X-ray inspection apparatus and inspection method therefor

Abstract

An X-ray inspection apparatus is disclosed. The apparatus comprises: an anode on which a target is provided; a cathode for emitting an electron beam at the target; a grid positioned toward a cathode side between the cathode and the anode; a power source unit for applying voltage to each of the cathode, the grid, and the anode; and a control unit. The control unit controls the power source unit such that a cathode voltage of a preset magnitude is applied to the cathode and an anode voltage of a preset magnitude is applied to the anode, and controls the power supply unit such that a grid voltage within a preset voltage range is selectively applied to the grid, thereby adjusting the amount of electron beam.

Description

X-ray inspection device and inspection method thereof

[0001] The present invention relates to an X-ray inspection device and an inspection method thereof that perform an inspection by controlling the voltage of a grid in an X-ray tube.

[0002] X-ray inspection technology is being used as a method to determine the internal properties of an object without destroying it. X-ray inspection equipment that performs X-ray inspections can be used to examine not only the human body but also various other objects, such as secondary batteries.

[0003] An X-ray inspection device is a device that emits an electron beam toward a target and uses the X-rays emitted from the target to inspect the subject. An X-ray inspection device can generate X-rays using an X-ray tube. An X-ray tube typically includes a heater, a cathode, a grid, and an anode. A target is placed on the anode, and the electron beam emitted from the cathode is projected toward the anode through the grid and strikes the target.

[0004] For this operation, a high voltage of approximately 100 kV is applied to the anode. Technical limitations existed in controlling this high voltage by turning it on and off at short intervals. Furthermore, individually controlling the heater, cathode, grid, and anode on and off could lead to unexpected discharges or adversely affect the vacuum within the X-ray tube.

[0005] As a result, conventional X-ray inspection devices cannot precisely control X-ray emission because they cannot control the on / off of the electron beam itself. Therefore, there was a problem in that radiation exposure to the subject or user could not be reduced.

[0006] Therefore, in order to solve the above-described problem, it is necessary to provide an X-ray inspection device and an inspection method thereof that can perform an inspection while precisely controlling X-ray emission.

[0007] According to one embodiment of the present invention for achieving the above object, an X-ray inspection device includes an anode on which a target is installed, a cathode for emitting an electron beam to the target, a grid located on the cathode side between the cathode and the anode, a power supply unit for applying voltage to each of the cathode, the grid, and the anode, and a control unit. Here, the control unit controls the power supply unit to apply a cathode voltage of a preset size to the cathode and an anode voltage of a preset size to the anode, and controls the power supply unit to selectively apply a grid voltage within a preset voltage range to the grid, thereby adjusting the amount of the electron beam emitted from the cathode and transmitted to the anode side.

[0008] The control unit can adjust the magnitude of the grid voltage within a voltage range between a first voltage for blocking the electron beam and a second voltage for passing the electron beam. Here, the first voltage has the same polarity as the cathode voltage and is set to a magnitude such that the electron beam emitted from the cathode can be blocked by a repulsive force generated by the grid, and the second voltage has the same polarity as the cathode voltage and is set to a magnitude such that the electron beam emitted from the cathode can pass through the grid while being focused by a repulsive force generated by the grid.

[0009] Meanwhile, the X-ray inspection device may further include a transport belt for transporting the subject to be inspected. The control unit may control the power supply unit to alternately adjust the grid voltage to the first voltage and the second voltage during a section in which the subject to be inspected passes the inspection location, when the subject to be inspected is transported to the inspection location by the transport belt while the cathode voltage is applied to the cathode and the anode voltage is applied to the anode.

[0010] In addition, the control unit may control the power supply unit to alternately adjust the grid voltage within the preset voltage range based on the breathing cycle of the human body, which is the subject of the test.

[0011] The power supply unit may include a first power supply connected to the cathode, a second power supply connected to a node between the first power supply and the grid, and a third power supply connected to the anode. The second power supply is a power supply for providing a voltage that varies within a preset voltage range, and the grid voltage may be a voltage having a magnitude that is the sum of the voltages of the first power supply and the second power supply.

[0012] Meanwhile, an inspection method of an X-ray inspection device according to an embodiment of the present invention includes a step of applying an anode voltage and a cathode voltage of a preset size to an anode and a cathode, respectively, and a step of selectively applying a grid voltage within a preset voltage range to a grid located on the cathode side between the cathode and the anode, thereby adjusting the amount of an electron beam emitted from the cathode and transmitted to the anode side.

