KR20240053227A - X-ray source driving device and X-ray generator using the same - Google Patents

Abstract

The present invention relates to a driving device for a field emission type X-ray source and an A driving device for a field emission type X-ray source including a gate electrode between
a voltage converter that generates an anode voltage, a cathode voltage, and a gate voltage respectively applied to the anode electrode, the cathode electrode, and the gate electrode using a voltage supplied from a power supply unit; a current detection unit for detecting tube current; a tube current comparison unit that compares the detected tube current with the target tube current; and a voltage control unit that adjusts the gate voltage applied to the gate electrode so that the detected tube current reaches the target tube current.

Description

X-ray source driving device and X-ray generator using the same}

The present invention relates to a driving device for an X-ray source, and particularly to a driving device for a field emission type X-ray source and an X-ray generating device using the same.

An X-ray imaging device is a device that irradiates a certain amount of X-rays to an object to be photographed, detects the X-rays that pass through the object with an

Such an X-ray imaging device includes an X-ray generator that generates X-rays and irradiates them to a subject, and the X-ray generator includes an X-ray generators are used in various inspection devices (diagnostic devices) such as medical, dental, non-destructive testing, and chemical analysis.

A conventional X-ray source uses a hot cathode made of tungsten as an electron emission source, heats the tungsten filament at a high voltage to emit hot electrons, and has a hot cathode type structure in which the emitted hot electrons collide with the target on the anode electrode side to generate X-rays. It was common, but recently, as the advantages of room temperature operation and fast switching compared to hot cathodes have been highlighted, the field emission type X-ray source using nanostructures such as carbon nanotubes (CNTs), which are cold cathode electron emission sources, as emitters Dissemination is occurring rapidly.

As shown in FIG. 1, the field emission type X-ray source (hereinafter referred to as the X-ray source) applies a tube voltage, which is an By inducing electron emission (e) of the emitter, electrons collide with the target on the anode electrode (A) to produce X-ray output.

In this general X-ray source, the amount of electron emission from the emitter is controlled by the gate voltage applied to the gate electrode (G), which in turn determines the tube current of the X-ray source. Therefore, in general, the tube current is controlled by adjusting the gate voltage applied to the gate electrode (G), and for this purpose, the gate voltage (G) is used as feedback. That is, in the case of a general Since it is a voltage control method that adjusts the gate voltage (Vg) by reflecting it on the signal (Vref), the process of controlling the tube current is delayed, and there is a problem of requiring an additional circuit for the gate voltage reference signal (Vref).

In addition, since X-ray sources have individual characteristic differences during the manufacturing stage, the gate voltage that must be applied to obtain the target tube current is different as shown in FIG. 2, resulting in the inconvenience of having to calibrate it in advance. Figure 2 shows gate voltages for obtaining a certain amount of tube current (1 to 6 mA) from different X-ray sources (K0000092 to K0000098).

Republic of Korea Patent Publication No. 10-2008-0056341 Republic of Korea Patent Publication No. 10-2010-0007046

Accordingly, the present invention is an invention created to solve the above-mentioned problem. The main purpose of the present invention is to provide a driving device for an X-ray source that can quickly adjust the tube current to a target value and an X-ray generating device using the same,

Furthermore, another object of the present invention is to provide a driving device for a field emission type

Another object of the present invention is to drive an X-ray source that can quickly control the tube current of each X-ray source by minimizing the power supply that supplies the gate voltage to each To provide a device and an X-ray generator using the same.

A driving device for an As a driving device for an X-ray source,

a voltage converter that generates an anode voltage, a cathode voltage, and a gate voltage respectively applied to the anode electrode, the cathode electrode, and the gate electrode using a voltage supplied from a power supply unit;

a current detection unit for detecting tube current;

a tube current comparison unit that compares the detected tube current with the target tube current;

and a voltage control unit that adjusts the gate voltage applied to the gate electrode so that the detected tube current reaches the target tube current.

In the X-ray source driving device including the above-described configuration, the current detection unit is connected between the voltage converter and the anode electrode or between the voltage converter and the cathode electrode to detect the tube current,

The voltage converter includes a second power supply unit that generates a gate voltage applied to the gate electrode with a voltage supplied from the power supply unit, and the voltage control unit controls the second power supply unit to adjust the gate voltage. It is characterized by

In addition, the X-ray generator according to an embodiment of the present invention is characterized by including an X-ray source driving device including the above-described configuration and the field emission type X-ray source.

