Flat panel detector and X-ray imaging system

Abstract

The invention discloses a flat panel detector and an X-ray imaging system, the flat panel detector comprises a scintillator layer, a microcapsule layer and an image sensor layer, and the scintillator layer is used for converting X-rays into visible light; the microcapsule layer is arranged below the scintillator layer and is used for absorbing part of visible light; the image sensor layer is arranged below the micro-capsule body layer and is used for receiving the visible light passing through the micro-capsule body layer and converting the visible light into an induction current signal; wherein a visible light absorption layer is arranged in the micro-capsule body layer, and the micro-capsule body layer is used for adjusting the thickness of the visible light absorption layer so as to change the absorption capacity of the visible light absorption layer on the visible light. According to the flat panel detector, the thickness of the visible light absorption layer is changed by arranging the micro-capsule layer, so that the phenomenon that the image sensor is prone to overexposure when the light intensity is large is improved, and the detection accuracy of the flat panel detector is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a flat panel detector and an X-ray imaging system. Background Technology

[0002] Flat panel detectors are widely used in medical radiation imaging, industrial flaw detection, security inspection, and other fields. Flat panel detectors that typically use amorphous silicon technology include an image sensor layer, which consists of several pixel-like areas composed of thin-film transistors and photodiodes. Within each pixel area, light is collected by a photodiode and converted into an electrical signal. The thin-film transistor connected to the photodiode reads out each electrical signal, and then an X-ray image is formed using an A / D (analog-to-digital) converter and a low-noise amplifier circuit.

[0003] However, as the PPI of image sensors gradually increases, the pixel area becomes smaller and smaller. When the pixel area gradually decreases, its light receiving and conversion capacity is prone to saturation. This results in the pixel area being unable to detect the corresponding light intensity when the light intensity is high, leading to overexposure. Summary of the Invention

[0004] The purpose of this application is to provide a flat panel detector and an X-ray imaging system that, by setting a microcapsule layer to change the thickness of the visible light absorption layer, improves the overexposure phenomenon that image sensors are prone to when the light intensity is high, thereby enhancing the detection accuracy of the flat panel detector.

[0005] This application discloses a flat panel detector, which includes a scintillator layer, a microcapsule layer, and an image sensor layer. The scintillator layer is used to convert X-rays into visible light. The microcapsule layer is disposed below the scintillator layer and is used to absorb part of the visible light. The image sensor layer is disposed below the microcapsule layer and is used to receive the visible light after it has passed through the microcapsule layer and convert it into an induced current signal. A visible light absorption layer is disposed within the microcapsule layer, and the microcapsule layer is used to adjust the thickness of the visible light absorption layer to change the absorption capacity of the visible light absorption layer for visible light.

[0006] Optionally, the microcapsule layer includes multiple microcapsule portions, each microcapsule portion including an encapsulation capsule and a dispersion liquid, the dispersion liquid being disposed within the encapsulation capsule; the visible light absorption layer includes multiple visible light absorption portions, each of the multiple visible light absorption portions being disposed within the multiple microcapsule portions; wherein, each of the visible light absorption portions includes multiple nanospheres, each of the multiple nanospheres containing a photoelectric conversion material; the multiple nanospheres are disposed within the encapsulation capsule and are used to move within the dispersion liquid to change the thickness of the visible light absorption portion.

[0007] Optionally, the microcapsule portion is provided with a first electrode and a second electrode, the first electrode being a light-transmitting electrode and the second electrode being a non-light-transmitting electrode. The first electrode is disposed on the top or bottom surface of the microcapsule portion, and the second electrode is disposed on the side surface of the microcapsule portion. The plurality of nanospheres have a first electrical property. The first electrode is used to move the nanospheres toward the first electrode when energized, and the second electrode is used to move the nanospheres toward the second electrode when energized. The more nanospheres the first electrode has under the orthographic projection of the image sensor layer, the greater the thickness of the visible light absorbing portion.

[0008] Optionally, when the first electrode is energized and the second electrode is not energized, the nanosphere moves toward the first electrode and is located within the orthogonal projection area of ​​the first electrode in the image sensor layer, and the visible light absorbing portion has a first thickness; when the first electrode is not energized and the second electrode is energized, the nanosphere moves toward the second electrode and is located within the orthogonal projection area of ​​the second electrode in the image sensor layer, and the visible light absorbing portion has a second thickness; the first thickness is greater than the second thickness.