[0013] The step of adjusting the amount of the electron beam may adjust the magnitude of the grid voltage within a voltage range between a first voltage for blocking the electron beam and a second voltage for passing the electron beam. Here, the first voltage may be a voltage having the same polarity as the cathode voltage and set to a magnitude such that the electron beam emitted from the cathode can be blocked by a repulsive force generated by the grid, and the second voltage may be a voltage having the same polarity as the cathode voltage and set to a magnitude such that the electron beam emitted from the cathode can pass through the grid while being focused by a repulsive force generated by the grid.

[0014] In addition, the step of adjusting the amount of the electron beam may include a step of alternately adjusting the grid voltage to the first voltage and the second voltage during a section in which the test object passes the test position when the test object is transported to the test position by the transport belt while the cathode voltage is applied to the cathode and the anode voltage is applied to the anode.

[0015] Alternatively, the step of adjusting the amount of the electron beam may include a step of alternately adjusting the grid voltage within the preset voltage range based on the breathing cycle of the human body being examined.

[0016] FIG. 1 is a drawing showing an example of the appearance of an X-ray tube used in an X-ray inspection device according to one embodiment of the present invention;

[0017] Figure 2 is a drawing for explaining the configuration of an X-ray inspection device according to one embodiment of the present invention;

[0018] Figures 3 and 4 are drawings for explaining the operation of an X-ray inspection device according to one embodiment of the present invention.

[0019] FIG. 5 is a drawing for explaining the detailed configuration of the power supply unit of an X-ray inspection device according to one embodiment of the present invention.

[0020] FIG. 6 is a drawing showing an example of the appearance of an X-ray inspection device according to an embodiment of the present invention;

[0021] Figures 7 to 9 are drawings for explaining the control operation of an X-ray inspection device according to one embodiment of the present invention, and

[0022] Figure 10 is a flowchart for explaining an inspection method according to one embodiment of the present invention.

[0023] Below, terms used in this disclosure will first be briefly explained, and then this disclosure will be described in detail.

[0024] The terms described in this specification have been selected from widely used, current terms, taking into account the functions of the present disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the description of the relevant disclosure. Therefore, the terms used in this disclosure should be defined based on their meaning and the overall content of the present disclosure, rather than simply their names.

[0025] Terms like "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms are used solely to distinguish one component from another.

[0026] Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" or "consist of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] The expression "at least one of A or B" should be understood to mean either "A" or "B" or "A and B".

[0028] In the present disclosure, a "module" or "part" performs at least one function or operation and may be implemented in hardware or software, or a combination of hardware and software. Furthermore, multiple "modules" or multiple "parts" may be integrated into at least one module and implemented by one or more processors (not shown), excluding any "modules" or "parts" that need to be implemented in specific hardware.

[0029] Below, with reference to the attached drawings, embodiments of the present disclosure are described in detail so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description are omitted for clarity of description of the present disclosure, and similar parts are designated with similar reference numerals throughout the specification.

[0030] One or more embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings.

[0031] FIG. 1 is a drawing showing an example of the appearance of an X-ray tube used in an X-ray inspection device according to an embodiment of the present invention. Referring to FIG. 1, the X-ray tube (50) includes an electron generator (51) and a vacuum chamber (52). A heater, a cathode, and a grid are arranged inside the electron generator (51), and an anode is arranged inside the vacuum chamber (52). A target may be installed on the anode.

[0032] On one side of the electron generating unit (51), a plurality of electrodes (54) connected to internal components are exposed. Each electrode is connected to a power supply, and the power supply provides an electric signal to each electrode (54) according to the control of the processor. When voltage is applied to the heater, cathode, grid, and anode through the electrode (54), the cathode emits an electron beam, and the emitted electron beam passes through the grid and is projected onto a target on the anode side inside the vacuum chamber (52). The electron beam colliding with the target generates X-rays, and the generated X-rays are emitted through the transmission window (53).

[0033] In an X-ray inspection device, preset voltages are applied to the heater, cathode, and anode, respectively, and the voltage applied to the grid can be adjusted to control the amount of electron beam transmitted from the cathode to the anode. If the grid voltage is set to a specific voltage, the electron beam may not be able to penetrate the grid. Therefore, X-ray generation can be blocked while maintaining the voltage applied to the cathode, anode, and heater.