Meanwhile, a multi-X-ray source driving device according to another embodiment of the present invention includes X-ray sources each including a cathode electrode having an electron emission source, an anode electrode having a target, and a gate electrode between the cathode electrode and the target surface. As a driving device for a field emission type X-ray source,

a voltage converter that generates anode voltage, cathode voltage, and gate voltage respectively applied to the anode electrode, cathode electrode, and gate electrode of each of the X-ray sources using voltage supplied from the power supply unit;

a controller that outputs a selection signal to select one or more of the X-ray sources;

a power supply switching unit that supplies the gate voltage output from the voltage converter to a gate electrode of one or more of the X-ray sources selected according to the selection signal;

Current detection units for detecting tube currents of each of the one or more X-ray sources to which the gate voltage is applied;

tube current comparison units that compare the detected tube current with a target tube current;

Characterized by comprising a voltage control unit that adjusts the gate voltage so that the detected tube current reaches the target tube current,

Among the above-described configurations, the voltage converter is connected to the input terminal of the power supply switching unit and includes second power supply units that generate a gate voltage applied to the gate electrode of each of the X-ray sources with the voltage supplied from the power supply unit. And the voltage control unit controls the second power supply unit to adjust the gate voltage.

According to the means for solving the technical problem described above, the Therefore, it has the advantage of being able to control the tube current much more simply and easily than the previous method, and has the advantage of not requiring a separate calibration process to correct the characteristic deviation of each X-ray source.

1 is a diagram showing the connection relationship between the structure of an X-ray source and a driving device.
Figure 2 is an example table of tube current and gate voltage for each X-ray source.
Figure 3 is an exemplary configuration diagram of an X-ray generator according to an embodiment of the present invention.
Figure 4 is a diagram for further explaining the operation of the X-ray source driving device according to an embodiment of the present invention.
Figure 5 is an exemplary configuration diagram of a multi-X-ray source driving device according to another embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings. The technical idea of the present invention may be more clearly understood through examples. In addition, the present invention is not limited to the embodiments described below, but may be modified into various forms within the scope of the technical idea to which the present invention pertains. Meanwhile, the same reference numerals indicate components with the same characteristics, and the description of components with the same reference numerals as those mentioned in the description of one drawing may be omitted in the description of other drawings.

Figure 3 illustrates a configuration diagram of an X-ray generator according to an embodiment of the present invention.

Referring to FIG. 3, the X-ray generator according to an embodiment of the present invention includes a field emission type ) and an X-ray source driving device for driving the X-ray source.

The X-ray source driving device according to an embodiment of the present invention applies voltage to the anode electrode, cathode electrode, and gate electrode of the It includes a high voltage generator 200 that generates the applied anode voltage, cathode voltage, and gate voltage.

The power supply unit 100 provides power of a predetermined voltage to the controller 400 and the high voltage generator 200 inside the device using power supplied from a battery or power supplied from a power adapter through a power cable.

For reference, in the case of the field emission It is possible to have a low potential difference. This is just an example and is not limited to this.

Meanwhile, the high voltage generator 200 receives power of a predetermined size from the power supply unit 100 and converts the voltage, and is controlled by the controller 400 to convert the voltage converter 210. It includes a voltage control unit 240 that controls driving, and more specifically, gate voltage.

The voltage converter 210 may include a first power supply for supplying anode and cathode voltages, and a second power supply for supplying a gate voltage. Each of these power supply units may include an inverter, a transformer, and a high voltage generator (boost circuit) that is connected to the secondary side of the transformer and generates a high voltage.

Furthermore, the high voltage generator 200 may further include a current detection unit 220 for detecting tube current flowing between the anode and cathode electrodes of the X-ray source 300. This current detection unit 220 may be connected to the front end of the X-ray source 300, that is, between the voltage converter 210 and the anode electrode, or between the voltage converter 210 and the cathode electrode to detect tube current. The current detection unit 220 may include, for example, a known current sensor or current detection circuit.

In addition to the above-described configurations, the driving device of the It further includes a voltage control unit 240 that adjusts the gate voltage applied to the gate electrode to reach the tube current.

The voltage control unit 240 adjusts the frequency or duty cycle of the inverter of the second power supply unit to control the gate voltage, adjusts the boost ratio of the high voltage generator (boost circuit), or controls the voltage converter ( It may include a separate voltage regulation circuit that reduces or boosts the gate voltage generated in the second power supply unit of 210) before applying it to the gate electrode.

