Radiographic flat panel detector and radiographic imaging device

Abstract

The present application discloses a radiation flat panel detector and a radiation imaging device, wherein the radiation flat panel detector is characterized in that it includes a substrate and a plurality of composite pixel units formed on the substrate, each composite pixel unit includes a switch element and a conversion component, the switch element is formed on the substrate; the conversion component is formed on the side of the switch element away from the substrate, and includes an imaging element and a detection element, and the orthographic projection of the detection element on the substrate at least partially overlaps with the orthographic projection of the switch element on the substrate. The radiation flat panel detector provided by the present application can achieve a balance between simplified device connection and flat panel detector performance.

Description

Technical Field

[0001] The present application belongs to the field of medical imaging diagnosis, and in particular, relates to a radiation flat panel detector and a radiation imaging device. Background Art

[0002] Digital X-ray photography (DR) technology is widely used in medical diagnosis, safety inspection, industrial flaw detection and other fields. It uses the short wavelength of X-rays to penetrate strongly and the different absorption characteristics of X-rays by different tissues to detect the intensity of X-rays passing through the target object to achieve internal structure imaging. DR devices include flat-panel detectors, high-voltage generators and tubes. The high-voltage generator and tube control the output of X-rays. X-rays pass through the target object and attenuate. The attenuated X-rays are converted into visible light by the flat-panel detector, and then converted into digital signals through photoelectric conversion and analog-to-digital conversion and transmitted to the computer for processing to form images.

[0003] The flat-panel detector is the core component of the DR device. Whether the flat-panel detector is exposed or not needs to be controlled according to whether X-rays are generated or not. The existing control method for whether the flat-panel detector is exposed or not is difficult to achieve a balance between simplifying the device connection and the performance of the flat-panel detector. Summary of the invention

[0004] The embodiments of the present application provide a radiation flat panel detector and a radiation imaging device, which can achieve a balance between simplified device connection and flat panel detector performance.

[0005] An embodiment of a first aspect of the present application provides a radiation flat panel detector, including a substrate and a plurality of composite pixel units formed on the substrate, each of the composite pixel units including:

[0006] a switching element formed on the substrate;

[0007] The conversion component is formed on the side of the switch element away from the substrate, and includes an imaging element and a detection element. The orthographic projection of the detection element on the substrate at least partially overlaps with the orthographic projection of the switch element on the substrate.

[0008] According to an implementation of the first aspect of the present application, an area of ​​an orthographic projection of the imaging element on the substrate is larger than an area of ​​an orthographic projection of the detection element on the substrate.

[0009] According to any of the aforementioned embodiments of the first aspect of the present application, the imaging element includes a first electrode, a first photoelectric conversion layer, and a second electrode; the detection element includes a third electrode, a second photoelectric conversion layer, and a fourth electrode, the first electrode and the third electrode are arranged in the same layer, the first photoelectric conversion layer and the second photoelectric conversion layer are arranged in the same layer, and the second electrode and the fourth electrode are arranged in the same layer;

[0010] Preferably, the second electrode and the fourth electrode are integrally formed.

[0011] According to any of the foregoing embodiments of the first aspect of the present application, it further includes display pixel units, and each of the display pixel units is multiplexed by the composite pixel units; or the display pixel units and the composite pixel units are alternately arranged.

[0012] According to any of the foregoing embodiments of the first aspect of the present application, the imaging element includes a first electrode, a first photoelectric conversion layer, and a second electrode, and the detection element includes a first photosensitive transistor that conducts at a high potential and a capacitor; the detection element includes a source-drain layer, a semiconductor layer, a gate insulating layer, a gate layer, a first insulating layer, and a capacitor layer that are stacked in a direction away from the substrate, the first electrode is disposed on the same layer as the source-drain layer, and the second electrode is disposed on the same layer as the capacitor layer.

[0013] According to any of the foregoing embodiments of the first aspect of the present application, the detection element includes a second photosensitive transistor that conducts at a low potential.

[0014] According to any of the foregoing embodiments of the first aspect of the present application, the display pixel unit and the composite pixel unit have the same opening area, the display pixel unit includes a switching device and an imaging device, the switching device is formed on the substrate, and the imaging device is formed on a side of the switching device away from the substrate.

[0015] According to any of the foregoing embodiments of the first aspect of the present application, the radiation flat panel detector includes a central region and an edge region surrounding the central region, the ratio of the number of composite pixel units to the number of display pixel units in the central region is A, and the ratio of the number of composite pixel units to the number of display pixel units in the edge region is B, and A≥B.