[0034] FIG. 2 is a drawing for explaining the configuration of an X-ray inspection device according to an embodiment of the present invention. According to FIG. 2, the X-ray inspection device (100) includes a cathode (110), a grid (120), an anode (130), a heater (140), a power supply (150), and a control unit (160). In FIG. 2, the cathode (110), the grid (120), the anode (130), and the heater (140) are illustrated as being disposed within the X-ray tube (50), and the power supply (150) and the control unit (160) are disposed outside the X-ray tube (50). However, this is merely an example, and at least one of the power supply (150) and the control unit (160) may be included together in the X-ray tube (50).

[0035] A target (131) can be installed on the anode (130). A detailed description of the placement location, placement form, type, etc. of the target (131) is omitted.

[0036] The cathode (110) is configured to emit an electron beam toward the anode (130).

[0037] The grid (120) is placed between the cathode (110) and the anode (130). Specifically, it may be placed closer to the cathode (110) with respect to the middle between the cathode (110) and the anode (130).

[0038] The power supply unit (150) is configured to provide electrical signals to various other components, such as the cathode (110), grid (120), anode (130), and heater (140).

[0039] The control unit (160) is a configuration for controlling the operation of various components included in the X-ray inspection device (100). For example, the control unit (160) can control the operation of the power supply unit (150) to apply an appropriate voltage to each of the cathode (110), grid (120), anode (130), heater (140), etc.

[0040] The control unit (160) can be implemented in various forms, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an APU (Accelerated Processing Unit), a MIC (Many Integrated Core), a DSP (Digital Signal Processor), an NPU (Neural Processing Unit), and other control logic. Although only one control unit (160) is illustrated in FIG. 2, the control unit (160) may be implemented with multiple processors. In addition, although a memory is not illustrated in FIG. 2, it may be implemented separately from the control unit (160) or may further include at least one memory integrated into the control unit (160).

[0041] The control unit (160) controls the power supply unit (150) to apply a cathode voltage of a preset size to the cathode (110) and to apply an anode voltage of a preset size to the anode (130). In addition, the control unit (160) controls the power supply unit (150) to apply an appropriate voltage to the heater (140). When voltage is applied to the heater (140) to heat the cathode (110) and voltages are applied to the cathode (110) and the anode (130), an electron beam is emitted from the cathode (110).

[0042] The control unit (160) can control the power supply unit (150) to selectively apply a grid voltage within a preset voltage range to the grid (120). Depending on the fluctuation of the grid voltage, the amount of electron beam emitted from the cathode (110) and transmitted toward the anode (130) can be adjusted. The range of the grid voltage can be set in various ways depending on the experiment. Specifically, when a first voltage having a level sufficient to block the electron beam and a second voltage having a level sufficient to appropriately focus and allow the electron beam to pass are determined, the first voltage or the second voltage can be selectively switched. Alternatively, the control unit (160) can select one level within a range greater than or equal to the first voltage and less than or equal to the second voltage, and control the voltage unit (150) to provide a grid voltage of the selected level.

[0043] The first voltage may have the same polarity as the cathode voltage applied to the cathode (110) and may be a voltage set to a level at which an electron beam emitted from the cathode (110) can be blocked by a repulsive force generated by the grid (120).

[0044] The second voltage may be a voltage having the same polarity as the cathode voltage and set to a level such that an electron beam emitted from the cathode (110) can pass through the grid while being focused by a repulsive force generated by the grid (120).

[0045] The magnitudes of the first and second voltages can be set differently depending on various factors such as the cathode voltage, anode voltage, and distance. Generally, a higher cathode voltage can lead to a higher grid voltage.

[0046] For example, assuming that the cathode voltage is -1000 V to emit an electron beam current of 500 μA, the electron beam current can be 500 μA when the grid voltage is -1100 V, and when the cathode voltage is -2000 V, the electron beam current can be 500 μA when the grid voltage is -2200 V.

[0047] Therefore, in the case of 0 electron beam current, the grid voltage may not be applied at the threshold voltage, but may be applied in excess. For example, if the grid voltage must be at least -1250 V for the electron beam current to be 0 (off) when the cathode voltage is -1000 V, the first voltage may be set to a value with a margin compared to the threshold voltage, such as -1300 V, -1400 V, or -1500 V.

[0048] The voltage difference between the cathode voltage and the grid voltage can be implemented in various ways. For example, when the cathode voltage is -500 V, the electron beam current can be 500 μA when the grid voltage is approximately -530 V, and when the cathode voltage is -500 V, the electron beam current can be 0 when the grid voltage is approximately -800 V. If the grid voltage is implemented as a floating voltage, the electron beam can be blocked or transmitted at 500 μA by alternately controlling the second power source (152) connected to the grid voltage to -30 V or -300 V with pulses. For example, the difference between the cathode voltage and the grid voltage that makes the electron beam current 0 can be approximately 200 to 400 V depending on the cathode voltage, but is not limited thereto, and can be changed depending on various factors as described above.

