals from necessary wavelength ranges, thereby increasing efficiency and reducing unnecessary data acquisition.

Implementation Method 1

a plurality of photodetection substrates having sensitivities in mutually different wavelength ranges

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4611381A1Photodetector, camera and imaging system
Publication Date: 2025.09.03 HAMAMATSU PHOTONICS KK
  • EP4611381A1 patent drawingFigure 1
  • EP4611381A1 patent drawingFigure 2
  • EP4611381A1 patent drawingFigure 3

AI summary

A photodetector includes a plurality of photodetection substrates having sensitivities in mutually different wavelength ranges, and a circuit board on which the plurality of photodetection substrates are placed so as to be aligned in a column direction. The plurality of photodetection substrates include a plurality of photodetection portions arranged in a row direction and the column direction. The circuit board includes a plurality of pixel circuits electrically connected to the plurality of photodetection portions, respectively, a row selection circuit for selecting a row from which signals are read from among the plurality of pixel circuits, and a column reading circuit for reading signals from the plurality of pixel circuits in the selected row for each column. The row selection circuit is configured to be able to select any row from among a plurality of rows of the plurality of pixel circuits.