[0016] According to any of the foregoing embodiments of the first aspect of the present application, the radiation flat panel detector further includes:

[0017] A row scanning driving module, connected to each of the switching elements and each of the switching devices, for controlling the conduction and cutoff of the switching elements and the switching devices;

[0018] A data reading module, connected to each of the imaging elements and each of the imaging devices, for reading the charge signals generated by the imaging elements and the imaging devices;

[0019] A signal control and processing module, connected to each detection element, for reading the charge signal of the detection element and for sending an exposure start signal, and sending an exposure termination signal when the number of charges read by the detection element reaches a preset threshold;

[0020] An image information acquisition module, connected to the row scanning drive module, the data readout module and the signal control processing module, for controlling each of the switch elements and each of the light-opening devices to turn off to start accumulating charges through the row scanning drive module when receiving the exposure start signal sent by the signal control processing module, and controlling the row scanning drive module and the data readout module to read out charges after receiving the exposure termination signal sent by the signal control processing module;

[0021] The image information processing and display module is connected to the image information acquisition module and is used for image information processing and display.

[0022] The embodiment of the second aspect of the present application further provides a radiation imaging device, any one of the radiation flat panel detectors provided in the first aspect of the present application.

[0023] The radiation flat panel detector provided by the present application includes a substrate and a plurality of composite pixel units formed on the substrate. The composite pixel unit includes a switch element and a conversion component. The conversion component is located on the side of the switch element away from the substrate, and includes an imaging element and a detection element. The imaging element is used to sense radiation so as to generate an image through subsequent signal conversion. The detection element is used to sense radiation, and when the radiation is sensed, a start exposure signal is sent, so that the imaging element starts sensing; when the radiation is sensed, a stop exposure signal is sent, that is, the detection element can realize automatic detection of the start time and end time of radiation exposure. Among them, the detection element is integrated into the composite pixel unit. On the one hand, compared with the additional automatic detection device set in the radiation flat panel detector alone, the difficulty of installation, connection, debugging and maintenance is reduced, and the flexibility and compatibility of the radiation flat panel detector are improved; on the other hand, the sacrifice of effective pixels in the radiation flat panel detector due to the setting of the automatic detection device is reduced, and the resolution of the radiation flat panel detector is guaranteed. At the same time, the positive projection of the detection element on the substrate overlaps at least partially with the positive projection of the switch element on the substrate, so as to reduce the sacrifice of the pixel area in the radiation flat panel detector due to the setting of the detection element and improve the aperture ratio of the radiation flat panel detector. Thereby, the performance of the radiation flat panel detector is improved. The radiation flat panel detector provided in the present application realizes the balance between simplified device connection and flat panel detector performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a schematic structural diagram of a radiation flat panel detector provided by an embodiment of the present application;

[0026] Figure 2 It is a schematic circuit diagram of a radiation flat panel detector provided by an embodiment of the present application;

[0027] Figure 3 It is one of the schematic structural diagrams of another radiation flat panel detector provided by an embodiment of the present application;

[0028] Figure 4 It is the second schematic structural diagram of another radiation flat panel detector provided by an embodiment of the present application;

[0029] Figure 5 It is one of the schematic circuit diagrams of another radiation flat panel detector provided by an embodiment of the present application;

[0030] Figure 6 It is the second schematic circuit diagram of another radiation flat panel detector provided by an embodiment of the present application;

[0031] Figure 7 It is the third schematic circuit diagram of another radiation flat panel detector provided by an embodiment of the present application;

[0032] Figure 8 It is the fourth schematic circuit diagram of another radiation flat panel detector provided by an embodiment of the present application;

[0033] Figure 9 It is the fifth schematic circuit diagram of another radiation flat panel detector provided by an embodiment of the present application;

[0034] Figure 10 It is a schematic circuit diagram of a radiation imaging device provided by an embodiment of the present application.