[0009] Optionally, the plurality of nanospheres includes a plurality of first nanospheres and a plurality of second nanospheres, wherein the first nanospheres and the second nanospheres are respectively provided with photoelectric conversion materials; the first nanospheres have a first electrical property, and the second nanospheres have a second electrical property, and a plurality of first nanospheres and a plurality of second nanospheres are respectively disposed in each microcapsule portion; the microcapsule portion is provided with a first electrode and a second electrode, the first electrode being a light-transmitting electrode and the second electrode being a light-blocking electrode, the first electrode being disposed on the top or bottom surface of the microcapsule portion, and the second electrode being disposed on the side surface of the microcapsule portion; the first electrode is used to move the first nanospheres or second nanospheres toward the first electrode when energized, and the second electrode is used to move the second nanospheres or first nanospheres toward the second electrode when energized; the greater the number of first nanospheres and second nanospheres under the orthographic projection of the first electrode onto the image sensor layer, the greater the thickness of the visible light absorbing portion.

[0010] Optionally, the number or size of the first nanospheres and the second nanospheres are the same; the first nanosphere is positively charged, and the second nanosphere is negatively charged.

[0011] Optionally, the first electrode is disposed parallel to the scintillator layer, and the second electrode forms a preset angle with the first electrode, and the preset angle is not 90 degrees; the cross-sectional shape of the microcapsule portion is an isosceles trapezoid, the microcapsule portion has an inclined side surface, and the second electrode is disposed on the side surface of the microcapsule portion.

[0012] Optionally, the first electrode includes a first sub-electrode, a second sub-electrode, and a third sub-electrode, which are disposed on the same layer and are disposed independently of each other.

[0013] Optionally, the image sensor layer is provided with multiple photoelectric sensors and multiple readout switches. The photoelectric sensors are used to receive the visible light and convert the visible light into an electrical signal. The readout switches are used to output the induced current signal. The image sensor layer includes multiple pixel regions, and each pixel region is provided with a photoelectric sensor. Multiple microcapsule portions are provided one-to-one with multiple pixel regions.

[0014] This application also discloses an X-ray imaging system, including an X-ray source, a display device, and the aforementioned flat panel detector, wherein the X-ray source emits X-rays and irradiates the object under test; the flat panel detector receives the X-rays carrying image information of the object under test and converts them into electrical signals; and the display device restores the electrical signals transmitted by the flat panel detector into image information.

[0015] This application incorporates a visible light absorption layer. By absorbing visible light, the intensity of visible light entering the image sensor layer is reduced when light intensity is excessive, thus preventing overexposure. Simultaneously, by controlling the thickness of the visible light absorption layer, it is possible to prevent overexposure when light intensity is low, while actively absorbing visible light when light intensity is high. This application utilizes controlled visible light absorption layer thickness to avoid overexposure caused by excessive light intensity, while still accurately detecting light intensity data even at low light intensities, resulting in accurate image information and improving the applicability, detection accuracy, and anti-interference capabilities of the flat panel detector. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings: Figure 1This is a schematic diagram of a flat panel detector according to the first embodiment of this application; Figure 2 This is a schematic diagram of the image sensor layer of this application; Figure 3 This is a schematic diagram of the microcapsule portion of the first embodiment of this application; Figure 4 This is a schematic diagram of the microcapsule portion of the second embodiment of this application; Figure 5 This is a schematic diagram of the microcapsule portion according to the third embodiment of this application; Figure 6 This is a schematic diagram of the X-ray imaging system of this application.

[0017] Among them, 100 is a flat panel detector; 110 is a scintillator layer; 120 is a microcapsule layer; 121 is a microcapsule portion; 1211 is an encapsulation capsule; 1212 is a dispersion liquid; 122 is a first electrode; 1221 is a first sub-electrode; 1222 is a second sub-electrode; 1223 is a third sub-electrode; 123 is a second electrode; 124 is a light-transmitting area; 125 is a light-blocking area; 130 is a visible light absorption layer; 131 is a visible light absorption portion; 132 is a nanosphere; 1321 is a first nanosphere; 1322 is a second nanosphere; 140 is an image sensor layer; 141 is a pixel area; 142 is a photoelectric sensor; 143 is a readout switch; 200 is an X-ray imaging system; 210 is an X-ray source; and 220 is a display device. Detailed Implementation

