X-ray generator

Abstract

An object of the present invention is to provide an X-ray source driving circuit that has a low possibility of dielectric breakdown and can reduce the insulation distance between high-voltage circuits, and an X-ray generating device using the same that can be made lightweight and compact. In order to achieve the above object, an X-ray generating device of the present invention includes an X-ray source including a cathode electrode, an anode electrode, and a gate electrode, and generating X-rays with a driving voltage applied to each of the electrodes; a first voltage conversion unit including a first transformer and at least one voltage doubler unit that doubles a first voltage output from the first transformer; and a second voltage conversion unit including a second transformer and a voltage doubler unit that doubles a second voltage output from the second transformer, wherein the voltage doubler unit of the first voltage conversion unit generates a cathode voltage and an anode voltage having a potential difference from each other from the first voltage, and the voltage doubler unit of the second voltage conversion unit generates a gate voltage from the second voltage, and one of the electrodes on the secondary side of the second transformer is commonly connected to the cathode voltage to substantially insulate the primary side and secondary side of the second transformer, and the voltage doubler unit connected to the secondary side of the first transformer and the voltage doubler unit connected to the second transformer can form a substantially single circuit with the cathode voltage as a common potential.

Description

【Technical Field】 【0001】 The present invention relates to an X-ray source drive circuit and an X-ray generating apparatus using the same. 【Background Art】 【0002】 For miniaturization and weight reduction of X-ray generating apparatuses, a field emission X-ray source using a cold cathode emitter such as a metal nano tip or a carbon nanotube (CNT) has been commercialized. 【0003】 Unlike a conventional thermionic cathode filament that emits isotropic thermoelectrons by high-temperature heating, a field emission (electric field emission) X-ray source uses a cold cathode emitter that emits anisotropic cold electrons quantum-mechanically tunneled at room temperature. Therefore, electron emission is possible with relatively low power, and since the directivity of electrons is excellent, the X-ray emission efficiency is very high. Also, pulsed X-ray emission is easy and can be used for video shooting. 【0004】 An X-ray generating apparatus using a field emission X-ray source includes an inverter for converting a DC power supply voltage into an AC voltage, a transformer for boosting the AC voltage to an appropriate magnitude, a voltage multiplier, etc., in order to apply appropriate drive voltages to the anode electrode, cathode electrode, and gate electrode of the field emission X-ray source. Thus, the potential difference between the cathode electrode and the gate electrode must be about 5 kV to 10 kV, and the potential difference between the cathode electrode and the anode electrode must be about 50 kV to 100 kV. 【0005】 ] Conventional X-ray generators using field emission X-ray sources require a potential difference of several to tens of kV between the cathode electrode and gate electrode, and a potential difference of several tens of kV between the cathode electrode and anode electrode, compared to conventional hot cathode filament systems, thus posing a risk of dielectric breakdown. To improve insulation stability, the insulation distance can be increased or a high-voltage shielding structure can be added, but this presents the problem of not being compatible with miniaturization and weight reduction. [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 The present invention aims to provide an X-ray source drive circuit that has a low dielectric breakdown potential and can reduce the insulation distance between high-voltage circuits, and an X-ray generator that can be made lighter and smaller using the same. [Means for solving the problem] 【0007】 To achieve the above objective, the present invention provides an X-ray generator comprising a cathode electrode, an anode electrode, and a gate electrode, an X-ray source that generates X-rays with a drive voltage applied to each electrode, a first transformer, and a voltage doubler that doubles the first voltage output from the first transformer. Then, the cathode voltage and anode voltage are generated such that the two voltages have a potential difference. vinegar The 1st A first voltage conversion unit including a voltage section, a second transformer, and a voltage doubling unit that doubles the second voltage output from the second transformer. and generate gate voltage do 2nd A second voltage conversion unit including a voltage