X-ray electron emission control device

Abstract

The present invention relates to an X-ray electron emission control device for constantly controlling an anode current by sensing the anode current, comprising: an electron emission unit for emitting electrons; the anode is used for collecting electrons; the grid voltage source is connected with the grid of the electron emission part; the cathode current source is connected with the cathode of the electron emission part; a current sensing unit connected to the cathode current source and sensing the anode current; and a current control unit that generates a current control signal based on the sensed anode current and outputs the current control signal to the cathode current source; one side of the gate voltage source may be connected to a gate of the electron emission section, and the other side may be connected to a branch point of a line connecting the cathode current source and the current sensing section.

Description

Technical Field

[0001] The present invention relates to an X-ray electron emission control device which controls the anode current to be constant by sensing the anode current. Background Art

[0002] Generally, types of electron emission devices used in X-ray tubes include a field emitter method using tunneling current and a heater emitter method using thermal electron emission.

[0003] In particular, as field emitter methods that have attracted much attention recently and can be driven digitally, there are carbon nanotubes, field emission tips using MEMS (Micro-Electro-Mechanical Systems) technology, MIM (Metal-Insulator-Metal) using semiconductor technology, and devices using MIS (Metal-Insulator-Semiconductor) elements.

[0004] The electron emission device is composed of a cathode end equipped with an emitter that emits electrons and a gate end that adjusts the amount of electron emission. The cathode end and the gate end are vacuum packaged together with the anode end that collects the emitted electrons to form an electron emission device.

[0005] The characteristics of the electron emission devices may differ due to slight differences in the manufacturing process, and in the case of using a plurality of electron emission devices, an additional device capable of automatically adjusting the current to match the respective characteristics is required.

[0006] As a method for obtaining a constant emission current, there is a method of sensing only the cathode current, or a method of sensing the cathode current and the gate current to control the anode current for precise control.

[0007] However, the method of controlling the anode current by sensing only the cathode current is difficult to control accurately, and the method of controlling the anode current by sensing the cathode current and the gate current makes the system structure complicated due to the need to sense and calculate the two currents, and there is a problem of additional costs due to the difficulty in mutual correction.

[0008] Therefore, it is necessary to develop an X-ray electron emission control device that can realize an easy, simple and low-cost circuit and can accurately control the anode current. Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention aims to solve the aforementioned problems and other problems.

[0011] The object of the present invention is to connect a current sensing part to a cathode current source and a gate voltage source to a branch point of a line connecting the cathode current source and the current sensing part, so that an anode current can be sensed in a low voltage region without being directly connected to an anode terminal, thereby realizing an X-ray electron emission control device with an easy, simple and low-cost circuit and capable of accurately controlling the anode current.

[0012] Technical solutions to the problem

[0013] An X-ray electron emission control device according to an embodiment of the present invention includes: an electron emission unit that emits electrons; an anode that collects electrons; a gate voltage source that is connected to the gate of the electron emission unit; a cathode current source that is connected to the cathode of the electron emission unit; a current sensing unit that is connected to the cathode current source and senses the anode current; and a current control unit that generates a current control signal based on the sensed anode current and outputs it to the cathode current source; one side of the gate voltage source can be connected to the gate of the electron emission unit, and the other side of the gate voltage source can be connected to a branch point of a line connecting the cathode current source and the current sensing unit.

[0014] Another embodiment of an X-ray electron emission control device of the present invention includes: a plurality of electron emission units, including a gate and a cathode; a plurality of anodes, respectively configured corresponding to the plurality of electron emission units; a plurality of cathode current sources, respectively connected to the cathodes corresponding to the plurality of electron emission units; a gate voltage source, connected to the gate of any specific electron emission unit among the plurality of electron emission units; a current sensing unit, connected to the plurality of cathode current sources, sensing the anode current; and a current control unit, generating a current control signal based on the sensed anode current and outputting it to the plurality of cathode current sources; one side of the gate voltage source can be connected to the gate of the specific electron emission unit, and the other side of the gate voltage source can be connected to a branch point of a line connecting the plurality of cathode current sources and the current sensing unit.

[0015] Effects of the Invention

[0016] According to one embodiment of the present invention, an X-ray electron emission control device connects a current sensing unit to a cathode current source, and connects a gate voltage source to a branch point of a line connecting the cathode current source and the current sensing unit, thereby being able to sense an anode current in a low voltage region without being directly connected to an anode terminal, thereby enabling an easy, simple and low-cost circuit to be realized and enabling precise control of the anode current.

[0017] In addition, the present invention can sense the anode current through a current sensing device, so the overall device is simple in structure, and only the anode current is corrected, so the current can be accurately controlled.

[0018] In addition, in the present invention, the anode current is sensed between the cathode end and the ground end of the device, so it can be composed of a device with a voltage range equivalent to several volts to tens of volts, and the stability of the entire device is high, and a high-precision current sensing device can be easily realized, and low cost can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a diagram for explaining an X-ray electron emission control device according to an embodiment of the present invention.

