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 and an image sensor layer, the image sensor layer comprises a peripheral area, a transition area and a middle area, the peripheral area is arranged around the transition area, and the transition area is arranged around the middle area; the peripheral area is provided with at least one column of first pixel areas, and the transition area is provided with a plurality of second pixel areas; each first pixel area is only provided with a first photosensitive area, and the first photoelectric sensor is arranged in the first photosensitive area; each second pixel region comprises a second photosensitive region and a first non-photosensitive region; the second photoelectric sensor is arranged in the second photosensitive area, and the second read-out switch is arranged in the first non-photosensitive area; wherein the first readout switch is arranged in the first non-photosensitive area of the second pixel area. The first reading switch originally arranged in the peripheral area is moved into the transition area, so that the first reading switch caused by water vapor invasion in the peripheral area is avoided, and the problem that the first reading switch is prevented from being invaded by the water vapor is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a flat panel detector and an X-ray imaging system. BACKGROUND

[0002] The flat panel detector is widely used in medical radiation molding, industrial flaw detection, security check and other fields. The flat panel detector adopting amorphous silicon technology generally comprises an image sensor layer, which is composed of a plurality of pixel regions similar to pixels composed of thin film transistors and photodiodes. Each pixel region collects light through a photodiode and converts it into an electrical signal, and each electrical signal is read out by a thin film transistor connected to the photodiode, and then an X-ray image is formed by the action of an A / D (analog / digital) conversion element and a low-noise amplifier circuit.

[0003] In this process, the thin film transistor is easily affected by water vapor, resulting in inconsistent photoelectric conversion efficiency in different pixel regions, especially the peripheral pixel regions of the flat panel detector are easily invaded by water vapor, resulting in differences in image conversion accuracy of the peripheral pixel regions, etc., causing poor imaging accuracy of the flat panel detector. SUMMARY

[0004] The purpose of the present application is to provide a flat panel detector and an X-ray imaging system, by moving the first readout switch originally arranged in the peripheral region to the transition region, avoiding the problem that the first readout switch is invaded by water vapor in the peripheral region, and protecting the first readout switch from being invaded by water vapor.

[0005] The present application discloses a flat panel detector, comprising a scintillator layer and an image sensor layer, the scintillator layer is used for converting X-rays into visible light, the image sensor layer is provided with a plurality of photoelectric sensors and a plurality of readout switches, the photoelectric sensor is used for receiving the visible light and converting the visible light into an electrical signal, and the readout switch is used for outputting the electrical signal; the photoelectric sensor comprises a first photoelectric sensor and a second photoelectric sensor, and the readout switch comprises a first readout switch and a second readout switch; the image sensor layer comprises a peripheral region, a transition region and a middle region, the peripheral region is arranged around the transition region, and the transition region is arranged around the middle region; the peripheral region is provided with at least one column of first pixel regions, and the transition region is provided with a plurality of second pixel regions; each first pixel region is provided with only a first light-sensitive region, and the first photoelectric sensor is arranged in the first light-sensitive region; each second pixel region comprises a second light-sensitive region and a first non-light-sensitive region; the second photoelectric sensor is arranged in the second light-sensitive region, and the second readout switch is arranged in the first non-light-sensitive region; wherein the first readout switch is arranged in the first non-light-sensitive region of the second pixel region.

[0006] Optionally, only one first readout switch and one second readout switch are arranged in each first non-light-sensing region; the intermediate region is provided with a plurality of third pixel regions, each third pixel region comprising a third light-sensing region and a second non-light-sensing region, and the second non-light-sensing region is provided with a third readout switch, and the third light-sensing region is provided with a third photoelectric sensor.

[0007] Optionally, the width of the peripheral region is between 1 mm and 2 mm, and the width of the transition region is equal to the width of the peripheral region.

[0008] Optionally, the area of the first light-sensing region, the area of the second light-sensing region, and the area of the third light-sensing region are equal.

[0009] Optionally, the area of the third light-sensing region is greater than the area of the second light-sensing region, and the area of the second non-light-sensing region is less than the area of the first non-light-sensing region; the first non-light-sensing region is provided with a light displacement structure, and the light displacement structure is used to displace the visible light entering the first non-light-sensing region to the second light-sensing region in the same second pixel region.

[0010] Optionally, the second light-sensing region comprises a first sub-light-sensing region and a second sub-light-sensing region, and the light displacement structure is used to displace the visible light entering the first non-light-sensing region to the first sub-light-sensing region and the second sub-light-sensing region in the same second pixel region; the light displacement structure comprises a displacement composite layer, the displacement composite layer is arranged between the scintillator layer and the image sensor layer, and the displacement composite layer is used to displace under the control of an electrical signal, so that the visible light entering the first non-light-sensing region is displaced and enters the first sub-light-sensing region and the second sub-light-sensing region, respectively.

