WO2021189490A1

WO2021189490A1 - X-ray flat panel detector and image correction method therefor

Info

Publication number: WO2021189490A1
Application number: PCT/CN2020/081869
Authority: WO
Inventors: 赵斌; 徐帅; 庞净
Original assignee: 京东方科技集团股份有限公司; 北京京东方传感技术有限公司
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-30
Also published as: CN113766878A; CN113766878B

Abstract

Disclosed are an X-ray flat panel detector and an image correction method therefor. Some pixels in a display region are configured to be dummy pixels, and the position coordinates of all the dummy pixels satisfy the following three conditions: (1) in the same coordinate system, the coordinate positions of all the dummy pixels are different from the coordinate positions of all the dummy pixels after the display region is horizontally turned over; (2) in the same coordinate system, the coordinate positions of all the dummy pixels are different from the coordinate positions of all the dummy pixels after the display region is vertically turned over; and (3) in the same coordinate system, the coordinate positions of all the dummy pixels after the display region is horizontally turned over are different from the coordinate positions of all the dummy pixels after the display region is vertically turned over.

Description

X-ray flat panel detector and its image correction method

Technical field

The present disclosure relates to the technical field of X-ray imaging, in particular to an X-ray flat panel detector and an image correction method thereof.

Background technique

In recent years, X-ray inspection has been widely used in various fields such as medical treatment, safety, non-destructive testing, and scientific research. At present, the more common X-ray detection technology is the X-ray digital radiography (DR) detection technology that appeared in the late 1990s. The flat panel detector (FPD) is used in the X-ray digital photography detection technology, and its pixel size can be less than 0.1mm, so its image quality and resolution can almost be comparable to the film camera system, and it also overcomes the film camera system. The shortcomings in, also provide convenience for the computer processing of the image.

In the existing flat panel detectors, when performing defect analysis on the product, it is first necessary to carry out image acquisition, and then combine the image to locate the defective position on the flat panel. Due to differences in the circuit boards used by different customers and the timing of image acquisition, the image generation rules are also different. Each is different and needs to be distinguished separately for specific circuit boards and drawing rules. The conventional method is to put an obstruction on the surface and expose it, and then locate the obstruction in the image as a reference. However, the above method is likely to cause scratches or other static mura defects on the surface of the plate due to touching the obstruction, and the image acquisition process is also more complicated.

Summary of the invention

The embodiments of the present disclosure provide an X-ray flat-panel detector and an image correction method thereof. The specific solutions are as follows:

On the one hand, an X-ray flat-panel detector provided by an embodiment of the present disclosure includes a display area and a frame area. The display area includes: a plurality of signal reading lines, a plurality of scanning lines, and a plurality of signals arranged in a matrix. Pixels; wherein at least one of the pixels in the display area is a pseudo pixel, and the pseudo pixel is in a dark state when the flat-panel detector collects an image;

The position coordinates of all the pseudo pixels meet the following conditions:

In the same coordinate system, the coordinate positions of all the pseudo pixels are different from the coordinate positions of all the pseudo pixels after the display area is horizontally flipped;

And in the same coordinate system, the coordinate positions of all the pseudo pixels are different from the coordinate positions of all the pseudo pixels after the display area is vertically flipped;

And in the same coordinate system, the coordinate positions of all the pseudo pixels after the display area is horizontally flipped are different from the coordinate positions of all the pseudo pixels after the display area is vertically flipped.

Optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, the number of the dummy pixels is greater than one and less than or equal to five.

Optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, all the dummy pixels are arranged adjacently along the row direction and/or the column direction.

Optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, some of the pseudo pixels are arranged adjacently among all the pseudo pixels.

Optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, all the dummy pixels are not adjacent to each other.

Optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, the coordinate positions of the dummy pixels are all set at a position where the display area is close to the frame area.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, the pixel includes: a photoelectric conversion unit and a thin film transistor; wherein, the photoelectric conversion unit is used to convert X-ray light into an electrical signal and For storage; the first stage of the thin film transistor is connected to the output terminal of the photoelectric conversion unit, the second electrode of the thin film transistor is connected to the signal reading line, and the gate of the thin film transistor is connected to the scan line; The thin film transistor is used to provide the signal output by the photoelectric conversion unit to the signal reading line under the control of the scan line.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, in the dummy pixel, the first electrode and the second electrode of the thin film transistor are directly electrically connected.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, in the dummy pixel, the gate of the thin film transistor is disconnected from the scan line.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, in the dummy pixel, the second electrode of the thin film transistor is disconnected from the signal reading line.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, in the dummy pixel, the first electrode of the thin film transistor is disconnected from the photoelectric conversion unit.

On the other hand, the embodiments of the present disclosure also provide an image correction method of any of the above-mentioned X-ray flat panel detectors provided by the embodiments of the present disclosure, which includes:

Acquiring an initial image collected by the flat panel detector;

Locating the direction of the initial image according to the position coordinates of the dark point in the initial image;

Repairing the dummy pixels in the initial image, wherein the brightness of the dummy pixels is determined according to the brightness of the surrounding pixels of the dummy pixels.

Optionally, in the image correction method provided by the embodiment of the present disclosure, the brightness of the dummy pixel is determined according to the brightness of the surrounding pixels of the dummy pixel, specifically:

The brightness of the dummy pixel is equal to the average value of the brightness of all adjacent pixels.

Description of the drawings

FIG. 1 is a schematic structural diagram of an X-ray flat-panel detector provided by an embodiment of the disclosure;

2a is a schematic comparison diagram of the positions of pseudo pixels in an X-ray flat panel detector provided by an embodiment of the disclosure;

2b is a schematic comparison diagram of the positions of pseudo pixels in the X-ray flat-panel detector provided by an embodiment of the disclosure;

2c is a schematic comparison diagram of the positions of pseudo pixels in the X-ray flat panel detector provided by the embodiments of the disclosure;

FIG. 3a is a schematic diagram of the positions of pseudo pixels that do not meet the conditions of the X-ray flat-panel detector of the present disclosure provided by an embodiment of the present disclosure;

3b is a schematic diagram of the positions of pseudo pixels that do not meet the conditions of the X-ray flat panel detector of the present disclosure provided by the embodiments of the present disclosure;

Fig. 3c is a schematic diagram of the positions of false pixels that do not meet the conditions of the X-ray flat-panel detector of the present disclosure provided by an embodiment of the present disclosure;

4 is a schematic structural diagram of another X-ray flat panel detector provided by an embodiment of the disclosure;

FIG. 5 is a schematic structural diagram of yet another X-ray flat panel detector provided by an embodiment of the disclosure;

6 is a schematic structural diagram of normal pixels in an X-ray flat-panel detector provided by an embodiment of the disclosure;

FIG. 7 is a schematic structural diagram of a pseudo pixel in the X-ray flat-panel detector provided by an embodiment of the disclosure;

FIG. 8 is a schematic structural diagram of another pseudo pixel in the X-ray flat-panel detector provided by an embodiment of the disclosure;

FIG. 9 is a schematic structural diagram of yet another pseudo pixel in the X-ray flat-panel detector provided by an embodiment of the disclosure;

10 is a schematic structural diagram of yet another pseudo pixel in the X-ray flat panel detector provided by an embodiment of the disclosure;

FIG. 11 is a schematic flowchart of an image correction method of an X-ray flat-panel detector provided by an embodiment of the disclosure;

FIG. 12 is a schematic diagram of the positions of pseudo pixels and pixels adjacent to them in the image correction method provided by an embodiment of the disclosure.

Detailed ways

Specifically, since there are many brands of flat panel detectors currently on the market, the circuit boards used by different brands of flat panel detectors are different, and the scanning method of the grid line and the scanning method of the signal reading line of the flat panel detector are different from each other. Related to the board settings. For example, for the difference between the forward and reverse scanning directions of the grid line, the corresponding collected image is upside down; the difference between the forward and reverse scanning directions of the signal reading line corresponds to the left and right reverse. As a result, there may be a variety of matching rules between images and real objects. The positioning of the product during poor analysis causes huge interference.