[0035] In the accompanying drawings:

[0036] 1 - Radiation flat panel detector; 10 - Substrate; 11 - Composite pixel unit; 12 - Switching element; 13 - Conversion component; 131 - Imaging element; 1311 - First electrode; 1312 - First photoelectric conversion layer; 1313 - Second electrode; 132 - Detection element; 1321 - Third electrode; 1322 - Second photoelectric conversion layer; 1323 - Fourth electrode; 14 - First photosensitive transistor; 15 - Capacitor; 16 - Source-drain layer; 17 - Semiconductor layer; 18 - Gate insulating layer; 19 - Gate layer; 20 - First insulating layer; 21 - Capacitor layer; 22 - Display pixel unit; 221 - Switching device; 222 - Imaging device; Q1 - Central region; Q2 - Edge region; V - Power supply line; D1 - First data readout line; D2 - Second data readout line; S1 - Scanning line; 23 - Buffer layer; 24 - First semiconductor layer; 25 - First gate insulating layer; 26 - First metal layer; 27 - Interlayer dielectric layer; 28 - Second metal layer; 29 - Insulating layer; 30 - Third metal layer; 31 - Photoelectric conversion layer; 32 - Transparent conductive layer; 33 - Second insulating layer; 34 - Planarization layer; 35 - Line scanning drive module; 36 - Data readout module; 37 - Signal control and processing module; 38 - Image information acquisition module; 39 - Image information processing module; 2 - Radiation imaging device. Detailed implementation manners

[0037] The features and exemplary embodiments of each aspect of the present application will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present application by showing examples of the present application.

[0038] It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, the elements defined by the statement "comprising..." do not exclude the presence of additional identical elements in the process, method, article or device comprising the elements.

[0039] The inventor has found through research that there are two ways to control whether the flat-panel detector is exposed or not: one is to control the exposure of the flat-panel detector by using the X-ray switch signal on the high-voltage generator, which requires that the flat-panel detector must be connected to the high-voltage generator, thereby causing complex equipment connection and poor flexibility; the other is to use an automatic exposure detection (AED) module composed of a sensor and related circuits to detect X-rays in real time. The AED module is integrated into the interior of the flat-panel detector. Specifically, some pixels in the flat-panel detector are replaced with the AED detection module. Once the AED detection module detects the arrival of X-rays, it sends a start exposure signal to the flat-panel detector, and when it detects that there are no X-rays, it sends a stop exposure signal to the flat-panel detector. There is no electrical connection between the AED module and the high-voltage generator, which reduces the difficulty of installation, debugging and maintenance and improves flexibility. However, since some pixels in the flat-panel detector are sacrificed, the overall resolution of the flat-panel detector is reduced, so that the positions of some pixels cannot be effectively imaged, affecting the overall image effect, thereby affecting the performance of the flat-panel detector. Therefore, the existing control method for whether the flat-panel detector is exposed or not is difficult to achieve a balance between simplifying the equipment connection and the performance of the flat-panel detector. Based on the research on the above problems, the inventor provides a radiation flat panel detector and a radiation imaging device to achieve a balance between simplifying device connection and flat panel detector performance.

[0040] In order to better understand this application, Figures 1 to 10 The radiation flat panel detector and the radiation imaging apparatus according to the embodiments of the present application are described in detail.

[0041] See also Figure 1 The embodiment of the present application provides a radiation flat panel detector 1, comprising a substrate 10 and a plurality of composite pixel units 11 formed on the substrate 10, each composite pixel unit 11 comprising a switch element 12 and a conversion component 13. The switch element 12 is formed on the substrate 10. The conversion component 13 is formed on the side of the switch element 12 away from the substrate 10, and comprises an imaging element 131 and a detection element 132, wherein the orthographic projection of the detection element 132 on the substrate 10 at least partially overlaps with the orthographic projection of the switch element 12 on the substrate 10.

[0042] In the flat panel detector 1 provided by the present application, it includes a substrate 10 and a plurality of composite pixel units 11 formed on the substrate 10. The composite pixel unit 11 includes a switching element 12 and a conversion component 13. The conversion component 13 is located on the side of the switching element 12 away from the substrate 10 and includes an imaging element 131 and a detection element 132. The imaging element 131 is used to sense radiation so as to generate an image after subsequent signal conversion. The detection element 132 is used to sense radiation to send a start exposure signal when radiation is sensed, so that the imaging element 131 starts to sense; and send a stop exposure signal when the sensing of radiation ends, that is, the detection element 132 can realize the automatic detection of the start time and end time of radiation exposure. Among them, the detection element 132 is integrated inside the composite pixel unit 11. On the one hand, compared with additionally arranging an automatic detection device separately in the flat panel detector 1, the installation connection, debugging and maintenance difficulties are reduced, and the flexibility and compatibility of the flat panel detector 1 are improved; on the other hand, the sacrifice of the effective pixels in the flat panel detector 1 due to the arrangement of the automatic detection device is reduced, ensuring the resolution of the flat panel detector 1. At the same time, the positive projection of the detection element 132 on the substrate 10 and the positive projection of the switching element 12 on the substrate 10 at least partially overlap to reduce the sacrifice of the pixel area in the flat panel detector 1 caused by the arrangement of the detection element 132 and improve the aperture ratio of the flat panel detector 1. Thereby, the performance of the flat panel detector 1 is improved. In the flat panel detector 1 provided by the present application, the simplification of device connection and the performance of the flat panel detector are taken into account.

