Tube current control device installable in x-ray generating device

Abstract

Disclosed is a tube current control device which can be installed in an X-ray generating device. Specifically, the tube current control device comprises: a switching unit for sensing the tube current of the X-ray generating device and performing switching on the basis of the driving voltage; a tube current detection unit for outputting a first voltage on the basis of the tube current; a voltage amplification unit for receiving the first voltage and outputting an amplified second voltage; and a driving voltage adjustment unit for receiving the second voltage and adjusting the driving voltage to control the tube current.

Description

Tube current control device that can be installed in an X-ray generator

[0001] The present disclosure relates to a tube current control device, and more specifically, to a tube current control device installed / connected to an X-ray generator to control and / or limit the tube current of the X-ray generator.

[0002] X-rays, a type of electromagnetic wave, are widely used as a non-destructive testing tool due to their linearity, penetrability, and differences in absorption characteristics depending on the properties of the material. Currently, most X-rays are fired continuously in an analog manner, but with technological advancements, X-ray pulsing technology is becoming increasingly important. This is because by switching continuous X-ray emission at high speeds, moving objects can be imaged more clearly and the patient's radiation exposure can be significantly reduced.

[0003] Typically, X-ray generators employ semiconductor switches to achieve high-speed switching, and the tube current is determined by the tube voltage and the charge of the X-ray source at the time the semiconductor switch switches from an off state to an on state. In other words, the tube current is determined by an uncontrollable transient state as the on and off states are repeated tens of thousands of times per second.

[0004] In the case of conventional technology, the tube current was limited by inserting a high-resistance resistor between the source terminal or emitter terminal of the semiconductor switch and the ground. However, this method has a problem in that when an abnormal current that greatly exceeds the size of the general tube current occurs (such as an arc occurrence), a voltage that greatly exceeds the voltage drop set in the inserted resistor is induced, destroying the semiconductor switch.

[0005] The present disclosure proposes a tube current control device that limits / controls not only the normal current of an X-ray generator but also the abnormal current (i.e., arc current).

[0006] In addition, the present disclosure proposes a tube current control device that can be easily installed in an existing X-ray generating device to control normal current / accident current.

[0007] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present invention pertains from the description below.

[0008] The present disclosure proposes a tube current control device that can be installed in an X-ray generating device.

[0009] The tube current control device of the present disclosure may include a switching unit that senses the tube current of an X-ray generator and performs switching based on a driving voltage, a tube current detection unit that outputs a first voltage based on the tube current, a voltage amplification unit that receives the first voltage and outputs an amplified second voltage, and a driving voltage control unit that receives the second voltage and controls the tube current by controlling the driving voltage.

[0010] In addition, in the device of the present disclosure, the switching unit may include a switching power supply unit, a tube current sensing unit that outputs a sensing signal for sensing the tube current of the X-ray generating device, a switch control unit that outputs a switching signal based on the sensing signal, a switch driving unit that outputs the driving voltage based on the switching signal, and a switch element that performs switching based on the driving voltage.

[0011] In addition, in the device of the present disclosure, the tube current detection unit may be a first shunt resistor, the voltage amplification unit may be a non-inverting amplifier, and the driving voltage control unit may include a bipolar junction transistor (BJT) and a resistor connected to the base of the BJT.

[0012] Additionally, in the device of the present disclosure, the tube current sensing unit may be a second shunt resistor, and the switch driving unit may include a gate driver and a gate resistor having one end connected to the gate driver.

[0013] In addition, in the device of the present disclosure, a first input terminal of the switch control unit may be connected to the switching power supply unit, a second input terminal of the switch control unit may be connected to the other terminal of the second shunt resistor, and an output terminal of the switch control unit may be connected to a first input terminal of the switch driver unit.

[0014] Additionally, in the device of the present disclosure, the output terminal of the switch driving unit can be connected to the gate of the MOSFET and the collector of the BJT.

[0015] Additionally, in the device of the present disclosure, the source of the MOSFET can be connected to one end of the first shunt resistor and the first input terminal of the non-inverting amplifier.

