Voltage control device and x-ray apparatus including same

Abstract

Proposed is a device for controlling the voltage applied to a triode X-ray tube. The control device may include: a voltage sensor for sensing the voltage of a cathode of the triode X-ray tube; a voltage controller which, on the basis of the sensed voltage of the cathode, generates a control signal for compensating for the voltage of a gate for operating the triode X-ray tube; and a power source for controlling the voltage of the gate of the triode X-ray tube according to the control signal.

Description

Voltage control device and X-ray device including same

[0001] The present invention relates to a voltage control device and an X-ray device including the same, and more specifically, to a method for controlling a voltage required for an X-ray device using a triode X-ray vacuum tube device (hereinafter, “triode X-ray tube”).

[0002] Figure 1 illustrates an X-ray device using a conventional triode X-ray tube.

[0003] An X-ray tube (100) composed of three poles (Anode, Gate, Cathode) is applied with a high voltage of tens to hundreds of kilovolts (KV) to the anode to generate X-rays, and the amount of current flowing to the anode is controlled by the voltage (VGC) between the gate (or grid) and the cathode.

[0004] Conventional X-ray devices fix the grid voltage (hundreds to thousands of volts) and control the cathode voltage (Vc in Fig. 2). The device (400) in Figs. 1 (a) and (b) is a device that controls the cathode voltage (VC) to control the current at the anode terminal at a constant level.

[0005] However, (1) in general, the characteristics of the triode X-ray tube (100) vary depending on the manufacturing process, temperature, and voltage.

[0006] (2) The characteristics of the triode X-ray tube (100) change even during use. During long-term use, the VGC voltage required to obtain the same anode current increases. In the case of an existing device with a fixed grid voltage, if the required VGC voltage increases during use, the desired current cannot be generated.

[0007] (3) Also, during use, an arcing problem may occur through the high-voltage anode terminal, in which case the required VGC voltage may suddenly increase for a considerable period of time. In such cases, since the existing technology devices cannot generate the current to obtain X-rays, the tube (100) must be replaced, or a grid voltage higher than necessary must be used considering all cases. Referring to Fig. 2, the grid voltage, Vgrid = V Grid(0) +V margin can be defined as, in this case, excessive grid voltage must always be used, which may cause equipment reliability problems.

[0008] (4) Furthermore, recently, devices using multiple X-ray tubes have been proposed, but when multiple X-ray tubes are used, the above problems appear in a complex manner and the number of defects increases exponentially.

[0009] The present invention proposes a voltage control device for an X-ray tube and / or an X-ray device including the same.

[0010] More specifically, we propose a voltage control device and / or an X-ray device including the same that controls and provides a grid voltage optimized for the deterioration or individual characteristics of an X-ray tube.

[0011] The problems to be solved by the present invention are not limited to the problems to be solved above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0012] A device for controlling a voltage applied to a triode X-ray tube is proposed, wherein the control device may include: a voltage sensor for sensing a voltage of a cathode of the triode X-ray tube; a voltage controller for generating a control signal for compensating a voltage of a gate for operation of the triode X-ray tube based on the sensed voltage of the cathode; and a power source for controlling a voltage of a gate of the triode X-ray tube according to the control signal.

[0013] An X-ray device driven by a triode X-ray tube is proposed, the X-ray device including: a triode X-ray tube for generating X-rays; a voltage sensor for sensing a voltage of a cathode of the triode X-ray tube; a voltage controller for generating a control signal for compensating a voltage of a gate for operation of the triode X-ray tube based on the sensed voltage of the cathode; and a power source for controlling a voltage of a gate of the triode X-ray tube according to the control signal.