[0018] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0019] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms such as "upper," "lower," "left," "right," "vertical," and "horizontal," indicating orientation or positional relationships, are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0021] Figure 1 This is a schematic diagram of the flat panel detector according to the first embodiment of this application. See also: Figure 1 As shown, this application discloses a flat panel detector 100, which includes a scintillator layer 110, a microcapsule layer 120, and an image sensor layer 140. The scintillator layer 110 is used to convert X-rays into visible light. The microcapsule layer 120 is disposed below the scintillator layer 110 and is used to absorb part of the visible light. The image sensor layer 140 is disposed below the microcapsule layer 120 and is used to receive the visible light after passing through the microcapsule layer 120 and convert it into an induced current signal. A visible light absorption layer 130 is disposed within the microcapsule layer 120, and the microcapsule layer 120 is used to adjust the thickness of the visible light absorption layer 130 to change the absorption capacity of the visible light absorption layer 130 for visible light.

[0022] This application relates to an X-ray flat panel detector 100. Since X-rays cannot generally be detected directly, a scintillator layer 110 is needed to convert them into visible light. An image sensor layer 140 is equipped with multiple photoelectric sensors 142. These sensors absorb visible light and convert it into induced current signals (photogenerated carriers). The readout circuit in the image sensor layer 140 reads these induced current signals line by line, thereby reconstructing the image. Within a certain light intensity range, the number of photogenerated carriers in the photoelectric sensors 142 is linearly related to the light intensity, and the output induced current signal increases linearly with increasing light intensity. However, when the light intensity exceeds a certain threshold, the mobile carriers within the photoelectric sensors 142 are fully excited. At this point, even if the light intensity continues to increase, the number of photogenerated carriers cannot increase further, causing the output signal to reach its maximum value and remain stable. In other words, the photoelectric sensors 142 are affected by light intensity; when the light intensity is too high, they may enter a saturation state, thus failing to detect higher light intensities. At this time, the flat panel detector 100 cannot distinguish between different light intensities above the saturation threshold, and the corresponding restored image shows that the area with excessive light intensity is overexposed.

[0023] This application incorporates a visible light absorption layer 130. By absorbing visible light, the intensity of visible light entering the image sensor layer 140 is reduced when light intensity is excessive, preventing overexposure of the image sensor layer 140. Simultaneously, by controlling the thickness of the visible light absorption layer 130, it is designed so that it does not absorb visible light when light intensity is low, but participates in absorbing visible light when light intensity is high, thus preventing overexposure. This application utilizes the controlled thickness of the visible light absorption layer 130 to avoid overexposure caused by excessive light intensity, while still accurately detecting light intensity data even at low light intensities, providing accurate image information and improving the applicability, detection accuracy, and anti-interference capability of the flat panel detector 100.

[0024] Figure 2 This is a schematic diagram of the image sensor layer of this application, see [link / reference]. Figure 2 As shown, the image sensor layer 140 generally includes multiple photoelectric sensors 142 and multiple readout switches 143. The photoelectric sensors 142 are used to receive the visible light and convert it into an electrical signal, and the readout switches 143 are used to output the electrical signal. The image sensor layer 140 includes multiple pixel areas 141, and each pixel area 141 is provided with a photoelectric sensor 142. The multiple photoelectric sensors 142 and multiple readout switches 143 are generally arranged in an array, located in the multiple pixel areas 141 respectively. The image sensor layer 140 is also provided with multiple control lines and multiple readout lines, with two adjacent control lines and two adjacent readout lines forming a pixel area 141. Multiple rows of control lines are turned on row by row, so that the readout switches 143 of multiple pixel areas 141 transmit the induced current signal to the readout lines, and multiple columns of data lines output the induced current signal.

[0025] The photoelectric sensor 142 in this embodiment can be a photodiode, also known as a PIN photodiode. A PIN photodiode is a three-layer structure device consisting of an intrinsic layer (I) sandwiched between heavily doped P and N layers. A window is provided on the metal surface to receive visible light. Thinning the top semiconductor region helps reduce the absorption of light by this layer. The width of the intrinsic layer (I) can be reasonably designed according to actual conditions. For example, by controlling the width of the I layer to be equal to the reciprocal of the absorption coefficient of the wavelength to be measured, the maximum response of the device in that wavelength band can be achieved. Since most of the photocurrent is generated in the I layer region, its frequency response speed is much greater than that of a traditional PN junction photodetector. In the depleted I layer region, the presence of a strong electric field ε enables efficient and rapid separation and collection of photogenerated carriers, thereby obtaining a high-frequency response.

