KR20230135994A - Method for examining object using x-ray detector - Google Patents

Abstract

Dividing an object that is a target for inspection through X-ray detection into a plurality of continuous areas in one direction; Performing X-ray detection using an X-ray detection device for each region that is not adjacent to each other among the plurality of regions; and performing X-ray detection using the X-ray detection device for each of the remaining areas where X-ray detection was not performed in the performing step. The X-ray detection device includes a pixel array, each of which has a switching transistor and a photodetection element, and includes a plurality of pixel units arranged in a matrix structure - the row direction of the matrix structure corresponds to the direction in which the plurality of regions are arranged; a first readout driver and a second readout driver including at least one readout IC that receives a detection signal output from the photodetector, and disposed on both sides of the pixel array in a row direction of the pixel unit; and a gate driver that includes at least one gate driver IC that outputs a gate signal that operates the switching transistor and is disposed outside the pixel array in the column direction of the pixel portion.

Description

Object inspection method using an X-ray detection device {METHOD FOR EXAMINING OBJECT USING X-RAY DETECTOR}

The present invention relates to an object inspection method using an X-ray detection device, and more specifically, to an object inspection method using a digital It's about method.

X-ray (radiation) is an electromagnetic wave that has transparency. The transmission amount of these X-rays corresponds to the density inside the object. Accordingly, X-ray images are widely used in fields such as medicine, security, and industry. In particular, X-ray images are not only frequently used as a basic tool for diagnosis in the medical field, but are also widely applied in the field of product inspection to detect physical defects or foreign substances occurring on the exterior or interior of the product.

Existing X-ray images were provided through the process of preparing a film made of photosensitive material, exposing the film to X-rays that passed through the object, and then transferring the image from the film to photographic paper. In this case, there is a problem that image information cannot be provided in real time due to the printing process, and image information is easily lost due to the inability to store and preserve the film for a long time.

Recently, due to the development of image processing technology and semiconductor technology, a digital X-ray detection device with a flat panel structure that can replace film has been proposed.

A typical digital X-ray detection device includes an array panel in the form of a flat plate for converting X-rays passing through an object into light and detecting the converted light. The array panel mainly includes a plurality of pixel units arranged in a matrix form, and each pixel unit includes a corresponding photodetector element and a switching transistor.

In a conventional digital X-ray detection device, a readout IC that reads the detection signal output from the photodetection element of the pixel unit is installed only on one side of the array panel. For example, when a readout IC is placed on one side of a row to read detection signals in row units of a matrix structure where pixel units are arranged, the readout IC must receive detection signals for all rows of the matrix structure, so read Due to the slow speed, a problem occurred in which the frame rate of the X-ray detection image was lowered. In addition, the length of the read-out line provided to connect the pixel unit and the read-out IC to transmit the detection signal has become longer, causing noise due to an increase in line capacitance, thereby degrading X-ray detection performance.

The matters described as background technology above are only for the purpose of improving understanding of the background of the present invention, and should not be taken as acknowledgment that they correspond to prior art already known to those skilled in the art.

Korean Patent No. 10-2361454 Korean Patent No. 10-1782429

Accordingly, the present invention aims to solve a technical problem of providing an object inspection method using an X-ray detection device that can improve the speed of X-ray detection and reduce noise generated in the X-ray detection signal.

As a means to solve the above technical problem, the present invention,

Dividing an object that is a target for inspection through X-ray detection into a plurality of continuous areas in one direction;

Performing X-ray detection using an X-ray detection device for each region that is not adjacent to each other among the plurality of regions; and

It includes performing X-ray detection using the X-ray detection device for each remaining area where X-ray detection was not performed in the performing step,

The X-ray detection device,

a pixel array including a plurality of pixel units each having a switching transistor and a photodetector and arranged in a matrix structure, wherein the row direction of the matrix structure corresponds to the direction in which the plurality of regions are arranged; a first readout driver and a second readout driver including at least one readout IC that receives a detection signal output from the photodetector, and disposed on both sides of the pixel array in a row direction of the pixel unit; and an object inspection using an Provides a method.