[0011] Optionally, the displacement composite layer comprises a displacement driving structure, a displacement film, and an elastic material layer, the displacement film is clamped in the elastic material layer, the displacement driving structure is arranged at both ends of the displacement film, and is used to drive the displacement film to displace in the elastic material layer, so that the normal direction of the displacement film forms a preset angle with the normally incident light emitted by the scintillator layer, and the preset angle is greater than 0 degrees; the elastic material layer is used to make the displacement film parallel to the scintillator layer when the displacement film is in an initial state or the displacement driving structure is not working; the refractive index of the displacement film is greater than the refractive index of the elastic material layer, and the displacement film is used to refract the visible light entering the first non-light-sensing region to the first sub-light-sensing region and the second sub-light-sensing region.

[0012] Optionally, the flat panel detector further comprises a plurality of humidity sensors, the humidity sensors are arranged in the first non-photosensitive area, the humidity sensors are used for sensing the humidity in the first non-photosensitive area, and the light conversion rate of the second readout switch in the first non-photosensitive area is calculated according to the humidity in the first non-photosensitive area.

[0013] Optionally, the flat panel detector comprises a plurality of scanning lines and a plurality of data lines, in the same first non-photosensitive area, the control end of the first readout switch and the control end of the second readout switch are respectively connected to the same scanning line; the output end of the first readout switch and the output end of the second readout switch are respectively connected to different data lines.

[0014] The application further discloses an X-ray imaging system, comprising an X-ray source, a display device and the flat panel detector, wherein the X-ray source emits X-rays and irradiates on a measured object; the flat panel detector receives the X-rays with image information of the measured object and converts the X-rays into electric signals; and the display device restores the electric signals transmitted by the flat panel detector into image information.

[0015] The application sets the first readout switch corresponding to the pixel area of the peripheral area in the transition area, that is, moves the first readout switch originally arranged in the peripheral area into the transition area, avoids the problem that the first readout switch is invaded by water vapor in the peripheral area, and protects the first readout switch from being invaded by water vapor. In the process that the light signal received by the first photoelectric sensor in the peripheral area is read out by the first readout switch after being converted into an electric signal, the problem that the data converted by the first photoelectric sensor is missing or inaccurate due to the influence of the first readout switch being invaded by water vapor is avoided. Therefore, the problem that the imaging quality of the peripheral area and other areas appear large differences due to the different electric signal conversion efficiency of the first readout switch affected by water vapor is avoided, and the detection precision of the flat panel detector is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings included to provide a further understanding of the embodiments of the application, constitute a part of the specification and are used to illustrate the embodiments of the application together with the text description. Obviously, the drawings in the following description only show some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort. In the drawings:

[0017] Figure 1 is a schematic diagram of a flat panel detector of the first embodiment of the application;

[0018] Figure 2 is a schematic diagram of an image sensor layer of the first embodiment of the application;

[0019] Figure 3 is a schematic diagram of another image sensor layer of the first embodiment of the present application;

[0020] Figure 4 is a schematic diagram of a data line shared by a first readout switch and a second readout switch of the first embodiment of the present application;

[0021] Figure 5 is a top view schematic diagram of a flat panel detector of the second embodiment of the present application;

[0022] Figure 6 is a cross-sectional schematic diagram of a light ray displacement structure of the second embodiment of the present application;

[0023] Figure 7 is a displacement schematic diagram of a light ray passing through a displacement film of the present application;

[0024] Figure 8 is a schematic diagram of a flat panel detector of the third embodiment of the present application;

[0025] Figure 9 is a schematic diagram of an X-ray imaging system of the present application.

[0026] wherein, 100, flat panel detector; 101, peripheral region; 102, transition region; 103, middle region; 110, scintillator layer; 120, image sensor layer; 121, scan line; 122, data line; 130, first pixel region; 1301, first photosensitive region; 131, first photosensor; 132, first readout switch; 140, second pixel region; 1401, second photosensitive region; 1401a, first sub-photosensitive region; 1401b, second sub-photosensitive region; 1402, first non-photosensitive region; 141, second photosensor; 142, second readout switch; 150, third pixel region; 1501, third photosensitive region; 1502, second non-photosensitive region; 151, third photosensor; 152, third readout switch; 160, light ray displacement structure; 161, displacement driving structure; 162, displacement film; 163, elastic material layer; 170, humidity sensor; 200, X-ray imaging system; 210, X-ray source; 220, display device. DETAILED DESCRIPTION

[0027] It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless otherwise indicated.

