Radiation Imaging Apparatus Pixel Determiner Exposure Control
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Solution Overview
Problem
Existing radiation imaging systems face challenges in achieving optimal automatic exposure control (AEC) due to fixed and low spatial resolution X-ray sensors, which fail to accurately detect X-ray doses in varying body portions, leading to inconsistent image quality.
Innovation Solution
A radiation imaging apparatus with an image detector and a pixel determiner that identifies typical low-value and high-value pixels based on pixel values, using integrated thresholds to control radiation emission, ensuring appropriate exposure regardless of body portion type, size, or shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed-size X-ray sensors are used for AEC, then device complexity is reduced, but measurement precision deteriorates due to low spatial resolution and inability to accurately detect X-ray doses across varying body portions
Solution Approach 1:
The patent divides the detection function into two types of pixels: normal pixels for image detection and detection pixels specifically for AEC. Each detection pixel is independently controllable through switching elements, allowing selective activation based on the body portion being imaged. This segmentation enables high measurement precision through spatially-resolved detection while maintaining manageable device complexity through modular pixel design
Solution Approach 2:
Different regions of the detection panel have different functional qualities - normal pixels provide image information while detection pixels provide dose measurement. The switching elements allow local activation of detection pixels in specific regions corresponding to the imaged body portion, optimizing measurement precision for each local area while avoiding the need for all sensors to be active simultaneously
2Adaptability or versatility
If multiple X-ray sensors are used for AEC, then adaptability improves for different body portions, but device complexity increases
Solution Approach 1:
The detection panel integrates both image detection and AEC functions within a single unified structure. Normal pixels and detection pixels coexist on the same panel, sharing the same physical substrate and detection architecture. The switching elements enable the detection pixels to be selectively activated for AEC measurements, allowing the same hardware to serve multiple functions - image detection and dose measurement - thereby improving adaptability without proportionally increasing device complexity
Solution Approach 2:
The patent merges the AEC sensor functionality with the image detection pixel structure. Instead of using separate external sensors, the detection pixels are integrated directly into the FPD matrix, combining AEC and image detection capabilities in a single unified system. This merging reduces overall device complexity while maintaining high adaptability through the selective activation mechanism
3Ease of manufacture
If conventional AEC sensors are used, then ease of manufacture is maintained, but image quality deteriorates due to inconsistent exposure control
Solution Approach 1:
The patent changes the operational parameters of the detection pixels through the switching elements, allowing dynamic adjustment of which pixels are active during AEC measurements. This enables optimization of exposure control parameters for different body portions (e.g., chest, abdomen, extremities) while using the same manufactured sensor array. The parameter changes occur through software/control logic rather than requiring different physical sensors, maintaining ease of manufacture while improving image quality consistency
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 simplifies the system structure and achieves favorable image quality by accurately controlling radiation exposure, preventing excessive exposure and ensuring consistent image quality across different body portions.
Implementation Method 1
an image detector, which detects a radiographic image of an object, includes a plurality of pixels arranged in an image capturing field. Each of the pixels receives radiation emitted from a radiation source and outputs a pixel value in accordance with a received radiation dose
Data Source
AI summary
An FPD detects an X-ray image of an object. The FPD includes a plurality of pixels arranged in its image capturing field. Each pixel receives X-rays emitted from an X-ray source, and outputs a pixel value in accordance with an X-ray dose applied thereto. A pixel determiner determines a minimum-value pixel out of the pixels based on the pixel values of the pixels. The minimum-value pixel is a pixel whose pixel value is the lowest. The pixel determiner sets the minimum-value pixel as an exposure control pixel. A comparator compares a first integrated value, which is an integrated value of the pixel values of the minimum-value pixel, with a predetermined first threshold value. The comparator performs X-ray emission control such that, when the first integrated value has reached the first threshold value, the X-ray source stops emitting the X-rays.