doubling unit, At least one of the first feedback control unit or the second feedback control unit, Includes The first feedback control unit compares the anode voltage or cathode voltage with a preset reference voltage and controls the first voltage conversion unit so that the first voltage can maintain an output at a constant frequency, and the second feedback control unit compares the gate voltage with the reference voltage and controls the second voltage conversion unit so that the second voltage can maintain an output at a constant frequency. One of the secondary electrodes of the second transformer is connected to the cathode voltage in common. death, The primary side of the preceding second transformer and The aforementioned Secondary side Absolutely Letting them be connected, The first voltage conversion unit and the second voltage conversion unit However, it is possible to form a virtually single circuit with the cathode voltage as a common potential. [Effects of the Invention] 【0009】 The present invention provides an X-ray source drive circuit that can reduce the insulation distance between high-voltage circuits, thereby providing an X-ray generator that has a low risk of dielectric breakdown and can be made lighter and smaller. [Brief explanation of the drawing] 【0010】 [Figure 1] This figure shows an X-ray generator according to one embodiment of the present invention. [Figure 2] This figure shows a field emission X-ray source applicable to the present invention. [Figure 3] This figure shows a part of the first voltage conversion unit according to one embodiment of the present invention. [Figure 4] This figure shows an X-ray generator according to another embodiment of the present invention. [Figure 5] This figure shows an X-ray generator according to another embodiment of the present invention, including a feedback circuit. [Figure 6] This figure shows an X-ray generator according to another embodiment of the present invention, including a feedback circuit. [Figure 7] This figure shows an X-ray generator according to another embodiment of the present invention, including a feedback circuit. [Figure 8] This figure shows an X-ray generator according to another embodiment of the present invention, including a feedback circuit. [Modes for carrying out the invention] 【0011】 The aforementioned objectives, features, and advantages will become more apparent from the following embodiments related to the attached drawings. 【0012】 The specific structural or functional descriptions are provided solely for illustrative purposes to illustrate embodiments of the concept of the present invention, and embodiments of the concept of the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described in the specification of this application. 【0013】 Embodiments based on the concept of the present invention can be modified in various ways and may take on various forms; therefore, specific embodiments are illustrated in the drawings and described in detail in the specification of this application. However, this should not be understood as limiting embodiments based on the concept of the present invention to any particular disclosure, but rather as including all modifications, equivalents, or substitutions that fall within the scope of the idea and art of the present invention. 【0014】 When it is mentioned that one component is "linked" or "connected" to another component, it should be understood that this may mean that it is directly linked or connected to the other component, or that another component may be intervening between them. On the other hand, when it is mentioned that one component is "directly linked" or "directly connected" to another component, it should be understood that there is no other component intervening between them. Other expressions used to describe the relationship between components, such as "between" and "immediately between," or "adjacent to" and "directly adjacent to," should be interpreted similarly. 【0015】 The terms used in the specification of this application are used solely to describe specific embodiments and are not intended to limit the invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, terms such as “includes” or “having” are intended to specify the presence of a described feature, figure, stage, operation, component, part, or combination thereof, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof. 【0016】 Unless otherwise defined, all terms used herein have the same meaning as generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted in the sense that they have in the context of the relevant art, and not in an ideal or overly formal sense unless expressly defined herein. 【0017】 Hereinafter, the present invention will be described in detail by explaining a preferred embodiment of the present invention with reference to the accompanying drawings. The same reference numerals presented in each drawing indicate the same members. 