Based on this, the embodiments of the present disclosure provide an X-ray flat-panel detector and an image correction method thereof, which are not limited by the raster scan mode of the X-ray flat-panel detector and the scanning mode of the signal reading line. Positioning.

In order to make the above objectives, features, and advantages of the present disclosure more obvious and understandable, the present disclosure will be further described below in conjunction with the accompanying drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be construed as being limited to the embodiments set forth herein; on the contrary, the provision of these embodiments makes the present disclosure more comprehensive and complete, and fully conveys the concept of the example embodiments To those skilled in the art. The same reference numerals in the figures indicate the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the present disclosure are all illustrated by taking the drawings as examples, but changes can also be made according to needs, and the changes are all included in the protection scope of the present disclosure. The drawings of the present disclosure are only used to illustrate the relative position relationship and do not represent the true ratio.

It should be noted that specific details are set forth in the following description in order to fully understand the present disclosure. However, the present disclosure can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of the present disclosure. Therefore, the present disclosure is not limited by the specific embodiments disclosed below. The subsequent description of the specification is a preferred embodiment for implementing the application, but the description is for the purpose of explaining the general principles of the application, and is not intended to limit the scope of the application. The protection scope of this application shall be subject to those defined by the appended claims.

The X-ray flat panel detector and its image correction method provided by the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

An X-ray flat-panel detector provided by an embodiment of the present disclosure, as shown in FIG. 1, includes a display area AA and a frame area SS. The display area AA includes: a plurality of signal reading lines R1 and a plurality of scanning lines G1 intersectingly arranged And a plurality of pixels pix arranged in a matrix; wherein at least one pixel pix in the display area AA is a pseudo pixel pix', and the pseudo pixel pix' is in a dark state when the flat panel detector collects an image;

The position coordinates of all pseudo pixels pix’ satisfy the following three conditions:

(1) As shown in Figure 2a, in the same coordinate system (in Figure 2a, the XY coordinate system is taken as an example for illustration), after the display area AA is horizontally flipped, the coordinate positions of all pseudo pixels pix' and the display area AA pass through the vertical After flipping, the coordinate positions of all the pseudo pixels pix' are not the same; for example, in Figure 1, the pseudo pixel pix' is located in the upper left corner of the display area AA, so when the pseudo pixel pix' in the collected image is located in the upper left corner of the display area AA, it is considered to be collected The image is in the correct direction. If the scanning mode of the flat panel detector along the pixel row direction is different, the collected images may be the two situations in Figure 2a. As long as the position of the pseudo pixel pix' is adjusted to the collected image When it is located in the upper left corner of the display area AA, the correct direction of the image can be positioned, so it can be ensured that the position of the dark spot formed by the pseudo pixel pix' is not affected by the scanning method along the pixel row direction when the image is collected.

(2) As shown in Figure 2b, and in the same coordinate system (in Figure 2b, the XY coordinate system is used as an example), the coordinate positions of all pseudo pixels pix' and the display area AA are vertically flipped. All pseudo pixels pix The coordinate positions of 'are not the same; for example, in Figure 1, the pseudo pixel pix' is located in the upper left corner of the display area AA, so when the pseudo pixel pix' in the captured image is located in the upper left corner of the display area AA, the captured image is considered to be in the correct direction If the scanning mode of the flat panel detector along the pixel column direction is different, the collected images may be the two situations in Figure 2b, as long as the position of the pseudo pixel pix' is adjusted to the upper left of the display area AA for the collected image The correct direction of the image can be positioned at the corner, so it can be ensured that the position of the dark spot formed by the pseudo pixel pix' is not affected by the scanning method along the pixel column direction when the image is collected.

As shown in Figure 2c, and in the same coordinate system (the XY coordinate system is used as an example in Figure 2c), the coordinate positions of all pseudo pixels pix' are different after vertical flipping. For example, in Figure 1, the pseudo pixels pix' are located The upper left corner of the display area AA, so when the pseudo pixel pix' in the collected image is located in the upper left corner of the display area AA, the collected image is considered to be in the correct direction. If the flat panel detector scans along the pixel column direction and along the pixel row direction When both are different, the collected images may be the two situations in Figure 2c. As long as the position of the pseudo pixel pix' is adjusted to the upper left corner of the display area AA for the collected image, the correct direction of the image can be positioned, so It can be ensured that the position of the dark spot formed by the pseudo pixel pix' when the image is collected is not affected by the scanning mode along the pixel column direction and the pixel row direction.