[0016] Additionally, in the device of the present disclosure, the other end of the first shunt resistor may be connected to one end of the second shunt resistor, the second input terminal of the non-inverting amplifier, the emitter of the BJT, and the second input terminal of the switch driver.

[0017] Additionally, in the device of the present disclosure, the output terminal of the non-inverting amplifier can be connected to the other terminal of the gate resistor.

[0018] Additionally, in the device of the present disclosure, the X-ray generating device may include a high-pressure supply unit, a filament heating unit, and an X-ray tube.

[0019] Additionally, in the device of the present disclosure, the first end of the high-voltage supply unit may be connected to the drain of the MOSFET, and the anode of the X-ray tube may be connected to the other end of the second shunt resistor.

[0020] Additionally, in the device of the present disclosure, the second end of the high-pressure supply unit may be connected to the cathode of the X-ray tube, and the filament heating unit may be connected to the cathode of the X-ray tube.

[0021] According to the present disclosure, there is an effect of limiting / controlling not only the normal current of the X-ray generating device but also the abnormal current (i.e., arc current).

[0022] In addition, according to the present disclosure, there is an effect that can be easily installed in an existing X-ray generating device to control the tube current (i.e., normal current / abnormal current).

[0023] In addition, according to the present disclosure, there is an effect of improving the performance and durability of an X-ray generator by controlling the tube current of an existing X-ray generator.

[0024] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0025] The accompanying drawings, which are incorporated in and are intended to aid in the understanding of the present disclosure and are part of the detailed description, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0026] Figure 1 illustrates an X-ray generating device to which the tube current control device of the present disclosure can be applied.

[0027] Figure 2 illustrates a tube current control device installed / connected to an X-ray generator.

[0028] Figure 3 is a block diagram of a tube current control device proposed in the present disclosure.

[0029] Figure 4 illustrates a circuit diagram of a tube current control device installed / connected to an X-ray generating device proposed in the present disclosure.

[0030] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0031] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0032] In the present disclosure, the terms ‘power’, ‘voltage’, ‘electric power’, ‘current’, ‘signal’, etc. may be applied interchangeably with each other.

[0033] In this disclosure, ' / ' means 'and', 'or' or 'and / or' depending on the context.

[0034] In the present disclosure, the tube current control device performs not only limiting / controlling tube current but also dose control, and may be referred to as a switching device, dose control device, etc.

[0035] Figure 1 illustrates an X-ray generating device to which the tube current control device of the present disclosure can be applied.

[0036] Referring to FIG. 1, an X-ray generating device may include an X-ray tube (100) and a high-voltage power supply unit (200). One end of the high-voltage power supply unit (200) may be connected to one end of the X-ray tube (100), and the other end of the high-voltage power supply unit (200) may be connected to the other end of the X-ray tube (100). The high-voltage power supply unit (200) may heat a filament of the X-ray tube (100). In addition, the high-voltage power supply unit (200) may apply a high voltage to the X-ray tube (100). Accordingly, the X-ray tube (100) generates a tube current and / or X-rays. That is, the X-ray tube (100) may generate / form a tube current and / or X-rays by accelerating free electrons generated by heating the filament from the filament toward the anode by the high voltage.

[0037] However, such conventional X-ray generating devices have a problem in that they cannot accurately control the X-ray dose by not being able to control and / or limit normal current and / or abnormal current, thereby damaging the human body or weakening the durability of the X-ray generating device.

[0038] Accordingly, the present disclosure proposes a tube current control device that can be easily installed / connected to an existing X-ray generating device to control / limit tube current.

[0039] For example, a current control device (300) can be (additionally) connected to an X-ray generator via a new cable to limit the current and / or control the current.

[0040] Figure 2 illustrates a tube current control device installed / connected to an X-ray generator.

[0041] Referring to FIG. 2, an X-ray generation system can be configured in which one end (e.g., anode / cathode) of an X-ray tube (100) and one end of a high-voltage power supply unit (200) maintain the existing connection via an existing cable (10), the other end (e.g., cathode / anode) of the X-ray tube (100) is connected to one end of a newly configured tube current control device (300) via an existing cable (20), and the other end of the tube current control device (300) is connected to the other end of the high-voltage power supply unit (200) via a new cable (30). That is, the tube current control device (300) can be connected / mounted to an existing X-ray generation device via a separate cable to limit / control tube current.

