WO2016159618A1

WO2016159618A1 - X-ray generation device and control method therefor

Info

Publication number: WO2016159618A1
Application number: PCT/KR2016/003157
Authority: WO
Inventors: 윤중석; 태진우; 이승호
Original assignee: 주식회사 쎄크
Priority date: 2015-03-31
Filing date: 2016-03-28
Publication date: 2016-10-06
Also published as: CN107637180B; KR101648063B1; CN107637180A

Abstract

Discloses are an X-ray generation device and a control method therefor. The disclosed X-ray generation device including a filament, a grid, and an anode comprises: a filament control unit for controlling voltage applied to the filament; and a grid control unit for controlling voltage applied to the grid, wherein the grid control unit controls the voltage such that a constant grid voltage is applied to the grid, and the filament control unit controls the voltage applied to the filament by receiving a measured tube current value and comparing the same with a predetermined reference tube current value, in order to maintain the temperature of the filament constant.

Description

X-ray generator and control method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray generator and a control method thereof, and more particularly, to an X-ray generator and a control method thereof capable of precisely controlling the primary focusing point of an electron beam and extending the life of the filament.

In general, the X-ray generator is classified into a closed type supplied for single use and an open type for exchanging a filament or a target which is a consumable, since it can arbitrarily generate a vacuum state.

In the conventional X-ray generator, the filament control unit applies a predetermined voltage to the filament to increase the temperature of the filament. Accordingly, when the filament reaches a constant temperature, electrons are emitted from the filament toward the target. At this time, the voltage applied to the filament was set to a value for raising the temperature of the filament to the extent that electrons are emitted from the filament to generate a predetermined tube current.

However, as the temperature of the filament rises, the temperature of the peripheral metal portion of the filament also rises with material properties, and the temperature of the vacuum chamber also rises with the vacuum property. In addition, since the temperature of the filament is increased again by the temperature of the surrounding metal part and the vacuum chamber of the filament thus raised, the temperature of the filament continues to rise beyond the preset temperature even when a constant voltage is applied to the filament.

In addition, since the filament continues to thin with use, the width of temperature rise became larger when the same voltage was applied. The increase of the filament temperature increased the amount of electrons emitted from the filament, causing the tube current to exceed the reference tube current value, and the primary focusing point of the electron beam was not precisely controlled. In addition, as the temperature of the filament rises, the filament is rapidly thinned, thereby reducing the life of the filament.

In order to solve this problem, the conventional X-ray generator adjusts the amount of electrons emitted from the filament by adjusting the voltage applied to the grid. That is, as the amount of electrons emitted from the filament increases, the voltage applied to the grid increases to decrease the amount of electrons emitted from the filament.When the amount of electrons emitted from the filament decreases, the voltage applied to the grid decreases the electrons emitted from the filament. Increased the amount.

However, in the conventional X-ray generator, the primary focusing point of the electron beam is continuously changed as the voltage applied to the grid is changed, so that electrons are not focused on the target precisely, and thus the resolution of the captured image is deteriorated. There was a problem.

In addition, although the amount of electrons emitted from the filament was controlled, the problem of decreasing the life of the filament remained because the temperature rise of the filament could not be controlled.

In order to solve the above problems, an object of the present invention is to provide an X-ray generator and control method capable of precisely controlling the primary focusing point of the electron beam.

In addition, another object of the present invention to provide an X-ray generator and a control method thereof that can extend the life of the filament by controlling the temperature of the filament.

In order to achieve the above object, the present invention is an X-ray generator comprising a target, filament, grid and anode, Filament control unit for controlling the voltage applied to the filament; And a grid controller for controlling a voltage applied to the grid, wherein the grid controller controls a constant grid voltage to be applied to the grid, and the filament controller measures a tube current to maintain a constant temperature of the filament. The present invention provides an X-ray generating apparatus characterized by controlling a voltage applied to the filament by receiving a value and comparing it with a preset reference tube current value.

Here, the grid voltage may have a reference grid voltage value for focusing electrons emitted from the filament to a primary focusing point of an electron beam according to a predetermined reference tube voltage and a reference tube current.

In addition, the reference grid voltage value according to the preset reference tube voltage and reference tube current may be stored in a reservoir provided in the grid controller.

The filament control unit may lower the voltage applied to the filament when the measurement tube current value is higher than the preset reference tube current value, and the measurement tube current value is lower than the preset reference tube current value. In this case, the voltage applied to the filament can be increased.

