Pixel Structure for Flat Panel Detection Devices
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Solution Overview
Problem
The low signal-to-noise ratio in digital X-ray flat panel detection devices due to the absorption of X-rays by human tissues results in poor image quality, with existing technologies struggling to effectively collect and convert weak X-ray signals into usable electrical signals.
Innovation Solution
A pixel structure for flat panel detection devices incorporating a photodiode, signal amplification circuit, and switching transistors, including a bootstrap circuit, which amplifies the signal output and improves the signal-to-noise ratio by converting optical signals into electrical signals and boosting the voltage, thereby enhancing the detection effect and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional photodiode structure is used to detect X-ray signals, then the device structure is simple, but the signal-to-noise ratio is low due to weak signal output
Solution Approach 1:
The patent combines the photodiode, signal amplification circuit, and switching transistors into an integrated pixel structure. The signal amplification circuit includes multiple transistors (first switching transistor, second switching transistor, third switching transistor) and capacitors that are merged with the photodiode to form a unified detection unit, thereby improving signal-to-noise ratio while maintaining compact structure
Solution Approach 2:
The patent introduces an X-ray conversion layer as an intermediary between the incident X-rays and the photodiode. This layer converts X-ray photons into optical photons, which are then detected by the photodiode, effectively bridging the detection gap and enhancing signal output
2Measurement precision
If signal amplification circuit is added to improve signal output, then the signal-to-noise ratio increases, but the manufacturing complexity increases
Solution Approach 1:
The signal amplification circuit is segmented into multiple functional blocks: first switching transistor for signal selection, second switching transistor for charge transfer, third switching transistor for signal amplification, and bootstrap capacitor for voltage stabilization. Each segment performs a specific function, making the complex circuit more manageable and manufacturable
Solution Approach 2:
The patent uses parameter changes in the transistor operating states (on/off states) and capacitor charging/discharging cycles to achieve signal amplification. By controlling the voltage parameters and timing sequences, the circuit transforms weak photodiode signals into amplified output signals suitable for detection
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 proposed pixel structure increases the signal output, improving the signal-to-noise ratio and image quality by effectively amplifying the weak X-ray signals, thus enhancing the detection effect of the flat panel detection device.
Implementation Method 1
a photodiode configured to collect optical signals and convert the optical signals into electrical signals
Implementation Method 2
an X-ray conversion layer disposed on the photodiode, and the X-ray conversion layer is configured to convert a X-ray into an optical signal
Data Source
AI summary
A pixel structure of flat panel detection device, a flat panel detection device, and a camera system. The pixel structure of the flat panel detection device includes a photodiode configured to collect optical signals and convert the optical signals into electrical signals, the photodiode includes a positive terminal and a negative terminal, the negative terminal is connected to a bias voltage signal terminal; a signal amplification circuit, a signal input terminal of the signal amplification circuit is connected to the negative terminal of the photodiode, a signal output terminal of the signal amplification circuit is connected to a first node; a first switching transistor, a control electrode of the first switching transistor is connected to a scanning signal line, a first terminal of the first switching transistor is connected to a data signal line, and a second terminal of the first switching transistor is connected to the first node.