[0042] The connection method of the tube current control device (300) of FIG. 2 is an example, and the tube current control device (300) may be connected / mounted to the X-ray generator in use in various other ways to perform current limiting and control operations. For example, the other end of the X-ray tube (100) may be connected to one end of the tube current control device (300) via a new cable, the other end of the tube current control device (300) may be connected to the other end of the high-voltage power supply unit (200) via an existing cable, and one end of the X-ray tube (100) and one end of the high-voltage power supply unit (200) may remain connected to each other via the existing cable. Alternatively, the tube current control device (300) may be connected / mounted between one end of the X-ray tube (100) and one end of the high-voltage power supply unit (200) via a new cable and / or an existing cable. And / or, it may be connected to an alternating current (AC) voltage output unit supplied from the system to secure operating power of the tube current control device (300).

[0043] Figure 3 is a block diagram of a tube current control device proposed in the present disclosure.

[0044] Referring to FIG. 3, the tube current control device (300) may include at least one of a switching unit (310), a tube current detection unit (320), a voltage amplification unit (330), and / or a driving voltage control unit (340).

[0045] The switching unit (310) may include at least one of a switching power supply unit (e.g., block 311 of FIG. 4), a tube current sensing unit (e.g., block 312 of FIG. 4), a switch control unit (e.g., block 313 of FIG. 4), a switch driving unit (e.g., block 314 of FIG. 4), and / or a switch element (e.g., block 315 of FIG. 4). The switching unit (310) may sense the tube current of the X-ray generating device and perform switching based on the driving voltage.

[0046] The tube current detection unit (320) can output a first voltage based on the tube current. The voltage amplification unit (330) can receive the first voltage and output an amplified second voltage.

[0047] The driving voltage control unit (340) can control the tube current by receiving a second voltage and controlling the driving voltage.

[0048] Hereinafter, the tube current control device will be described in more detail with reference to FIG. 4.

[0049] Figure 4 illustrates a circuit diagram of a tube current control device installed / connected to an X-ray generating device proposed in the present disclosure.

[0050] Referring to FIG. 4, the tube current control device (300) may include at least one of a switching power supply unit (311), a tube current sensing unit (312), a switch control unit (313), a switch driving unit (314), a switch element (315), a tube current detection unit (320), a voltage amplifier unit (330), and / or a driving voltage control unit (340).

[0051] For example, the tube current detection unit (320) may be a first shunt resistor, the voltage amplification unit (330) may be a non-inverting amplifier (e.g., an OP-AMP non-inverting amplifier), and / or the driving voltage control unit (340) may include a bipolar junction transistor (BJT) (341) (e.g., an NPN BJT) and a resistor (342) connected to the base of the BJT (341). And / or, the tube current sensing unit (312) is a second shunt resistor, and / or, the switch driving unit (314) includes a gate driver (314-1) and a gate resistor (314-2) having one end connected to the gate driver (314-1), and the switch element (315) may be a metal oxide semiconductor field effect transistor (MOSFET) or may include a MOSFET and a diode in which the anode is connected to the source and the cathode is connected to the drain. In the present disclosure, a MOSFET may also mean a MOSFET and a diode in which the anode is connected to the source and the cathode is connected to the drain.

[0052] And / or, the switch power supply unit (311) may be connected to the first input terminal of the switch control unit (313).

[0053] And / or, the first input terminal of the switch control unit (313) may be connected to the switching power supply unit (311), and / or, the second input terminal of the switch control unit (313) may be connected to the other terminal of the second shunt resistor, and / or, the output terminal of the switch control unit (313) may be connected to the first input terminal of the gate driver (314-1). For example, the switch control unit (313) may be implemented including a comparator using an operational amplifier (OP-AMP). For example, the comparator may be a hysteresis comparator for preventing jittering of an OP-AMP output signal that may occur due to external noise. And / or, an OP-AMP voltage follower may be applied to the input terminal of the comparator to prevent voltage loss of the input signal and maintain the original signal.