[0049] FIG. 3 and FIG. 4 are drawings for explaining the operation of an X-ray inspection device according to one embodiment of the present invention.

[0050] First, according to FIG. 3, a state in which a first voltage is applied to the grid (120) is illustrated while the cathode voltage and the anode voltage are each provided at fixed values. For example, if the anode voltage is determined within a range of about +40 to +150 kV and the cathode voltage is determined within a range of about 0 kV to -1.2 kV, the grid voltage can be determined as a value floated within a range of about 0 kV to -0.6 kV based on the cathode voltage.

[0051] Specifically, if the cathode voltage is -500 V and the anode voltage is 100 kV, the first voltage of the grid voltage can be set to about -800 V.

[0052] If the grid voltage is sufficiently more negative than the cathode voltage, the electric field formed by the grid (120) can act as a repulsive force on the electron beam. Accordingly, the electron beam is blocked from passing through the grid (120), as illustrated in FIG. 3.

[0053] Figure 4 illustrates a state in which a second voltage is applied to the grid (120). As in the example described above, if the cathode voltage is -500 V and the anode voltage is 100 kV, the second voltage of the grid voltage can be set to approximately -530 V.

[0054] The voltage range of the grid voltage can be set in various ways depending on the distance between the cathode (110) and the anode (130), the distance between the cathode (110) and the grid (120), the voltage size, the area, etc. For example, the cathode (110) and the grid (120) can be arranged as close as about 0.1 mm, but this is not limited thereto and can be modified in various ways depending on the design specifications.

[0055] As shown in FIG. 3, when the first voltage is applied, the electron beam is blocked, so that X-rays are not generated, and when the second voltage is applied, as shown in FIG. 4, the electron beam is focused and can be projected toward the anode (130). Accordingly, even without turning the X-ray inspection device itself on / off, it is easy to control whether or not X-rays are generated on / off. In the case of conventional equipment, once the X-ray inspection device is turned on, on / off control at the level of several to several hundred Hz is not possible. Accordingly, the life of the target is shortened, so that the X-ray tube itself must be replaced frequently, and the impact of radiation exposure is also very large. In addition, when the object to be inspected moves, there is a problem that an afterimage remains in the photo if the X-ray exposure time is long, which degrades the X-ray image quality. However, according to the present embodiment, since on / off control is possible quickly, high-quality images can be secured even for moving objects, and unnecessary X-ray generation can be minimized, thereby extending the target life and minimizing radiation exposure.

[0056] FIG. 5 is a drawing showing an example of the configuration of a power supply unit used in an X-ray inspection device according to one embodiment of the present invention.

[0057] According to FIG. 5, the power supply unit (150) may include first to fourth power supplies (151, 152, 153, 154).

[0058] A first power source (151) is connected to the cathode (110), and a second power source (152) is connected to a node between the first power source (151) and the grid (120). A third power source (153) is connected to the anode (130), and a fourth power source (154) is connected to the heater (140). The second power source (152) can provide a voltage that varies within a preset voltage range. Accordingly, the grid voltage can be a voltage that is the sum of the voltages of the first power source and the second power source.

[0059] As in the example described above, if the cathode voltage is -500 V, the anode voltage is 100 kV, and the grid voltage is controlled in the range of -800 to -530 V, the second power source (152) may be configured as a power source that provides a variable voltage within the range of about -300 to -30 V. Consequently, a voltage of -800 to -530 V, which is the sum of the voltage value of the first power source (151), may be applied to the grid (120).

[0060] Although the above examples illustrate a case where a high voltage is applied to the anode, this is not necessarily limited to this case, and the magnitude of the voltage applied to the anode or cathode may vary. For example, the high voltage may be applied to the cathode, or may be applied to both the anode and cathode.

[0061] By implementing the grid voltage as a floating voltage relative to the cathode voltage, the range of voltage scales to be controlled is reduced. Accordingly, on / off control at short time intervals can be facilitated. Although Fig. 5 illustrates a second power source (152) that provides a voltage of variable magnitude, the present invention is not limited thereto, and the voltage supply range can be varied by utilizing multiple power sources and at least one switch.