[0020] Figure 2 This is a diagram for explaining a current control unit of an X-ray electron emission control device according to an embodiment of the present invention.

[0021] Figure 3 This is a diagram for explaining a current control unit of an X-ray electron emission control device according to another embodiment of the present invention.

[0022] Figure 4 It is a diagram for explaining an X-ray electron emission control device according to another embodiment of the present invention.

[0023] Figure 5 It is a diagram for explaining a simulation X-ray electron emission control device according to an embodiment of the present invention.

[0024] Figure 6 and Figure 7 It is shown Figure 5 A graph of the simulation results of the X-ray electron emission control device. DETAILED DESCRIPTION

[0025] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. Regardless of the figure numbers, the same or similar constituent elements will be marked with the same figure numbers, and repeated descriptions thereof will be omitted. The suffixes "module" and "unit" of the constituent elements used in the following description are only given or mixed in consideration of the ease of writing of the description, and they themselves do not have meanings or functions that distinguish each other. In addition, when describing the embodiments disclosed in this specification, if it is determined that the specific description of the relevant known technology may confuse the subject matter of the embodiments disclosed in this specification, its detailed description will be omitted. In addition, the accompanying drawings are only used to make the embodiments disclosed in this specification easy to understand, and it should be understood that the technical ideas disclosed in this specification are not limited by the accompanying drawings, but cover all changes, equivalents and substitutes included in the idea and technical scope of the present invention.

[0026] Terms including ordinal numbers such as first, second, etc. may be used to describe various constituent elements, but the constituent elements are not limited by the terms. The terms are only used to distinguish one constituent element from other constituent elements.

[0027] When it is mentioned that a certain component is "connected" or "coupled" to another component, it should be understood that it can be directly connected or coupled to the other component, or other components may exist between them. On the contrary, when it is mentioned that a certain component is "directly connected" or "directly coupled" to another component, it should be understood that there are no other components between them.

[0028] Figure 1 It is a diagram for explaining an X-ray electron emission control device according to an embodiment of the present invention.

[0029] like Figure 1 As shown, the X-ray electron emission control device of the present invention may include: an electron emission portion 100 that emits electrons; an anode 200 that collects electrons; a gate voltage source 600 that is connected to the gate 110 of the electron emission portion 100; a cathode current source 500 that is connected to the cathode 120 of the electron emission portion 100; a current sensing portion 800 that is connected to the cathode current source 500 and senses the anode current; and a current control portion 300 that generates a current control signal based on the sensed anode current and outputs it to the cathode current source 500.

[0030] In order to smoothly emit and collect electrons, the anode 200 and the electron emission portion 100 may be vacuum-sealed.

[0031] Next, one side of the gate voltage source 600 may be connected to the gate 110 of the electron emission part 100 , and the other side may be connected to a branch point of a line 620 connecting between the cathode current source 500 and the current sensing part 800 .

[0032] Also, the cathode current source 500 may output the cathode current obtained by combining the gate current and the anode current to a branch point of the line 620 connecting the cathode current source 500 and the current sensing unit 800 .

[0033] At this time, the gate voltage source 600 may be connected to a first branch line 621 branched from a branch point of the line 620 , and the current sensing unit 800 may be connected to a second branch line 622 branched from the branch point of the line 620 .

[0034] Therefore, the gate voltage source 600 can receive the gate current branched from the cathode current outputted from the cathode current source 500 by the first branch line 621 , and the current sensing unit 800 can receive the anode current branched from the cathode current outputted from the cathode current source 500 by the second branch line 622 .

[0035] The anode current branched by the second branch line 622 may have a current flowing through I A =I CA -I G (Among them, I A is the anode current, I CA is the cathode current, I G is the gate current) formula to calculate the current value.

[0036] Furthermore, if the gate current increases, the anode current branched through the second branch line 622 increases in proportion to the increase rate thereof, and if the gate current decreases, the anode current branched through the second branch line 622 decreases in proportion to the decrease rate thereof.

[0037] The anode current branched by the second branch line 622 may have a current flowing through I A =(TR / (1-TR))I G (Among them, I A is the anode current, TR is the transmission rate, I G is the gate current) formula to calculate the current value.

[0038] Next, the gate voltage source 600 may include a gate cathode terminal connected to the first branch line 621 and a gate anode terminal connected to the gate line 610 of the electron emission portion 100 .

[0039] The gate current amount supplied to the gate 110 of the electron emission portion 100 through the gate line 610 connected to the gate anode terminal may be the same as the gate current amount input through the first branch line 621 connected to the gate cathode terminal.

[0040] At this time, if the cathode current of the cathode current source 500 increases, the gate voltage source 600 can increase the gate current proportionally thereto, and if the cathode current of the cathode current source 500 decreases, the gate voltage source 600 can decrease the gate current proportionally thereto.