[0054] And / or, the first input terminal of the gate driver (314-1) is connected to the output terminal of the switch control unit (313), and / or, the second input terminal of the gate driver (314-1) is connected to at least one of the emitter of the BJT, the second input terminal of the non-inverting amplifier (330), the other terminal of the first shunt resistor, and / or one terminal of the second shunt resistor, and / or, the output terminal of the gate driver (314-1) may be connected to one terminal of the gate resistor (314-2). For example, the second input terminal of the gate driver (314-1) may be utilized as a reference potential for the positive voltage or the positive and negative voltages of the gate driver (314-1). And / or, the second input terminal of the gate driver (314-1) can be used as a reference potential of the tube current detection unit (320), the driving voltage control unit (340), and the voltage amplification unit (330).

[0055] And / or, one end of the gate resistor (314-2) may be connected to the output terminal of the gate driver (314-1) and / or, the other end of the gate resistor (314-2) may be connected to at least one of the collector of the BJT (314) and / or the gate of the MOSFET (315).

[0056] And / or, the gate of the MOSFET (315) (e.g., N-Channel MOSFET) may be connected to at least one of the other terminal of the gate resistor (314-2) and / or the collector of the BJT (341), and / or, the source of the MOSFET (315) may be connected to at least one of the first terminal of the first shunt resistor (320) and / or the first input terminal of the non-inverting amplifier (330).

[0057] And / or, one end of the first shunt resistor (320) may be connected to at least one of the source of the MOSFET (315) and / or the first input terminal of the non-inverting amplifier (330), and / or, the other end of the first shunt resistor (320) may be connected to at least one of the one end of the second shunt resistor (312), the second input terminal of the gate driver (314-1), the emitter of the BJT, and / or the second input terminal of the non-inverting amplifier (330).

[0058] And / or, one end of the second shunt resistor (312) may be connected to at least one of the second input terminal of the gate driver (314-1), the emitter of the BJT (341), the second input terminal of the non-inverting amplifier (330), and / or the other end of the first shunt resistor (320).

[0059] And / or, the first input terminal of the non-inverting amplifier (330) may be connected to at least one of the source of the MOSFET (315) and / or one end of the first shunt resistor (320), and / or, the second input terminal of the non-inverting amplifier (330) may be connected to at least one of the other end of the first shunt resistor (320), one end of the second shunt resistor (312), the second input terminal of the gate driver (314-1), and / or the emitter of the BJT (341), and the output terminal of the non-inverting amplifier (330) may be connected to the other end of the base resistor (342).

[0060] And / or, one end of the base resistor (342) may be connected to the base of the BJT (341), and / or the other end of the base resistor (342) may be connected to the output terminal of the non-inverting amplifier (330).

[0061] And / or, the collector of the BJT (341) may be connected to at least one of the other terminal of the gate resistor (314-2) and / or the gate of the MOSFET (315), the base of the BJT (341) may be connected to one terminal of the base resistor (342), and / or the emitter of the BJT (341) may be connected to at least one of the second input terminal of the gate driver (314-1), the second input terminal of the non-inverting amplifier (330), the other terminal of the first shunt resistor (320), and / or one terminal of the second shunt resistor (312).

[0062] For example, when the tube current sensing unit (312) is implemented as a first shunt resistor as described above, the first shunt resistor may be configured with a capacitor, a varistor, and / or a transient voltage suppressor (TVS) diode, etc., to stabilize the voltage at both ends. For example, the first shunt resistor may be configured in parallel with a capacitor, a varistor, and / or a TVS diode, etc. In the present disclosure, the term 'shunt resistor' may also be referred to as the term 'resistance'. And / or, the tube current sensing unit (312) may be implemented as a circuit capable of detecting current, such as a current sensor, as a circuit for detecting current. For example, when the tube current sensing unit (312) is implemented as a current sensor, the output of the current sensor may be applied as a voltage type or a current type. And / or, a low-pass filter may be additionally configured at the output unit of the current sensor to stabilize the output.