[0043] In the radiation flat panel detector 1 provided in the present application, by integrating the detection element 132 for detecting whether radiation is emitted into the inside of the composite pixel unit 11, without replacing the pixel positions in the radiation flat panel detector 1 and without separately occupying the pixel area in the radiation flat panel detector 1, the effective pixels in the radiation flat panel detector 1 are not sacrificed, making the imaging effect of the radiation flat panel detector 1 better. At the same time, the detection element 132 is disposed on the side of the switching element 12 away from the substrate 10, and the orthographic projections of the switching element 12 and the detection element 132 on the substrate 10 overlap, so that the detection element 132 does not occupy the space of the imaging element 131. Specifically, since the requirements for the performance parameters of the imaging element 131 itself in the radiation flat panel detector 1 are relatively high, and parasitic capacitance will be generated in the overlapping part of the orthographic projections of the imaging element 131 and the switching element 12 on the substrate 10, which affects the performance of the imaging element 131 by the switching element 12. Therefore, the orthographic projections of the imaging element 131 and the switching element 12 on the substrate 10 can be misaligned to reduce the influence of the parasitic capacitance between the imaging element 131 and the switching element 12 on the performance of the imaging element 131. The requirements for the performance parameters of the detection element 132 itself in the radiation flat panel detector 1 are relatively low. Therefore, the detection element 132 can be arranged opposite to the switching element 12, that is, the orthographic projections of the switching element 12 and the detection element 132 on the substrate 10 overlap, so as to make full use of the space in the composite pixel unit 11 and reduce the influence on the aperture ratio of the imaging element 131.

[0044] In a feasible implementation manner, the area of the orthographic projection of the imaging element 131 on the substrate 10 is larger than the area of the orthographic projection of the detection element 132 on the substrate 10.

[0045] In the above implementation manner, the requirements for the performance parameters of the detection element 132 itself in the radiation flat panel detector 1 are lower than those for the performance parameters of the imaging element 131 itself. Therefore, the area of the orthographic projection of the imaging element 131 on the substrate 10 can be larger than the area of the orthographic projection of the detection element 132 on the substrate 10, so that while the detection element 132 can realize the detection function, the imaging element 131 can perform imaging better, ensuring the aperture ratio of the radiation flat panel detector 1.

[0046] In a feasible implementation manner, the imaging element 131 includes a first electrode 1311, a first photoelectric conversion layer 1312, and a second electrode 1313; the detection element 132 includes a third electrode 1321, a second photoelectric conversion layer 1322, and a fourth electrode 1323. The first electrode 1311 and the third electrode 1321 are arranged in the same layer, the first photoelectric conversion layer 1312 and the second photoelectric conversion layer 1322 are arranged in the same layer, and the second electrode 1313 and the fourth electrode 1323 are arranged in the same layer.

[0047] In the above-described embodiment, both the imaging element 131 and the detection element 132 are photodiodes, and the two photodiodes are arranged on the same layer. There is an isolation gap between the imaging element 131 and the detection element 132 to prevent mutual interference.

[0048] In the above-described embodiment, the first electrode 1311, the first photoelectric conversion layer 1312, and the second electrode 1313 in the imaging element 131 are stacked in a direction away from the substrate 10. The third electrode 1321, the second photoelectric conversion layer 1322, and the fourth electrode 1323 in the detection element 132 are stacked in a direction away from the substrate 10.

[0049] In a feasible embodiment, as Figure 2 shown, the composite pixel units 11 are arranged in rows and columns. Each column of composite pixel units 11 shares the same power supply line V, and the power supply line V is connected to the imaging element 131 and the detection element 132 in the composite pixel unit 11. Each column of composite pixel units 11 shares the same first data readout line D1, and the first data readout line D1 is connected to the detection element 132 in the composite pixel unit 11. Each column of composite pixel units 11 shares the same second data readout line D2, and the second data readout line D2 is connected to the imaging element 131 in the composite pixel unit 11. Each row of composite pixel units 11 shares the same scan line S1, and the scan line S1 is connected to the switching element 12. The switching element 12 in each composite pixel unit 11 is connected to the imaging element 131.