It should be noted that in FIGS. 2a to 2c, "1", "2", "3", and "4" in the display area represent pixels pix at 4 positions. When the display area AA is inverted, refer to FIGS. 2a to 2c. In Figure 2c, the positions of the pixels pix at the four positions "1", "2", "3", and "4" within the same coordinate system also change.

In order to further explain the positions of the pseudo pixels in the X-ray flat-panel detector provided by the embodiments of the present disclosure, a few counter-examples are given below for illustration. For example, as shown in Figure 3a, if the coordinate positions of all pseudo pixels pix' are the same as the coordinate positions of all pseudo pixels pix' after the horizontal flip of the display area AA, then scan from left to right and scan from right to left in the image collected The position of the pseudo pixel pix' is the same, so the correct direction of the image cannot be located according to the position of the pseudo pixel pix'. For example, as shown in Figure 3b, if the coordinate positions of all pseudo pixels pix' are the same as the coordinate positions of all pseudo pixels pix' after vertical flipping of the display area AA, then the pseudo-pixels in the images collected by scanning from top to bottom and from bottom to top will be The position of the pixel pix' is the same, so the correct direction of the image cannot be located according to the position of the pseudo pixel pix'. For example, as shown in Figure 3c, if the coordinate positions of all the pseudo pixels pix' after the horizontal inversion of the display area AA are the same as the coordinate positions of all the pseudo pixels pix' after the vertical inversion of the display area AA, then scan from right to left and from bottom to top The position of the pseudo pixel pix' in the scanned image is the same, so the correct direction of the image cannot be located according to the position of the pseudo pixel pix'.

In summary, in the X-ray flat panel detector provided by the embodiments of the present disclosure, since some pixels are set as pseudo pixels in the display area, the position coordinates of all the pseudo pixels meet the three conditions mentioned above: (1) In the same coordinate system , The coordinate positions of all the pseudo pixels are different from the coordinate positions of all the pseudo pixels after the display area is flipped horizontally; (2) And in the same coordinate system, the coordinate positions of all the pseudo pixels are the same as those of all the pseudo pixels after the display area is flipped vertically. The coordinate positions are not the same; (3) In the same coordinate system, the coordinate positions of all the pseudo pixels after the display area is flipped horizontally are different from the coordinate positions of all the pseudo pixels after the display area is flipped vertically. Therefore, no matter how the X-ray flat-panel detector scans along the pixel row direction and how it scans along the pixel column direction, the correct direction of the image can be located according to the position of the pseudo pixel in the collected image.

In addition, the X-ray flat panel detector provided by the embodiments of the present disclosure has simple method operation, less changes than existing products, and does not affect other characteristics of the product, and has better implementation.

It should be noted that in the X-ray flat-panel detector provided by the embodiments of the present disclosure, the pseudo pixels are relative to the normal pixels, that is, the pseudo pixels are pixels that cannot work normally like normal pixels. The normal pixels are collecting the initial image The middle is a bright spot, but the pseudo-pixels are dark spots in the collected initial image. Therefore, the correct direction of the image can be determined according to the position of the dark spots in the collected initial image.

In specific implementation, in the X-ray flat panel detector provided by the embodiment of the present disclosure, the number of pseudo pixels is not limited, but if the number of pseudo pixels is too large, the pseudo pixels may affect the X-ray flat panel detection during use. The collection of target products by the device.

Specifically, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, the number of pseudo pixels can be one, but when collecting images, if a dark spot is collected, it is easy to be confused with the pseudo pixels. It is easy to misjudge.