【0018】 FIG. 1 is a diagram showing an X-ray generating apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a field emission X-ray source applicable to the present invention. FIG. 3 is a diagram showing a part of a first voltage conversion unit according to an embodiment of the present invention. 【0019】 Referring to FIG. 1, the X-ray generating apparatus according to the present embodiment includes a power supply unit 10, a drive voltage generation unit 20 that converts the power supply voltage applied from the power supply unit 10 into a drive voltage for the X-ray source, and an X-ray source 30 that generates and emits X-rays with the drive voltage of the drive voltage generation unit 20. 【0020】 The power supply unit 10 provides a DC power supply voltage to the drive voltage generation unit 20. The power supply voltage may be 5 to 30 V, for example, about 24 V, or may be 12 V or a voltage of other magnitudes. The power supply unit 10 can be realized by an adapter that converts commercial AC power into a power supply voltage of a predetermined magnitude, or various types of batteries that provide a DC voltage, and may include a boost circuit that boosts the DC voltage supplied from the power supply as needed. 【0021】 The X-ray source 30 generates and emits X-rays using a drive voltage transmitted from the drive voltage generation unit 20. Referring to Figure 2, the field emission X-ray source 30 applicable to the X-ray generator according to the present invention has a cathode electrode 31 located at one end of a tubular vacuum vessel H, and an emitter E is provided on one surface of the cathode electrode 31 facing the other end of the vacuum vessel H. The emitter E is provided with an electron emission chip realized by a metal nanochip or carbon nanotube. An anode electrode 33 is located at the other end of the vacuum vessel H, and a target surface T realized by tungsten or the like is provided on one surface of the anode electrode 33 facing the emitter E. A gate electrode 32 is located between the cathode electrode 31 and the anode electrode 33 inside the vacuum vessel H. The gate electrode 32 may have a mesh shape through which a number of holes corresponding to the electron emission chip of the emitter E pass. A focusing electrode for focusing the electric field may be provided between the gate electrode 32 and the anode electrode 31. 【0022】 The drive voltage for driving the X-ray source 30 includes the cathode voltage applied to the cathode electrode 31, the gate voltage applied to the gate electrode 32, and the anode voltage applied to the anode electrode 33. In embodiments of the present invention, if the cathode voltage applied to the cathode electrode 31 is taken as the reference potential, the anode voltage can have a potential difference of 50kV to 100kV, specifically 60kV to 65kV, relative to the reference potential. The gate voltage applied to the gate electrode 32 can have a potential difference of 0.5kV to 20kV, specifically about 10kV, relative to the reference potential. That is, the relationship anode voltage > gate voltage > cathode voltage holds, and when these voltages are applied to each electrode, electrons emitted from the emitter can be sufficiently accelerated to emit X-rays. The specific numerical ranges of the anode voltage, gate voltage, and cathode voltage described above are set to meet the tube voltage standards of X-ray generators for different applications, but the present invention is not limited thereto. 【0023】 When a gate voltage is applied to the gate electrode 32 while the cathode voltage and anode voltage are applied to the cathode electrode 31 and anode electrode 33 respectively, electrons are emitted from the emitter E by switching this signal. The emitted electrons are accelerated towards the anode electrode 33 by the potential difference between the cathode electrode 31 and the anode electrode 33, passing through the mesh structure of the gate electrode 32 and striking the target surface T, thereby generating and emitting X-rays. 【0024】 The drive voltage generation unit 20 receives a power supply voltage from the power supply unit 10 to generate drive voltages, i.e., anode voltage, gate voltage, and cathode voltage, and includes first and second voltage conversion units 21 and 22. The first voltage conversion unit 21 is for generating a cathode-anode voltage of several tens to several hundreds of kV and may include a first inverter I1, a first transformer T1, and first and second voltage multiplier units M1 and M2. The second voltage conversion unit 22 is for generating a cathode-gate voltage of several kV to several tens of kV and may include a second inverter I2, a second transformer T2, and a third voltage multiplier unit M3. The first and second voltage multiplier units M1 and M2 can be implemented as voltage multiplier circuits that amplify the input voltage by n times, preferably Cockcroft-Walton voltage multiplier circuits. The first inverter I1 of the first voltage conversion unit 21 converts the DC voltage provided from the power supply unit 10 into a first AC voltage. The first transformer T1 boosts the first AC voltage output from the first inverter I1 and input to the primary side, and outputs the first boosted voltage to the secondary side. 