[0028] In the description of the present application, the terms "first", "second", are only used for the purpose of description, and cannot be understood as indicating relative importance, or implying the number of the indicated technical features. Therefore, unless otherwise specified, the features defined with "first", "second" can explicitly or implicitly include one or more of the features; the meaning of "multiple" is two or more. In addition, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "vertical", "horizontal", etc. are described based on the orientation or relative position relationship shown in the drawings, only for the convenience of the simplified description of the present application, and do not indicate that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments.

[0030] Figure 1 is a schematic diagram of a flat panel detector of the first embodiment of the present application, Figure 2 is a schematic diagram of an image sensor layer of the first embodiment of the present application, Figure 3 is a schematic diagram of another image sensor layer of the first embodiment of the present application, see Figures 1 to 3As shown, the present application discloses a flat panel detector 100, which comprises a scintillator layer 110 for converting X-rays into visible light and an image sensor layer 120 provided with a plurality of photoelectric sensors for receiving visible light and converting the visible light into electrical signals and a plurality of readout switches for outputting the electrical signals; the photoelectric sensors comprise first photoelectric sensors 131 and second photoelectric sensors 141, and the readout switches comprise first readout switches 132 and second readout switches 142; the image sensor layer 120 comprises a peripheral region 101, a transition region 102 and a middle region 103, the peripheral region 101 is arranged around the transition region 102, and the transition region 102 is arranged around the middle region 103; the peripheral region 101 is provided with at least one column of first pixel regions 130, and the transition region 102 is provided with a plurality of second pixel regions 140; each first pixel region 130 is provided with only a first light-sensitive region 1301, and the first photoelectric sensor 131 is arranged in the first light-sensitive region 1301; each second pixel region 140 comprises a second light-sensitive region 1401 and a first non-light-sensitive region 1402; the second photoelectric sensor 141 is arranged in the second light-sensitive region 1401, and the second readout switch 142 is arranged in the first non-light-sensitive region 1402; wherein the first readout switch 132 is arranged in the first non-light-sensitive region 1402 of the second pixel region 140.

[0031] By arranging the first readout switch 132 corresponding to the pixel region of the peripheral region 101 in the transition region 102, i.e. by moving the first readout switch 132 originally arranged in the peripheral region 101 into the transition region 102, the problem of water vapor invasion into the first readout switch 132 in the peripheral region 101 is avoided, and the first readout switch 132 is protected from water vapor invasion. In the process of reading out the electrical signal converted by the first photoelectric sensor 131 in the peripheral region 101 after receiving the light signal, the problem of missing or inaccurate data converted by the first photoelectric sensor 131 due to the influence of water vapor invasion on the first readout switch 132 is avoided. Thus, the problem of large difference in imaging quality between the peripheral region 101 and other regions caused by different electrical signal conversion efficiencies of the first readout switch 132 affected by water vapor is avoided, and the detection accuracy of the flat panel detector 100 is improved.

[0032] It is worth mentioning that the first photoelectric sensor 131 is connected to the first readout switch 132, and the second photoelectric sensor 141 is connected to the second readout switch 142 in the present application. In the exemplary technology, the first photoelectric sensor 131 and the first readout switch 132 are generally arranged in the same pixel area, i.e., the first pixel area 130 mentioned above. The present application moves the position of the first readout switch 132 to reduce the possibility of water vapor invading the first readout switch 132, thereby protecting the first readout switch 132. The readout switch mentioned in the present application is generally a thin film transistor. By controlling the gate voltage of the thin film transistor, the photoelectric signal sensed by the photoelectric sensor can be transmitted to the processing module through the thin film transistor. The processing module can be a data processing module in an X-ray imaging system. After the data processing module processes the photoelectric signal, the photoelectric signal is transmitted to a display device in the X-ray imaging system for display. Of course, the flat panel detector 100 in the present embodiment can also have display function, realizing the function of scanning and displaying at the same time.

[0033] In the present application, the peripheral area 101 refers to an area arranged around the middle area 103. This area is most likely to be invaded by water vapor because it is located at the outermost side of the flat panel detector 100, which causes the problem of change in light readout efficiency of the first readout switch 132 in the peripheral area 101 after being invaded by water vapor. For the first pixel area 130 in the peripheral area 101, a circle arranged around the transition area 102 is a column. Multiple circles of pixel areas arranged around the transition area 102 are considered as multiple columns in the subsequent description. Among them, the column of first pixel areas 130 farthest from the transition area 102 can be called the outermost first pixel area 130, and the column of first pixel areas 130 closest to the transition area 102 can be called the innermost first pixel area 130. When considering that the peripheral area 101 has multiple columns of first pixel areas 130, all the first readout switches 132 can be moved into multiple second pixel areas 140 in the transition area 102, for example, one or more first readout switches 132 are arranged in each second pixel area 140.