In one embodiment of the present invention, the matrix structure may have a ratio of the number of columns to the number of rows of 1:2 or more.

In one embodiment of the present invention, the first readout driver and the second readout driver each receive input of the detection signal and a plurality of pixel units included in n (n is a natural number) rows arranged relatively close to each other. Lead-out lines for each can be connected.

In one embodiment of the present invention, the gate driver may simultaneously operate the switching transistor of the pixel unit connected to the first readout driver and the switching transistor of the pixel unit connected to the second readout driver.

In one embodiment of the present invention, the gate driver sequentially row-by-row starting from the switching transistor of the pixel unit included in the row closest to the center in the row direction among the pixel units connected to the first readout driver and the second readout driver. The switching transistor can be operated symmetrically.

In one embodiment of the present invention, the gate driver may include a first gate driver and a second gate driver respectively disposed on both sides of the pixel array in the column direction of the pixel unit.

In one embodiment of the present invention, the first gate driver and the second gate driver each have a gate line that transmits a gate signal to a plurality of pixel units included in n (n is a natural number) columns arranged relatively close to each other. can be connected

According to the object inspection method using the The X-ray detection time can be significantly reduced compared to performing X-ray detection by applying an X-ray detection device.

In particular, the X-ray detection device applied to the object inspection method using the By reducing the number, the frame rate of the X-ray detection device can be improved.

In addition, the X-ray detection device applied to the object inspection method using the By reducing , noise caused by the line capacitance of the readout line can be reduced.

In addition, the X-ray detection device applied to the object inspection method using the By simultaneously operating pixel units belonging to rows close to each other symmetrically, not only can the detection speed be improved and noise reduced, but the effect of motion blur can be minimized.

In addition, the X-ray detection device applied to the object inspection method using the By reducing the delay that may occur in gate signal transmission, more accurate X-ray detection can be achieved.

The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 is a plan view showing an example of an X-ray detection device applied to an object inspection method according to an embodiment of the present invention.
FIG. 2 is a circuit diagram illustrating the pixel portion of the X-ray detection device shown in FIG. 1 in detail.
3 and 4 are diagrams for explaining an object inspection method using an X-ray detection device according to an embodiment of the present invention.

Hereinafter, an object inspection method using an X-ray detection device according to various embodiments of the present invention will be described in more detail with reference to the attached drawings.

The advantages and features of the present invention and how to achieve it will become clear by referring to the embodiments described in detail below along with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and are within the scope of common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

Additionally, in describing the present invention, if it is determined that related known techniques may obscure the gist of the present invention, detailed description thereof will be omitted.

FIG. 1 is a plan view showing an example of an X-ray detection device applied to an object inspection method according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a detailed pixel portion of the X-ray detection device shown in FIG.

1 and 2, the X-ray detection device 1 applied to the object inspection method according to an embodiment of the present invention includes a plurality of pixel units 10 arranged in the form of a matrix consisting of rows and columns. It may be configured to include a pixel array 100 and a plurality of driving units 21, 22, 31, and 32 disposed on one or both sides of the pixel array 100.

A plurality of driving units for driving the pixel array 100 may include readout driving units 21 and 22 and gate driving units 31 and 32, and, although not shown, a bias driving unit and a gate driving unit ( 31, 32) may include a timing controller that adjusts the operation timing.

Each pixel unit 10 of the pixel array 100 includes a photodetection device (PD; Photo Diode) that detects light and a switching transistor (ST: Switching) disposed between the photodetection device (PD) and the readout line (RL). Transistor) may be included.

The pixel array 100 may include a gate line (GL) and a readout line (RL) connected to the switching transistor (ST) of each pixel unit (10).