【0025】 The first voltage multiplier unit M1 doubles the first boosted voltage output from the first transformer T1 to a positive (+) anode voltage. The second voltage multiplier unit M2 doubles the first boosted voltage output from the first transformer T1 to a negative (-) cathode voltage. The third voltage multiplier unit M3 doubles the second boosted voltage output from the second transformer T2 to a gate voltage. 【0026】 Referring to Figure 3, the first voltage conversion unit can include a first transformer T1 and first and second voltage multiplier units M1 and M2. The first and second voltage multiplier units M1 and M2 are connected to the secondary side of the first transformer T1. The first voltage multiplier unit M1 doubles the voltage output from the secondary side of the first transformer T1 to generate a positive (+) anode voltage, and the second voltage multiplier unit M2 doubles the voltage output from the secondary side of the first transformer T1 with respect to a common potential of the voltage multiplier units to generate a negative (-) cathode voltage. The first and second voltage multiplier units M1 and M2 each include a plurality of first voltage multiplier terminals G1 and second voltage multiplier terminals G2. When the same number of first pressure multiplier terminals G1 and second pressure multiplier terminals G2 are provided, the anode voltage and cathode voltage have the same absolute value. When the number of first pressure multiplier terminals G1 and second pressure multiplier terminals G2 are different, the anode voltage and cathode voltage have different absolute values. 【0027】 Multiple voltage doubler terminals G1 of the first voltage doubler unit M1 are connected in parallel to each other. As shown in Figure 3, the voltage doubler terminal G1 includes a first capacitor C1 connected to the first electrode on the secondary side of the first transformer T1, a second capacitor C2 connected to the second electrode on the secondary side of the first transformer T1, a first diode D1 positioned between the first capacitor C1 and the second capacitor C2, and a second diode D2 positioned between the first capacitor C1 and the second capacitor C2 in the opposite direction to the first diode D1. Depending on the polarity change of the first boosted voltage output from the secondary winding of the first transformer T1, the first diode D1 and the second diode D2 are connected to opposite sides of the first and second capacitors C1 and C2. 【0028】 The second voltage multiplier section M2 includes a number of second voltage multiplier terminals G2 connected in parallel. As shown in Figure 3, the second voltage multiplier terminals G2 include a third capacitor C3 connected to the first electrode on the secondary side of the first transformer T1, a fourth capacitor C4 connected to the second electrode on the secondary side of the first transformer T1, a third diode D3 positioned between the third capacitor C3 and the fourth capacitor C4, and a fourth diode D4 positioned between the third capacitor C3 and the fourth capacitor C4 in the opposite direction to the third diode D3. 【0029】 Returning to Figure 1, the second inverter I2 of the second voltage conversion unit 22 converts the DC power supply voltage input from the power supply unit 10 into a second AC voltage. The second transformer T2 boosts the second AC voltage of the second inverter I2, which is input to the primary side, and outputs it to the secondary side. The third voltage multiplier unit M3 connects one of the secondary side electrodes of the second transformer T2 to the cathode electrode 303 in common, and doubles the boosted voltage output to the secondary side of the second transformer T2 to generate a gate voltage. That is, when one of the secondary side electrodes of the second transformer T2 is connected to the cathode electrode 31 in common, the reference potential of the second voltage multiplier unit M2 shows the same (-) potential as the cathode voltage. Therefore, the second voltage multiplier unit M2 doubles the boosted voltage output from the second transformer T2 to a voltage higher than the common reference potential, generating a gate voltage that is relatively higher than the cathode voltage and has a negative (-) value. By connecting one of the electrodes on the secondary side of the second transformer T2 to the cathode electrode 31, the third voltage multiplier unit M3 effectively isolates the primary and secondary sides of the second transformer T2. The first and second voltage multiplier units M1 and M2 connected to the secondary side of the first transformer T1, and the third voltage multiplier unit M3 including the secondary side of the second transformer T2, effectively form a single circuit with a common cathode voltage. Therefore, the insulation distance between the first voltage conversion unit 21 and the second voltage conversion unit 22 can be reduced. 