[0034] Specifically, the width of the peripheral area 101 is between 1 mm and 2 mm, and the width of the transition area 102 is equal to the width of the peripheral area 101. The present embodiment mainly considers that the flat panel detector 100 is more likely to be invaded by water vapor in the peripheral area, and the farther away from the middle area 103, the lower the possibility of being invaded by water vapor. Relatively, the width of the peripheral area 101 can be set to be between 1 mm and 2 mm, and the end value is included, and the first readout switch 132 in this part of the area is moved to the transition area 102.

[0035] However, considering that the first readout switch 132 and the second readout switch 142 are arranged in the same first non-photosensitive region 1402 of the second pixel region 140 at the same time, the area of the first non-photosensitive region 1402 is easily increased, thereby reducing the area of the second photosensitive region 1401. Therefore, the data of the thin film transistor in the first non-photosensitive region 1402 and the area of the second pixel region 140 can be designed.

[0036] In an embodiment, only one first readout switch 132 and one second readout switch 142 are arranged in each first non-photosensitive region 1402.

[0037] In the embodiment, by limiting each first non-photosensitive region 1402 to only have one first readout switch 132 and one second readout switch 142, the impact on the area of the second photosensitive region 1401 can be minimized. Avoiding the situation that the number of first readout switches 132 arranged in the same first non-photosensitive region 1402 is too large, which reduces the area of the second photosensitive region 1401.

[0038] For example, when the peripheral region 101 is provided with a column of first pixel regions 130, the first readout switches 132 of the column of first pixel regions 130 can be respectively transferred to the plurality of second pixel regions 140 in the transition region 102, and only one first readout switch 132 is arranged in each second pixel region 140.

[0039] For example, when the peripheral region 101 is provided with a plurality of columns of first pixel regions 130, the first readout switches 132 of the outermost first pixel regions 130 can be arranged in the second pixel regions 140 closest to the peripheral region 101 in the transition region 102. The first readout switches 132 of the innermost first pixel regions 130 can be arranged in the second pixel regions 140 closest to the middle region 103 in the transition region 102. The first readout switches 132 of the plurality of columns of first pixel regions 130 are sequentially arranged in the plurality of columns of second pixel regions 140 according to the above order. In the embodiment, by uniformly distributing the first readout switches 132 in the first non-photosensitive regions 1402 of the second pixel regions 140, the safe transfer of the first readout switches 132 is realized. And by being uniformly distributed in the plurality of second pixel regions 140, the problem that the area cannot detect light due to the concentration of the first readout switches 132 is avoided.

[0040] In another embodiment, the size of the first pixel region 130 and the second pixel region 140 is changed so that the area of the first light-sensing region 1301 and the area of the second light-sensing region 1401 are consistent. In this case, even if the number of the first readout switches 132 in the same first non-light-sensing region 1402 is increased, the area of the second light-sensing region 1401 will not be affected. However, relatively, the area of the second pixel region 140 is increased, and more light falls into the first non-light-sensing region 1402, and the absence of this part of light can cause inaccurate detection. Therefore, the number of the first readout switches 132 in the same first non-light-sensing region 1402 is not more than four.

[0041] It can be understood that the size of the area of the first pixel region 130 and the second pixel region 140 in the embodiment can be changed, and by fixing the area of the first light-sensing region 1301 and the second light-sensing region 1401, in the case of increasing the number of the first readout switches 132 in the first non-light-sensing region 1402, the area of the second pixel region 140 is increased.

[0042] Specifically, the middle region 103 is provided with a plurality of third pixel regions 150, the third pixel region 150 includes a third light-sensing region 1501 and a second non-light-sensing region 1502, the second non-light-sensing region 1502 is provided with a third readout switch 152, and the third light-sensing region 1501 is provided with a third photoelectric sensor 151.

[0043] In the embodiment, in the plurality of third pixel regions 150 of the middle region 103, each third pixel region 150 is provided with only one third readout switch 152 and one third photoelectric sensor 151, the first pixel region 130 is provided with only one first photoelectric sensor 131, and the second pixel region 140 is provided with one second photoelectric sensor 141, one second readout switch 142 and at least one first readout switch 132.

[0044] In yet another embodiment, the area of the first light-sensing region 1301, the area of the second light-sensing region 1401 and the area of the third light-sensing region 1501 are equal.

[0045] In the embodiment, by setting the areas of the first light-sensing region 1301, the second light-sensing region 1401 and the third light-sensing region 1501 to be the same, the light-sensing areas at different positions are consistent, and the area of the light-sensing region is avoided from being occupied due to the different number of thin film transistors provided in different pixel regions.

[0046] Specifically, the first readout switch 132 and the second readout switch 142 in the same first non-photosensitive region 1402 can be connected to the same scan line 121 or the same data line 122. When the first readout switch 132 and the second readout switch 142 are connected to the same scan line 121, the first readout switch 132 and the second readout switch 142 need to be connected to different data lines 122.

