Solid-State X-Ray Imaging Pixel Binning Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In solid-state imaging devices, especially those used in X-ray imaging systems, improving the signal-to-noise ratio (S/N ratio) and frame rate is challenging, particularly when the device moves during imaging, as the elongated shape of photodiodes in the movement direction is not practical for various movement speeds and imaging modes, and conventional binning techniques complicate image reconstruction and handling of output signals.
Innovation Solution
The implementation of a solid-state imaging device with a photodetecting unit that allows flexible binning by dividing pixels into unit and binning regions, enabling the output of digital values corresponding to the sum of charges from multiple pixels, which can be easily handled and processed, even when the device moves, by using a control unit to manage readout switches and integration circuits to output signals in a column order.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If photodiodes are elongated in the movement direction to improve S/N ratio and frame rate, then imaging performance improves, but the device cannot adapt to various movement speeds and imaging modes
Solution Approach 1:
The photodetecting unit is divided into multiple independently controllable pixel regions that can be selectively activated. Instead of using a fixed elongated photodiode structure, the system segments the detection area into discrete pixels that can be dynamically configured through row and column selection signals, allowing adaptation to different movement speeds and imaging modes while maintaining high S/N ratio where needed.
2Reliability
If conventional binning techniques are used to improve S/N ratio, then signal quality improves, but image reconstruction and handling of output signals become complicated
Solution Approach 1:
The system performs preliminary spatial summation of pixel signals through the integration circuit before output. By accumulating charges from multiple pixels in the integration circuit and then reading out the summed signal, the system achieves S/N ratio improvement without requiring complex post-processing reconstruction algorithms. The binning operation is executed in advance during signal integration, simplifying subsequent image processing.
3Productivity
If binning is performed to improve frame rate, then imaging speed improves, but the number of output data decreases and signal handling becomes complex
Solution Approach 1:
Multiple pixel signals are merged through spatial summation in the integration circuit, combining charges from multiple pixels into a single integrated signal per readout line. This merging process reduces the total number of separate output data channels while simultaneously improving the frame rate, as fewer integrated signals need to be processed and transmitted compared to individual pixel outputs.
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 allows for improved S/N ratio and frame rate without altering the reconstruction process, enabling flexible setting of binning region sizes and maintaining constant frame rates, even when binning is performed, and reduces image quality degradation during reconstruction.
Implementation Method 1
a photodiode that generates a charge of an amount according to an incident light intensity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A solid-state imaging device includes a photodetecting unit 10 including MN pixels arrayed two-dimensionally in M rows and N columns, an output unit outputting a digital value generated on the basis of the amount of charge input from the pixels, and a control unit. The control unit divides the MN pixels in the photodetecting unit into unit regions each including pixels in Q rows and R columns, divides the unit regions arrayed two-dimensionally in (M/Q) rows and (N/R) columns into binning regions each including unit regions in K rows and one column, and repeatedly outputs the digital value according to the sum of amounts of the charges output from KQR pixels included in each binning region from the output unit K times in a column order for each row sequentially for the binning regions arrayed two-dimensionally in (M/KQ) rows and (N/R) columns. Accordingly, a solid-state imaging device capable of outputting a signal that is easy to handle even when binning is performed can be realized.