[0014] An X-ray device driven by a plurality of triode X-ray tubes is proposed, the X-ray device comprising: a plurality of triode X-ray tubes for generating X-rays; a voltage sensor for sensing a voltage of a cathode of each of the plurality of triode X-ray tubes; a voltage controller for generating a control signal for compensating a voltage of a gate for operation of the triode X-ray tubes based on the sensed cathode voltage; and a power source for controlling a voltage of a gate of the triode X-ray tubes according to the control signal, wherein each of the plurality of triode X-ray tubes is sequentially operated according to a preset order, and the voltage of the gate for each of the plurality of triode X-ray tubes can be set independently of each other.

[0015] The above problem solving methods are only some of the embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by a person having ordinary knowledge in the relevant technical field based on the detailed description of the present invention described below.

[0016] The present invention has the following effects.

[0017] The present invention can control and supply an optimal grid voltage for generating a normal X-ray generation current.

[0018] In addition, the present invention enables normal X-ray generation even when the characteristics of the X-ray tube change or when a change in the characteristics occurs due to use, thereby extending the life of the X-ray tube or ensuring a longer life.

[0019] Furthermore, when multiple X-ray tubes are used, individual voltage control and supply are possible, tailored to the characteristics of each X-ray tube. This eliminates the need for strict constraints on the characteristic requirements for each individual X-ray tube. Ultimately, this maximizes the productivity and utility of the X-ray device, thereby securing product competitiveness.

[0020] The effects according to the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the detailed description of the invention below.

[0021] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present invention, provide embodiments of the present invention and, together with the detailed description, explain the technical idea of ​​the present invention.

[0022] Figure 1 illustrates an X-ray apparatus having a tripolar X-ray tube according to the prior art.

[0023] Figure 2 shows the voltages on the grid or gate and cathode of a triode X-ray tube.

[0024] Figure 3 illustrates an X-ray device having a tripolar X-ray tube according to the present invention.

[0025] Figure 4 shows the voltage of the grid or gate and cathode of the triode X-ray tube according to the present invention.

[0026] FIG. 5 illustrates an embodiment of a cathode voltage sensor of a triode X-ray tube according to the present invention.

[0027] FIG. 6 illustrates an embodiment of a cathode voltage sensor of a triode X-ray tube according to the present invention.

[0028] Figure 7 illustrates voltages for driving multiple triode X-ray tubes according to the prior art.

[0029] Figure 8 illustrates an X-ray apparatus having a plurality of tripolar X-ray tubes according to the present invention.

[0030] FIG. 9 illustrates an example of a configuration of a cathode voltage sensor of an X-ray device having a plurality of triode X-ray tubes according to the present invention.

[0031] Figure 10 illustrates voltages for driving a plurality of triode X-ray tubes according to the present invention.

[0032] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0033] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0034] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0035] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0036] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0037]

[0038] Figure 3 illustrates an X-ray device (1) equipped with a tripolar X-ray tube according to the present invention.

[0039] An X-ray device (1) may include a triode X-ray tube (100) for generating X-rays, an anode voltage source (300), and a current controller (400) for controlling an anode current, a cathode current, or a cathode voltage. The current controller (400) may include a controller (410), a current controller (420), and a current detector (430) for controlling a current controller (420) and a current detector (e.g., impedance (resistance)) (430) or obtaining detection information. A current (I_A) is generated by applying a voltage between the anode of the X-ray tube (100) and a grid and a cathode, and controlling the current in the current controller (400) can control the amount of current (I_A) flowing from the anode.

[0040] Additionally, unlike conventional X-ray devices, the X-ray device (1) includes a voltage sensor (500), a voltage controller (600), and a power source (700) that provides a variable voltage.

[0041] The minimum grid voltage (V_Grid(0)) required to operate the X-ray device (1) is determined by the grid-cathode voltage (V_GC) for obtaining a constant anode current and the minimum cathode voltage (V_C(min)) for allowing the current controller (400) to operate normally. The minimum grid voltage (V_Grid(0)) required to generate a constant anode current in the triode X-ray tube (100) can be expressed by the following mathematical equation.

[0042]

[0043] Here, V_GC is the gate-cathode voltage value of the triode X-ray tube (100). Fig. 4 shows the voltage relationship according to mathematical expression 1.