[0050] Specifically, the switching element 12 can be a thin-film transistor. The third electrode 1321 is connected to the first data readout line D1, and the fourth electrode 1323 is connected to the power supply line V. The first electrode 1311 is connected to the first pole of the thin-film transistor, the second pole of the thin-film transistor is connected to the second data readout line D2, the gate of the thin-film transistor is connected to the scan line S1, and the second electrode 1313 is connected to the power supply line V.

[0051] In a feasible embodiment, as Figure 1As shown, the radiation flat panel detector 1 includes a substrate 10, a buffer layer 23, a first semiconductor layer 24, a first gate insulating layer 25, a first metal layer 26, an interlayer dielectric layer 27, a second metal layer 28, and an insulating layer 29. Among them, the buffer layer 23 is formed on the substrate 10 and functions to protect and buffer. The material of the first semiconductor layer 24 can be polysilicon or an oxide semiconductor material and is used to form the active layer of the thin film transistor. The first gate insulating layer 25 is formed on the first semiconductor layer 24. The first metal layer 26 is formed on the first gate insulating layer 25 and is used to form the gate of the thin film transistor. The interlayer dielectric layer 27 is formed on the first metal layer 26. The second metal layer 28 is formed on the interlayer dielectric layer 27 and is used to form the source and drain electrodes of the thin film transistor. The insulating layer 29 is formed on the second metal layer 28, and the material can be selected as silicon nitride, etc.

[0052] When both the imaging element 131 and the detection element 132 include photodiodes, the radiation flat panel detector 1 further includes a third metal layer 30, a photoelectric conversion layer 31, a transparent conductive layer 32, a second insulating layer 33, etc. The third metal layer 30 is formed on the insulating layer 29 and is used to form the first electrode 1311 and the third electrode 1321. The photoelectric conversion layer 31 is formed on the third metal layer 30 and is used to form the first photoelectric conversion layer 1312 and the second photoelectric conversion layer 1322. The transparent conductive layer 32 is formed on the photoelectric conversion layer 31, and a transparent conductive material needs to be selected, such as indium tin oxide. The transparent conductive layer 32 is used to form the second electrode 1313 and the fourth electrode 1323. The second insulating layer 33 is formed on the transparent conductive layer 32, and the material can be selected as silicon oxide.

[0053] In a feasible implementation manner, as Figure 2 and Figure 3 shown, the second electrode 1313 and the fourth electrode 1323 are integrally formed.

[0054] In the above implementation manner, both the second electrode 1313 and the fourth electrode 1323 are used to be connected to the power supply line V, so that the second electrode 1313 and the fourth electrode 1323 can be integrally formed to simplify the manufacturing process.

[0055] In a feasible implementation manner, as Figure 4 shown, the imaging element 131 includes a first electrode 1311, a first photoelectric conversion layer 1312, and a second electrode 1313. The detection element 132 includes a first photosensitive transistor 14 that conducts at a high potential and a capacitor 15; the detection element 132 includes a source-drain layer 16, a semiconductor layer 17, a gate insulating layer 18, a gate layer 19, a first insulating layer 20, and a capacitor layer 21 that are stacked in a direction away from the substrate 10. The first electrode 1311 is disposed on the same layer as the source-drain layer 16, and the second electrode 1313 is disposed on the same layer as the capacitor layer 21.

[0056] In the above-described embodiment, as Figure 5 shown, the first photosensitive transistor 14 is a photosensitive transistor that conducts when at a high potential, and the power supply line V provides a low potential for the imaging element 131. Therefore, a capacitor 15 needs to be provided to play a coupling role, converting the low potential of the power supply line V into a high potential to turn on the first photosensitive transistor 14.

[0057] In the above-described embodiment, the source-drain layer 16 and the first electrode 1311 are provided on the same layer and can be fabricated using the same process. The semiconductor layer 17 is located on the side of the source-drain layer 16 away from the substrate 10, and the material can be selected as amorphous silicon. The gate insulating layer 18 is located on the side of the semiconductor layer 17 away from the substrate 10. The gate layer 19 is used to form the gate and the lower plate of the capacitor 15, with the gate and the lower plate being multiplexed, and the orthographic projection of the gate on the substrate 10 partially overlaps with the orthographic projection of the semiconductor layer 17 on the substrate 10 to expose part of the semiconductor layer 17. The first insulating layer 20 is formed on the side of the gate layer 19 away from the substrate 10. The capacitor layer 21 is formed on the side of the first insulating layer 20 away from the substrate 10, and the capacitor layer 21 is used to form the upper plate of the capacitor 15. The capacitor layer 21 can be provided on the same layer as the second electrode 1313 and can be fabricated using the same process.