[0063] And / or, the switch element (315) may be implemented as a semiconductor switch (or transistor) other than a MOSFET. For example, unlike FIG. 4, the switch element (315) may be implemented as a junction transistor (JT), a BJT, a field effect transistor (FET), or an insulated gate bipolar transistor (IGBT). And / or, at least one of a resistor-capacitor-diode snubber (RCD snubber) circuit, a resistor-capacitor (RC) series circuit, a varistor, and / or a TVS diode may be configured in parallel with the switch element (315) to stabilize the voltage across the two terminals of the switch element (315).

[0064] And / or, the voltage amplifier (330) may be implemented in various forms to control the level of the input current (e.g., base current) of the driving voltage control unit (341) (or BJT). Unlike FIG. 4, it may be implemented as an inverting amplifier, and / or a direct / direct converter (DC / DC converter), etc.

[0065] And / or, unlike in Fig. 4, the driving voltage control unit (340) may be implemented by various transistors other than BJT. For example, the driving voltage control unit (340) may be implemented by a MOSFET, JT, FET, IGBT, etc.

[0066] The above-described tube current control device (300) can be installed / connected / mounted in an X-ray generator. The X-ray generator can include a high-voltage supply unit (210), a filament heating unit (220), and an X-ray tube (100). For example, the high-voltage power supply unit (200) of FIGS. 1 and 2 can mean one including the high-voltage supply unit (210) and the filament heating unit (220) of FIG. 4.

[0067] For example, a first end (e.g., anode / cathode) of the high-pressure supply unit (210) may be connected to one end (e.g., anode) of the X-ray tube (100), and a second end (e.g., cathode / anode) of the high-pressure supply unit (210) may be connected to the other end (e.g., cathode) of the X-ray tube (100). And / or, the filament heating unit (220) may be connected to the cathode of the X-ray tube (100).

[0068] At this time, the connection between the first terminal of the high-voltage supply unit (210) of the X-ray generator and the anode of the X-ray tube (100) of the X-ray generator is disconnected, and as shown in FIG. 4, the drain of the MOSFET (315) of the tube current control device (300) may be connected to the first terminal of the high-voltage supply unit (210), and / or the other terminal of the second shunt resistor (312) of the tube current control device (300) may be connected to the anode of the X-ray tube (100). Here, at least one of the connection (1) between the drain of the MOSFET (315) of the tube current control device (300) and the first terminal of the high-voltage supply unit (210), and / or the connection (2) between the other terminal of the second shunt resistor (312) of the tube current control device (300) and the X-ray tube (100) may use a new cable. Alternatively, the connection (1) between the drain of the MOSFET (315) of the tube current control device (300) and the first terminal of the high-voltage supply unit (210), and / or the connection (2) between the other terminal of the second shunt resistor (312) of the tube current control device (300) and the X-ray tube (100) may all be connected via an existing cable. This connection method is an example, and the X-ray generator and the tube current control device (300) may be connected in various ways.

[0069] Below, the operation and / or function of each component of the tube current control device (300) will be examined.

[0070] The switching power supply unit (311) can supply power to the tube current control device (300). For example, the switching power supply unit (310) can receive AC commercial power and supply power to the tube current control device (330). For example, the AC commercial power can be single-phase AC 220V 60Hz, single-phase AC 380V, three-phase AC 200V, three-phase AC 380V 60Hz / 50Hz, etc. For example, the switching power supply unit (311) can supply power to generate a low-voltage DC voltage required for the operation of the switch control unit (313) and the gate driver (314-1). At this time, the low-voltage DC voltage can be configured in a structure that is electrically isolated from the AC input voltage. For example, the switching power supply unit (311) may be configured with a rectifier unit that receives an AC input voltage and converts it into a DC voltage, and / or a DC / DC converter unit (e.g., a DC / DC converter) that converts the rectified DC voltage into a DC voltage. For example, for insulation separation, the DC / DC converter may be configured as an insulated type using a transformer or the like.