Therefore, optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, the number of dummy pixels is greater than one and less than or equal to five.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, all the dummy pixels are arranged adjacently along the row direction; or, all the dummy pixels are arranged adjacently along the column direction; or, some of the dummy pixels are arranged adjacently along the row direction. Adjacently arranged, and some dummy pixels are arranged adjacently along the column direction.

Or, optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, some of the pseudo pixels are arranged adjacent to each other.

Or, optionally, in the X-ray flat-panel detector provided by the embodiment of the present disclosure, all the dummy pixels are not adjacent to each other.

Specifically, the display area AA of the X-ray flat-panel detector is generally rectangular, and the following takes the number of pseudo pixels as an example to describe the X-ray flat-panel detector provided by the embodiment of the present disclosure.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 4, the number of pseudo pixels pix' is 3, of which two pseudo pixels pix' are arranged adjacently, and the other pseudo pixel pix' 'It is not adjacent to the other 2 pseudo pixels pix', so the area of the dark spot formed by 2 pseudo pixels pix' is different from the area of the dark spot formed by 1 pseudo pixel pix', which can prevent confusion .

Further, in a specific implementation, as shown in FIG. 4, the display area AA is rectangular, and two dummy pixels pix' arranged adjacently are arranged close to one of the corners of the display area AA. For example, in the upper left corner of FIG. 4, another pseudo pixel pix' is located close to another corner of the display area AA, such as the lower right corner in FIG.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 5, the number of pseudo pixels pix' is 3, none of the 3 pseudo pixels pix' are adjacent, and the 3 pseudo pixels pix' In this way, the shape of the triangle formed by the connection of 3 pseudo pixels pix' can be used to determine the direction of the collected image.

Further, in specific implementation, as shown in FIG. 5, the display area AA is rectangular, and the three pseudo pixels pix' of the triangle formed by the connection are arranged close to one of the corners of the display area AA, such as the lower right corner of FIG.

Specifically, when the X-ray flat-panel detector is in use, the target product is generally imaged in the center area of the display area. Therefore, in order to avoid false pixels from affecting the X-ray flat-panel detector to collect the image of the target product, optionally, In the X-ray flat panel detector provided by the embodiment of the present disclosure, the coordinate positions of the dummy pixels are all set at the position where the display area AA is close to the frame area SS, that is, the distance between the dummy pixels and the frame area SS is less than the distance between the dummy pixels and the center of the display area AA. distance.

In specific implementation, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 6, the pixel pix includes: a photoelectric conversion unit 01 and a thin film transistor 02; Converted into an electrical signal and stored; the first stage of the thin film transistor 02 is connected to the output terminal of the photoelectric conversion unit 01, the second pole of the thin film transistor 02 is connected to the signal reading line R1, and the gate of the thin film transistor 02 is connected to the scanning line G1 Connection; the thin film transistor 02 is used to provide the signal output by the photoelectric conversion unit 01 to the signal reading line R1 under the control of the scan line G1. Thereby, an image is generated based on the signal of the signal reading line R1.

In specific implementation, one of the first electrode and the second electrode of the thin film transistor is a source electrode and the other electrode is a drain electrode, which is not limited herein.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 6, the photoelectric conversion unit generally includes an X-ray conversion layer 011, a photodiode 012, and a capacitor C1. The X-ray conversion layer 011 is converted into visible light of about 550 nm, and then the visible light is converted into an electrical signal by the photodiode 012, which is stored in the capacitor C1. When the thin film transistor 02 is turned on, the signal reading line R1 reads electric charges and generates gray scale data, thereby generating an image. Among them, the bias voltage Vb connected to the anode of the photodiode 012 keeps the photodiode 012 reversely cut off, and the voltage at point VP is derived from the charge generated by the photodiode 012 after being illuminated.

Optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 7, in the dummy pixel pix', the first electrode and the second electrode of the thin film transistor 02 are directly electrically connected. That is, in a normal pixel, the first electrode and the second electrode of the thin film transistor are independent of each other, and only when the gate controls the thin film transistor to turn on, the first electrode and the second electrode will be turned on. In the pseudo pixel, the first electrode and the second electrode of the thin film transistor are directly electrically connected, so that the electrical signal converted by the X-ray light by the photoelectric conversion unit cannot be stored, and will be directly transmitted through the first electrode and the second electrode of the thin film transistor To the signal reading line, so when the scanning line scans to the thin film transistor, there is no charge on the signal reading line and the dummy pixel is a dark spot.