Hereinafter, the operation of the X-ray source driving device including the above-described configurations will be described in more detail with reference to FIG. 4.

First, the voltage control unit 240 controls the first power supply unit in the voltage converter 210 so that the anode voltage and cathode voltage are applied to the anode and cathode electrodes, respectively, in order to detect the tube current under the control of the controller 400. In addition, the voltage control unit 240 controls the second power supply unit within the voltage converter 210 so that the gate voltage is applied to the gate electrode. Accordingly, electrons are emitted from the electron emission source disposed on the cathode electrode, thereby forming a tube current. Since this tube current corresponds to the current flowing between the anode electrode and the cathode electrode, the current detection unit 220 is connected to the front end of the X-ray source 300, that is, between the voltage converter 210 and the anode electrode, or the voltage converter 210. ) and outputs the tube current level between the cathode electrode (step S100), and the tube current comparison unit 230, which can be implemented with a comparator, compares the detected tube current level with the preset target tube current level (step S110) and operates the voltage control unit (step S110). 240) or output to the controller 400.

Accordingly, the voltage control unit 240 or the controller 400 controls the voltage converter 210 to adjust the voltage applied to the gate electrode so that the detected tube current reaches the target tube current (step S120), and then the tube current reaches the target tube current. By controlling the voltage converter 210 to maintain the X-ray source driving device according to an embodiment of the present invention, the tube current value can be kept constant at the target tube current value.

In this way, the present invention has the advantage of being able to adjust the tube current of the X-ray source much more simply and easily than the conventional method because the tube current of the It has the advantage of not requiring a separate calibration process to correct for characteristic deviations.

Figure 5 illustrates the configuration of a driving device for an X-ray source according to another embodiment of the present invention, and more specifically, shows the configuration of a driving device for a multi-X-ray source having a plurality of X-ray sources.

Referring to FIG. 5, an X-ray generator according to another embodiment of the present invention includes X-ray sources 300, 310, and 320 for generating and outputting X-rays, respectively, and a driving device for the X-ray source. In Figure 5, only three X-ray sources are shown as an example, but the number is not limited to this and the number may vary depending on the size, purpose, and usage of the X-ray generator. As described in FIG. 3, each of the X-ray sources 300, 310, and 320 also includes a cathode electrode having an electron emission source, an anode electrode having a target, and a gate electrode between the electron emission source and the target.

The driving device of the multi-X-ray source according to another embodiment of the present invention is an anode voltage and cathode applied to the anode electrode, cathode electrode, and gate electrode of each of the A voltage converter 210 that generates a voltage and a gate voltage, a controller 400 that outputs a selection signal (CS) for selecting one or more of the X-ray sources (300, 310, and 320), and the selection signal (CS) A power supply switching unit 330 that supplies the gate voltage output from the voltage converter 210 to the gate electrode of one or more of the X-ray sources 300, 310, and 320 selected accordingly, and each of the X-ray sources 300, 310, and 320 Current detection units 220, 221, 222 for detecting the tube current, current comparison units 230 for comparing the tube current detected from each of the X-ray sources 300, 310, 320 with the target tube current, and X-rays selected according to the selection signal CS It includes a voltage control unit 240 that adjusts each gate voltage of the voltage converter 210 so that the tube current detected from the source reaches the target tube current.

Among the above-described configurations, the voltage converter 210 is a first power supply (not shown) that is commonly connected to the anode and cathode electrodes of each of the X-ray sources 300, 310, and 320 and supplies common anode and cathode voltages. , It may include second power supply units that generate gate voltages applied to the gate electrodes of each of the X-ray sources (300, 310, 320) and are respectively connected to the input terminal of the power supply switching unit 330, The voltage control unit 240 may individually control the second power supply units so that the tube currents of each of the X-ray sources 300, 310, and 320 are maintained at the target tube current.

The power supply switching unit 330 includes electrical or mechanical switching elements (FET, IGBT, relay elements) that switch on and off according to the selection signal CS, and the switching elements are the same as the X-ray sources. It can be provided with .

For reference, a positive (+) voltage or a negative (-) voltage may be applied or a ground power source may be connected to each cathode electrode of each of the plurality of A voltage having a higher potential may be applied. In addition, the above-described first power supply unit and the second power supply unit are connected to an inverter for converting DC power to AC power, a transformer for boosting AC power, and the secondary side of the transformer, respectively, to generate a high voltage to be applied to the anode or gate electrode. It may include a high voltage generator.