[0026] Figure 3This is a schematic diagram of the microcapsule portion of the first embodiment of this application, see [link / reference]. Figure 3 In this embodiment, the microcapsule layer 120 includes a plurality of microcapsule portions 121, each microcapsule portion 121 comprising an encapsulation capsule 1211 and a dispersion liquid 1212, the dispersion liquid 1212 being disposed within the encapsulation capsule 1211; the visible light absorption layer 130 includes a plurality of visible light absorption portions 131, each of which is disposed within a plurality of microcapsule portions 121, generally within the encapsulation capsule 1211, and movable within the dispersion liquid 1212. Each of the plurality of microcapsule portions corresponds one-to-one with a plurality of pixel regions, meaning that on the orthographic projection of the scintillator layer, one microcapsule portion overlaps with one pixel region. Alternatively, one microcapsule portion can correspond to multiple pixel regions to reduce complexity.

[0027] Specifically, each visible light absorbing part 131 includes a plurality of nanospheres 132, and each of the nanospheres 132 contains a photoelectric conversion material; the nanospheres 132 are disposed within the encapsulation capsule 1211 and are used to move within the dispersion liquid 1212 to change the thickness of the visible light absorbing part 131.

[0028] The dispersion 1212 is encapsulated inside the encapsulation capsule 1211 and is typically an alkane solvent with high insulation and low viscosity. This characteristic allows the charged nanospheres 132 located in the dispersion 1212 to move directionally under electrode control. The microcapsule portion 121 used in this embodiment is a microcapsule in electronic paper display technology, which typically encapsulates a dispersion medium and two types of electrophoretic particles with opposite charges within a polymer capsule. Through the control of an electric field, the particles are subjected to a balance effect of van der Waals forces, electrostatic forces, etc., resulting in a relatively uniform or fixed distribution in the dispersion medium, thereby achieving the function of absorbing light.

[0029] In this embodiment, the thickness of the nanospheres 132 along the visible light propagation path is controlled, thereby increasing the thickness of the visible light absorption section 131 along the visible light propagation path. This enhances the absorption capacity of the visible light absorption section 131, especially when overexposure may occur due to high light intensity. By increasing the thickness of the visible light absorption section 131, the absorption of visible light with high intensity can be achieved.

[0030] In this embodiment, the nanosphere 132 contains a photoelectric conversion material, which can be gallium arsenide photoelectric conversion material. In one embodiment, each nanosphere 132 contains the same mass or quantity of photoelectric conversion material, and each nanosphere 132 has the same radial width or size.

[0031] The thickness of the visible light absorbing portion 131 is primarily determined by controlling the number of nanospheres 132 via electrodes. The visible light absorbing portion 131 includes a light-transmitting region 124 and a non-light-transmitting region 125, with the non-light-transmitting region 125 surrounding the light-transmitting region 124. A greater number of nanospheres 132 in the light-transmitting region 124 of the visible light absorbing portion 131, corresponding to a thicker visible light absorbing portion 131, and a smaller number of nanospheres 132 in the non-light-transmitting region 125, corresponds to a thinner visible light absorbing portion 131, and a greater number of nanospheres 132 in the non-light-transmitting region 125. The thickness of the visible light absorbing portion 131 referred to in this application actually represents the photoelectric conversion material, specifically the absorption capacity of the light-transmitting region 124 for visible light.

[0032] In this embodiment, the microcapsule portion 121 can adopt a steady-state control structure, that is, when a voltage is applied to the electrode, the nanosphere 132 moves, and after the voltage is removed, the nanosphere 132 can maintain its current state. The thickness of the visible light absorbing portion 131 can be set to its maximum or minimum when no electrode is applied, so that the thickness of the visible light absorbing portion 131 decreases or increases after an electric field is applied.

[0033] In one embodiment, the microcapsule portion 121 is provided with a first electrode 122 and a second electrode 123. The first electrode 122 is a light-transmitting electrode, and the second electrode 123 is a light-blocking electrode. The first electrode 122 is disposed on the top or bottom surface of the microcapsule portion 121, and the second electrode 123 is disposed on the side surface of the microcapsule portion 121. A plurality of nanospheres 132 have a first electrical property. The first electrode 122 is used to move the nanospheres 132 closer to the first electrode 122 when energized, and the second electrode 123 is used to move the nanospheres 132 closer to the second electrode 123 when energized. The more nanospheres 132 under the orthographic projection of the first electrode 122 onto the image sensor layer 140, the greater the thickness of the visible light absorbing portion 131. It is understood that the second electrode 123 is disposed in the light-blocking region 125, and the first electrode 122 is disposed in the light-transmitting region 124.