【0030】 Figure 4 shows an X-ray generator according to another embodiment of the present invention. 【0031】 For convenience, common components that have the same configuration and function as those in Figure 1 are assigned the same reference numerals to avoid unnecessary redundant explanations. 【0032】 Referring to Figure 4, the drive voltage generation unit 20 according to this embodiment includes first and second voltage conversion units 23 and 24. 【0033】 The first voltage conversion unit 23 includes a first inverter I1, a first transformer T2, and a first voltage multiplier unit MA. The second voltage conversion unit 24 includes a second inverter I2, a second transformer T2, and a second voltage multiplier unit MB. The first and second voltage multiplier units MA and MB may include a voltage multiplier circuit that amplifies the input voltage by n times, preferably a Cockcroft-Walton voltage multiplier circuit. The first voltage multiplier unit MA of the first voltage conversion unit 23 sets the anode electrode 33 to ground potential and, using this as a reference, doubles the boosted voltage output to the secondary side of the first transformer T1 to generate a cathode voltage with a negative (-) value. Then, the second voltage multiplier MB of the second voltage conversion unit 24 connects one of the secondary electrodes of the second transformer T2 to the cathode electrode 31 in common, and doubles the boosted voltage output from the second transformer T2 to generate a gate voltage that has a relatively higher negative (-) value than the cathode voltage. 【0034】 By connecting the negative (-) electrode on the secondary side of the second transformer T2 and the cathode electrode 31 in common with the second voltage multiplier unit MB, the primary and secondary sides of the second transformer T2 are effectively isolated. The first voltage multiplier unit MA connected to the secondary side of the first transformer T1 and the second voltage multiplier unit MB connected to the secondary side of the second transformer T2 become essentially a single circuit with a common cathode voltage. Therefore, the insulation distance between the first voltage conversion unit 23 and the second voltage conversion unit 24 can be reduced. 【0035】 Furthermore, as in this embodiment, when the anode electrode 33 is at ground potential, the anode electrode 33 exhibits an electrically stable state. Therefore, it is not difficult to attach a conductive cooling system such as a heat sink to the anode electrode 33, where high heat due to electron collisions is relatively concentrated, and thus the entire system can be stabilized. The functions and operations of the first inverter I1 and first transformer T1 of the first voltage conversion unit 23, and the second inverter I2 and second transformer T2 of the second voltage conversion unit 24 are substantially the same as in the previous embodiment, so a separate explanation is omitted. 【0036】 Figures 5 to 8 show an X-ray generator according to another embodiment of the present invention, including a feedback circuit. 【0037】 Figure 5 shows that the X-ray generator of Figure 1 may further include a plurality of feedback control units. The X-ray generator according to this embodiment may include a power supply unit 10, a drive voltage generation unit 20 that converts the power supply voltage applied from the power supply unit 10 into a drive voltage for the X-ray source, an X-ray source 30 that generates and emits X-rays with the drive voltage of the drive voltage generation unit 20, and first and second feedback control units F1 and F2. 【0038】 The first feedback control unit F1 can calculate the error between the anode voltage and cathode voltage and a preset reference voltage, and control the first voltage conversion unit 21 so that the first inverter I1 can maintain an output at a constant frequency. 【0039】 The first feedback control unit F1 may include at least one comparator (OP-amp) for comparing the anode voltage and cathode voltage with a predetermined reference voltage. The comparator for comparing the anode voltage with the reference voltage may be connected in common to the anode voltage. The comparator for comparing the cathode voltage with the reference voltage may be connected in common to the cathode voltage. By comparing the anode voltage and cathode voltage with the reference voltage via the comparator, the first feedback control unit F1 can adjust the duty cycle of the pulses input to the first inverter I1 so that the difference between the anode voltage, cathode voltage, and reference voltage is minimized. 