To further explain the operation of the driving device of the multi-X-ray source including the above-described configurations, the voltage control unit 240 applies anode voltage and The first power supply unit in the voltage converter 210 is controlled so that the cathode voltage is applied.

Meanwhile, the controller 400 selects one or more X-ray sources for applying the gate voltage and outputs the corresponding selection signal CS to the voltage control unit 240 and the power supply switching unit 330. If the selection signal (CS) is a signal that selects the X-ray source 300, the first switch (SW1) of the power supply switching unit 330 is switched on by the selection signal (CS), thereby causing the A gate voltage is applied to the gate electrode of the X-ray source 300. Accordingly, an electron beam is emitted from the electron emission source disposed on the cathode electrode of the X-ray source 300, thereby forming a tube current.

This tube current is detected by the current detection unit (A, 220), and the detected tube current level is transmitted to the current comparison unit corresponding to the After being compared with the level, the comparison result is output to the voltage control unit 240 or controller 400.

Accordingly, the voltage control unit 240 or the controller 400 controls the voltage converter 210 to adjust the voltage applied to the gate electrode of the X-ray source 300 so that the detected tube current reaches the target tube current. Accordingly, the tube current value of the X-ray source 300 can be maintained constant.

In this way, the controller 400 adjusts the tube current value of each X-ray source 300, 310, and 320 by outputting a selection signal CS so that the gate voltage is applied to the gate electrode of the

The driving device of the above-mentioned multi-X-ray source can also adjust the tube current detected for each It has the advantage of not requiring a separate calibration process to correct for characteristic deviations for each X-ray source.

In addition, since the structure allows multiple

The present invention has been described above with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom. For example, the X-ray source driving device according to an embodiment of the present invention can be applied to and utilized in various X-ray imaging devices, X-ray diagnostic devices, or X-ray inspection devices, such as for medical, dental, non-destructive testing, and chemical analysis. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached claims.

Claims (8)

A driving device for a field emission type X-ray source including a cathode electrode having an electron emission source, an anode electrode having a target, and a gate electrode between the electron emission source and the target,
a voltage converter that generates an anode voltage, a cathode voltage, and a gate voltage respectively applied to the anode electrode, the cathode electrode, and the gate electrode using a voltage supplied from a power supply unit;
a current detection unit for detecting tube current;
a tube current comparison unit that compares the detected tube current with the target tube current;
A voltage control unit that adjusts a gate voltage applied to the gate electrode so that the detected tube current reaches the target tube current. The method of claim 1, wherein the current detection unit,
A driving device for an X-ray source, characterized in that it is connected between the voltage converter and the anode electrode or between the voltage converter and the cathode electrode to detect the tube current. The method of claim 1, wherein the voltage converter,
A driving device for an . An X-ray generator comprising a driving device for an X-ray source according to any one of claims 1 to 3,
a driving device for the X-ray source;
An X-ray generator including the field emission type X-ray source. A driving device for a field emission type X-ray source including X-ray sources each including a cathode electrode having an electron emission source, an anode electrode having a target, and a gate electrode between the cathode electrode and the target surface,
a voltage converter that generates anode voltage, cathode voltage, and gate voltage respectively applied to the anode electrode, cathode electrode, and gate electrode of each of the X-ray sources using voltage supplied from the power supply unit;
a controller that outputs a selection signal to select one or more of the X-ray sources;
a power supply switching unit that supplies the gate voltage output from the voltage converter to a gate electrode of one or more of the X-ray sources selected according to the selection signal;
Current detection units for detecting tube currents of each of the one or more X-ray sources to which the gate voltage is applied;
tube current comparison units that compare the detected tube current with a target tube current;
A driving device for a multi-X-ray source, comprising: a voltage control unit that adjusts the gate voltage so that the detected tube current reaches the target tube current. The method of claim 5, wherein the voltage converter,
Second power supply units connected to the input terminal of the power supply switching unit and generating gate voltages applied to gate electrodes of each of the A driving device for a multi-X-ray source that controls the power supply to adjust the gate voltage. The method of claim 5, wherein the power supply switching unit,
A driving device for a multi-X-ray source, comprising electrical or mechanical switching elements that switch on and off according to the selection signal, wherein the switching elements are provided in equal numbers as the X-ray sources. An X-ray generator comprising a driving device for a multi-X-ray source according to any one of claims 5 to 7, comprising:
a driving device for the multi-X-ray source;
An X-ray generator including the field emission type X-ray sources.

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