[0034] In this embodiment, all nanospheres 132 can have a first electrical charge, and the first electrode 122 can be positively or negatively charged. The first electrode 122 and the second electrode 123 are negatively or positively charged, respectively, and have an attractive effect on the nanospheres 132. The charge intensity on the first electrode 122 and the second electrode 123 is adjustable. When a larger thickness of the visible light absorbing portion 131 is required, the voltage of the first electrode 122 is increased, attracting more nanospheres 132 to the light-transmitting region 124. At this time, the voltage of the second electrode 123 can be reduced or made to a zero voltage state. When a smaller thickness of the visible light absorbing portion 131 is required, the voltage of the first electrode 122 is decreased, and the voltage of the second electrode 123 is increased, attracting more nanospheres 132 to the non-light-transmitting region 125. By changing the voltage of the first electrode 122 and the second electrode 123, the thickness of the visible light absorbing portion 131 is controlled, thereby controlling the absorption capacity of visible light.

[0035] Specifically, when the first electrode 122 is energized and the second electrode 123 is not energized, the nanosphere 132 moves towards the first electrode 122 and is located within the orthogonal projection area of ​​the first electrode 122 in the image sensor layer 140, and the visible light absorbing portion 131 has a first thickness. When the first electrode 122 is not energized and the second electrode 123 is energized, the nanosphere 132 moves towards the second electrode 123 and is located within the orthogonal projection area of ​​the second electrode 123 in the image sensor layer 140, and the visible light absorbing portion 131 has a second thickness. The first thickness is greater than the second thickness.

[0036] When the second electrode 123 is not energized, all the nanospheres 132 are attracted to the light-transmitting region 124, resulting in the maximum thickness of the visible light absorption section 131, i.e., the first thickness is the maximum thickness of the visible light absorption section 131. When the first electrode 122 is not energized, all the nanospheres 132 are attracted to the light-transmitting region 124, resulting in the minimum thickness of the visible light absorption section 131, i.e., the second thickness is the minimum thickness of the visible light absorption section 131. By energizing the first electrode 122 and the second electrode 123 respectively, and controlling the voltage of the first electrode 122 and the second electrode 123, the thickness of the visible light absorption section 131 can vary between the first thickness and the second thickness.

[0037] Figure 4 This is a schematic diagram of the microcapsule portion of the second embodiment of this application, see below. Figure 4As shown, in this embodiment, controlling the thickness of the visible light absorbing portion 131 of the light-transmitting region 124 solely by voltage magnitude is quite complex. Furthermore, even under the same voltage, the thickness of the visible light absorbing portion 131 can vary at different locations of the microcapsule portion 121. Therefore, in this embodiment, the nanospheres 132 are divided into positively charged nanospheres 132 and negatively charged nanospheres 132.

[0038] Specifically, the plurality of nanospheres 132 include a plurality of first nanospheres 1321 and a plurality of second nanospheres 1322, wherein the first nanospheres 1321 and the second nanospheres 1322 are respectively provided with photoelectric conversion materials; the first nanospheres 1321 have a first electrical property, and the second nanospheres 1322 have a second electrical property, and a plurality of first nanospheres 1321 and a plurality of second nanospheres 1322 are respectively disposed within each microcapsule portion 121. The following description uses an example where the first electrode 122 is positively charged and the second electrode 123 is negatively charged.

[0039] Furthermore, the microcapsule portion 121 is provided with a first electrode 122 and a second electrode 123. The first electrode 122 is a light-transmitting electrode, and the second electrode 123 is a non-light-transmitting electrode. The first electrode 122 is disposed on the top or bottom surface of the microcapsule portion 121, and the second electrode 123 is disposed on the side surface of the microcapsule portion 121. The first electrode 122 is used to move the first nanosphere 1321 or the second nanosphere 1322 closer to the first electrode 122 when energized, and the second electrode 123 is used to move the second nanosphere 1322 or the first nanosphere 1321 closer to the second electrode 123 when energized. The more first nanospheres 1321 and second nanospheres 1322 under the orthogonal projection of the first electrode 122 onto the image sensor layer 140, the greater the thickness of the visible light absorbing portion 131.

[0040] In this embodiment, by assigning different electrical values ​​to the first electrode 122 and the second electrode 123, the first electrode 122 and the second electrode 123 are made to have different electric fields, thereby controlling the two nanospheres 132 with different electrical values ​​to selectively perform directional movements.