[0071] When a high voltage is applied to the X-ray tube (100) by the high-voltage power supply unit (210), the tube current sensing unit (312) can sense / detect this and transmit a sensing signal to the switch control unit (313). For example, the tube current sensing unit (312) can operate in a manner of detecting the tube current of the X-ray tube (100).

[0072] The switch control unit (313) can receive a sensing signal (e.g., voltage) from the tube current sensing unit (312) and output a switching signal. For example, the switching signal can be a pulse width modulation (PWM) signal. For example, the switch control unit (313) can be a control device that is driven by receiving a direct current voltage generated from the switching power supply unit (311). For example, the control device can be composed of a microcontroller unit (MCU) and can be composed of an input operation and an output operation. In the output operation, the MCU can transmit a switching operation command to the gate driver (314-1) in the PWM method or the intermittent pulse method according to a pre-programmed rule. At this time, the switching frequency and the duty ratio of the PWM can be programmed by the user as needed.

[0073] And / or, the MCU can detect the voltage of the second shunt resistor (312) in the input operation to detect the start time of X-ray generation of the X-ray imaging equipment (e.g., X-ray generator) and use it as a start signal for the output operation of the MCU, thereby limiting unnecessary output operations of the MCU. At this time, an amplifier that amplifies the detected voltage to a voltage corresponding to a required input voltage condition for inputting the MCU may be included. For example, it can be implemented by including a comparator using an operational amplifier (OP-AMP). For example, the comparator can be a hysteresis comparator to prevent jittering of the OP-AMP output signal that may occur due to external noise. And / or, an OP-AMP voltage follower can be applied to the input terminal of the comparator to prevent voltage loss of the input signal and maintain the original signal.

[0074] And / or, the switch control unit (313) may include a voltage regulator for generating a required operating voltage of the MCU and a voltage regulator for generating a required operating voltage of the gate driver (314-1). At this time, both voltage regulators can transform the isolated DC voltage generated by the switching power supply unit (311) into an appropriate DC voltage. At this time, a linear voltage regulator can be applied as the voltage regulator. At this time, the magnitude of the DC voltage supplied to the MCU varies depending on the voltage value required by the applied MCU. And / or, the DC voltage supplied to the gate driver (314-1) may supply only a positive voltage or both positive and negative voltages as needed. For example, the magnitude of the positive voltage can be supplied from above the threshold voltage (or gate threshold voltage), which is the voltage at which the semiconductor switch starts to turn on, to below the maximum gate voltage, which is the applied limit voltage, and the magnitude of the negative voltage can be supplied from above the minimum gate voltage, which is the applied limit voltage.

[0075] The switch driver (314) can drive the switch element (315). For example, the switch driver (314) can supply a positive voltage or positive and negative voltages supplied from the switch control unit (313) to the gate terminal of the switch element (315) through the gate resistor (314-2) according to a switching operation command supplied to the switch control unit (313). At this time, the gate driver (314-1) can be configured as an insulated gate driver to protect the switch control unit (313). And / or, the switch driver (314) can include a DC / DC converter that generates an insulated driving voltage based on the driving voltage supplied to the switch control unit (313). And / or, the driving voltage of the switch driving unit (314) is controlled based on the driving voltage control unit (340) below at the rear end (or other end) of the gate resistor (314-2), and thereby the switch element (315) can control and / or limit the tube current.

[0076] The switch element (315) can perform a tube current switching operation by receiving a driving voltage from the switch driving unit (314). For example, the switch element (315) can perform a tube current switching operation by receiving a +V gate turn-on voltage or a -V gate turn-off voltage. That is, the tube current and / or X-ray dose can be controlled through the switching operation of the switch element. The switching operation can be performed at a preset cycle while the X-ray generating device (or X-ray photographing device) is completed. And / or, the switch element (315) can control and / or limit the tube current by controlling the gate voltage by the driving voltage control unit (340).

[0077] The X-ray tube (100) can generate X-rays by generating hot electrons and / or free electrons in a filament based on energy supplied from a high-voltage power supply unit (200) and accelerating electrons from the filament (i.e., cathode) to the anode. Here, the X-ray dose and / or tube current of the X-ray tube (100) can be controlled by the switching operation of the switching element as described above. And / or, the X-ray tube (100) can control and / or limit the tube current by a tube current detection unit (320), a voltage amplifier unit (330), a driving voltage control unit (340), etc., as described below.