Furthermore, the filament may have a temperature of 1000 ° C to 3300 ° C.

In addition, the tube current can be measured at the anode.

In addition, the filament may be made of any one of tungsten, CeB ₆ (Cerium Hexaboride), and LaB ₆ (Lanthanum Hexaboride).

In addition, the amount of electrons colliding with the target may be constant.

The present invention also provides a control method of an X-ray generator including a target, a filament, a grid and an anode, comprising: a setting step of setting a reference tube current and a reference tube voltage; A grid voltage applying step of constantly applying a reference grid voltage according to the reference tube current and the reference tube voltage to the grid; A filament voltage applying step of applying a reference filament voltage according to the reference tube current and the reference tube voltage to the filament; And a comparison step of the filament control unit receiving the measurement tube current measured at the anode and comparing it with the reference tube current. When the measurement tube current is higher than the reference tube current in the comparing step, the voltage applied to the filament is lowered. When the measurement tube current is lower than the reference tube current, the above object can be achieved by providing a control method of the X-ray generator, characterized in that to increase the voltage applied to the filament.

Here, the comparing step may be repeated.

In addition, the temperature of the filament may be 1000 ℃ ~ 3300 ℃.

As described above, the present invention can precisely control the primary focusing point of the electron beam emitted from the filament by setting a voltage applied to the grid to a reference grid voltage value according to a preset reference tube voltage and keeping it constant.

In addition, the present invention can provide an X-ray generator that can control the voltage applied to the filament to prevent the temperature of the filament is too high to extend the life of the filament.

1 is a view schematically showing an X-ray generating apparatus according to an embodiment of the present invention.

2 is a flowchart illustrating a control method of an X-ray generator according to an exemplary embodiment of the present invention.

Hereinafter, an X-ray generator 100 according to the present invention will be described with reference to the accompanying drawings. However, in the following description of the present invention, if it is determined that the detailed description of the related known functions or components may unnecessarily obscure the subject matter of the present invention, the detailed description and the detailed illustration will be omitted. In addition, in order to facilitate understanding of the invention, the accompanying drawings may not be drawn to scale, but the dimensions of some of the components may be exaggerated.

Referring to FIG. 1, the X-ray generating apparatus 100 according to an embodiment of the present invention irradiates X-rays toward an object to be inspected, and includes a tubular part 110, a main controller 120, and a mold power supply 130. And an electron gun 140.

The tubular part 110 is provided with a vacuum chamber 111 in which a vacuum state is selectively formed at a rear end thereof. In this case, the vacuum chamber 111 is in communication with the vacuum pump 117 through the connection pipe 112.

In addition, the cylindrical portion 110 is the target 113 is disposed at the tip, the inner side is provided with an electronic passage 114 leading to the target 113. In this case, the electron path 114 is surrounded by

coils

115 and 116 for aligning the moving direction of the electrons.

The main controller 120 includes a tube voltage controller 121, a grid controller 122, and a filament controller 123 to control each part of the X-ray generator 100.

The tube voltage controller 121 is connected to the high voltage generator 131 to control the tube voltage to be applied to the X-ray generator 100. That is, when a user inputs a tube voltage to be applied to the X-ray generator 100 to the main controller 120, the tube voltage controller 121 may generate the predetermined voltage so that the high voltage generator 131 generates a predetermined voltage. Control 131.

The grid controller 122 controls the voltage applied to the grid G. In detail, the grid controller 122 is connected to the grid generator 132, and the grid generator 132 controls the reference grid voltage according to the reference tube current and the reference tube voltage set when the X-ray generator 100 operates. The grid generator 132 is controlled to be applied to the grid G. In this case, the reference grid voltage value data according to the set reference tube current and the reference tube voltage is stored in the storage 122a connected to the grid control unit 122.

In addition, the grid controller 122 receives the tube current measured from the anode A and does not perform a task of comparing it with the reference tube current, and continuously applies the reference grid voltage constantly. By making the voltage applied to the grid constant, the point where the electrons emitted from the filament F are focused is kept constant. Therefore, the imaging device using the X-ray generator 100 according to an embodiment of the present invention can capture a clearer image.