[0041] Then, when a current control signal is input from the current control unit 300 , the cathode current source 500 may adjust the cathode current according to the current control signal.

[0042] The cathode current source 500 may adjust the cathode current in accordance with the current control signal to keep the gate terminal voltage of the electron emission unit 100 fixed and adjust the cathode terminal voltage of the electron emission unit 100 .

[0043] At this time, the cathode current source 500 may reduce the cathode terminal voltage of the electron emission portion 100 by increasing the cathode current in accordance with the current control signal or increase the cathode terminal voltage of the electron emission portion 100 by reducing the cathode current in accordance with the current control signal.

[0044] Also, the current sensing unit 800 may receive the anode current from a branch point of the line 620 connecting the cathode current source 500 and the current sensing unit 800 to output a voltage proportional to the anode current to the current control unit 300 .

[0045] The voltage output from the current sensing unit 800 may have a voltage through V S =Z S I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the voltage value calculated by the anode current) formula.

[0046] As an example, the current sensing unit 800 may include a passive element including a capacitor and an inductor, a hall sensor, and a current transformer, but this is only an embodiment and is not limited thereto.

[0047] In addition, the X-ray electron emission control device of the present invention may further include a voltage source VC900 , one side of the voltage source VC900 is connected to the current sensing unit 800 , and the other side of the voltage source VC900 is connected to the grounding unit 400 .

[0048] The voltage source VC900 can supply a constant voltage to the line 620 , the first branch line 621 , and the second branch line 622 connecting the cathode current source 500 and the current sensing unit 800 via the current sensing unit 800 .

[0049] Then, the current control unit 300 may include: an anode current sensing amplifier unit, which amplifies the output voltage of the current sensing unit 800; an error amplifier unit, which amplifies the error value by comparing the output voltage of the anode current sensing amplifier unit and the reference voltage of the reference voltage source; and a frequency compensation unit, which generates a current control signal based on the output voltage of the error amplifier unit.

[0050] Among them, the input side of the anode current sensing amplifier is connected to the current sensing unit 800, and the output side is respectively connected to the reference voltage source connected to the ground unit 400 and the error amplifier. If the output voltage of the current sensing unit 800 is input, a voltage proportional to the input can be output with the ground terminal as the reference.

[0051] In addition, the error amplifier includes a first input terminal connected to the anode current sensing amplifier, a second input terminal connected to the reference voltage source, and an output terminal connected to the cathode current source. One side of the frequency compensation unit can be connected to the connecting line between the first input terminal of the error amplifier and the anode current sensing amplifier, and the other side can be connected to the connecting line between the output terminal of the error amplifier and the cathode current source.

[0052] In addition, the error amplifier and the frequency compensation unit may generate a current control signal that is controlled so that the output voltage of the current sensing unit 800 is the same as the reference voltage.

[0053] In addition, the current control unit 300 can be A =V ref / αZ s , V ref =αV s , V s =Z s I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage, αV s is the output voltage of the current sensing unit) formula to generate a current control signal for controlling the anode current.

[0054] As another embodiment, the current control unit 300 may include: a first analog-to-digital conversion unit (ADC), which converts the output voltage of the current sensing unit 800 into a first digital signal; a second analog-to-digital conversion unit (ADC), which converts the reference voltage of the reference voltage source into a second digital signal; a control unit, which calculates and processes the first digital signal and the second digital signal; and an output unit, which generates and outputs a current control signal based on the processing results calculated and processed in the control unit.

[0055] The current control unit 300 may output the current control signal as an analog signal or as a digital signal including any one of a PWM (Pulse Width Modulation) signal and a PFM (Pulse Frequency Modulation) signal.

[0056] Furthermore, the control unit may perform calculation processing based on a control algorithm including a PID (Proportional Integral Derivative) method, but this is only one embodiment and is not limited thereto.

[0057] In addition, the X-ray electron emission control device of the present invention may further include an anode voltage source 700 , one side of the anode voltage source 700 is connected to the anode 200 , and the other side of the anode voltage source 700 is connected to the grounding portion 400 .

[0058] Then, the electron emission unit 100 is composed of a gate 110 and a cathode 120 having an electron emission emitter. One side of a cathode current source 500 for adjusting cathode current is connected to the cathode 120 , and the other side is connected to a first branch line 621 connected to the gate cathode end of a gate voltage source 600 .

[0059] The current flowing in the line 620 connected to the cathode current source 500 may be branched into a first branch line 621 connected to the gate cathode terminal of the gate voltage source 600 and a second branch line 622 connected to the current sensing unit 800 .

[0060] The gate voltage source 600 can be connected between the gate line 610, i.e., the Vgate+ line, connected to the gate 110 of the electron emission unit 100 and the first branch line 621, i.e., the Vgate- line. A voltage difference may be generated between the Vgate+ line serving as the gate line 610 and the Vgate- line serving as the first branch line 621.