[0044] In general, the minimum cathode voltage is about 0.2 to several tens of volts (V), and when a voltage higher than this value is applied, the X-ray device (1) or the triode X-ray tube (100) operates normally. That is, the ON / OFF of the triode X-ray tube (100) is controlled by controlling the voltage of the cathode through current control of the current controller (400).

[0045] The present invention includes a device for controlling the gate voltage (or grid voltage) of a triode X-ray tube (100) to obtain a constant anode current, which may be composed of a voltage sensor (500), a voltage controller (600), and a power source (700). According to the present invention, the grid (gate) voltage can be controlled or adjusted to an optimal value or a minimum value while maintaining the anode current of the triode X-ray tube (100) constant.

[0046]

[0047] Below, each configuration will be described in more detail.

[0048] The voltage sensor (500) senses the voltage of the cathode of the triode X-ray tube (100). In addition, the voltage sensor (500) can convert the voltage of the sensed cathode into a voltage (V_CO) within a preset range or a comparable range.

[0049] The voltage controller (600) generates a control signal for generating a voltage of a gate for the operation of the triode X-ray tube (100) based on the voltage of the cathode of the sensed triode X-ray tube (100). The control signal for voltage generation is a signal for controlling the voltage of the gate, and as described below, is transmitted to a power source (700) so that the power source (700) generates a gate voltage.

[0050] More specifically, the voltage controller (600) can compare the voltage of the cathode or the converted voltage (V_CO) with a preset reference voltage (Vset), and as a result, generate a control signal for the grid voltage or the voltage of the gate of the triode X-ray tube. The voltage controller (600) can generate a control signal for the voltage generation of the gate of the triode X-ray tube according to the difference between the voltage value of the cathode or the voltage value converted therefrom and the preset value.

[0051] In order to solve the problem of the prior art mentioned above, the required VGC is usually high, and in this situation, the gate voltage must be increased to maintain the minimum value of the cathode voltage, so the voltage value of the cathode or the voltage value converted therefrom will be lower than Vset. Accordingly, the voltage controller (600) can generate a control signal for voltage compensation of the gate of the triode X-ray tube as the voltage value of the cathode or the voltage value converted therefrom is lower than Vset.

[0052] As a more specific example, the voltage controller (600) may be configured with an operational amplifier (610). Accordingly, as illustrated in FIG. 3, V_CO is input to the - terminal of the operational amplifier, and Vset is input to the + terminal, so that a value corresponding to the difference between V_CO and Vset (hereinafter, “voltage difference value”) is output to the output terminal of the operational amplifier. The voltage difference value may be directly used as a voltage control signal for the gate of the triode X-ray tube, and may be converted into a control signal through a separate control signal generator (620) and then used for control. An example of the control signal generator (620) may be a PID (Proportional Integral Derivation) controller. The output signal of the control signal generator (620) may be a pulse width modulated signal or a pulse frequency modulated signal, and may also be a digital signal or an analog signal.

[0053] The power source (700) can supply a gate voltage input to the gate of the triode X-ray tube according to a control signal for a required voltage. The power source (700) can include a DC-DC converter that receives a control signal and generates an output voltage.

[0054]

[0055] Meanwhile, the cathode voltage (V_C) may range from several tens of volts to several kilovolts depending on the operating characteristics of the triode X-ray tube (100). Voltage values ​​in this range are too high to be applied to devices (500, 600, 700) for voltage control.

[0056] Therefore, the cathode voltage (V_C) can be converted into a voltage value (V_CO) within a preset range. Various methods for this are described through FIGS. 5 and 6.

[0057] FIG. 5 illustrates an embodiment of a cathode voltage sensor of a triode X-ray tube according to the present invention.