[0047] Figure 4 is a schematic diagram of the first readout switch and the second readout switch sharing a data line in the first embodiment of the present application, referring to Figure 4 When the first readout switch 132 and the second readout switch 142 are connected to different scan lines 121, the first readout switch 132 and the second readout switch 142 can share a data line 122.

[0048] The flat panel detector 100 includes a plurality of scan lines 121 and a plurality of data lines 122, and the scan lines 121 and the data lines 122 have different running directions. The scan lines 121 are used to open the first readout switch 132, the second readout switch 142 and the third readout switch 152 row by row, so that the photoelectric signal received and converted by each row of photoelectric sensors is output from the corresponding data line 122. Generally, the area surrounded by two adjacent scan lines 121 and two adjacent data lines 122 is a pixel region. For the first pixel region 130, the data line 122 has the same running direction as the data line 122 of other pixel regions, and the first readout switch 132 is connected to the corresponding data line 122 of the first pixel region 130 by an extension line. That is, in this embodiment, the data line 122 of the first pixel region 130 does not need to be changed.

[0049] Figure 5 is a top view of a flat panel detector in the second embodiment of the present application, Figure 6 is a sectional view of a light displacement structure in the second embodiment of the present application, referring to Figures 5 to 6 The present application also discloses another flat panel detector 100, which has the same structure as the flat panel detector 100 in the previous embodiment, and the difference is that the light displacement structure 160 is arranged above the first non-photosensitive region 1402 in the second pixel region.

[0050] Specifically, the first non-photosensitive region 1402 is provided with the light displacement structure 160, and the light displacement structure 160 is used to displace the visible light entering the first non-photosensitive region 1402 to the second photosensitive region 1401 in the same second pixel region 140.

[0051] In the embodiment, the light of the first non-photosensitive area 1402 corresponding to the second pixel area 140 is transferred to the second photosensitive area 1401, so that the visible light that cannot be utilized by the first non-photosensitive area 1402 can also be added to the image detection, which improves the utilization of light and improves the accuracy of the flat panel detector 100.

[0052] In the embodiment, the influence of the first non-photosensitive area 1402 on the second photosensor 141 of the second pixel area can be no longer considered. That is, by transferring the visible light of the first non-photosensitive area 1402 to the second photosensitive area 1401, even if the area of the first non-photosensitive area 1402 increases, the photosensitive range of the second photosensor 141 will not be affected.

[0053] In the embodiment, the photosensor and the readout switch of each pixel area are arranged in the same layer, which causes the readout switch to occupy the photosensitive area of the photosensor. Of course, the general scanning line 121 and the data line 122 mentioned above also occupy the photosensitive area, and the light displacement structure 160 can be arranged in the area other than the photosensitive area to improve the photosensitive area of the photosensor of the pixel area.

[0054] In combination with the light position structure 160 in the first embodiment, Figure 2 In the embodiment, the light position structure is arranged in the second pixel area, but for the third pixel area 150, the third readout switch 152 arranged in the third pixel area 150 also occupies the second non-photosensitive area 1502, which affects the photosensitive area of the third photosensor 151.

[0055] In the embodiment, the actual photosensitive areas of the first photosensor 131, the second photosensor 141, and the third photosensor 151 are consistent. In the specific arrangement, for the third pixel area 150 and the second pixel area 140, the area of the third photosensitive area 1501 is greater than the area of the second photosensitive area 1401, and the area of the second non-photosensitive area 1502 is less than the area of the first non-photosensitive area 1402.

[0056] By arranging the light displacement structure 160 on the first non-photosensitive area 1402, the light on the first non-photosensitive area 1402 is displaced to the second photosensitive area 1401, thereby improving the actual photosensitive range of the second pixel area 140, and making the actual photosensitive areas of the first photosensor 131, the second photosensor 141, and the third photosensor 151 consistent. In the embodiment, the areas of the first pixel area 130, the second pixel area 140, and the third pixel area 150 are consistent.

[0057] Continuing to refer toFigure 5 As shown, the second light-sensing region 1401 includes a first sub-light-sensing region 1401a and a second sub-light-sensing region 1401b, and the light displacement structure 160 is configured to displace the visible light entering the first non-light-sensing region 1402 to the first sub-light-sensing region 1401a and the second sub-light-sensing region 1401b in the same second pixel region 140. The light displacement structure 160 includes a displacement composite layer disposed between the scintillator layer 110 and the image sensor layer 120, and the displacement composite layer is configured to be displaced under electrical signal control so that the visible light entering the first non-light-sensing region 1402 is displaced to enter the first sub-light-sensing region 1401a and the second sub-light-sensing region 1401b, respectively.