[0061] Furthermore, the gate voltage source 600 may be separated from the ground portion 400 . This type of voltage source may be formed by an isolated power converter.

[0062] The isolated power converter can fix one of two output terminals (among which, a gate anode terminal Vgate+ and a gate cathode terminal Vgate-) to an arbitrary power source.

[0063] Next, the voltage source VC900 is a voltage source for fixing the gate cathode terminal Vgate- to an appropriate voltage. The voltage source VC900 can apply a constant voltage to the first branch line 621, the second branch line 622 and the connecting line 620 of the cathode current source 500 connected to the gate cathode terminal Vgate- via the current sensing unit 800.

[0064] The present invention constructed as described above operates as follows.

[0065] If the gate current I G and the anode current I generated by the emitted electrons A flows, the cathode current I CA =I G +I A Flows into the electron emission portion 100 .

[0066] And, the gate current I G It is regulated by the voltage difference between the gate terminal and the cathode terminal, such as I A =(TR / (1-TR))I G (Among them, I A is the anode current, TR is the transmission rate, I G is the gate current) formula, the anode current I A Proportional to the gate current.

[0067] Therefore, in the present invention, if the voltage difference between the gate terminal and the cathode terminal is adjusted, the anode current can be adjusted.

[0068] In the present invention, the voltage at the cathode terminal can be adjusted by fixing the gate terminal voltage and adjusting the current of the cathode current source 500 .

[0069] For example, when the current of the cathode current source 500 is increased, the voltage at the cathode terminal of the electron emission portion 100 decreases, and the voltage difference between the gate terminal and the cathode terminal increases.

[0070] Therefore, the gate current increases due to the I A =(TR / (1-TR))I G (Among them, I A is the anode current, TR is the transmission rate, I G is the gate current) formula, the anode current also increases in proportion to the rate of increase of the gate current.

[0071] Furthermore, the anode current sensing operation of the present invention is as follows.

[0072] Typically, the current supplied by the voltage source and the current recovered are the same, so the gate current supplied to the gate line 610 connected to the gate anode terminal Vgate+ of the gate voltage source 600 will be recovered to the first branch line 621 connected to the gate cathode terminal Vgate- of the gate voltage source 600 with the same amount of current.

[0073] In the present invention, the cathode current (I CA =I G +I A ), the gate current I in the cathode current G The anode current I A The current branches to the second branch line 622 and flows into the current sensing unit 800 .

[0074] Therefore, the current sensing part 800 senses the input anode current, and the current control part 300 controls the cathode current source 500 that adjusts the cathode current based on the sensed anode current, thereby maintaining the anode current constant.

[0075] As described above, in the present invention, by connecting the current sensing part to the cathode current source and connecting the gate voltage source to the branch point of the line connecting the cathode current source and the current sensing part, the anode current can be sensed in a low voltage region without being directly connected to the anode terminal, thereby realizing an easy, simple and low-cost circuit and being able to accurately control the anode current.

[0076] In addition, the present invention can sense the anode current through a current sensing device, so the overall device structure is simple, and only the anode current is corrected, so the current can be accurately controlled.

[0077] In addition, in the present invention, the anode current is sensed between the cathode end and the ground end of the device, so it can be composed of a device with a voltage range equivalent to several volts to tens of volts, and the stability of the entire device is high, and a high-precision current sensing device can be easily realized, and low cost can also be achieved.

[0078] Figure 2 This is a diagram for explaining a current control unit of an X-ray electron emission control device according to an embodiment of the present invention. The current control unit is implemented by a simulation device.

[0079] like Figure 2 As shown, the current control unit 300 of the present invention can generate a current control signal based on the sensed anode current and output the current control signal to the cathode current source 500 .

[0080] The current sensing part 800 may receive the anode current from a branch point of the line 620 connecting the cathode current source 500 and the current sensing part 800 , and output a voltage proportional thereto to the current control part 300 .

[0081] The voltage output from the current sensing unit 800 may have a voltage through V S =Z S I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the voltage value calculated by the anode current) formula.

[0082] Furthermore, the current control unit 300 may include: an anode current sensing amplifier unit 340, which amplifies the output voltage of the current sensing unit 800; an error amplifier unit 310, which amplifies the error value by comparing the output voltage of the anode current sensing amplifier unit 340 with a reference voltage of a reference voltage source; and a frequency compensation unit 330, which generates a current control signal based on the output voltage of the error amplifier unit.

[0083] Among them, the input side of the anode current sensing amplifier 340 is connected to the current sensing unit 800, and the output side is respectively connected to the reference voltage source 320 and the error amplifier 310 connected to the ground unit 400. If the output voltage of the current sensing unit 800 is input, a voltage proportional to the input can be output with the ground terminal as the reference.

[0084] In addition, the error amplifier 310 may include a first input terminal connected to the anode current sensing amplifier 340 , a second input terminal connected to the reference voltage source 320 , and an output terminal connected to the cathode current source 500 .