By way of example, the gate line GL may be arranged in the row direction of the row-column structure in which the pixel portions 10 of the pixel array 100 are arranged. That is, the gate line GL corresponds to a horizontal line each composed of pixel units 10 arranged in the row direction among the plurality of pixel units 10. Accordingly, the gate line GL may be connected to the switching transistor ST of the pixel unit 10 belonging to one row among the plurality of pixel units 10.

According to the connection structure of the gate line GL, the gate drivers 31 and 32 include a gate driving IC (not shown) that generates and outputs a driving signal to the gate of the switching transistor ST through the gate line GL. ) may be disposed on one or both sides of the column direction of the row-column structure formed by the pixel unit 10.

The lead-out line RL may be arranged in the column direction of the row-column structure in which the pixel portions 10 of the pixel array 100 are arranged. That is, the lead-out line RL corresponds to a vertical line each composed of pixel units 10 arranged in a column direction among the plurality of pixel units 10. Accordingly, the lead-out line RL may be connected to the switching transistor ST of the pixel unit 10 belonging to one column among the plurality of pixel units 10.

Although not shown, the bias line that provides the bias voltage is arranged in the row and column directions of the row-column structure in which the pixel units 10 are arranged and extends to the outside of the plurality of photodetection elements (PD) included in the plurality of pixel units 10. It can be arranged in the form of an enclosing mesh.

Meanwhile, although not shown, the X-ray detection device may further include a scintillator disposed on a surface facing the light source device that radiates X-rays to the object. The scintillator can convert X-rays emitted from a light source device into visible light and supply it to a photodetection device (PD).

The first electrode (eg, anode electrode) of the photodetection element (PD) belonging to each pixel unit 10 is connected to the switching transistor (ST), and the second electrode (eg, cathode electrode) is connected to the bias line. It may be connected to and a bias voltage may be applied.

The photodetection element (PD) absorbs visible light supplied from the scintillator and generates electrons in response to the visible light, thereby generating a detection signal corresponding to the amount of X-ray transmission in each pixel unit 10.

When the switching transistor (ST) is turned on based on the gate signal provided through the gate line (GL), it transfers the detection signal of the photodetection device (PD) to the readout line (RL) to the readout driver (21, 22) A detection signal can be provided to.

Although not shown, the timing controller supplies start signals and clock signals for controlling the driving timing of the gate drivers 31 and 32 to the gate drivers 31 and 32, and controls the driving timing of the readout drivers 21 and 22. A readout control signal and a readout clock signal can be supplied to the readout driver.

The gate drivers 31 and 32 and the readout drivers 21 and 22 may include prefabricated integrated circuit (IC) chips to perform their respective operations.

Additionally, although not shown, the bias driver may supply a predetermined bias voltage to the bias line. The bias driver may selectively supply a bias voltage for reverse bias operation or a bias voltage for forward bias operation.

Before and after the light source device irradiates X-rays, the bias driver may supply a bias voltage to the photodetection elements (PD) of the plurality of pixel units 10. While the light source device radiates X-rays, the photodetection element (PD) of each pixel unit 10 may generate a detection signal corresponding to the amount of light incident on each pixel unit 10. After the light source device irradiates .

The gate drivers 31 and 32 sequentially supply gate signals for turning on and driving the switching transistors ST of the pixel units 10 included in each row to each gate line GL, and the readout drivers 21 and 32 sequentially supply gate signals to each gate line GL. 22) can receive the detection signal of each pixel unit 10 included in each row through the readout line RL. Next, the readout drivers 21 and 22 may generate image signals based on the detection signals of the plurality of pixel units 10.

Exemplarily, the readout drivers 21 and 22 amplify the detection signal, perform correction to remove the noise signal from the amplified detection signal, convert the corrected detection signal into a digital signal, and then combine the digital signals. A video signal can be generated from. Here, the image signal may be a signal representing the luminance value corresponding to the plurality of pixel units 10 as bit information.