The filament controller 123 controls the voltage applied to the filament (F). Specifically, the filament control unit 123 is connected to the filament generating unit 133, the filament generating unit 133 is a reference filament voltage according to the reference tube current and the reference tube voltage set during the operation of the X-ray generator 100 The filament generating unit 133 is controlled to be applied to the filament (F).

In addition, the filament control unit 123 is connected to the tube current measuring unit 124 receives the measurement tube current from the tube current measuring unit 124. Specifically, the tube current measuring unit 124 receives the measured tube current value from the anode (A) measuring the tube current value flowing as the X-ray generator 100 is operated and transfers it to the filament controller 123. . The filament control unit 123, which has received the measured tube current value from the anode A through the tube current measuring unit 124, is compared with the reference tube current value to adjust the voltage applied to the filament F. Control 133.

Specifically, when the measurement tube current is higher than the reference tube current, the filament generator 133 is controlled to lower the voltage applied to the filament (F). Thereby, the temperature of the filament F can be prevented from becoming unnecessarily high, and the life of the filament F can be prevented from being shortened. On the other hand, when the measured tube current is lower than the reference tube current, the filament generator 133 is controlled to increase the voltage applied to the filament (F). As a result, the amount of electrons emitted from the filament F is reduced, thereby preventing the problem of not being able to capture a desired image.

The mold power supply unit 130 is made of an insulating resin (silicon, epoxy, etc.) and is fixedly coupled to the lower end of the vacuum forming unit 111. This coupling structure may be made of a conventional screw fastening structure or a conventional locking structure. In addition, the mold power supply unit 130 includes a high voltage generator 131, a grid generator 132, a filament generator 133, and a conversion branch unit 134 therein.

The high voltage generator 131 generates a high voltage to provide a high voltage to the electron gun 130, and transmits the high voltage to the conversion branch unit 134.

The grid generator 132 is connected to the grid controller 122 and applies a reference grid voltage to the grid G under the control of the grid controller 122. The grid generator 132 is composed of a high voltage transformer.

Specifically, the grid generator 132 receives a predetermined tube voltage from the conversion branch unit 134. The received tube voltage is a voltage slightly lower than the voltage to be applied to the actual grid G. Accordingly, the grid generator 132 generates an insufficient voltage to generate a voltage to be applied to the actual grid G. Through the base 134 to the grid G.

The filament generating unit 133 is connected to the filament control unit 132 and applies a predetermined voltage to the filament F under the control of the filament control unit 132. The filament generator 133 is composed of a high voltage transformer.

In detail, the filament generator 133 receives a predetermined tube voltage from the conversion branch unit 134. The received tube voltage is a voltage slightly lower than the voltage to be applied to the actual filament (F), accordingly, the filament generator 133 generates a voltage that is to be applied to the actual filament (F) by generating a insufficient voltage It is applied to the filament (F) through the base 134.

The conversion branch unit 134 receives a voltage from the high voltage generator 131 to operate the electron gun 140 as a triode, and provides different voltages to the anode A, the filament F, and the grid G. Do it.

In detail, the conversion branch unit 134 branches the high voltage generated by the high voltage generator 131 to the grid generator 132 and the filament generator 133, respectively. At this time, as described above, since the voltage to be actually applied to the grid G and the filament F has a smaller value than the branched voltage, the grid generator 132 and the filament generator 133 composed of high voltage transformers are provided. ) Generates the required small voltage to generate the required voltage. The generated necessary voltage is applied to the electron gun 140 through the conversion branch unit 134 to apply a voltage to the grid G and the filament F.

Accordingly, a negative voltage is applied to the filament F compared to the anode A, and a higher negative voltage is applied to the grid G than the filament F.

The electron gun 140 is disposed inside the vacuum chamber 111 and includes a filament F and a grid G therein. The filament F may be formed of a hot electron source such as tungsten, CeB ₆ (Cerium Hexaboride), and LaB ₆ (Lanthanum Hexaboride).

In addition, the electron gun 140 may be indirectly connected to the head 135 of the mold power supply unit 130 through the heat deformation preventing member 141. In this case, the electron gun 140 is precisely set in advance so as to emit electrons toward the target 113. The heat deformation preventing member 141 may block the high temperature heat generated from the electron gun 140 from being transmitted to the head 135 of the mold power supply 130.

In addition, between the heat deformation preventing member 141 and the head 135 of the mold power supply unit 130 may be provided with a surface discharge preventing electrode 142 having a substantially disc shape. The surface discharge prevention electrode 142 may prevent the surface discharge from being concentrated on the top of the head 135.