[0085] Furthermore, one side of the frequency compensation unit 330 can be connected to the connection line between the first input terminal of the error amplifier unit 310 and the anode current sensing amplifier unit 340 , and the other side can be connected to the connection line 311 between the output terminal of the error amplifier unit 310 and the cathode current source 500 .

[0086] In addition, the error amplifier 310 and the frequency compensation unit 330 may generate a current control signal that is controlled so that the output voltage of the current sensing unit 800 is the same as the reference voltage.

[0087] The current control unit 300 configured as described above can be controlled by I A =V ref / αZ s , V ref =αV s , V s =Z s I A(Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage, αV s is the output voltage of the current sensing unit) formula to generate a current control signal for controlling the anode current.

[0088] The X-ray electron emission control device of the present invention may include: an electron emission portion 100 that emits electrons; an anode 200 that collects electrons; a gate voltage source 600 that is connected to the gate 110 of the electron emission portion 100; a cathode current source 500 that is connected to the cathode 120 of the electron emission portion 100; a current sensing portion 800 that is connected to the cathode current source 500 and senses the anode current; an anode voltage source 700 that is connected to the anode 200 and the ground portion 400; and a voltage source VC900 that is connected to the current sensing portion 800 and the ground portion 400.

[0089] The voltage source VC900 can supply a constant voltage to the line 620 , the first branch line 621 , and the second branch line 622 connecting the cathode current source 500 and the current sensing unit 800 via the current sensing unit 800 .

[0090] If the anode current is input, the current sensing unit 800 can output a voltage (V S =Z S I A , where V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current).

[0091] Also, the anode current sensing amplifier 340 of the current control unit 300 may appropriately amplify the output voltage of the current sensing unit 800 , and the error amplifier 310 may amplify the error value as the difference value by comparing the output voltage of the anode current sensing amplifier with a reference voltage.

[0092] Next, the frequency compensation unit 330 , together with the error amplifier 310 , may generate a current control signal by appropriately integrating or differentiating the output voltage.

[0093] The current control signal may then be used as a signal to control the cathode current source 500 which regulates the cathode current along the connection line 311 .

[0094] The anode current sensing amplifier 340 receives the voltage across the output of the current sensing unit 800, and outputs a voltage αV proportional to the input with the grounding unit 400 as a reference. s .

[0095] Furthermore, the error amplifier 310 and the frequency compensation unit 330 can be controlled to adjust the cathode current source 500 of the cathode current so that the output voltage αV of the anode current sensing amplifier 340 is s With reference voltage V ref same.

[0096] Therefore, the current control unit 300 of the present invention can be controlled by I A =V ref / αZ s , V ref =αV s , V s =Z s I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage, αV s is the output voltage of the current sensing unit) formula to accurately control the anode current.

[0097] Figure 3 This is a diagram for explaining a current control unit of an X-ray electron emission control device according to another embodiment of the present invention, and the current control unit is implemented by a digital device.

[0098] like Figure 3 As shown, the current control unit 300 of the present invention can generate a current control signal based on the sensed anode current and output the current control signal to the cathode current source 500 .

[0099] The current sensing part 800 may receive the anode current from a branch point of the line 620 connecting the cathode current source 500 and the current sensing part 800 , and output a voltage proportional thereto to the current control part 300 .

[0100] The voltage output from the current sensing unit 800 may have a voltage through V S =Z S I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the voltage value calculated by the anode current) formula.

[0101] Furthermore, the current control unit 300 may include: a first analog-to-digital conversion unit 3021, which converts the output voltage of the current sensing unit 800 into a first digital signal; a second analog-to-digital conversion unit 3022, which converts the reference voltage of the reference voltage source 3040 into a second digital signal; a control unit 3010, which calculates and processes the first digital signal and the second digital signal; and an output unit 3030, which generates and outputs a current control signal based on the processing results calculated and processed in the control unit 3010.

[0102] The current control unit 300 may output the current control signal as an analog signal or as a digital signal including any one of a PWM (Pulse Width Modulation) signal and a PFM (Pulse Frequency Modulation) signal.

[0103] Furthermore, the control unit 3010 may perform calculation processing based on a control algorithm including a PID (Proportional Integral Derivative) method, which is only an embodiment and is not limited thereto.

[0104] The current control unit 300 of the present invention configured as described above receives the output voltage V of the current sensing unit 800. S =Z S I A , and is converted into a digital signal by the first analog-to-digital conversion unit 3021 , and the reference voltage is also converted into a digital signal by the second analog-to-digital conversion unit 3022 .

[0105] Then, the two signals converted into digital signals can perform calculations including control algorithms in the MCU (micro processing unit) as the control part 3010 , and output a current control signal for controlling the cathode current source 500 through the output part 3030 .

[0106] At this time, the output signal may be an analog signal via a DAC (Digital to Analog converter) or a digital signal.