[0041] Specifically, when no electric field is applied to the first electrode 122 and the second electrode 123, the plurality of first nanospheres 1321 and the plurality of second nanospheres 1322 are in the dispersion liquid 1212 within the encapsulation capsule 1211 and are located in the light-transmitting region 124, in their initial state. At this time, the visible light absorbing portion 131 has the largest thickness and the strongest absorption capacity for visible light. When different electric fields are applied to the first electrode 122 and the second electrode 123, for example, a positive voltage is applied to the first electrode 122 and a negative voltage is applied to the second electrode 123, the negatively charged second nanospheres 1322 move towards the first electrode 122, and the positively charged first nanospheres 1321 move towards the second electrode 123. At this time, the first nanospheres 1321 move to the light-transmitting region 124, and the second nanospheres 1322 move to the non-light-transmitting region 125. The thickness of the visible light absorbing portion 131 is equal to the thickness of the plurality of first nanospheres 1321. When the opposite electric fields are applied to the first electrode 122 and the second electrode 123, the second nanosphere 1322 will move to the light-transmitting region 124, and the first nanosphere 1321 will move to the non-light-transmitting region 125. The thickness of the visible light absorbing part 131 is equal to the thickness of the plurality of second nanospheres 1322.

[0042] In this embodiment, by setting different numbers of first nanospheres 1321 and second nanospheres 1322, two different thicknesses of visible light absorbing portion 131 can be defined. That is, by controlling the first electrode 122 and the second electrode 123, the visible light absorbing portion 131 can have three thickness variations, including the initial state, thereby achieving different degrees of light absorption capacity. It is understood that the aforementioned non-transparent region 125 needs sufficient space to store the first nanospheres 1321 or the second nanospheres 1322, preventing them from entering the transparent region 124.

[0043] In one specific embodiment, the first electrode 122 is disposed parallel to the scintillator layer 110, and the second electrode 123 forms a preset angle with the first electrode 122, wherein the preset angle is not 90 degrees; the microcapsule portion 121 has an isosceles trapezoidal cross-sectional shape and has an inclined side surface, and the second electrode 123 is disposed on the side surface of the microcapsule portion 121. Specifically, the microcapsule portion 121 has an isosceles trapezoidal cross-sectional shape, and the surface area of ​​the microcapsule portion 121 on the side away from the image sensor layer 140 is smaller than the surface area of ​​the microcapsule portion 121 on the side closer to the image sensor layer 140.

[0044] In this embodiment, by tilting the side of the microcapsule portion 121, a second electrode 123 is disposed on the side. This opaque second electrode 123 can block visible light from entering, thereby forming an opaque region 125. It is understood that two first electrodes 122 can be disposed, one on the side of the microcapsule portion 121 away from the image sensor layer 140 and the other on the side of the microcapsule portion 121 closer to the image sensor layer 140. Correspondingly, four second electrodes 123 can be disposed, located on the four sides of the microcapsule portion 121.

[0045] Figure 5 This is a schematic diagram of the microcapsule portion of the third embodiment of this application, see below. Figure 5 As shown, in this embodiment, based on the second embodiment, the first electrode 122 is further designed so that the first electrode 122 includes multiple independently powered sub-electrodes, and the thickness of the visible light absorption part 131 is changed by providing an electric field to each sub-electrode.

[0046] Specifically, the first electrode 122 includes a first sub-electrode 1221, a second sub-electrode 1222, and a third sub-electrode 1223. These three sub-electrodes are disposed on the same layer and are independently configured. In this embodiment, the first electrode 122 is configured as three sub-electrodes, and power is supplied to each of the first, second, and third sub-electrodes 1221 and 1222, respectively. For example, the first, second, and third sub-electrodes 1221 and 1222, and 1223, respectively, carry positive and negative voltages, thereby ensuring that the first nanosphere 1321 and the second nanosphere 1322 are simultaneously located in the light-transmitting region 124.

[0047] The first sub-electrode 1221 is disposed between the second sub-electrode 1222 and the third sub-electrode 1223.

[0048] In this embodiment, the number or size of the first nanosphere 1321 and the second nanosphere 1322 can also be the same. Specifically, the first nanosphere 1321 and the second nanosphere 1322 have the same size, and the mass or quantity of the photoelectric conversion material in the first nanosphere 1321 and the second nanosphere 1322 are the same, the only difference being their electrical properties.

