Radiographic Imaging Device Back-Side Irradiation Organic Substrate
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Solution Overview
Problem
Radiographic imaging devices face a trade-off between image sharpness and sensitivity, with back-side irradiation providing high sharpness but reduced sensitivity due to radiation absorption in the substrate, and front-side irradiation maintaining sensitivity but compromising sharpness due to increased distance between the scintillator and substrate.
Innovation Solution
A radiographic imaging device is designed with a light-emitting layer and sensor portions using organic photoelectric conversion material, positioned to receive radiation from the substrate side, allowing light emission close to the substrate for high sharpness while minimizing radiation absorption by the sensor portions to maintain sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If back-side irradiation is used, then image sharpness is improved, but sensitivity deteriorates due to radiation absorption in the substrate
Solution Approach 1:
The patent changes the material parameter of the substrate from conventional inorganic materials to organic photoelectric conversion material, which has different radiation absorption characteristics. This parameter change allows the substrate to maintain mechanical support functions while reducing radiation absorption, thereby resolving the contradiction between sharpness and sensitivity
Solution Approach 2:
The patent uses composite structure combining organic photoelectric conversion material with scintillator layer. The organic substrate material serves dual functions: providing mechanical support and enabling photoelectric conversion, while the scintillator converts radiation to light. This composite approach allows back-side irradiation to achieve both high sharpness and maintained sensitivity
2Reliability
If front-side irradiation is used, then sensitivity is maintained, but image sharpness deteriorates due to increased distance between scintillator and substrate
Solution Approach 1:
The patent inverts the conventional irradiation direction by using back-side irradiation instead of front-side irradiation. By irradiating from the substrate side rather than the scintillator side, the light emission distance is minimized while the organic substrate's low absorption特性 maintains sensitivity, thus resolving the contradiction through inverted approach
3Reliability
If scintillator thickness is increased, then sensitivity is improved, but image sharpness deteriorates due to increased light emission distance from substrate
Solution Approach 1:
The patent changes the fundamental parameter of substrate material from inorganic to organic photoelectric conversion material. This enables the system to use back-side irradiation geometry, where the scintillator can be positioned closer to the substrate regardless of thickness, because the organic substrate absorbs minimal radiation. This parameter change decouples the trade-off between scintillator thickness and image sharpness
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 device achieves high sharpness in radiographic images while suppressing sensitivity drops, utilizing a substrate configuration that minimizes radiation absorption and enhances image quality.
Implementation Method 1
a light-emitting layer that generates light due to irradiation of radiation
Implementation Method 2
sensor portions configured including an organic photoelectric conversion material that generates electric charges by receiving light
Data Source
AI summary
The present invention provides a radiographic imaging device that may image radiographic images with high sharpness while suppressing a drop in sensitivity. Namely, a radiation detector, in which a scintillator that generates light due to irradiation of radiation and a TFT substrate on which plural sensor portions configured including an organic photoelectric conversion material that generates electric charges by receiving light are disposed are sequentially layered, is positioned in such a way that radiation that has passed through a subject is made incident from the TFT substrate side.