[0107] The digital signal may include a PWM (Pulse Width Modulation) signal output by changing a pulse width or a PFM (Pulse Frequency Modulation) signal output by changing a pulse frequency, and other signals capable of controlling the cathode current source 500 .

[0108] Furthermore, as an example of a control algorithm, there is a PID method, and other various control algorithms can be included.

[0109] Figure 4 It is a diagram for explaining an X-ray electron emission control device according to another embodiment of the present invention, which is implemented by an X-ray electron emission control device capable of controlling a plurality of electron emission devices.

[0110] like Figure 4 As shown, the present invention may include: a plurality of electron emission parts 1001 to 100 n , including a grid and a cathode; a plurality of anodes 2001 to 200 n , respectively with a plurality of electron emitting portions 1001 to 100 n Correspondingly configured; a plurality of cathode current sources 5001 to 500 n , respectively with a plurality of electron emitting portions 1001 to 100 n Correspondingly connected to cathodes 1201-120 n ; Gate voltage source 600, and a plurality of electron emission units 1001 to 100 n The current sensing unit 800 is connected to the gate of any specific electron emission unit in the embodiment; and the plurality of cathode current sources 5001 to 500 n and a current control unit 300, which generates a current control signal based on the sensed anode current and outputs it to a plurality of cathode current sources 5001 to 500 n .

[0111] One side of the gate voltage source 600 may be connected to the gate of a specific electron emission unit 100, and the other side may be connected to a plurality of cathode current sources 5001 to 5002. n and a branch point of a line between the current sensing unit 800 .

[0112] Furthermore, the plurality of electron emitting portions 1001 to 100 n The gate electrodes can be connected in series with each other, and the plurality of anodes 2001 to 200 n Can be connected in series with each other.

[0113] Next, a plurality of cathode current sources 5001-500 n The electrodes may be connected in parallel to each other and to the current sensing part 800 .

[0114] Then, the current control section 300 may generate a current control signal including a first control signal that individually turns on / off the cathode current source 500 and a second signal that individually controls a current value of the cathode current source 500 .

[0115] The current control unit 300 can be connected through the lines 3011 to 301 n and a plurality of cathode current sources 5001 to 500 nThey are connected separately and output current control signals to each cathode current source 500 separately.

[0116] Furthermore, a plurality of cathode current sources 5001 to 500 n The cathode current in which the gate current and the anode current merge may be output to the line 620 connecting the current sensing part 800 and the gate voltage source 600 .

[0117] At this time, the gate voltage source 600 may be connected to a first branch line 621 branched from a branch point of the line 620 , and the current sensing unit 800 may be connected to a second branch line 622 branched from the branch point of the line 620 .

[0118] Therefore, the gate voltage source 600 can receive the gate current branched from the cathode current outputted from the cathode current source 500 through the first branch line 621 , and the current sensing unit 800 can receive the anode current branched from the cathode current outputted from the cathode current source 500 through the second branch line 622 .

[0119] If the gate current increases, the anode current branched through the second branch line 622 may increase in proportion to its increase rate; if the gate current decreases, the anode current branched through the second branch line 622 may decrease in proportion to its decrease rate.

[0120] As an example, the anode current branched by the second branch line 622 may have a current flowing through I A =(TR / (1-TR))I G (Among them, I A is the anode current, TR is the transmission rate, I G is the gate current) formula.

[0121] Next, the gate voltage source 600 may include a gate cathode terminal connected to the first branch line 621 and a gate anode terminal connected to the gate line of the electron emission portion 100 .

[0122] Here, the gate current amount supplied to the gate 110 of the electron emission portion 100 through the gate line connected to the gate anode terminal may be the same as the gate current amount input through the first branch line 621 connected to the gate cathode terminal.

[0123] At this time, if the cathode current of the cathode current source 500 increases, the gate voltage source 600 can increase the gate current proportionally thereto, and if the cathode current of the cathode current source 500 decreases, the gate voltage source 600 can decrease the gate current proportionally thereto.

[0124] Then, when a current control signal is input from the current control unit 300 , the cathode current source 500 may adjust the cathode current according to the current control signal.

[0125] The cathode current source 500 may adjust the cathode current in accordance with the current control signal to keep the gate terminal voltage of the electron emission unit 100 fixed and adjust the cathode terminal voltage of the electron emission unit 100 .

[0126] At this time, the cathode current source 500 may reduce the cathode terminal voltage of the electron emission portion 100 by increasing the cathode current in accordance with the current control signal or increase the cathode terminal voltage of the electron emission portion 100 by reducing the cathode current in accordance with the current control signal.

[0127] Also, the current sensing part 800 may receive the anode current from a branch point of the line 620 connecting the cathode current source 500 and the current sensing part 800 , and output a voltage proportional to the anode current to the current control part 300 .

[0128] The voltage output from the current sensing unit 800 may have a voltage through V S =Z S I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the voltage value calculated by the anode current) formula.

