Imaging System Charge Sharing Reduction via Pulsed Radiation Gating
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Solution Overview
Problem
Imaging systems face performance degradation due to charge sharing among pixels when multiple radiation particles are incident on a detector area during a frame, leading to inaccurate signal detection and image formation.
Innovation Solution
An imaging system with a pulsed radiation source and a radiation detector configured to operate below a threshold probability of multiple particles incident during a frame, where signals are combined or recorded based on the number of locations detecting radiation, reducing charge sharing by synchronizing the detector with the radiation source's ON and OFF periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the radiation detector operates with a higher probability of multiple particles incident during a frame, then the detection speed and productivity are improved, but the charge sharing among pixels increases leading to degraded measurement precision
Solution Approach 1:
The patent applies periodic action by using a pulsed radiation source that emits radiation in periodic pulses rather than continuously. The detector is synchronized to detect signals only during specific time windows following each pulse, when charge sharing has subsided. This temporal gating approach allows the system to operate at higher productivities while maintaining measurement precision by excluding periods when charge sharing degrades signal accuracy.
2Measurement precision
If the imaging system combines signals from multiple locations to handle charge sharing, then the measurement precision is improved, but the device complexity increases due to additional signal processing requirements
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing charge sharing probability maps and signal combination strategies before actual imaging. The system pre-processes reference data to determine optimal signal combination methods for different spatial configurations, so that during actual operation, the complex signal processing can be executed efficiently using pre-determined parameters and lookup tables, reducing real-time computational burden.
3Measurement precision
If the threshold probability for multiple particle incidence is lowered, then the measurement precision is improved by reducing charge sharing events, but the productivity decreases due to fewer detectable particles per frame
Solution Approach 1:
The patent applies dimensionality change by transitioning from spatial signal combination to temporal signal combination. Instead of combining signals from multiple spatial locations within a single frame (spatial dimension), the system combines signals from multiple temporal frames acquired during periodic radiation pulses (temporal dimension). This allows the system to maintain lower threshold probabilities for charge sharing while recovering detection efficiency through time-domain integration.
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 enhances image accuracy by minimizing charge sharing, allowing for effective detection and recording of signals, thereby improving the imaging system's performance and reducing noise.
Implementation Method 1
a radiation detector of this type may have a semiconductor layer that absorbs the radiation and generate charge carriers (e.g., electrons and holes)
Data Source
AI summary
Disclosed herein is a method comprising: exposing an imaging system to a scene of a radiation, the imaging system comprising a radiation detector, wherein a probability of having two or more particles of the radiation from the scene incident on an area of the radiation detector during a frame within a time period of detection is below a threshold; detecting particles of the radiation from the scene with the imaging system; if the imaging system detects two or more particles in the area within the frame, combining signals caused by the two or more particles as a combined signal and recording the combined signal, or disregarding the signals caused by the two or more particles; if the imaging system detects only one particle, recording a signal caused by the only one particle; after an end of the time period of detection, forming an image with signals recorded.