[0058] Figure 5 (a) shows a voltage converter (510) that outputs a specific voltage when the cathode voltage (V_C) is higher than a specific voltage (V_limit), and outputs the cathode voltage (V_C) when the cathode voltage (V_C) is lower than the specific voltage. The voltage converter (510) is included in the voltage sensor (500).

[0059] Fig. 5 (b) shows a specific example of Fig. 5 (a). Referring to Fig. 5 (b), the voltage converter is composed of an N-type MOSFET (511) and an OP amplifier (512) operating as a buffer. When a voltage (V_clmap) to be limited is applied to the gate of the N-type MOSFET (511), a converted voltage (V_CO) is obtained as shown in the following mathematical equation.

[0060]

[0061] Here, V_T is the threshold voltage of the N-type MOSFET (511), which means the gate-source voltage that determines the ON / OFF state of the N-type MOSFET (511).

[0062] Let us explain the general characteristics of the N-type MOSFET (511).

[0063] The N-type MOSFET (511) is a device whose drain current (I_D) changes depending on the gate-source voltage (V_Clamp). If the gate-source voltage is less than V_T, the N-type MOSFET is turned off and no drain current is generated (i.e., in an open state). This is referred to as a cut-off region.

[0064] When the gate-source voltage becomes higher than V_T, the drain current flows and its size changes depending on the drain-source voltage value and the gate-source voltage value.

[0065] As the voltage between the drain and the source increases, there is a region where the drain current increases, which is called the non-saturation region, and in this region, the circuit becomes short-circuited. This is expressed by the following equation in mathematical equation 2 (V C < VClamp - V T , V CO = V C )am.

[0066] When the drain-source voltage increases further and becomes the gate-source voltage minus V_T, the pinch-off state occurs. From the pinch-off state, if the gate-source voltage is fixed, as the drain-source voltage increases, the gate-drain voltage (Vgd=Vgs-Vds, Vgd is the gate-drain voltage, Vgs is the gate-source voltage, Vds is the drain-source voltage) decreases, and eventually reaches the threshold voltage (V_T). That is, when the gate-drain voltage becomes the threshold voltage in a state where a channel is formed, the channel disappears near the drain, and the drain voltage no longer affects the change in drain current. The region after the pinch-off is called the saturation region.

[0067] In the saturation region, the magnitude of the drain current is not affected by the voltage value between the drain and source, but only by the voltage value between the gate and source, and has the characteristics of a constant current.

[0068] In the end, since the present invention also fixes the gate-source voltage to V_clamp, even if the sensed cathode voltage (V_C) has a large value, the N-type MOSFET (511) will operate in the pinch-off or saturation region, so Vds = Vgs - Vgd is established, and the switch on the equivalent circuit of the MOSFET is in the open state. Accordingly, the output voltage (V_CO) corresponding to the source voltage is expressed by the above equation (V C ≥ V Clamp - V T , V CO = V Clamp - V T ) can be obtained as follows.

[0069] In summary, the voltage sensor of Fig. 5 (b) outputs V_C as is when V_C is a relatively small value; and if V_C is a relatively large value, the output value can be limited to V_Clamp-V_T.

[0070]

[0071] FIG. 6 illustrates an embodiment of a cathode voltage sensor of a triode X-ray tube according to the present invention.

[0072] Fig. 6 (a) illustrates a voltage converter (520) that attenuates the cathode voltage (V_C) by a specific ratio (alpha, α). Fig. 6 (b) is a specific example of Fig. 6 (a), and illustrates a voltage converter comprised of a voltage divider (521) comprised of impedance or resistance and a buffer (522).

[0073] In (b) of Fig. 6, alpha (α) is as follows.

[0074]

[0075] In this way, various voltage converters can be applied to reduce risks depending on the magnitude (level) of the cathode voltage (V_C). The present invention is not limited to the configuration of the voltage converter illustrated.

[0076] Meanwhile, while X-ray devices have typically been equipped with a single X-ray tube, the use of multiple X-ray tubes is gradually becoming more common. This article will explain the problems associated with conventional methods and solutions for using multiple X-ray tubes.