[0129] In addition, the X-ray electron emission control device of the present invention may further include a voltage source VC900 , one side of the voltage source VC900 is connected to the current sensing unit 800 , and the other side of the voltage source VC900 is connected to the grounding unit 400 .

[0130] The voltage source VC900 can supply a constant voltage to the line 620 , the first branch line 621 , and the second branch line 622 connecting the cathode current source 500 and the current sensing unit 800 via the current sensing unit 800 .

[0131] Then, the current control unit 300 can pass I A =V ref / αZ s 、V ref =αV s 、V s =Z s I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage, αVs is the output voltage of the current sensing unit) formula to generate a current control signal for controlling the anode current.

[0132] In addition, the present invention may further include an anode voltage source 700 , one side of the anode voltage source 700 is connected to the anode 200 , and the other side of the anode voltage source 700 is connected to the grounding portion 400 .

[0133] As described above, when driving a plurality of electron emission devices, if the characteristics of the plurality of electron emission devices are different, control parameters must be set individually to suit the characteristics of each corresponding electron emission device. However, in the present invention, even if the individual characteristics of the electron emission devices are different, the anode current can be constantly controlled without setting control parameters individually.

[0134] Furthermore, in the present invention, even if the electron emission device deteriorates or the surrounding environment changes during use of the electron emission device, the anode current can be constantly controlled regardless of this.

[0135] Figure 5 is a diagram for explaining a simulation X-ray electron emission control device according to an embodiment of the present invention. Figure 6 and Figure 7 It is shown Figure 5 A graph of the simulation results of the X-ray electron emission control device.

[0136] like Figure 5 As shown, the simulation X-ray electron emission control device may include: a cathode current source 500, connected to the cathode of the electron emission unit 100; a current sensing unit 800, connected to the cathode current source 500, sensing the anode current; and a current control unit 300, generating a current control signal based on the sensed anode current and outputting it to the cathode current source 500.

[0137] One side of the gate voltage source 600 may be connected to the gate of the electron emission unit 100 , and the other side may be connected to a branch point of a line connecting the cathode current source 500 and the current sensing unit 800 .

[0138] Also, the cathode current source 500 may output the cathode current obtained by combining the gate current and the anode current to a branch point of a line connecting the cathode current source 500 and the current sensing unit 800 .

[0139] At this time, the gate voltage source 600 can receive the gate current branched through the first branch line from the cathode current outputted from the cathode current source 500 , and the current sensing unit 800 can receive the anode current branched through the second branch line from the cathode current outputted from the cathode current source 500 .

[0140] Also, the current sensing part 800 may receive the anode current from a branch point of a line connecting the cathode current source 500 and the current sensing part 800 , and output a voltage proportional thereto to the current control part 300 .

[0141] The voltage output from the current sensing unit 800 may have a voltage through V S =Z S I A (Wherein, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the voltage value calculated by the anode current) formula.

[0142] By simulating the X-ray electron emission control device configured as described above, it can be confirmed whether the anode current measured at the anode terminal side is consistent with the current flowing in the current sensing part 800, and whether the anode current is accurately controlled.

[0143] Figure 6 is the electron emission device TR = I A / I CA (Among them, I A is the anode current, TR is the transmission rate, I CA is cathode current), when the ratio of TR is 80 / 100, the simulation Figure 5 The results of the device of the present invention are shown.

[0144] like Figure 6 As shown, Figure 6 Yes Figure 5 The anode current I measured at the anode 200 terminal A (anode) and the current I flowing in the current sensing unit 800 A (Z S )(where Z S is the proportionality constant of the current sensing section, I A 2 is a graph showing the results of comparison of the anode current and the current. It can be seen that the two currents are almost the same.

[0145] Figure 7 is obtained by setting the proportional constant Z of the current sensing sensor as the current sensing unit 800 differently. S value to simulate the results of the anode current.

[0146] like Figure 7 As shown, it can be confirmed that based on the proportional constant Z of the current sensing sensor S The value of the anode current is precisely controlled.

[0147] It can be seen that the anode current can be calculated by the proportional constant value of the current sensing sensor and IA =V ref / αZ s , V ref =1, α=1 (where Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage) formula is precisely controlled.

[0148] As described above, in the present invention, by connecting the current sensing part to the cathode current source and connecting the gate voltage source to the branch point of the line connecting the cathode current source and the current sensing part, the anode current can be sensed in a low voltage region without being directly connected to the anode terminal, thereby realizing an easy, simple and low-cost circuit and being able to accurately control the anode current.

[0149] In addition, the present invention can sense the anode current through a current sensing device, so the overall device is simple in structure, and only the anode current is corrected, so the current can be accurately controlled.

[0150] In addition, in the present invention, the anode current is sensed between the cathode end and the ground end of the device, so it can be composed of a device with a voltage range equivalent to several volts to tens of volts, and the stability of the entire device is high, and a high-precision current sensing device can be easily realized, and low cost can also be achieved.