The dummy pixel is realized by directly electrically connecting the first electrode and the second electrode of the thin film transistor. From the manufacturing process, only the patterns of the first electrode and the second electrode of the thin film transistor at the position of the dummy pixel need to be changed, and the operation is simple and easy Realize without adding process steps.

Or, optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 8, in the pseudo pixel pix', the gate of the thin film transistor 02 is disconnected from the scan line G1. Wherein, the gate of the thin film transistor 02 and the scan line G1 in FIG. 8 are connected by a dotted line to indicate an open circuit. In this way, when the scan line scans to the thin film transistor, the thin film transistor is still in an off state, so there is no charge on the signal reading line, and the dummy pixel is a dark spot. In the manufacturing process, it is only necessary to disconnect the originally electrically connected gate and the scan line, the operation is simple and easy to implement, and no additional process steps are required.

Or, optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 9, in the pseudo pixel pix', the second electrode of the thin film transistor 02 is disconnected from the signal reading line R1. Wherein, the second pole of the thin film transistor 02 in FIG. 9 and the signal reading line R1 are connected by a dotted line to indicate an open circuit. In this way, there is always no charge on the signal reading line, and the pseudo pixel is a dark spot. In the manufacturing process, it is only necessary to disconnect the originally electrically connected thin film transistor from the signal reading line, the operation is simple and easy to implement, and no additional process steps are required.

Or, optionally, in the X-ray flat panel detector provided by the embodiment of the present disclosure, as shown in FIG. 10, in the pseudo pixel pix', the first electrode of the thin film transistor 02 is disconnected from the photoelectric conversion unit 01. Wherein, the first pole of the thin film transistor 02 and the photoelectric conversion unit 01 in FIG. 10 are connected by a dotted line to indicate an open circuit. In this way, there is always no charge on the signal reading line, and the pseudo pixel is a dark spot. In the manufacturing process, it is only necessary to disconnect the first electrode of the originally electrically connected thin film transistor from the photoelectric conversion unit, and the operation is simple and easy to implement without adding process steps.

Of course, in specific implementation, pseudo pixels can also be implemented in other ways, for example, no photoelectric conversion unit, or no photodiode, or no thin film transistor is provided in the pseudo pixel, or neither the photoelectric conversion unit nor the thin film transistor is provided. The settings, etc., are not limited here, as long as the dummy pixels are dark spots when the image pixels are collected.

In specific implementation, the images collected by the X-ray flat panel detectors we see in daily life, such as the X-ray images taken by the hospital imaging room, are all formed after correcting the collected initial pixels. Therefore, the X-ray flat-panel detector provided by the embodiments of the present disclosure can correct the brightness of the pseudo pixels when correcting the initial image.

Therefore, based on the same inventive concept, the embodiments of the present disclosure also provide an image correction method of any of the above-mentioned X-ray flat-panel detectors, as shown in FIG. 11, including:

S101. Obtain an initial image collected by a flat-panel detector;

S102: Position the direction of the initial image according to the position coordinates of the dark point in the initial image;

S103. Repair the dummy pixels in the initial image, where the brightness of the dummy pixels is determined according to the brightness of the pixels surrounding the dummy pixels.

The brightness of a dummy pixel is equal to the average value of the brightness of all pixels adjacent to it.

Specifically, taking the pseudo pixel pix' shown in FIG. 12 as an example, there are 8 pixels adjacent to the pseudo pixel pix', so the brightness of the pseudo pixel pix' is equal to the average brightness of the 8 pixels of 1-8. Of course, in specific implementation, the brightness of the pseudo pixel pix′ can also be determined according to the average brightness of several of the 8 pixels, which is not limited here.