[0058] In the above-described embodiment, the switching element 12 can be a thin-film transistor. The first electrode 1311 is connected to the first pole of the thin-film transistor, the second pole of the thin-film transistor is connected to the second data readout line D2, the gate of the thin-film transistor is connected to the scan line S1, and the second electrode 1313 is connected to the power supply line V. The upper plate of the capacitor 15 is connected to the power supply line V, the lower plate is connected to the first pole and the gate of the first photosensitive transistor 14, and the second pole of the first photosensitive transistor 14 is connected to the first data readout line D1.

[0059] In the above-described embodiment, the radiation flat panel detector 1 may further include a planarizing layer 34 located on the side of the capacitor layer 21 and the second electrode 1313 away from the substrate 10, and a second insulating layer 33 located on the side of the planarizing layer 34 away from the substrate 10, etc., which are not particularly limited in this application.

[0060] In a feasible embodiment, the detection element 132 includes a second photosensitive transistor that conducts when at a low potential.

[0061] In the above-described embodiment, the second photosensitive transistor conducts when at a low potential, and the power supply line V provides a low potential. Therefore, no capacitor needs to be provided. The structure of the second photosensitive transistor is similar to that of the first photosensitive transistor 14, and will not be elaborated in this application. The gate and the first pole of the second photosensitive transistor are connected to the power supply line V, and the second pole is connected to the second data readout line D2.

[0062] In a feasible embodiment, as Figure 5As shown, the radiation flat panel detector 1 further includes a display pixel unit 22. Each display pixel unit 22 is formed by multiplexing the composite pixel unit 11, that is, all the pixels in the radiation flat panel detector 1 are composite pixel units 11, so that automatic exposure detection in the full field of view can be realized, and the detection effect is more accurate.

[0063] In a feasible implementation manner, as Figure 6 shown, the radiation flat panel detector 1 further includes a plurality of display pixel units 22. The display pixel units 22 and the composite pixel units 11 are arranged alternately. The opening areas of the display pixel units 22 and the composite pixel units 11 are the same. The display pixel unit 22 includes a switching device 221 and an imaging device 222. The switching device 221 is formed on the substrate 10, and the imaging device 222 is formed on the side of the switching device 221 away from the substrate 10. Thus, the switching device 221 and the same functional layer of the switching element 12 are arranged on the same layer, and the imaging device 222 and the same functional layer of the imaging element 131 are arranged on the same layer.

[0064] In the above implementation manner, the radiation flat panel detector 1 includes a composite pixel unit 11 and a display pixel unit 22. The display pixel unit 22 is only used for imaging, and the composite pixel unit 11 can be used for imaging and automatic exposure detection. The manufacturing process of the composite pixel unit 11 is more complex. By simultaneously arranging the composite pixel unit 11 and the display pixel unit 22 in the radiation flat panel detector 1, the manufacturing process can be simplified and the manufacturing cost can be reduced while realizing automatic exposure detection, and at the same time, the circuit complexity is lower and the data processing is also simpler.

[0065] In a feasible implementation manner, as Figure 6 shown, the display pixel units 22 and the composite pixel units 11 are arranged in rows and columns. Along the row direction, the number of display pixel units 22 spaced between adjacent composite pixel units 11 is the same. Along the column direction, the number of display pixel units 22 spaced between adjacent composite pixel units 11 is the same.

[0066] In the above implementation manner, the composite pixel units 11 and the display pixel units 22 in the radiation flat panel detector 1 are evenly distributed, and the manufacturing process is relatively simple.

[0067] In a feasible implementation manner, the radiation flat panel detector 1 includes a central region Q1 and an edge region Q2 surrounding the central region Q1. The ratio of the number of composite pixel units 11 to the number of display pixel units 22 in the central region Q1 is A, and the ratio of the number of composite pixel units 11 to the number of display pixel units 22 in the edge region Q2 is B, and A≥B.

[0068] Specifically, when A = B, the composite pixel units 11 and the display pixel units 22 in the radiation flat panel detector 1 are evenly distributed, and the manufacturing process is relatively simple; when A > B, as Figure 7 shown, since during radiation detection, the imaging is mostly located in the central region Q1, the distribution density of the composite pixel units 11 in the central region Q1 of the radiation flat panel detector 1 can be set to be greater than the distribution density of the composite pixel units 11 in the edge region Q2, so as to obtain better accuracy of automatic exposure detection.