[0058] In this embodiment, the displacement composite layer is disposed between the scintillator layer 110 and the image sensor layer 120, and the displacement of the light from the first non-light-sensing region 1402 to the second light-sensing region 1401 is achieved by changing the inclination angle of the displacement composite layer to refract the light passing through the displacement composite layer, thereby causing a displacement. The displacement is related to the structure and material of the displacement composite layer and the inclination angle, and can be designed by considering the actual application.

[0059] In this embodiment, the displacement composite layer is disposed between the scintillator layer 110 and the image sensor layer 120, and the displacement of the light from the first non-light-sensing region 1402 to the second light-sensing region 1401 is achieved by changing the inclination angle of the displacement composite layer to refract the light passing through the displacement composite layer, thereby causing a displacement. The displacement is related to the structure and material of the displacement composite layer and the inclination angle, and can be designed by considering the actual application.

[0060] It can be understood that the inclination angles of the displacement composite layers corresponding to the first sub-light-sensing region 1401a and the second sub-light-sensing region 1401b are opposite, so that the light from the first non-light-sensing region 1402 is displaced to different regions, respectively. The main consideration is that when the displacement distance of the displacement composite layer is limited, the light from the first non-light-sensing region 1402 can be displaced to different second light-sensing regions 1401, respectively. That is, the displacement directions of the light in the first non-light-sensing region 1402 can be different, and the light can be displaced to the second light-sensing region 1401 from different directions. Of course, in another embodiment, the light falling into the first non-light-sensing region 1402 can also be displaced to the second light-sensing region 1401 by the same displacement composite layer.

[0061] Continuing to refer to Figure 6As shown, specifically, the displacement composite layer includes a displacement driving structure 161, a displacement film 162 and an elastic material layer 163, the displacement film 162 is sandwiched in the elastic material layer 163, the displacement driving structure 161 is arranged at two ends of the displacement film 162, for driving the displacement film 162 to displace in the elastic material layer 163, so that the normal direction of the displacement film 162 forms a preset included angle with the normally incident light emitted by the scintillator layer, the preset included angle is greater than 0 degree; the elastic material layer 163 is used for making the displacement film 162 parallel to the scintillator layer 110 in the initial state of the displacement film 162 or when the displacement driving structure 161 does not work; the refractive index of the displacement film 162 is greater than the refractive index of the elastic material layer 163, and the displacement film 162 is used for refracting the visible light incident into the first non-photosensitive region 1402 into the first sub-photosensitive region 1401a and the second sub-photosensitive region 1401b.

[0062] In the embodiment, the displacement film 162 is formed of high light transmission material, such as glass or hard transparent plastic, and the main function of the displacement film 162 is to refract and displace the incident light and then emit the light. When the light enters from a medium with low refractive index into a medium with high refractive index, the incident light is deviated near the normal direction in the medium with high refractive index. However, when the light is emitted, it is deviated away from the normal direction in the medium with low refractive index, which is consistent with the angle of the incident light. Therefore, the displacement film 162 used in the embodiment does not change the angle of the incident light, but only displaces the light.

[0063] The elastic material layer 163 includes a transparent elastic material layer 163 such as silica gel or foam, which mainly provides a moving space for the displacement film 162 and has great elasticity and small strength. When the displacement driving structure 161 does not work, the transparent elastic material layer 163 is used to make the displacement film 162 in the initial state. Generally, the initial state of the displacement film 162 is that the normal direction of the displacement film 162 is perpendicular to the scintillator layer 110.

[0064] Specifically, the displacement driving structure 161 includes at least one transparent electro-actuated structure, the transparent electro-actuated structure is arranged below the displacement film 162, the transparent electro-actuated structure is used to expand or contract in a direction perpendicular to the scintillator under the control of an electric field, and the transparent electro-actuated structure is used to support the displacement of the displacement film 162, so that the normal direction of the displacement film 162 forms a preset included angle with the normally incident light emitted by the scintillator layer.

[0065] In the embodiment, the transparent electro-deformation structure has the ability to deform under the control of electric field, such as piezoelectric ceramic material or other electro-expansion materials with light transmission capability, etc. can be deformed to a preset degree under the control of electric field, so as to realize the deflection of the angle of the displacement film 162. Of course, different expansion degrees can also be reached under the driving of different voltages, but the complexity is higher. In the embodiment, in order to simplify the design, the transparent electro-deformation structure can also be formed by using memory material, which has two morphological transitions between conductive and non-conductive, so as to realize the movement of the displacement film 162 to the preset angle state.