[0077]

[0078] Figure 7 illustrates voltages for driving multiple triode X-ray tubes according to the prior art.

[0079] The characteristics of an X-ray tube are expressed as grid (gate)-cathode voltage (VGC) when a constant current is generated. The VGC voltage may vary depending on the manufacturing process, operating temperature, and operating voltage, and may also vary due to deterioration during long-term use. If the characteristics of the X-ray tube device are different, the VGC voltage must be applied differently to obtain the same anode current. Fig. 7 (a) shows the minimum grid voltages (V_G1, V_G2, …, V_GN) required for each X-ray tube to operate normally when X-ray tubes (1, 2, …, N) with different characteristics are configured and used in an array. V_c(min) refers to the minimum cathode voltage mentioned above, and although it is shown as being the same for each X-ray tube in the drawing, the minimum cathode voltage, like the grid-cathode voltage, may also vary for each X-ray tube.

[0080] In the past, in order to normally drive multiple X-ray tubes with a fixed grid voltage, the highest voltage among the minimum grid voltages required (i.e., the grid voltage of the X-ray tube with the worst characteristics) (V_G2 in Fig. 7(a)) had to be designed based on this, and a voltage margin (V_G(margin)) had to be added to account for changes in deterioration characteristics during operation or changes in the surrounding environment. As a result, V_G(real) shown in Fig. 7(a) corresponds to the grid voltage value actually required. If nanotubes are used as X-ray generators, V_G(margin) can range from several hundred volts to several thousand volts.

[0081] Figure 7 (b) shows the actual applied voltage when the grid voltage is fixed to V_G (real). Since a scenario in which multiple X-ray tubes are configured as an array and sequentially turned ON / OFF is assumed, V_GCi and V_Ci in Figure 7 (b) represent the gate-cathode voltage and cathode voltage of X-ray tube i when X-ray tube i is turned ON and the remaining X-ray tubes are turned OFF. V_Cioff represents V_GCi (gate-cathode voltage) when X-ray tube i is turned OFF.

[0082] Since V_GCi applied to the X-ray tube is controlled by the current controller (400), the voltage by the actual V_G(margin) can be expressed as the cathode voltage (V_Ci). In addition, when all the X-ray tubes in the array are off, the cathode voltage rises to a voltage that can turn off the X-ray tubes.

[0083] The prior art, described with reference to Figures 7(a) and (b), constantly uses a fixed, high voltage, which can cause system degradation and lower drive system efficiency. Furthermore, because the grid voltage is fixed, there is a potential problem in that if the X-ray tube characteristics change, the X-ray tube can no longer be driven.

[0084]

[0085] Figure 8 illustrates an X-ray apparatus having a plurality of tripolar X-ray tubes according to the present invention.

[0086] The X-ray device (10) of FIG. 8, unlike the device (1) of FIG. 3, includes a plurality of X-ray tubes (1000) and a plurality of voltage sensors (5100) for the same, and further includes an off control signal generator and multiplexer (8000) for supporting a grid voltage control signal when all X-ray tubes are turned off. Unlike that illustrated in FIG. 8, modifications are possible except for the plurality of X-ray tubes (1000).

[0087] The X-ray device (10) of Fig. 8 includes a configuration for compensating for a grid voltage by sensing the cathode voltage of a plurality of X-ray tubes (1000). Fig. 8 illustrates the configuration assuming a scenario in which a plurality of X-ray tubes (1000) are sequentially turned ON (i.e., only one X-ray tube can be turned ON at a time at most). For other assumed scenarios, at least two X-ray tubes can be turned ON, and for this, a modification of a channel selection signal for generating a plurality of V_COi and a modification of a multiplexer (8000) for multiplexing them are required.

[0088] Below, an X-ray device (10) that drives multiple X-ray tubes (1000) will be described, focusing on parts different from the device (1) of FIG. 3.