In one embodiment of the present invention, the row-column structure in which the pixel portions 10 in the pixel array 100 are arranged has a ratio of the number of rows to columns of 1:2 or more, such as 1:4, 1:5... It is desirable to configure a larger number of columns, such as 1:10. This embodiment can improve the operating speed (frame rate) of the X-ray detection device by reducing the number of rows sequentially operated by the gate drivers 31 and 32, and the length of the leadout line extending in the row direction By reducing , noise caused by line capacitance can be reduced.

In addition, in one embodiment of the present invention, the readout drivers 21 and 22 are described on both sides of the row direction in the row-column structure in which the pixel units 10 in the pixel array 100 are arranged, that is, as shown in FIG. 1. In this case, it can be implemented to read the detection signal of the pixel portion 10 disposed at the upper and lower portions of the pixel array 100 and at a relatively closer distance in the row direction.

For example, if the total number of rows is 2n (n is a natural number), the detection signal of the pixel unit 10 belonging to the n rows located at the top is transmitted to the first readout disposed at the top of the pixel array 100. The detection signal of the pixel unit 10, which is provided to the driver 21 and belongs to the n rows located at the bottom, is provided to the second readout driver 22 located at the bottom of the pixel array 100 to process the detection signal. can be achieved.

In addition, in one embodiment of the present invention, the gate drivers 31 and 32 include a pixel unit 10 connected to the first readout driver 21 and a readout line, and a second readout driver 22 and a readout line. The switching transistors of the pixel unit 10 connected to can be operated simultaneously. For example, the gate drivers 31 and 32 are sequentially symmetrical row by row, starting from the pixel unit 10 belonging to the row closest to the center in the row direction in the row-column structure in which the pixel units 10 in the pixel array 100 are arranged. By operating the switching transistor, the first readout driver 21 and the second readout driver 22 can simultaneously read the detection signal.

This embodiment not only improves the operating speed (frame rate) of the X-ray detection device and reduces noise generated in the detection signal, but also increases the detectable area in the row direction. Additionally, the effect of motion blur can be minimized.

Meanwhile, in one embodiment of the present invention, the gate driver includes a first gate driver 31 and a second gate driver disposed on both sides of the pixel array 100 in the column direction of the row-column structure in which the pixel portion 10 is disposed. (32) may be included.

The first gate driver 31 and the second gate driver 32 may operate to output gate signals to the plurality of pixel units 10 included in n (n is a natural number) columns arranged relatively close to each other.

In this embodiment, by reducing the length of the gate line connecting the gate drivers 31 and 32 and the plurality of pixel units 10, delays that may occur in gate signal transmission can be reduced and more accurate X-ray detection can be achieved. let it be

3 and 4 are diagrams for explaining an object inspection method using an X-ray detection device according to an embodiment of the present invention.

An example of the object inspection method shown in FIGS. 3 and 4 is to apply an 43) It is about a method of examining the entirety of.

An example of an object having a long vertical length may be a cylindrical secondary battery module.

The conventional inspection method for a cylindrical secondary battery module only performed the electrode tab area at both ends of the cylindrical secondary battery module due to the speed limit of the conventional X-ray detection device. In other words, in order to perform an inspection of the entire area of the cylindrical secondary battery module, X-ray irradiation and detection had to be done for the entire length of the cylindrical secondary battery module, but panel-type X-ray inspection that can cover a cylindrical secondary battery module with a long length is possible. When the device was applied, the inspection time was so long that it was impossible to meet the inspection speed requirements. For this reason, conventionally, only the limited area where the electrode tabs on both ends of the cylindrical secondary battery module were inspected was inspected. However, problems such as short circuits due to foreign substances inside the secondary battery module may occur, so not only the electrode tab area but the entire area of the secondary battery module. There was a need to inspect.

The X-ray detection device according to an embodiment of the present invention has a relatively small number of rows in the row structure in which the pixel portion for detecting light is arranged, making it impossible to inspect an object with a long vertical length with a single X-ray detection device. By dividing the object into a plurality of areas vertically and inspecting the divided areas with a plurality of You can do it.