[0049] Specifically, when no electric field is applied to the first electrode 122 and the second electrode 123, the plurality of first nanospheres 1321 and the plurality of second nanospheres 1322 are in the dispersion liquid 1212 within the encapsulation capsule 1211 and are located in the light-transmitting region 124, in their initial state. At this time, the visible light absorbing portion 131 has the largest thickness, denoted as the first thickness, and has the strongest absorption capacity for visible light.

[0050] When different electric fields are applied to the first electrode 122 and the second electrode 123, for example, a positive voltage is applied to the first electrode 122 and a negative voltage is applied to the second electrode 123, while the first sub-electrode 1221, the second sub-electrode 1222, and the third sub-electrode 1223 of the first electrode 122 are applied the same voltage, the negatively charged second nanosphere 1322 moves towards the first electrode 122, and the positively charged first nanosphere 1321 moves towards the second electrode 123. At this time, the first nanosphere 1321 moves to the light-transmitting region 124, and the second nanosphere 1322 moves to the opaque region 125. The thickness of the visible light absorbing part 131 is equal to the thickness of the plurality of first nanospheres 1321. When the aforementioned opposing electric fields are applied to the first electrode 122 and the second electrode 123, the second nanospheres 1322 move to the light-transmitting region 124, and the first nanospheres 1321 move to the non-light-transmitting region 125. The thickness of the visible light absorbing portion 131 is equal to the thickness of the plurality of second nanospheres 1322. Since the number and mass of the first nanospheres 1321 and the second nanospheres 1322 are the same, the thickness of the plurality of first nanospheres 1321 is equal to the thickness of the plurality of second nanospheres 1322, and this thickness is taken as the third thickness.

[0051] When a negative electric field is applied to the first sub-electrode 1221, and positive electric fields are applied to the second sub-electrode 1222 and the third sub-electrode 1223 respectively, and the second electrode 123 is applied with a negative electric field, some of the positively charged first nanospheres 1321 will be attracted by the first sub-electrode 1221, causing the first nanospheres 1321 and the second nanospheres 1322 in the light-transmitting region 124 to coexist, thereby increasing the thickness of the visible light absorbing portion 131. This thickness is greater than the third thickness and can be referred to as the fourth thickness.

[0052] When a positive electric field is applied to the first sub-electrode 1221, and negative electric fields are applied to the second sub-electrode 1222 and the third sub-electrode 1223 respectively, and the second sub-electrode 123 applies a negative electric field, at this time, due to the action of the second sub-electrode 1222 and the third sub-electrode 1223, more first nanospheres 1321 enter the light-transmitting region 124, making the thickness of the visible light absorbing part 131 thicker, which is greater than the fourth thickness and less than the first thickness.

[0053] In another embodiment, the visible light absorption section 131 can have a more controllable thickness by setting a greater number of sub-electrodes, which is not limited herein.

[0054] Figure 6 This is a schematic diagram of the X-ray imaging system of this application, see [link / reference]. Figure 6As shown, this application also discloses an X-ray imaging system 200, which includes an X-ray source 210, a display device 220, and the aforementioned flat panel detector 100. The X-ray source 210 emits X-rays and irradiates the object under test; the flat panel detector 100 receives X-rays carrying image information of the object under test and converts them into electrical signals; the display device 220 restores the electrical signals transmitted by the flat panel detector 100 into image information.

[0055] In this embodiment, the flat panel detector 100 can be used solely for detection, while the display can be externally connected to the display device 220. Alternatively, the display device 220 can be built into the flat panel detector 100. The X-ray imaging system primarily emits X-rays from an X-ray source. When the X-rays pass through different objects being measured, they have different intensities. The scintillator layer 110 mainly converts the aforementioned X-rays into visible light of different intensities. This visible light at different locations carries information about the object being measured. Finally, the visible light is sensed by an image sensor, and the sensed image is displayed by a display device.

[0056] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0057] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A flat panel detector, characterized in that, The flat panel detector includes: Scintillator layer, used to convert X-rays into visible light; The microcapsule layer, located beneath the scintillator layer, is used to absorb some visible light; An image sensor layer, disposed below the microcapsule layer, is used to receive the visible light after it passes through the microcapsule layer and convert it into an induced current signal; The microcapsule layer contains a visible light absorption layer, and the microcapsule layer is used to adjust the thickness of the visible light absorption layer to change the absorption capacity of the visible light absorption layer for visible light.