[0066] Figure 7 is a displacement schematic diagram of light rays passing through the displacement film of the present application, as shown in Figure 7 When the thickness of the displacement film 162 is h, the refractive index of the displacement film 162 is n2, and the refractive index of the elastic material layer 163 on the upper and lower sides of the displacement film 162 is n1, the displacement of the incident light in the displacement film 162 is x, and the displacement of the incident light in the displacement film 162 is x. When the displacement of the incident light from the normal line of the displacement film 162 is α1, the displacement of the incident light from the normal line in the displacement film 162 is α2, and the displacement of the incident light in the displacement film 162 is x. According to the refraction law n1*sin(α1)=n2*sin(α2), the value of α2 can be calculated, wherein α1 is a predetermined angle, n1 and n2 are known data, and the value of α2 can be calculated. Combined with x=h*tan(α2), the value of x, i.e. the displacement of the incident light passing through the displacement film 162, can be calculated, so as to calculate the values of n1, n2 and α1 required for displacing the visible light from the non-photosensitive area to the photosensitive area.

[0067] Figure 8 is a schematic diagram of a flat panel detector of the third embodiment of the present application, as shown in Figure 8 On the basis of any one of the flat panel detectors 100 described above, the embodiment additionally provides a humidity sensor 170. Specifically, the flat panel detector 100 further comprises a plurality of humidity sensors 170, the humidity sensors 170 are arranged in the first non-photosensitive area 1402, the humidity sensors 170 are used to sense the humidity in the first non-photosensitive area 1402, and the light conversion rate of the second readout switch 142 in the first non-photosensitive area 1402 is calculated according to the humidity in the first non-photosensitive area 1402.

[0068] The humidity sensor 170 in the embodiment can be formed by a humidity-sensitive element. The humidity-sensitive element mainly includes resistive and capacitive types. The resistive humidity-sensitive element mainly has a film made of a humidity-sensitive material on a substrate. When the humidity in the air is adsorbed on the humidity-sensitive film, the resistivity and resistance of the humidity-sensitive element change, so that the humidity can be measured by using the characteristics. The capacitive humidity-sensitive element is generally made of a high polymer film capacitor, such as polystyrene, polyimide, and cellulose acetate. When the environmental humidity changes, the dielectric constant of the humidity-sensitive capacitor changes, so that the capacitance also changes. The capacitance change is proportional to the relative humidity. The humidity sensor 170 in the embodiment does not need to be arranged in each second pixel area 140, but one or more humidity sensors can be arranged at key positions.

[0069] The humidity sensor 170 in the embodiment is mainly arranged to detect the specific humidity when a small amount of water vapor invades the transition area 102. The conversion efficiency of the readout switch under the corresponding humidity can be determined, and the detection data of the second pixel area 140 and the first pixel area 130 can be corrected. In the test process, the readout efficiency of the readout switch under different humidity ranges can be tested. For example, when the humidity is 40%, the readout efficiency of the readout switch is 80%. According to the photoelectric signal read by the readout switch, the photoelectric signal with a readout efficiency of 100% under no humidity influence can be deduced, so as to improve the accuracy of the flat panel detector 100.

[0070] It is worth mentioning that the water vapor invasion degree mentioned in the present application is generally within the range of not affecting the normal work of the readout switch. When the water vapor invasion degree is serious, the readout switch in the transition area 102 is also invaded by water vapor. For example, the readout switch is affected by water vapor and cannot work normally. It is not within the scope of consideration of the embodiment.

[0071] Figure 9 FIG. 1 is a schematic diagram of an X-ray imaging system according to the present application. As shown in FIG. 1, the present application discloses an X-ray imaging system 100. The X-ray imaging system 100 includes an X-ray source 110, a display device 120, and a flat panel detector 100. The X-ray source 110 emits X-rays, which are irradiated onto a measured object. The flat panel detector 100 receives the X-rays with image information of the measured object and converts the X-rays into an electrical signal. The display device 120 restores the electrical signal transmitted by the flat panel detector 100 into image information. Figure 9 As shown in FIG. 1, the present application further discloses an X-ray imaging system 200. The X-ray imaging system 200 includes an X-ray source 210, a display device 220, and the flat panel detector 100 described above. The X-ray source 210 emits X-rays, which are irradiated onto a measured object. The flat panel detector 100 receives the X-rays with image information of the measured object and converts the X-rays into an electrical signal. The display device 220 restores the electrical signal transmitted by the flat panel detector 100 into image information. The X-ray source emits X-rays. When the X-rays pass through different measured objects, the X-rays have different intensities. The scintillator layer 110 mainly converts the X-rays into visible light with different intensities. The visible light at different positions carries information of the measured object.

[0072] The application avoids the problem that the first readout switch is invaded by water vapor due to the existence of water vapor in the peripheral area by moving the readout switch of the peripheral area of the flat panel detector to the transition area, that is, by moving the first readout switch originally arranged in the peripheral area to the transition area. The first readout switch is protected from water vapor invasion. Moreover, by arranging the light displacement structure, the problem of the area reduction of the second photosensitive area caused by the large number of readout switches arranged in the second pixel area is avoided. Moreover, even if a small amount of water vapor invades, the photoelectric signal output by the readout switch can be compensated after being detected by the humidity sensor. Thus, the problem of the large difference in imaging quality between the peripheral area and other areas caused by the different electrical signal conversion efficiencies of the first readout switch affected by water vapor is avoided, and the detection precision of the flat panel detector is improved.

