Dual-Gain Pixel Elements for Wide Dynamic Range Microscopy
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Solution Overview
Problem
Current particle beam microscopy image sensors face limitations in dynamic range, struggling to accurately represent a wide range of incident particle beam signal magnitudes due to insufficient sensitivity and noise interference.
Innovation Solution
The development of pixel elements with dual-gain capabilities, featuring a radiation-sensitive element, a floating diffusion node, and a charge storage device, which generate high-gain and low-gain charge signals. These pixel elements are calibrated to operate in both high-gain and low-gain modes, with a high-gain charge signal representing the radiation-sensitive element's charge and a low-gain signal representing the combined charge storage, achieving a total dynamic range of at least 100,000:1.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-gain pixel element is used, then the device complexity is low, but the dynamic range is insufficient to represent a wide range of incident particle beam signal magnitudes
Solution Approach 1:
The pixel element is segmented into multiple independent charge storage regions (first charge storage region and second charge storage region) with different charge capacities. Each region is associated with a separate readout circuit that can independently read out charge signals. This segmentation allows the pixel to handle both weak and strong incident particle beam signals simultaneously, achieving a wide dynamic range of at least 100,000:1 without requiring an overly complex structure.
2Measurement precision
If the radiation-sensitive element charge capacity is increased to improve sensitivity, then the signal detection capability is enhanced, but the signal-to-noise ratio deteriorates due to increased dark noise
Solution Approach 1:
The pixel element divides the charge storage function across multiple regions with different capacities. The first charge storage region has a smaller capacity optimized for detecting weak signals with low dark noise, while the second charge storage region has a larger capacity for strong signals. This segmentation allows the system to maintain high signal-to-noise ratio for weak signals while still being able to handle strong signals, resolving the contradiction between sensitivity and noise.
Solution Approach 2:
The system changes the effective charge storage capacity parameter by selecting which charge storage region to use based on the incident particle beam signal magnitude. For weak signals, the smaller first charge storage region is used to minimize dark noise; for strong signals, the larger second charge storage region is used. This dynamic parameter adjustment maintains optimal signal-to-noise ratio across the full dynamic range.
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 significantly enhances the dynamic range of particle beam microscopy image sensors, allowing for more accurate representation of diverse signal magnitudes and improved signal-to-noise ratios, effectively addressing the limitations of existing technologies.
Implementation Method 1
a scintillator configured to receive a particle beam and to generate an electromagnetic signal at an average photon conversion rate
Implementation Method 2
The sensor comprises at least one pixel element configured to produce a high-gain charge signal and a low-gain charge signal
Data Source
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AI summary
Pixel elements and associated methods are disclosed herein. A pixel element can comprise a radiation-sensitive element configured to generate an electric charge, a floating diffusion node, a charge storage device, and an output stage configured to generate a charge signal. The pixel element is configured to operate in a high-gain mode and a low-gain mode and can have a total dynamic range that is at least 100,000:1. A method of operating a pixel element can comprise reading out a high-gain charge signal with the pixel element in a high-gain mode and reading out a low-gain charge signal with the pixel element in a low-gain mode. The reading out the low-gain charge signal comprises configuring a low-gain channel charge capacity of the pixel element such that a ratio of the low-gain channel charge capacity to a high-gain channel charge capacity is at least 30:1.