[0089] A plurality of X-ray tubes (1000) may be composed of a plurality of X-ray tube modules (1001). That is, the device (10) includes a plurality of X-ray tube modules (1001), a voltage sensor module (5000), a voltage controller (6000), and an off control signal / multiplexer (8000).

[0090] An X-ray tube module (1001) may include an X-ray tube (1000), a current controller (4002) and a current detector (4003) connected to a cathode of the X-ray tube (1000), and a switch (4001) for connecting the current controller (4002) and the current detector (4003) to a controller (4010) when the X-ray tube (1000) is in operation. The anode of the X-ray tube (1000) is connected to an anode voltage source (300), and the gate of the X-ray tube (1000) is connected to a grid voltage source (7000). The anode voltage source (300) and the grid voltage source (7000) are provided one by one, as in FIG. 3.

[0091] The switch (4001) is opened and closed by a channel selection signal (CS), and a channel selection signal (CS) for closing the switch (4001) is input or received when the corresponding X-ray tube (1000) is turned ON. The channel selection signal (CS) is associated with a signal for controlling the current controller (4002) of each X-ray tube, and can be generated by the controller (4010).

[0092] The controller (4010) corresponds to the controller (410) of FIG. 3 and can be connected to each X-ray tube (1000) or to a current controller (4002) and a current detector (4003) connected to each X-ray tube via a switch (4001).

[0093] The voltage sensor module (5000) includes a plurality of voltage sensors (5100) and a buffer (5200) selectively connected to any one of the plurality of voltage sensors. The output of the buffer (5200) is connected to the input of the voltage controller (6000).

[0094] A plurality of voltage sensors (5100) sense the cathode voltage of each of the plurality of X-ray tubes (1000). At this time, each voltage sensor (5100) senses a channel selection signal (CS) for selecting an operating X-ray tube, and can recognize or determine whether each of the voltage sensors should sense the cathode voltage or convert the sensed cathode voltage. At the same time, in a scenario where only one of the plurality of X-ray tubes is turned ON, the channel selection signal (CS) is also set to select or turn ON one of the voltage sensors (5100).

[0095] The voltage sensor (5100) that senses the channel selection signal can convert V_C into V_CO as described above. In addition, a buffer (5200) for outputting V_C or V_CO as a buffered voltage may be provided at the output terminal of the voltage sensor (5100). The specific configuration of the voltage sensor (5100) is illustrated in FIG. 9. Referring to FIG. 9, the input of each voltage sensor (5100) is connected to the cathode of each X-ray tube (1000); and the output of each voltage sensor (5100) is configured to be connected in parallel with each other and connected to the input of the buffer (5200). This specific configuration of the voltage sensor (5100) is only an example and does not limit the scope of the present invention.

[0096] The voltage controller (6000) can compare the buffered voltage with the comparison voltage (Vset) and generate a grid voltage or gate voltage control signal of the triode X-ray tube (1000) as a result. The voltage controller (6000) includes an OP amplifier (6010) and a control signal generator (6020), similar to the voltage controller (600) of FIG. 3, but a detailed description thereof will be omitted and reference will be made to the description of the voltage controller (600) of FIG. 3.

[0097] The off control and multiplexer (8000) may include a multiplexer (8100) and an off control signal generator (8200).

[0098] The multiplexer (8100) can multiplex a control signal for the grid voltage (V_Gi) when each X-ray tube is in operation and a control signal for the grid voltage (V_Goff) when all X-ray tubes are OFF. The control signal for the grid voltage (V_Goff) when all X-ray tubes are OFF is generated by the off controller (8220).

[0099] The off controller (8200) can generate an off control signal that generates or fixes the required voltage when all of the plurality of X-ray tubes are turned off according to a channel selection signal (CS).

[0100] The off control and multiplexer (8000) multiplexes the voltage control signal (V_gctl) based on the V_COi selected according to the channel selection signal (CS) and the off control signal and inputs them to the grid power (7000).