[0069] In the above embodiment, the composite pixel units 11 and the display pixel units 22 in the same column share a power supply line V, the composite pixel units 11 in the same column share a first data readout line D1, and the composite pixel units 11 and the display pixel units 22 in the same column share a second data readout line D2.

[0070] The radiation flat panel detector 1 provided in this application further includes a scintillator (not shown in the figure) located on the side of the second insulating layer 33 away from the substrate 10. The scintillator is used to convert radiation into visible light, so as to be sensed by the photosensitive device in the display pixel unit 22, as well as by the photosensitive element and the detection element 132 in the composite pixel unit 11.

[0071] In a feasible embodiment, as Figure 8 shown, the radiation flat panel detector 1 further includes:

[0072] A row scanning driving module 35, connected to each switching element 12 and each switching device 221, for controlling the conduction and cut-off of the switching element 12 and the switching device 221.

[0073] A data readout module 36, connected to each imaging element 131 and each imaging device 222, for reading out the charge signals generated by the imaging element 131 and the imaging device 222.

[0074] A signal control and processing module 37, connected to each detection element 132, for reading out the charge signal of the detection element 132 and for sending an exposure start signal, and sending an exposure termination signal when the number of charges read out by the detection element 132 reaches a preset threshold.

[0075] An image information acquisition module 38, connected to the row scanning driving module 35, the data readout module 36, and the signal control and processing module 37, for, when receiving the exposure start signal sent by the signal control and processing module 37, controlling each switching element 12 and each switching device to turn off through the row scanning driving module 35 to start accumulating charges, and controlling the row scanning driving module 35 and the data readout module 36 to read out the charges after receiving the exposure termination signal sent by the signal control and processing module 37.

[0076] The image information processing and display module 39 is connected to the image information acquisition module 38 and is used for image information processing and display.

[0077] In the above embodiment, the radiation first enters the scintillator, is converted into visible light by the scintillator, and then is sensed by the detection element 132 in the composite pixel unit 11. The signal control and processing module 37 reads out the charge signal of the detection element 132 and sends an exposure start signal to the image information acquisition module 38. After receiving the exposure start signal, the image information acquisition module 38 sends the exposure start signal to the line scan driving module 35. The line scan driving module 35 controls the turn-off of the switching element 12 and the switching device to enable each imaging element 131 and each imaging device 222 to start accumulating charges. When the number of charges read out by the detection element 132 reaches a preset threshold, the signal control and processing module 37 sends an exposure termination signal to the image information acquisition module 38. After receiving the exposure termination signal, the image information acquisition module 38 sends the exposure termination signal to the line scan driving module 35 and the data readout module 36. The data readout module 36 reads out the charge signals generated by the imaging element 131 and the imaging device 222. The image information processing module 39 acquires the charge signals generated by the imaging element 131 and the imaging device 222, and processes and displays the image information, etc.

[0078] It can be understood that, as Figure 9 shown, when the radiation flat panel detector 1 only includes the composite pixel unit 11, in the radiation flat panel detector 1: The line scan driving module 35 is connected to each switching element 12 and is used for controlling the conduction and turn-off of the switching element 12. The data readout module 36 is connected to each imaging element 131 and is used for reading out the charge signal generated by the imaging element 131. The signal control and processing module 37 is connected to each detection element 132, is used for reading out the charge signal of the detection element 132 and for sending an exposure start signal, and sends an exposure termination signal when the number of charges read out by the detection element 132 reaches a preset threshold. The image information acquisition module 38 is connected to the line scan driving module 35, the data readout module 36, and the signal control and processing module 37, and is used for, when receiving the exposure start signal sent by the signal control and processing module 37, controlling the turn-off of each switching element 12 and each switching device through the line scan driving module 35 to start accumulating charges, and controlling the line scan driving module 35 and the data readout module 36 to read out charges after receiving the exposure termination signal sent by the signal control and processing module 37. The image information processing and display module 39 is connected to the image information acquisition module 38 and is used for image information processing and display.

[0079] This application also provides a radiation imaging device 2, as Figure 10 shown, including any one of the radiation flat panel detectors 1 provided in the above embodiments of this application.

[0080] The radiation imaging device 2 further includes a high-voltage generator 21, an X-ray tube (not shown in the figure), etc. The high-voltage generator 21 and the X-ray tube control the output of radiation, and the radiation can be X-rays.