[0151] Industrial Applicability

[0152] According to the X-ray electron emission control device of the present invention, there are effects that an easy, simple and low-cost circuit can be realized and an anode current can be accurately controlled, and therefore industrial applicability is remarkable.

Claims

1. An X-ray electron emission control device, characterized in that: include: An electron emitting unit for emitting electrons; an anode to collect the electrons; A gate voltage source connected to the gate of the electron emission portion; a cathode current source connected to the cathode of the electron emission portion; A current sensing unit, connected to the cathode current source, for sensing the anode current; as well as a current control unit, generating a current control signal based on the sensed anode current and outputting the current control signal to the cathode current source; One side of the gate voltage source is connected to the gate of the electron emission portion, and the other side of the gate voltage source is connected to a branch point of a line connecting the cathode current source and the current sensing portion.

2. The X-ray electron emission control device according to claim 1, characterized in that: The cathode current source outputs a cathode current obtained by combining a gate current and an anode current to a branch point of a line connecting the cathode current source and the current sensing unit.

3. The X-ray electron emission control device according to claim 2, characterized in that: The gate voltage source is connected to a first branch line branched from a branch point of the line; The current sensing section is connected to a second branch line branched from a branch point of the line.

4. The X-ray electron emission control device according to claim 3, characterized in that: The gate voltage source receives a gate current branched through the first branch line from the cathode current output by the cathode current source; The current sensing section receives an anode current branched through the second branch line from among cathode currents output from the cathode current source.

5. The X-ray electron emission control device according to claim 4, characterized in that: The gate voltage source includes a gate cathode terminal connected to the first branch line and a gate anode terminal connected to the gate line of the electron emission portion; The amount of gate current supplied to the gate of the electron emission portion through the gate line connected to the gate anode terminal is the same as the amount of gate current input through the first branch line connected to the gate cathode terminal.

6. The X-ray electron emission control device according to claim 1, characterized in that: The current sensing part receives the anode current from a branch point of a line connecting the cathode current source and the current sensing part, and outputs a voltage proportional to the anode current to the current control part.

7. The X-ray electron emission control device according to claim 6, characterized in that: The voltage output from the current sensing unit has a voltage through V S =Z S I A The voltage value calculated by the formula; Among them, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current.

8. The X-ray electron emission control device according to claim 1, characterized in that: The current control unit comprises: an anode current sensing amplifier, amplifying an output voltage of the current sensing unit; an error amplifying unit that amplifies an error value by comparing an output voltage of the anode current sensing amplifying unit with a reference voltage of a reference voltage source; and The frequency compensating unit generates the current control signal based on the output voltage of the error amplifying unit.

9. The X-ray electron emission control device according to claim 8, characterized in that: The current control unit is connected through I A =V ref / αZ s 、V ref =αV s 、V s =Z s I A The formula generates a current control signal for controlling the anode current; Among them, V S is the output voltage of the current sensing section, Z S is the proportionality constant of the current sensing section, I A is the anode current, V ref is the reference voltage, αV s is the output voltage of the current sensing unit.

10. The X-ray electron emission control device according to claim 1, characterized in that: The current control unit comprises: a first analog-to-digital conversion unit, converting the output voltage of the current sensing unit into a first digital signal; A second analog-to-digital conversion unit converts a reference voltage of a reference voltage source into a second digital signal; a control unit, configured to calculate and process the first digital signal and the second digital signal; and The output unit generates and outputs a current control signal based on a processing result of the calculation processing in the control unit.

11. An X-ray electron emission control device, characterized in that: include: A plurality of electron emitting portions including a grid and a cathode; A plurality of anodes are respectively arranged corresponding to the plurality of electron emitting portions; A plurality of cathode current sources are connected to the cathode corresponding to the plurality of electron emitting portions respectively; a gate voltage source connected to a gate of any specific electron emission portion among the plurality of electron emission portions; A current sensing unit connected to the plurality of cathode current sources to sense the anode current; as well as a current control unit, which generates a current control signal based on the sensed anode current and outputs the current control signal to the plurality of cathode current sources; One side of the gate voltage source is connected to the gate of the specific electron emission portion, and the other side of the gate voltage source is connected to a branch point of a line connecting a plurality of the cathode current sources and the current sensing portion.

12. The X-ray electron emission control device according to claim 11, characterized in that: A plurality of gate electrodes of a plurality of the electron emission portions are connected in series with each other; A plurality of the anodes are connected in series.

13. The X-ray electron emission control device according to claim 11, characterized in that: A plurality of cathode current sources are connected in parallel to each other and connected to the current sensing unit.

14. The X-ray electron emission control device according to claim 11, characterized in that: The current control section generates a current control signal including a first control signal that individually turns on / off the cathode current source and a second signal that individually controls a current value of the cathode current source.

15. The X-ray electron emission control device according to claim 11, characterized in that: The current control unit is individually connected to the plurality of cathode current sources, and outputs the current control signal to each cathode current source individually.

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