[0062] Meanwhile, X-ray inspection devices can be used in a variety of fields, including industrial non-destructive testing and medical projection imaging. When used in industrial non-destructive testing, multiple test objects can be transported and inspected while being transported to rapidly inspect them. Figure 6 illustrates an example of an X-ray inspection device that transports and inspects test objects.

[0063] According to FIG. 6, the X-ray inspection device (100) may further include a transport belt (170) for transporting the test subject (10). The test subject (10) may be transported into the interior through an inlet (102) formed in the housing (101) of the X-ray inspection device (100) while being placed on the transport belt (170). In FIG. 6, a state in which one test subject (10) is placed on the transport belt (170) is illustrated, but a plurality of test subjects (10) may be sequentially placed on the transport belt (170) and sequentially introduced into the X-ray inspection device (100).

[0064] The control unit (160) applies a set voltage to each of the heater (140), the cathode (110), and the anode (120), and waits while applying a first voltage to the grid (120). When the subject (10) is transferred to the inspection location, the control unit (160) controls the power supply unit (150) to apply a second voltage to the grid (120). The control unit (160) can control the power supply unit (150) to alternately adjust the grid voltage to the first voltage and the second voltage during the section in which the subject (10) passes the inspection location. Accordingly, the control unit (160) can capture a plurality of X-ray images.

[0065] Fig. 7 is a drawing for explaining the operation of an X-ray inspection device. According to Fig. 7, during inspection section 1 until the first inspection object reaches and passes the inspection position, the control unit (160) can control the power supply unit (150) to alternately apply a first voltage and a second voltage. Thereafter, until the next inspection object reaches the inspection position, the first voltage capable of blocking X-ray generation is applied to the grid (120) and waits. Thereafter, when the next inspection object arrives, the voltage magnitude is alternately adjusted again during inspection section 2.

[0066] In the above, the case where the first voltage and the second voltage are alternately provided has been described, but the X-ray inspection device may also control the amount of the electron beam by applying a voltage having a magnitude within the range between the first voltage and the second voltage to the grid, if necessary.

[0067] Figure 8 illustrates a case where the first voltage and the second voltage are alternately applied in the first inspection section 1, and the first voltage and the third voltage are alternately applied in the second inspection section 2. The control unit (160) can selectively adjust the size of the grid voltage depending on the size, type, material, shape, etc. of the inspection object.

[0068] Meanwhile, during the inspection, photography can be performed while adjusting the amount of electron beam without completely blocking the electron beam. Figure 9 illustrates a case where the amount of electron beam is adjusted during the inspection period.

[0069] According to FIG. 9, when the inspection section is initiated, the control unit (160) applies the second voltage to the grid (120) while applying the first voltage, and then controls the power supply unit (150) to alternately apply the second voltage and the fourth voltage. Thereafter, during the waiting time, the power supply unit (150) is controlled to apply the first voltage again.

[0070] Meanwhile, when the subject is a human, the chest thickness can vary during inhalation and exhalation. Therefore, to ensure accurate imaging, the X-rays generated during inhalation and exhalation can be controlled to generate different amounts.

[0071] Specifically, the control unit (160) can control the power supply unit (150) to alternately adjust the grid voltage within a preset voltage range based on the breathing cycle of the human body, which is the subject of examination. In the above-described example, the grid voltage can be alternately provided between -800 and -530 V, but is not necessarily limited thereto, and the magnitude range of the grid voltage can be determined to be an appropriate magnitude based on the magnitude range of the voltage applied to at least one of the anode and the cathode. The inhalation and exhalation cycles can be directly input by the examiner or identified based on the sensing value of at least one sensor attached to the subject of examination.

[0072] FIG. 10 is a flowchart illustrating an inspection method according to various embodiments of the present invention. According to FIG. 10, while anode voltage and cathode voltage of preset magnitudes are applied to the anode and cathode, respectively (S1010), a grid voltage within a preset voltage range can be selectively applied to a grid positioned between the cathode and the anode (S1020). Accordingly, the amount of electron beam emitted from the cathode and transmitted to the anode can be controlled.

[0073] The step (S1020) of controlling the amount of electron beam by adjusting the grid voltage can be controlled within a voltage range between a first voltage for blocking the electron beam and a second voltage for passing the electron beam. The voltage range of the grid voltage and the structure and operation of the anode, grid, cathode, etc. have been specifically described in the above-described embodiments, and therefore, a redundant description thereof will be omitted.