[0101] The grid voltage (V_Goff) when all X-ray tubes are turned OFF can be set to a voltage size to make the difference with the grid voltage (V_Gi) when the X-ray tubes that follow in time relatively small. For example, considering a scenario where X-ray tube 1 is turned ON and then X-ray tube 2 is turned ON, the output voltage of the grid power supply (7000) changes from V_G1 to V_G2, and the larger the difference in magnitude between V_G1 and V_G2, the longer it takes for the transformation. To reduce the time for this transformation, V_Goff is set, and the size of V_Goff can be updated as the ON / OFF operations of multiple X-ray tubes are continuously repeated. For example, if all X-ray tubes are turned ON / OFF once in one cycle, the size of V_Goff used in the second cycle can be based on the average value of V_Gi in the first cycle.

[0102] Meanwhile, the grid voltage in the case where all X-ray tubes are turned OFF can be set to maintain the grid voltage of the X-ray tube that was operated immediately before, without setting V_Goff.

[0103] The grid power supply (7000) is connected to supply the grid voltage of each X-ray tube (1000) or X-ray tube module (1001), and can vary its output voltage according to the off control signal and the control signal output from the multiplexer (8000).

[0104]

[0105] Figure 9 illustrates an example of a configuration of a cathode voltage sensor of an X-ray apparatus having a plurality of triode X-ray tubes according to the present invention. The depicted voltage converter (5110, 5120) may be included in the voltage sensor (5100).

[0106] The voltage converter (5110) corresponds to the voltage converter of Fig. 5 (b), and the voltage converter (5120) corresponds to the voltage converter of Fig. 6 (b). Each of the voltage converters (5110, 5120) may include a switch (5112, 5122) that opens and closes the switch according to a channel selection signal. Accordingly, when a channel selection signal of an operating X-ray tube is received, the voltage converters (5110, 5120) may convert the cathode voltage (V_Ci) of the corresponding X-ray tube using an N-type MOSFET and a voltage divider (5111, 5121), respectively, and output the converted voltage (V_COi).

[0107]

[0108] Figure 10 illustrates voltages for driving a plurality of triode X-ray tubes according to the present invention.

[0109] Referring to Fig. 10, it can be seen that, unlike in (b) of Fig. 7, the grid voltage for multiple X-ray tubes is variably provided. For reference, when one X-ray tube is in operation, the same grid voltage (V_Gi) is applied to all X-ray tubes. However, the magnitude of the grid voltage (V_Gi) can be changed through the voltage controller of Fig. 3 or Fig. 8 depending on which X-ray tube is in operation. The ON / OFF of the X-ray tube is controlled by the cathode voltage of the X-ray tube. In addition, when all X-ray tubes are not in operation, the same grid voltage (V_Goff) is applied to all X-ray tubes.

[0110] The cathode voltage (V_Coff) when each X-ray tube is OFF is determined based on the physical characteristics of each X-ray tube. Therefore, although they are depicted almost identically in Fig. 10, their sizes can be determined independently of each other.

[0111] The X-ray device (10) detects the cathode voltage of each X-ray tube during operation, and operates to provide a grid voltage (V_Gi) so as to maintain a minimum cathode voltage (V_C(min)). By using the X-ray device (10), even if a plurality of X-ray tubes with different characteristics are used, the grid voltage can be maintained at an optimal value (minimum value that can be operated) for each X-ray tube, and even if the characteristics of the X-ray tube deteriorate during operation or change due to environmental changes, the grid voltage can be adjusted to an optimal value suitable for the changed characteristics.

[0112]

[0113] In addition, as another aspect of the present invention, the operation of the proposal or invention described above may be implemented, performed or executed by a “computer” (a comprehensive concept including a system on chip (SoC) or a (micro) processor, etc.), or may be provided as a code or a computer-readable storage medium storing or including the code or a computer program product, and the scope of the present invention may be extended to the code or the computer-readable storage medium storing or including the code or the computer program product.

