X-Ray Detector Illumination Control for Polarization Drift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct-converting radiation detectors, such as X-ray detectors, experience polarization-induced signal drift due to defects and operational conditions, leading to undesirable changes in signal characteristics and image quality degradation.
Innovation Solution
A method involving illumination with a combined pulsed and DC signal from an LED unit, controlled by a control device with separate current sources, is used to reduce electron-hole pair drift and stabilize the signal by comparing charge pulses before and after exposure to X-rays, employing cost-effective electronic switches for precise polarization adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a direct-converting radiation detector is used to achieve fast response and high spatial resolution, then the detector's response speed and spatial resolution are improved, but signal drift occurs due to polarization effects during operation
Solution Approach 1:
The patent applies preliminary action by illuminating the semiconductor material with light pulses before X-ray exposure to induce charge carriers in advance. This pre-illumination step creates a reservoir of charge carriers that compensates for polarization effects during subsequent X-ray detection, thereby maintaining signal stability without sacrificing the fast response characteristic of direct-converting detectors.
Solution Approach 2:
The patent implements feedback by continuously monitoring the polarization state of the semiconductor material through light pulse illumination and using this information to adjust subsequent measurements. The system measures polarization effects in real-time and compensates for them, creating a closed-loop control that maintains signal stability while preserving the fast response capability.
2Measurement precision
If complex control components are used to meet LED switching time requirements, then the polarization control precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent applies this principle by using standard, cost-effective electronic switches instead of specialized expensive components. The invention demonstrates that conventional switches with moderate switching times are sufficient for controlling LED illumination sequences, eliminating the need for high-end expensive components while maintaining adequate polarization control precision.
Solution Approach 2:
The patent changes the operational parameters of standard electronic switches by optimizing the LED illumination sequence timing and intensity. Instead of relying on fast-switching expensive components, the system achieves precise polarization control by carefully managing the timing and characteristics of light pulses, thereby maintaining measurement precision while using simpler, more cost-effective hardware.
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 method stabilizes the radiation detector's signal over time, reducing long-term drift and improving image quality by using cost-effective components to manage polarization effects.
Implementation Method 1
The illumination unit (4) includes a control device (2) for the LED unit (6)
Implementation Method 2
The X-rays striking the semiconductor generate charge carriers within the semiconductor in the form of electron-hole pairs
Data Source
Figure 1~2
AI summary
A method for operating a radiation detector (5), in particular an X-ray detector, is described. The radiation detector (5) has a control device (2) for generating a control signal (SA) for an illumination unit (4). The control signal (SA) is generated by means of a pulsed current source (12) and a direct current source (14), wherein the pulsed current source (12) generates a pulsed signal component (SP) and the direct current source (14) generates a direct component (SG). The pulsed signal component (SP) and the direct component (SG) are superimposed to generate the control signal (SA) and supplied to the illumination unit (4). A radiation detector (5) is also described.