In the examples of Figures 3 and 4, the The objects 41, 42, and 43 are cylindrical secondary battery modules whose vertical length is longer than that of the X-ray detection devices 1a, 1b, and 1c (corresponding to the row direction in the matrix arrangement of the pixel portion 10). It is the same object.

As shown in FIG. 3, the object inspection method using an Based on this, it is divided into a plurality of continuous areas (A1-A6) for X-ray detection in the vertical direction, and a plurality of 1a, 1b, 1c), the examination is performed through X-ray detection.

Next, as shown in FIG. 4, a plurality of X-ray detection devices (1a, 1b, 1c) are moved to the remaining areas (A2, A4, A6) other than the area where the Perform inspection through .

In the case of the conventional method of examining the entire object 41, 42, and 43 at once through X-ray detection, assuming that the pixel portion of the The X-ray detection device according to may be applied to a pixel unit consisting of n rows. In particular, the are performed simultaneously. That is, considering the gate driving characteristics of the X-ray detection device that acquires the detection signal of the pixel portion 10 on a row-by-row basis, the conventional ), the X-ray detection device according to an embodiment of the present invention can acquire the detection signals of the pixel portion 10 included in 6 rows at one gate driving timing.

That is, when applying the X-ray detection device according to an embodiment of the present invention, X-ray detection for the entire area can be reduced to 1/6 compared to the conventional method.

Figures 3 and 4 show an example of performing X-ray detection by dividing the object into a total of 6 areas. However, the number of areas can be appropriately modified in consideration of the length of the object, the length of the row direction of the pixel of the X-ray detection device, etc. You can.

In this way, the method of inspecting an object by applying an X-ray detection device according to an embodiment of the present invention can significantly reduce the time required to inspect the area of the object, and the The problem of inspecting only a portion of an object can be resolved and the entire area of the object can be inspected within the required inspection time.

Although the present invention has been shown and described in relation to specific embodiments of the present invention in the above, it is understood that various improvements and changes can be made to the present invention without departing from the technical spirit of the present invention provided by the following claims. This will be self-evident to those with ordinary knowledge in the technical field.

1, 1a, 1b, 1c: X-ray detection device
10: Pixel unit 100: Pixel array
21, 22: Readout driver 31, 32: Gate driver
41, 42, 43: Object

Claims (7)

Dividing an object that is a target for inspection through X-ray detection into a plurality of continuous areas in one direction;
Performing X-ray detection using an X-ray detection device for each region that is not adjacent to each other among the plurality of regions; and
It includes performing X-ray detection using the X-ray detection device for each remaining area where X-ray detection was not performed in the performing step,
The X-ray detection device,
a pixel array including a plurality of pixel units each having a switching transistor and a photodetector and arranged in a matrix structure, wherein the row direction of the matrix structure corresponds to the direction in which the plurality of regions are arranged; a first readout driver and a second readout driver including at least one readout IC that receives a detection signal output from the photodetector, and disposed on both sides of the pixel array in a row direction of the pixel unit; and an object inspection using an method. In claim 1,
The matrix structure is an object inspection method using an X-ray detection device, characterized in that the ratio of the number of columns to the number of rows is 1:2 or more. In claim 1 or claim 2,
The first readout driver and the second readout driver each connect a plurality of pixel units included in n (n is a natural number) rows arranged relatively close to each other and a readout line for receiving the detection signal. A method of inspecting an object using an X-ray detection device. In claim 3,
An object inspection method using an In claim 4,
The gate driver operates the switching transistors sequentially and symmetrically row by row, starting from the switching transistors of the pixel units included in the row closest to the center in the row direction among the pixel units connected to the first readout driver and the second readout driver. An object inspection method using an X-ray detection device, characterized in that: In claim 1,
The gate driver includes a first gate driver and a second gate driver disposed on both sides of the pixel array in the column direction of the pixel unit. In claim 6,
An X-ray detection method, wherein the first gate driver and the second gate driver each have gate lines connected to each other to transmit gate signals to a plurality of pixel units included in n (n is a natural number) columns arranged relatively close to each other. .