Hereinafter, the control method of the X-ray generator 100 according to an embodiment of the present invention configured as described above will be described with reference to FIG.

First, the user sets the reference tube current and the reference tube voltage through the main controller 120 (S1). Accordingly, the grid controller 122 controls the grid generator 132 to apply the reference grid voltage according to the input reference tube current and the reference tube voltage to the grid G.

In addition, the filament control unit 123 controls the filament generator 133 to apply the reference filament voltage according to the input reference tube current and the reference tube voltage to the filament (F) (S2).

Accordingly, the filament F gradually rises in temperature, and then starts to emit electrons when the temperature is in the range of 1000 ° C to 3300 ° C. The electrons emitted from the filament F pass through the anode A, and the electron passing through the anode A passes through the tube current measuring unit 124 disposed between the anode A and the filament controller 123. Is measured by.

The measured tube current is transferred to the filament controller 123, and the filament controller 123 compares the measured tube current with the reference tube current (S3).

At this time, when the measured tube current is greater than the reference tube current, the filament controller 123 controls the filament generator 133 to lower the voltage applied to the filament (F) (S4).

On the other hand, when the measured tube current is smaller than the reference tube current, the filament controller 123 controls the filament generator 133 to increase the voltage applied to the filament (F) (S5).

Thereafter, the filament control unit 123 continuously receives the measurement tube current and repeatedly performs steps S3 to S5 to prevent the temperature of the filament F from rising.

As described above, the X-ray generator according to the exemplary embodiment may maintain the voltage applied to the grid to control the primary focusing point of the electron beam to an optimal point according to the reference tube current and the reference tube voltage.

In addition, it is possible to control the amount of electrons emitted from the filament by controlling the voltage applied to the filament, it is possible to prevent the temperature of the filament rises excessively to prevent the life of the filament is shortened.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and it should be understood by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims to be described.

Claims

An X-ray generator comprising a target, a filament, a grid, and an anode,

A filament control unit controlling a voltage applied to the filament; And

And a grid controller for controlling a voltage applied to the grid.

The grid control unit controls to apply a constant grid voltage to the grid,

The filament control unit X-ray generator characterized in that to control the voltage applied to the filament by receiving a measurement tube current value in comparison with a predetermined reference tube current value in order to maintain a constant temperature of the filament.
The method of claim 1,

And the grid voltage has a reference grid voltage value for focusing electrons emitted from the filament to a primary focusing point of an electron beam according to a predetermined reference tube voltage and a reference tube current.
The method of claim 2,

And the reference grid voltage value according to the preset reference tube voltage and reference tube current is stored in a reservoir provided in the grid control unit.
The method of claim 1,

The filament control unit,

When the measured tube current value is higher than the preset reference tube current value, the voltage applied to the filament is lowered,

And the voltage applied to the filament is increased when the measured tube current value is lower than the preset reference tube current value.
The method of claim 1,

X-ray generator, characterized in that the temperature of the filament is 1000 ℃ ~ 3300 ℃.
The method of claim 1,

The tube current is measured at the anode.
The method of claim 1,

The filament is X-ray generator, characterized in that made of any one of tungsten, CeB 6 (Cerium Hexaboride) and LaB 6 (Lanthanum Hexaboride).
The method of claim 1,

X-ray generator, characterized in that the amount of electrons impinging on the target is constant.
In the control method of the X-ray generator comprising a target, filament, grid and anode,

A setting step of setting a reference tube current and a reference tube voltage;

A grid voltage applying step of constantly applying a reference grid voltage according to the reference tube current and the reference tube voltage to the grid;

A filament voltage applying step of applying a reference filament voltage according to the reference tube current and the reference tube voltage to the filament;

And a comparison step of the filament controller, which has received the measured tube current measured at the anode, with the reference tube current.

In the comparing step, when the measured tube current is higher than the reference tube current, the voltage applied to the filament is lowered, and when the measured tube current is lower than the reference tube current, X-ray generation, characterized in that to increase the voltage applied to the filament Control method of the device.
The method of claim 9,

The comparing step is repeated control method of the X-ray generator.
The method of claim 9,

The temperature of the filament is a control method of the X-ray generator, characterized in that 1000 ℃ ~ 3300 ℃.