Radiation Detector Subpixel Design for Spatial Resolution

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Solution Overview

Problem

Current radiation detectors face challenges in accurately measuring radiation flux and spectrum, particularly in achieving high spatial resolution while maintaining efficient radiation absorption, which is crucial for applications like medical imaging and cargo scanning.

Innovation Solution

A detector comprising multiple subpixels that generate electrical signals upon radiation exposure, allowing for the determination of radiation particle counts and intensity, with a semiconductor radiation absorption layer that directly converts radiation into electric signals, eliminating the need for scintillators and enabling energy spectrum analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If scintillators are used to convert radiation to visible light, then radiation absorption is improved, but spatial resolution deteriorates due to light spreading and scattering

Engineering Contradiction:
Improveradiation absorption efficiencyVSAvoidspatial resolution
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent removes the scintillator component from the detection system entirely. Instead of converting radiation to light and then detecting it, the system directly detects radiation-induced electrical signals in the semiconductor layer, eliminating the light spreading and scattering problem that degrades spatial resolution.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the optical detection mechanism (scintillator + photodetector) with a direct electrical detection mechanism. Radiation is converted directly into electrical signals within the semiconductor layer, bypassing the optical conversion step that causes light diffusion and resolution loss.

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

2Manufacturing precision

If scintillator thickness is reduced to improve spatial resolution, then spatial resolution is improved, but radiation absorption efficiency deteriorates

Engineering Contradiction:
Improvespatial resolutionVSAvoidradiation absorption efficiency
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent eliminates the need for a thick scintillator by removing the scintillator entirely. Direct conversion in the semiconductor layer allows for sufficient radiation absorption without the light diffusion problems that would occur even in thinner scintillators.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the detection mechanism from optical to electrical, fundamentally altering how radiation is converted and detected. This parameter change allows for direct measurement of radiation effects without the intermediate optical conversion step that limits scintillator design options.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple measurement modes (particle count and intensity) are implemented in separate subpixels, then measurement capability is improved, but device complexity increases

Engineering Contradiction:
Improvemeasurement capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple measurement functions within a single integrated pixel structure. Each pixel contains multiple subpixels that can operate in different measurement modes (particle count, intensity, energy spectrum), allowing versatile measurements without requiring separate detector systems for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal pixel design that can perform multiple measurement functions. The same basic pixel structure with its subpixels can be configured for particle counting, intensity measurement, or energy spectrum analysis, making the detector adaptable to different measurement needs without redesigning the fundamental architecture.

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

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 solution provides enhanced accuracy in radiation imaging and spectroscopy by effectively measuring radiation particle counts and intensity, improving spatial resolution and energy spectrum analysis without the limitations of scintillators, suitable for medical imaging, cargo scanning, and other applications.

Implementation Method 1

When a particle of radiation is absorbed in the semiconductor layer, multiple charge carriers (e.g., electrons and holes) are generated and swept under an electric field towards electric contacts on the semiconductor layer

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3847481B1A radiation detector
Publication Date: 2023.11.29 SHENZHEN XPECTVISION TECH CO LTD
  • EP3847481B1 patent drawingFigure 1A
  • EP3847481B1 patent drawingFigure 1B
  • EP3847481B1 patent drawingFigure 1C

AI summary

Disclosed herein is a detector (100), comprising: a pixel (150) comprising a first subpixel (151A) and a second subpixel (151B), wherein the first subpixel (151A) is configured to generate a first electrical signal upon exposure to radiation, and wherein the second subpixel (151B) is configured to generate a second electrical signal upon exposure to the radiation; wherein the detector is configured to determine a number of particles of the radiation incident on the first subpixel (151A) over a first period of time, based on the first electrical signal; wherein the detector is configured to determine an intensity of the radiation by integrating the second electrical signal over a second period of time.