[0081] The radiation imaging device 2 provided in this application includes the radiation flat panel detector 1 provided in this application. A detection element 132 with the function of detecting the start time and end time of radiation exposure is integrated inside the radiation flat panel detector 1 without sacrificing effective pixels, so that while simplifying the device connection, the image quality can be guaranteed, and the performance of the flat panel detector can be taken into account. Furthermore, the imaging effect of the radiation imaging device 2 equipped with the radiation flat panel detector 1 is better, which is more helpful for reducing the difficulty of clinical diagnosis operations and fully ensuring the acquisition of high-quality images, and has a wide application prospect.

[0082] According to the embodiments of the present application as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, according to the above description, many modifications and variations can be made. These embodiments are selected and specifically described in this specification in order to better explain the principle and practical application of the present application, so that those skilled in the art can make good use of the present application and its modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A flat panel detector for radiation, characterized in that, it includes a substrate and a plurality of composite pixel units formed on the substrate, and each of the composite pixel units includes: a switching element formed on the substrate; a conversion component formed on a side of the switching element away from the substrate, including an imaging element and a detection element, and a positive projection of the detection element on the substrate at least partially overlaps a positive projection of the switching element on the substrate; the imaging element includes a first electrode, a first photoelectric conversion layer, and a second electrode, and the detection element includes a first photosensitive transistor that conducts at a high potential and a capacitor; the detection element includes a source-drain layer, a semiconductor layer, a gate insulating layer, a gate layer, a first insulating layer, and a capacitor layer that are stacked in a direction away from the substrate, the first electrode is disposed on the same layer as the source-drain layer, and the second electrode is disposed on the same layer as the capacitor layer.

2. The flat panel detector for radiation according to claim 1, characterized in that, an area of a positive projection of the imaging element on the substrate is larger than an area of a positive projection of the detection element on the substrate.

3. The flat panel detector for radiation according to claim 1, characterized in that, the imaging element includes a first electrode, a first photoelectric conversion layer, and a second electrode; the detection element includes a third electrode, a second photoelectric conversion layer, and a fourth electrode, the first electrode is disposed on the same layer as the third electrode, the first photoelectric conversion layer is disposed on the same layer as the second photoelectric conversion layer, and the second electrode is disposed on the same layer as the fourth electrode.

4. The flat panel detector for radiation according to claim 3, characterized in that, the second electrode and the fourth electrode are integrally formed.

5. The flat panel detector for radiation according to claim 1, characterized in that, it further includes display pixel units, and each of the display pixel units is formed by multiplexing the composite pixel units; or the display pixel units and the composite pixel units are alternately arranged.

6. The flat panel detector for radiation according to claim 1, characterized in that, the detection element includes a second photosensitive transistor that conducts at a low potential.

7. The flat panel detector for radiation according to claim 5, characterized in that, the display pixel units and the composite pixel units have the same opening area, the display pixel units include switching devices and imaging devices, the switching devices are formed on the substrate, and the imaging devices are formed on a side of the switching devices away from the substrate.

8. The flat panel detector for radiation according to claim 7, characterized in that, the flat panel detector for radiation includes a central region and an edge region surrounding the central region, a ratio of the number of the composite pixel units to the number of the display pixel units in the central region is A, and a ratio of the number of the composite pixel units to the number of the display pixel units in the edge region is B, and A≥B.

9. The flat panel detector for radiation according to claim 7 or 8, characterized in that, the flat panel detector for radiation further includes: a row scanning driving module connected to each of the switching elements and each of the switching devices, and configured to control conduction and cutoff of the switching elements and the switching devices; A data reading module, connected to each of the imaging elements and each of the imaging devices, for reading out the charge signals generated by the imaging elements and the imaging devices; A signal control and processing module, connected to each of the detection elements, for reading out the charge signals of the detection elements and for sending an exposure start signal, and sending an exposure termination signal when the number of charges read out by the detection elements reaches a preset threshold; An image information acquisition module, connected to the line scan driving module, the data reading module, and the signal control and processing module, for, when receiving the exposure start signal sent by the signal control and processing module, controlling each of the switching elements and each of the switching devices to turn off through the line scan driving module to start accumulating charges, and controlling the line scan driving module and the data reading module to read out charges after receiving the exposure termination signal sent by the signal control and processing module; An image information processing and display module, connected to the image information acquisition module, for image information processing and display.

10. A radiation imaging device, characterized in that, it includes a radiation flat panel detector according to any one of claims 1-9.

Images