【0040】 When the same number of first pressure multiplier terminals G1 and second pressure multiplier terminals G2 are provided, the anode voltage and cathode voltage have the same absolute value, and in this case, the absolute values ​​of the anode voltage and cathode voltage connected to the first feedback control unit F1, respectively, may be the same. 【0041】 If the number of first pressure-doubler terminals G1 and second pressure-doubler terminals G2 are different, the anode voltage and cathode voltage will have different absolute values, and in this case, the absolute values ​​of the anode voltage and cathode voltage connected to the first feedback control unit F1 may be different from each other. 【0042】 The second feedback control unit F2 can control the second voltage converter 22 so that the second inverter I2 can maintain a constant frequency output by calculating the error between the gate voltage and a preset reference voltage. The second feedback control unit F2 may include a comparator for comparing the gate voltage and the reference voltage. The comparator for comparing the gate voltage and the reference voltage can be connected to the gate voltage in common. The second feedback control unit F2 can adjust the duty cycle of the pulses input to the second inverter I2 so that the difference between the gate voltage and the reference voltage is minimized. 【0043】 The functions and operations of the first inverter I1, first transformer T1, first and second voltage multiplier units M1 and M2 of the first voltage conversion unit 21, the second inverter I2, second transformer T2, and third voltage multiplier unit M3 of the second voltage conversion unit 22 are substantially the same as in the previous embodiment, so their description is omitted. 【0044】 Figure 6 shows that the four X-ray generators may further include a plurality of feedback control units. The X-ray generator according to this embodiment may include a power supply unit 10, a drive voltage generation unit 20 that converts the power supply voltage applied from the power supply unit 10 into a drive voltage for the X-ray source, an X-ray source 30 that generates and emits X-rays with the drive voltage of the drive voltage generation unit 20, and first and second feedback control units F1 and F2. The first and second feedback control units F1 and F2 may each include a comparator. 【0045】 The first feedback control unit F1 can calculate the error between the cathode voltage and a preset reference voltage and control the first voltage conversion unit 23 so that the first inverter I1 can maintain an output at a constant frequency. The first feedback control unit F1 may include a comparator for comparing the cathode voltage and the reference voltage. The comparator for comparing the cathode voltage and the reference voltage may be connected to the cathode voltage in common. The first feedback control unit F1 can adjust the duty cycle of the pulses input to the first inverter I1 so that the difference between the cathode voltage and the reference voltage is minimized. 【0046】 The second feedback control unit F2 can calculate the error between the gate voltage and a preset reference voltage and control the second voltage converter 23 so that the second inverter I2 can maintain an output at a constant frequency. The second feedback control unit F2 may include a comparator for comparing the gate voltage and the reference voltage. The comparator for comparing the gate voltage and the reference voltage may be connected to the gate voltage in common. The second feedback control unit F2 can adjust the duty cycle of the pulses input to the second inverter I2 so that the difference between the gate voltage and the reference voltage is minimized. 【0047】 The functions and operations of the first inverter I1, first transformer T1, first and second voltage multiplier units M1 and M2 of the first voltage conversion unit 23, the second inverter I2, second transformer T2, and third voltage multiplier unit M3 of the second voltage conversion unit 24 are substantially the same as in the previous embodiment, so their description is omitted. 【0048】 Figure 7 shows the X-ray generator in Figure 1 with multiple feedback control units and dummy transistors. Sformer The X-ray generator according to this embodiment may further include a power supply unit 10, a drive voltage generation unit 20 that converts the power supply voltage applied from the power supply unit 10 into a drive voltage for the X-ray source, an X-ray source 30 that generates and emits X-rays with the drive voltage of the drive voltage generation unit 20, first and second feedback control units F1 and F2, and a dummy voltage conversion unit 20D. 