[0074] The above inspection method can be performed in an X-ray inspection device having the configuration described in the various embodiments described above, but is not necessarily limited thereto, and can also be performed by an inspection device having various other configurations.

[0075] According to various embodiments of the present invention, as described above, X-ray generation can be easily and quickly controlled without turning the X-ray inspection device itself on or off. Accordingly, X-rays can be generated only during actual imaging, thereby minimizing radiation exposure to people or objects. Furthermore, the lifespan of the target or X-ray tube can be maximized. Furthermore, inspection of moving objects can be performed more precisely. Consequently, inspection of a large number of products can be performed quickly and accurately.

[0076] The above description is merely an illustrative description of the technical idea of ​​the present disclosure, and those skilled in the art to which the present disclosure pertains will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present disclosure. In addition, the embodiments according to the present disclosure are not intended to limit the technical idea of ​​the present disclosure, but rather to illustrate it, and the scope of the technical idea of ​​the present disclosure is not limited by these embodiments. Therefore, the scope of protection of the present disclosure should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of rights of the present disclosure.

Claims

1. Anode with target installed; A cathode for emitting an electron beam to the target; A grid located on the cathode side between the cathode and the anode; A power supply for applying voltage to each of the cathode, the grid, and the anode; and including a control unit; The above control unit An X-ray inspection device that controls the power supply to apply a cathode voltage of a preset size to the cathode and an anode voltage of a preset size to the anode, and controls the power supply to selectively apply a grid voltage within a preset voltage range to the grid, thereby adjusting the amount of the electron beam emitted from the cathode and transmitted toward the anode.

2. In paragraph 1, The above control unit, The size of the grid voltage is adjusted within a voltage range between a first voltage for blocking the electron beam and a second voltage for passing the electron beam, The first voltage has the same polarity as the cathode voltage and is a voltage set to a level at which the electron beam emitted from the cathode can be blocked by a repulsive force generated by the grid. An X-ray inspection device wherein the second voltage has the same polarity as the cathode voltage and is set to a voltage of a magnitude such that the electron beam emitted from the cathode can pass through the grid while being focused by a repulsive force generated by the grid.

3. In paragraph 2, It further includes a transport belt for transporting the test specimen; The above control unit, An X-ray inspection device, wherein, when the subject is transported to an inspection position by the transport belt while the cathode voltage is applied to the cathode and the anode voltage is applied to the anode, the power supply is controlled to alternately adjust the grid voltage to the first voltage and the second voltage during the section in which the subject passes through the inspection position.

4. In paragraph 1, The above control unit, An X-ray examination device that controls the power supply to alternately adjust the grid voltage within the preset voltage range based on the breathing cycle of the human body being examined.

5. In paragraph 1, The above power supply unit, A first power source connected to the cathode; a second power source connected to a node between the first power source and the grid; and A third power source connected to the anode; The above second power source is a power source for providing a voltage that varies within a preset voltage range. An X-ray inspection device, wherein the grid voltage is a voltage having a magnitude that is the sum of the voltage of the first power source and the voltage of the second power source.

6. In the inspection method of the X-ray inspection device, A step of applying an anode voltage and a cathode voltage of preset sizes to the anode and cathode, respectively; An inspection method comprising: a step of selectively applying a grid voltage within a preset voltage range to a grid located on the cathode side between the cathode and the anode, thereby adjusting the amount of an electron beam emitted from the cathode and transmitted to the anode side.

7. In paragraph 6, The step of adjusting the amount of the electron beam is: The size of the grid voltage is adjusted within a voltage range between a first voltage for blocking the electron beam and a second voltage for passing the electron beam, The first voltage has the same polarity as the cathode voltage and is a voltage set to a level at which the electron beam emitted from the cathode can be blocked by a repulsive force generated by the grid. The inspection method wherein the second voltage has the same polarity as the cathode voltage and is set to a voltage of a magnitude such that the electron beam emitted from the cathode can pass through the grid while being focused by a repulsive force generated by the grid.

8. In paragraph 7, The step of adjusting the amount of the electron beam is: An inspection method comprising: a step of alternately adjusting the grid voltage to the first voltage and the second voltage during a section in which the inspection object passes through the inspection position when the cathode voltage is applied to the cathode and the anode voltage is applied to the anode, when the inspection object is transported to the inspection position by a transport belt; 9. In paragraph 6, The step of adjusting the amount of the electron beam is: A test method, comprising: a step of alternately adjusting the grid voltage within the preset voltage range based on the respiratory cycle of a human body as a test subject.

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