CT Detector Module With Integrated Column ADC and Segmented Readout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Computed tomography (CT) detectors face challenges with noise and thermal degradation due to the need for rapid readout and the proximity of digital conversion circuitry to photodiode structures, which degrades detection performance.
Innovation Solution
A detector module with a 3-side buttable CMOS active pixel array and integrated column analog-to-digital conversion circuitry, where pixels are multiplexed to readout channels and readout circuitry is positioned away from sensitive elements, enabling fast frame rates and improved thermal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If digital conversion circuitry is placed near photodiode structures to enable rapid readout, then readout speed is improved, but thermal performance deteriorates due to heat degrading detection circuitry
Solution Approach 1:
The detector is divided into multiple independent detector modules, each handling a portion of the pixel array. This segmentation allows heat generated by readout circuitry in one module to not affect other modules, effectively distributing thermal load while maintaining rapid readout capabilities across the entire detector array.
Solution Approach 2:
The patent transitions from a two-dimensional arrangement where readout circuitry is integrated within the pixel array plane to a three-dimensional configuration where readout circuitry is positioned in a separate layer or region. This spatial separation in another dimension allows rapid signal readout while isolating heat-generating circuits from sensitive photodiode structures.
2Speed
If each pixel has its own readout channel to facilitate rapid readout, then readout speed is improved, but device complexity increases due to massively parallel architecture
Solution Approach 1:
The pixel array is segmented into blocks, with each detector module handling a specific portion. Within each module, readout circuitry is shared among multiple pixels rather than having dedicated circuitry for each pixel. This segmentation reduces the overall number of readout channels needed while maintaining fast readout performance across the complete detector array.
Solution Approach 2:
Readout circuitry in each detector module is designed to serve multiple pixels within that module, making the circuitry universal rather than dedicated to a single pixel. This multi-functional approach reduces the total number of readout channels required, simplifying the overall system architecture while preserving rapid readout capabilities.
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 allows for operation at frame rates greater than 10kHz, enhances thermal performance by isolating heat sources from sensitive detector components, and supports scalable detector architectures for various CT applications.
Implementation Method 1
a detector, where representative signals are acquired
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present approach relates to implementations of a CT detector integrating CT scintillator packs on a fast, low electronic noise and scalable CMOS active pixel sensor substrate. In one embodiment, a large 3-side buttable CMOS active pixel array with built-in column analog-to-digital conversion (ADC) circuitry (e.g., ASICs) integrated onto the same wafer is used.