【0049】 The first feedback control unit F1 can control the first voltage conversion unit 21 so that the first inverter I1 can maintain an output at a constant frequency by calculating the error between the anode voltage and cathode voltage and a preset reference voltage. 【0050】 The first feedback control unit F1 may include comparators for comparing the anode voltage and cathode voltage with a predetermined reference voltage. A comparator for comparing the anode voltage with the reference voltage may be connected in common to the anode voltage. A comparator for comparing the cathode voltage with the reference voltage may be connected in common to the cathode voltage. The first feedback control unit F1 can adjust the duty cycle of the pulses input to the first inverter I1 by comparing the anode voltage and cathode voltage with the reference voltage via the comparators, so as to minimize the difference between the anode voltage, cathode voltage, and the reference voltage. 【0051】 The dummy voltage conversion unit 20D may include a dummy transformer DT and a dummy voltage doubler unit DM. The dummy transformer DT and the dummy voltage doubler unit DM may include the same circuitry as the second transformer T2 and third voltage doubler unit M3 of the second voltage conversion unit 22. 【0052】 The input terminal of the dummy voltage conversion unit 20D can be commonly connected to the input terminal of the second transformer T2 of the second voltage conversion unit 22. That is, the dummy voltage conversion unit 20D can be commonly connected to the primary side of the second transformer T2 of the second voltage conversion unit 22. The dummy voltage conversion unit 20D can utilize the output voltage of the dummy transformer DT as the input signal of the second feedback control unit F2 by generating the same voltage as the gate voltage via the dummy voltage doubler unit DM. 【0053】 The second feedback control unit F2 can calculate the error between the gate voltage and a preset reference voltage and control the second voltage converter 22 so that the second inverter I2 can maintain an output at a constant frequency. The second feedback control unit F2 may include a comparator for comparing the gate voltage and the reference voltage. The comparator for comparing the gate voltage and the reference voltage may be connected to the output terminal of the dummy voltage converter 20D. The second feedback control unit F2 can compare the voltage input from the dummy voltage converter 20D, i.e., the gate voltage, with the reference voltage and adjust the duty cycle of the pulse input to the second inverter I2 so that the difference between the gate voltage and the reference voltage is minimized. 【0054】 The functions and operations of the first inverter I1, first transformer T1, first and second voltage multiplier units M1 and M2 of the first voltage conversion unit 21, the second inverter I2, second transformer T2, and third voltage multiplier unit M3 of the second voltage conversion unit 22 are substantially the same as in the previous embodiment, so their description is omitted. 【0055】 Figure 8 shows the X-ray generator in Figure 4 with multiple feedback circuits and dummy transistors. SformerThe X-ray generator according to this embodiment may further include a power supply unit 10, a drive voltage generation unit 20 that converts the power supply voltage applied from the power supply unit 10 into a drive voltage for the X-ray source, an X-ray source 30 that generates and emits X-rays with the drive voltage of the drive voltage generation unit 20, first and second feedback control units F1 and F2, and a dummy voltage conversion unit 20D. 【0056】 The first feedback circuit F1 is connected in common with the cathode voltage and may be connected to the dummy voltage converter 20D. 【0057】 The first feedback circuit F1 compares the cathode voltage with a reference voltage and can adjust the duty cycle of the pulse input to the first inverter I1 of the first voltage conversion unit 23 so that the difference between the cathode voltage and the reference voltage is minimized. 【0058】 The dummy voltage conversion unit 20D may include a dummy transformer DT and a dummy voltage doubler unit DM. The dummy transformer DT and the dummy voltage doubler unit DM may include the same circuitry as the second transformer T2 and third voltage doubler unit M3 of the second voltage conversion unit 22. 【0059】 The input terminal of the dummy voltage conversion unit 20D can be commonly connected to the input terminal of the second transformer T2 of the second voltage conversion unit 24. That is, the dummy voltage conversion unit 20D can be commonly connected to the primary side of the second transformer T2 of the second voltage conversion unit 24. The dummy voltage conversion unit 20D can utilize the output voltage of the dummy transformer DT as the input signal of the second feedback control unit F2 by generating the same voltage as the gate voltage via the dummy voltage doubler unit DM. 