[0078] The tube current detection unit (320) can receive tube current and transmit a detection signal (or control signal) (e.g., voltage) to the voltage amplifier unit (330). For example, the tube current detection unit (320) can detect tube current flowing through the switch element (315).

[0079] The voltage amplifier (330) can output an amplified signal (e.g., voltage) for driving and controlling the driving voltage control unit (340) based on a detection signal (e.g., voltage) from the tube current detection unit (320). For example, the voltage amplifier (330) can receive a voltage from the tube current detection unit (320) and amplify it.

[0080] For example, if the voltage amplifier (330) is implemented as an OP-AMP non-inverting amplifier (330) that receives the voltage of the tube current detection unit (320) as shown in FIG. 4 and amplifies it, the driving voltage control unit (340) is implemented including a BJT (341), and the switch element (315) is implemented as a MOSFET (315), the OP-AMP non-inverting amplifier (315) can amplify the voltage input from the tube current detection unit (320) according to a preset amplification rate and input it to the base terminal of the driving voltage control unit (340), thereby generating a collector current that is amplified compared to the base current. This collector current is supplied to the BJT (341) of the driving voltage control unit (340) through the gate resistor (314-2) of the switch driver (314), and the increased collector current of the BJT (341) can cause a voltage drop in the gate resistor (314-2) according to Ohm's law. Therefore, a voltage reduced by the voltage drop of the gate resistor (314-2) from the fixed semiconductor switch turn-on voltage output from the switch driver (314) can be applied as the gate voltage to the switch element (315). The magnitude of the voltage drop of the gate resistor (314-2) is determined by the collector current of the BJT (341), and thus can be adjusted according to the base current and the amplification ratio of the BJT (341).

[0081] And / or, the adjusted gate voltage (+V -> +V') is supplied to the gate and source of the MOSFET (315), and the gate voltage of the MOSFET (315) can be reduced to a level similar to the threshold voltage value of the MOSFET (315). Through this, the magnitude of the conduction current of the MOSFET (315) can be limited or adjusted (or controlled).

[0082] As described above, the driving voltage control unit (340) can limit the tube current based on the correlation between the driving voltage of the switch element (315) and the tube current size. The driving voltage control unit (340) can readjust the switch driving voltage of +V size supplied from the switch driving unit (314) to voltage +V' to generate the tube current setting value I.

[0083] The switch element (315) blocks the tube current in the off state, but can limit the tube current and arc current as described above in the on state. That is, the switch element (315) periodically repeats the on state and the off state, and can limit the tube current and arc current as described above in the on state.

[0084] As described above, in order to limit / control the tube current, a circuit constant design is required to reduce the gate voltage of the MOSFET (315) to a level similar to the threshold voltage value of the MOSFET (315). At this time, the amplification factor of the BJT (341), the base saturation voltage of the BJT (341), the base resistance value of the BJT (341) and / or the gate voltage of the gate driver (314-1), whose values ​​are determined according to the device characteristics, are relatively difficult to change in design values ​​after device selection, so the amplification factor of the OP-AMP non-inverting amplifier (330) and / or the resistance value of the first shunt resistor (320), which are relatively free to change, can be designed based on mathematical equations 1 to 2. And / or, the amplification factor of the OP-AMP non-inverting amplifier (330) and the resistance value of the first shunt resistor (320) may be automatically adjusted to achieve the following design purpose based on mathematical expressions 1 and 2.

[0085] Here, the amplification design of the OP-AMP non-inverting amplifier (330) may mean designing the amplification design so that the gate voltage of the MOSFET (315) decreases to a level similar to the threshold voltage value of the MOSFET (315) by appropriately amplifying the voltage drop value due to the tube current of the first shunt resistor (320) assuming that the remaining values ​​except the amplification value have been selected. And / or, the design of the value of the first shunt resistor (320) may mean designing so that the voltage drop value due to the tube current of the first shunt resistor (320) occurs at a level similar to the threshold voltage value of the MOSFET (315) at a set related current limit level. The amplification design of the above OP-AMP non-inverting amplifier (330) and the resistance value design of the first shunt resistor (320) can be applied to either one or both depending on the designer's choice.