In the X-ray flat-panel detector and its image correction method provided by the embodiments of the present disclosure, since some pixels are set as pseudo pixels in the display area, the position coordinates of all the pseudo pixels meet the following three conditions: (1) In the same coordinate system, The coordinate positions of all pseudo pixels are different from the coordinate positions of all pseudo pixels after the display area is flipped horizontally; (2) In the same coordinate system, the coordinate positions of all pseudo pixels are the coordinates of all pseudo pixels after the display area is flipped vertically The positions are not the same; (3) In the same coordinate system, the coordinate positions of all the pseudo pixels after the display area is flipped horizontally are different from the coordinate positions of all the pseudo pixels after the display area is flipped vertically. Therefore, no matter how the X-ray flat-panel detector scans along the pixel row direction and how it scans along the pixel column direction, the correct direction of the image can be located according to the position of the pseudo pixel in the collected image.

Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. In this way, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and equivalent technologies, the present disclosure is also intended to include these modifications and variations.

Claims

An X-ray flat panel detector includes a display area and a frame area. The display area includes: a plurality of signal reading lines, a plurality of scanning lines, and a plurality of pixels arranged in a matrix; wherein the display area At least one of the pixels is a pseudo pixel, and the pseudo pixel is in a dark state when the flat-panel detector collects an image;

The position coordinates of all the pseudo pixels meet the following conditions:

In the same coordinate system, the coordinate positions of all the pseudo pixels are different from the coordinate positions of all the pseudo pixels after the display area is horizontally flipped;

And in the same coordinate system, the coordinate positions of all the pseudo pixels are different from the coordinate positions of all the pseudo pixels after the display area is vertically flipped;

And in the same coordinate system, the coordinate positions of all the pseudo pixels after the display area is horizontally flipped are different from the coordinate positions of all the pseudo pixels after the display area is vertically flipped.
The X-ray flat-panel detector according to claim 1, wherein the number of the dummy pixels is greater than 1 and less than or equal to 5.
3. The X-ray flat panel detector according to claim 2, wherein all the dummy pixels are arranged adjacently along the row direction and/or the column direction.
3. The X-ray flat panel detector according to claim 2, wherein some of the pseudo pixels among all the pseudo pixels are arranged adjacent to each other.
The X-ray flat panel detector according to claim 2, wherein all the dummy pixels are not adjacent to each other.
8. The X-ray flat-panel detector according to claim 1, wherein the coordinate positions of the dummy pixels are all set at a position where the display area is close to the frame area.
The X-ray flat-panel detector according to any one of claims 1-6, wherein the pixel comprises: a photoelectric conversion unit and a thin film transistor; wherein the photoelectric conversion unit is used to convert X-ray light into electrical signals and For storage; the first stage of the thin film transistor is connected to the output terminal of the photoelectric conversion unit, the second electrode of the thin film transistor is connected to the signal reading line, and the gate of the thin film transistor is connected to the scan line; The thin film transistor is used to provide the signal output by the photoelectric conversion unit to the signal reading line under the control of the scan line.
8. The X-ray flat panel detector according to claim 7, wherein in the dummy pixel, the first electrode and the second electrode of the thin film transistor are directly electrically connected.
8. The X-ray flat panel detector according to claim 7, wherein in the dummy pixel, the gate of the thin film transistor is disconnected from the scan line.
8. The X-ray flat panel detector according to claim 7, wherein in the dummy pixel, the second electrode of the thin film transistor is disconnected from the signal reading line.
8. The X-ray flat panel detector according to claim 7, wherein, in the dummy pixel, the first electrode of the thin film transistor is disconnected from the photoelectric conversion unit.
An image correction method for an X-ray flat-panel detector according to any one of claims 1-11, which comprises:

Acquiring an initial image collected by the flat panel detector;

Locating the direction of the initial image according to the position coordinates of the dark point in the initial image;

Repairing the dummy pixels in the initial image, wherein the brightness of the dummy pixels is determined according to the brightness of the surrounding pixels of the dummy pixels.
The image correction method according to claim 12, wherein the brightness of the dummy pixel is determined according to the brightness of the surrounding pixels of the dummy pixel, specifically:

The brightness of the dummy pixel is equal to the average value of the brightness of all adjacent pixels.