【0060】 The second feedback control unit F2 can control the second voltage converter 24 so that the second inverter I2 can maintain a constant frequency output by calculating the error between the gate voltage and a preset reference voltage. The second feedback control unit F2 may include a comparator for comparing the gate voltage and the reference voltage. The comparator for comparing the gate voltage and the reference voltage may be connected to the output terminal of the dummy voltage converter 20D. The second feedback control unit F2 can compare the voltage input from the dummy voltage converter 20D, i.e., the gate voltage, with the reference voltage and adjust the duty cycle of the pulse input to the second inverter I2 so that the difference between the gate voltage and the reference voltage is minimized. 【0061】 The functions and operations of the first inverter I1, first transformer T1, first and second voltage multiplier units M1 and M2 of the first voltage conversion unit 21, the second inverter I2, second transformer T2, and third voltage multiplier unit M3 of the second voltage conversion unit 22 are substantially the same as in the previous embodiment, so their description is omitted. 【0062】 Although the present invention has been described above, for example, by limited embodiments and drawings, the present invention is not limited to the above embodiments, and various substitutions, modifications, and changes can be made from such descriptions without departing from the technical spirit of the present invention by persons with ordinary skill in the art to which the present invention pertains. 【0063】 Therefore, the scope of the present invention should not be limited to the embodiments described, but should be defined not only by the claims described below, but also by claims equivalent to those described below.

Claims

[Claim 1] An X-ray source comprising a cathode electrode, an anode electrode, and a gate electrode, which generates X-rays with a driving voltage applied to each electrode, A first voltage conversion unit including a first transformer and a first voltage multiplier unit that doubles the first voltage output from the first transformer and generates cathode voltage and anode voltage such that the two voltages have a potential difference, A second voltage conversion unit including a second transformer and a second voltage multiplier unit that doubles the second voltage output from the second transformer and generates a gate voltage, At least one of the first feedback control unit or the second feedback control unit, Includes, The first feedback control unit compares the anode voltage or cathode voltage with a preset reference voltage and controls the first voltage conversion unit so that the first voltage can maintain an output at a constant frequency. The second feedback control unit compares the gate voltage with the reference voltage and controls the second voltage conversion unit so that the second voltage can maintain an output at a constant frequency. An X-ray source generator in which one of the electrodes on the secondary side of the second transformer is connected to the cathode voltage in common, the primary side and the secondary side of the second transformer are isolated, and the first voltage conversion unit and the second voltage conversion unit form a substantially single circuit with the cathode voltage as a common potential. [Claim 2] The X-ray generator according to claim 1, wherein the first feedback control unit is connected in common to the anode voltage and the cathode voltage, and includes a comparator that compares the anode voltage and the cathode voltage with the reference voltage, respectively. [Claim 3] The anode voltage is the ground potential. The X-ray generator according to claim 1, wherein the first feedback control unit is connected in common with the cathode voltage and includes a comparator for comparing the cathode voltage with the reference voltage. [Claim 4] The X-ray generator according to claim 1, wherein the second feedback control unit is connected in common with the gate voltage and includes a comparator for comparing the gate voltage with the reference voltage. [Claim 5] The X-ray generator according to claim 1, further comprising a dummy voltage conversion unit which is connected in common with the primary side of the second transformer of the second voltage conversion unit and outputs the same voltage as the gate voltage. [Claim 6] The X-ray generator according to claim 5, wherein the second feedback control unit includes a comparator that compares the voltage output from the dummy voltage conversion unit with the reference voltage.

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