[0114]

[0115] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations of the present invention, as defined by the following claims, are possible. Accordingly, the present invention is not intended to be limited to the embodiments disclosed herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. In a device for controlling the voltage applied to a triode X-ray tube, A voltage sensor for sensing the voltage of the cathode of the above triode X-ray tube; A voltage controller for generating a control signal for compensating the voltage of the gate for the operation of the triode X-ray tube based on the voltage of the sensed cathode; and A control device including a power source that controls the voltage of the gate of the triode X-ray tube according to the control signal.

2. In paragraph 1, A control device wherein the control signal is generated based on the difference between the voltage of the cathode or the voltage corresponding to the voltage of the cathode and a preset reference voltage value.

3. In paragraph 1, A control device wherein the above control signal causes the voltage of the cathode to follow a preset reference voltage value.

4. In the first paragraph, the voltage controller: A control device that converts the voltage of the cathode of the above triode X-ray tube into a voltage of a comparable range.

5. In paragraph 1, A control device further comprising a current controller for controlling the cathode current of the triode X-ray tube to turn off the triode X-ray tube.

6. In the first paragraph, the voltage sensor: A control device comprising a circuit for outputting the voltage of the cathode as a voltage lower than a preset value or a voltage reduced by a preset ratio.

7. In the first paragraph, the voltage controller: Generate a control signal for the voltage of the gate for the operation of multiple triode X-ray tubes, A control device in which each of the above plurality of triode X-ray tubes is sequentially operated according to a preset order.

8. In the 7th paragraph, a control device in which the gate of each of the plurality of triode X-ray tubes is connected to the output terminal of the power source.

9. In paragraph 7, A control device wherein the voltage of the gate for each of the plurality of triode X-ray tubes is set independently of each other.

10. In paragraph 7, the voltage controller: A control device that converts the voltage of the cathode of one of the plurality of triode X-ray tubes in operation into a voltage of a comparable range.

11. In paragraph 7, A control device comprising a multiplexer for multiplexing a control signal for a voltage of a gate for the operation of any one of the plurality of triode X-ray tubes and a control signal for a voltage of a gate for turning off all of the plurality of triode X-ray tubes.

12. In paragraph 7, A control device comprising an off controller for generating a control signal for a preset gate voltage for turning off all of the plurality of triode X-ray tubes.

13. In paragraph 12, A control device in which the voltage of the preset gate is updated according to the operation of the plurality of triode X-ray tubes.

14. In the 7th paragraph, the voltage sensor includes a voltage sensing circuit that senses the voltage of the cathode of each of the plurality of triode X-ray tubes, The above voltage sensing circuit is a control device that transmits the cathode voltage of the selected triode X-ray tube or a voltage corresponding thereto to the voltage controller according to a channel selection signal that selects one of the plurality of triode X-ray tubes.

15. An X-ray device driven by a triode X-ray tube, A triode X-ray tube that produces X-rays; A voltage sensor for sensing the voltage of the cathode of the above triode X-ray tube; A voltage controller for generating a control signal for compensating the voltage of the gate for the operation of the triode X-ray tube based on the voltage of the sensed cathode; and An X-ray device comprising a power source that controls the voltage of the gate of the triode X-ray tube according to the control signal.

16. An X-ray device driven by a plurality of triode X-ray tubes, Multiple triode X-ray tubes that produce X-rays; A voltage sensor for sensing the voltage of each cathode of the plurality of triode X-ray tubes; A voltage controller for generating a control signal for compensating the voltage of the gate for the operation of the triode X-ray tube based on the voltage of the sensed cathode; and Includes a power source that controls the voltage of the gate of the triode X-ray tube according to the control signal, Each of the above plurality of triode X-ray tubes is operated sequentially according to a preset order, An X-ray device, wherein the voltage of the gate for each of the plurality of triode X-ray tubes is set independently of each other.

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