[0073] It should be noted that the inventive concept of the present application can form a very large number of embodiments, but the length of the application file is limited and cannot list them one by one. Therefore, on the premise of not conflicting, the above-described embodiments or technical features can be combined to form new embodiments. Each embodiment or technical feature combination will enhance the original technical effect.

[0074] The above is a further detailed description of the present application in combination with specific optional embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A flat panel detector, characterized in that, It includes a scintillator layer and an image sensor layer. The scintillator layer is used to convert X-rays into visible light. 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 electrical signals. The photoelectric sensor includes a first photoelectric sensor and a second photoelectric sensor, and the readout switch includes a first readout switch and a second readout switch; The image sensor layer includes an outer region, a transition region, and an inner region. The outer region surrounds the transition region, and the transition region surrounds the inner region. The outer perimeter region is provided with at least one column of first pixel regions, and the transition region is provided with multiple second pixel regions; Each of the first pixel regions is provided with only a first photosensitive area, and the first photoelectric sensor is disposed within the first photosensitive area; Each second pixel region includes a second photosensitive region and a first non-photosensitive region; the second photoelectric sensor is disposed in the second photosensitive region, and the second readout switch is disposed in the first non-photosensitive region; The first readout switch is located within the first non-photosensitive area.

2. The flat panel detector according to claim 1, characterized in that, Each of the first non-photosensitive areas is provided with only one first readout switch and one second readout switch; The intermediate area is provided with multiple third pixel areas, each including a third photosensitive area and a second non-photosensitive area. A third readout switch is provided in the second non-photosensitive area, and a third photoelectric sensor is provided in the third photosensitive area.

3. The flat panel detector according to claim 1, characterized in that, The width of the outer perimeter is between 1 mm and 2 mm, and the width of the transition area is equal to the width of the outer perimeter.

4. The flat panel detector according to claim 2, characterized in that, The areas of the first photosensitive area, the second photosensitive area, and the third photosensitive area are equal.

5. The flat panel detector according to claim 2, characterized in that, The area of ​​the third photosensitive area is larger than the area of ​​the second photosensitive area, and the area of ​​the second non-photosensitive area is smaller than the area of ​​the first non-photosensitive area; A light-shifting structure is provided on the first non-photosensitive area, and the light-shifting structure is used to transfer the visible light entering the first non-photosensitive area to the second photosensitive area within the same second pixel area.

6. The flat panel detector according to claim 5, characterized in that, The second photosensitive area includes a first sub-photosensitive area and a second sub-photosensitive area. The light displacement structure is used to transfer the visible light incident on the first non-photosensitive area to the first sub-photosensitive area and the second sub-photosensitive area within the same second pixel area. The light displacement structure includes a displacement composite layer disposed between the scintillator layer and the image sensor layer. The displacement composite layer is used to be displaced under the control of the electrical signal, so that the visible light entering the first non-photosensitive area is displaced and enters the first sub-photosensitive area and the second sub-photosensitive area respectively.

7. The flat panel detector according to claim 6, characterized in that, The displacement composite layer includes a displacement driving structure, a displacement film, and an elastic material layer. The displacement film is sandwiched within the elastic material layer. The displacement driving structure is disposed at both ends of the displacement film and is used to drive the displacement film to move within the elastic material layer, so that the normal direction of the displacement film forms a preset angle with the perpendicular incident light emitted by the scintillator layer, and the preset angle is greater than 0 degrees. The elastic material layer is used to make the displacement film parallel to the scintillator layer when the displacement film is in its initial state or when the displacement driving structure is not working; The refractive index of the displacement film is greater than that of the elastic material layer. The displacement film is used to refract the visible light incident on the first non-photosensitive area into the first sub-photosensitive area and the second sub-photosensitive area.

8. The flat panel detector according to claim 5, characterized in that, The flat panel detector also includes multiple humidity sensors, which are disposed in the first non-photosensitive area. The humidity sensors are used to sense the humidity in the first non-photosensitive area and calculate the light conversion rate of the second readout switch in the first non-photosensitive area based on the humidity in the first non-photosensitive area.

9. The flat panel detector according to claim 5, characterized in that, The flat panel detector includes multiple scan lines and multiple data lines. Within the same first non-photosensitive area, the control terminals of the first readout switch and the second readout switch are respectively connected to the same scan line; the output terminals of the first readout switch and the second readout switch are respectively connected to different data lines.

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