[0086] For example, the resistance value of the first shunt resistor can be the same as mathematical expression 1.

[0087]

[0088] For example, the amplification factor of an OP-AMP non-inverting amplifier can be the same as mathematical expression 2.

[0089]

[0090]

[0091] In the above mathematical equations 1 and 2, is the threshold voltage of MOSFET (315), is the gate voltage of the gate driver (314-1), is the resistance value of the gate resistor (314-2), is the amplification factor of BJT(341), is the base saturation voltage of BJT(341), is the base resistance value of BJT(341), is the amplification factor of the OP-AMP non-inverting amplifier (330), can represent the current size value of the tube current to be limited.

[0092] According to the tube current control device of the present disclosure, not only the size of the tube current can be controlled, but also the fault current (or abnormal current / arc current) can be controlled, thereby improving circuit stability.

[0093] Additionally, according to the tube current control device of the present disclosure, the current of the X-ray generator can be controlled simply by installing the proposed device through an existing cable and / or a new cable.

[0094] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0095] Embodiments according to the present disclosure may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0096] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, or the like that performs the functions or operations described above. The software code may be stored in memory and executed by a processor. The memory may be located within or external to the processor and may exchange data with the processor via various known means.

[0097] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

Claims

1. A switching unit that senses the tube current of an X-ray generator and performs switching based on the driving voltage; A tube current detection unit that outputs a first voltage based on the above tube current; A voltage amplifier that receives the first voltage and outputs the amplified second voltage; and A tube current control device including a driving voltage control unit that receives the second voltage and controls the tube current by controlling the driving voltage.

2. In paragraph 1, The above switching unit, switching power supply; A tube current sensing unit that outputs a sensing signal for sensing the tube current of the above X-ray generating device; A switch control unit that outputs a switching signal based on the above sensing signal; A switch driving unit that outputs the driving voltage based on the switching signal; and A tube current control device including a switch element that performs switching based on the above driving voltage.

3. In paragraph 2, A tube current control device in which the above tube current detection unit is a first shunt resistor, the voltage amplification unit is a non-inverting amplifier, and the driving voltage control unit includes a bipolar junction transistor (BJT) and a resistor connected to the base of the BJT.

4. In paragraph 3, A tube current control device in which the above tube current sensing unit is a second shunt resistor, and the switch driving unit includes a gate driver and a gate resistor having one end connected to the gate driver.

5. In paragraph 4, A tube current control device in which a first input terminal of the switch control unit is connected to the switching power supply unit, a second input terminal of the switch control unit is connected to the other end of the second shunt resistor, and an output terminal of the switch control unit is connected to the first input terminal of the switch driver unit.

6. In paragraph 5, The output terminal of the above switch driving unit is a tube current control device connected to the gate of the MOSFET and the collector of the BJT.

7. In paragraph 6, A tube current control device in which the source of the above MOSFET is connected to one end of the first shunt resistor and the first input terminal of the above non-inverting amplifier.

8. In paragraph 7, A tube current control device in which the other end of the first shunt resistor is connected to one end of the second shunt resistor, the second input terminal of the non-inverting amplifier, the emitter of the BJT, and the second input terminal of the switch driver.

9. In paragraph 8, The output terminal of the above non-inverting amplifier is a tube current control device connected to the other terminal of the above gate resistor.

10. In paragraph 9, The above X-ray generating device is a tube current control device including a high-pressure supply unit, a filament heating unit, and an X-ray tube.

11. In paragraph 10, A tube current control device in which the first terminal of the high-voltage supply unit is connected to the drain of the MOSFET, and the anode of the X-ray tube is connected to the other terminal of the second shunt resistor.

12. In paragraph 11, A tube current control device in which the second stage of the high-pressure supply unit is connected to the cathode of the X-ray tube and the filament heating unit is connected to the cathode of the X-ray tube.

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