2. The flat panel detector according to claim 1, characterized in that, The microcapsule layer includes multiple microcapsule portions, each microcapsule portion including an encapsulation capsule and a dispersion liquid, the dispersion liquid being disposed within the encapsulation capsule; The visible light absorption layer includes a plurality of visible light absorption portions, and the plurality of visible light absorption portions are respectively disposed within the plurality of microcapsule portions; Each of the visible light absorbing portions includes multiple nanospheres, and each of the multiple nanospheres is provided with a photoelectric conversion material; Multiple nanospheres are disposed within the encapsulation capsule and are used to move within the dispersion to change the thickness of the visible light absorbing portion.

3. The flat panel detector according to claim 2, characterized in that, The microcapsule portion is provided with a first electrode and a second electrode. The first electrode is a light-transmitting electrode, and the second electrode is a non-light-transmitting electrode. The first electrode is disposed on the top or bottom surface of the microcapsule portion, and the second electrode is disposed on the side surface of the microcapsule portion. The nanospheres described herein possess a first electrical property; The first electrode is used to move the nanosphere closer to the first electrode when energized, and the second electrode is used to move the nanosphere closer to the second electrode when energized. The more nanospheres the first electrode has under the orthographic projection of the image sensor layer, the greater the thickness of the visible light absorbing portion.

4. The flat panel detector according to claim 3, characterized in that, When the first electrode is energized and the second electrode is not energized, the nanosphere moves toward the first electrode and is located within the orthogonal projection area of ​​the first electrode in the image sensor layer, and the visible light absorbing part has a first thickness. When the first electrode is not energized and the second electrode is energized, the nanosphere moves toward the second electrode and is located in the orthogonal projection area of ​​the second electrode in the image sensor layer, and the visible light absorbing part has a second thickness. The first thickness is greater than the second thickness.

5. The flat panel detector according to claim 2, characterized in that, The plurality of nanospheres includes a plurality of first nanospheres and a plurality of second nanospheres, wherein the first nanospheres and the second nanospheres are respectively provided with photoelectric conversion materials; The first nanosphere has a first electrical property, and the second nanosphere has a second electrical property. A plurality of first nanospheres and a plurality of second nanospheres are respectively disposed in each of the microcapsule portions. The microcapsule portion is provided with a first electrode and a second electrode. The first electrode is a light-transmitting electrode, and the second electrode is a non-light-transmitting electrode. The first electrode is disposed on the top or bottom surface of the microcapsule portion, and the second electrode is disposed on the side surface of the microcapsule portion. The first electrode is used to cause the first nanosphere or the second nanosphere to move toward the first electrode when energized, and the second electrode is used to cause the second nanosphere or the first nanosphere to move toward the second electrode when energized. The more first nanospheres and second nanospheres the first electrode has under the orthogonal projection of the image sensor layer, the greater the thickness of the visible light absorbing portion.

6. The flat panel detector according to claim 5, characterized in that, The number or size of the first nanospheres are the same as those of the second nanospheres; The first electrical property is positive, and the second electrical property is negative.

7. The flat panel detector according to claim 3 or 5, characterized in that, The first electrode is disposed parallel to the scintillator layer, and the second electrode forms a preset angle with the first electrode, wherein the preset angle is not 90 degrees. The cross-sectional shape of the microcapsule is an isosceles trapezoid, and the microcapsule has an inclined side surface. The second electrode is disposed on the side surface of the microcapsule.

8. The flat panel detector according to claim 5, characterized in that, The first electrode includes a first sub-electrode, a second sub-electrode, and a third sub-electrode. The first sub-electrode, the second sub-electrode, and the third sub-electrode are disposed on the same layer and are disposed independently of each other.

9. The flat panel detector according to claim 2, characterized in that, The image sensor layer is provided with multiple photoelectric sensors and multiple readout switches. The photoelectric sensors are used to receive the visible light and convert the visible light into electrical signals. The readout switches are used to output the induced current signal. The image sensor layer includes multiple pixel regions, and each pixel region is provided with a photoelectric sensor. Each of the microcapsule portions is arranged in a one-to-one correspondence with a plurality of pixel regions.

10. An X-ray imaging system, characterized in that, The device includes an X-ray source, a display device, and a flat panel detector as described in any one of claims 1-9, wherein the X-ray source emits X-rays and irradiates the object under test; the flat panel detector receives the X-rays carrying image information of the object under test and converts them into electrical signals; and the display device restores the electrical signals transmitted by the flat panel detector into image information.

Images