Filament protection circuit of X-ray tube and X-ray machine

Abstract

The invention relates to a filament protection circuit of an X-ray tube and an X-ray machine, and the circuit can collect a common end current value of a large-focus filament and a small-focus filament, and converts the common end current value into a filament feedback value through a filament protection unit. The filament protection unit is used for receiving a filament feedback value and comparing the filament feedback value with a filament threshold signal output by the central processing unit based on a filament set value, so that the filament is protected on the hardware level, and the filament protection unit can also convert the filament feedback value into an analog quantity feedback value and input the analog quantity feedback value into the central processing unit. The central processing unit can perform comparison operation according to the analog quantity feedback value and the threshold analog quantity corresponding to the lamp filament threshold signal, so that the lamp filament is protected on the software level, and the lamp filament set value for controlling the X-ray tube to work can be limited on the hardware level and the software level at the same time. And a large-focus filament and a small-focus filament of the X-ray tube can be effectively protected.

Description

Technical Field

[0001] This application relates to the field of circuit technologies, and particularly to a filament protection circuit for an X-ray tube and an X-ray machine. Background Art

[0002] In the medical industry of X-ray equipment, as a main component, the X-ray tube has a relatively high price. The X-ray tube is a vacuum glass tube with a filament inside that is heated to release electrons, and then a high voltage is applied to them. These electrons will be strongly attracted to the other end of the tube. There is a metal target at this end. When the electrons collide with the atoms of the target material, their energy will suddenly decrease, and this change in energy will cause the generation of X-rays.

[0003] Generally, an X-ray tube has a large-focus filament and a small-focus filament. The filament currents that the two focus filaments can withstand are different, and the powers that can be emitted are also different. If the selected large-focus filament corresponds to the branch where the small-focus filament is actually conducted, or if the selected small-focus filament corresponds to the branch where the large-focus filament is actually conducted, it will cause the actual X-ray dose to be abnormal and may also damage the X-ray tube. For example, if the large-focus filament is supposed to emit electrons, due to software or hardware defects, the small-focus filament actually emits electrons, resulting in the small-focus filament being loaded with the voltage that should be for the large-focus filament, which may burn out the small-focus filament and cause damage to the X-ray tube. Therefore, how to effectively protect the filament of the X-ray tube has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a filament protection circuit for an X-ray tube and an X-ray machine to solve the technical problem of how to effectively protect the filament of the X-ray tube.

[0005] In a first aspect, this application provides a filament protection circuit for an X-ray tube. The circuit includes: a central processing unit, a filament startup focus switching unit, a filament current sampling unit, and a filament protection unit;

[0006] Among them, the filament startup focus switching unit is used to control the operation of the X-ray tube according to the filament set value output by the central processing unit when the central processing unit outputs a filament turn-on enable signal; the X-ray tube includes a large-focus filament and a small-focus filament;

[0007] The filament current sampling unit is used to collect the common terminal current value of the large-focus filament and the small-focus filament and output it to the filament protection unit;

[0008] The filament protection unit is used to convert the common terminal current value into a filament feedback value, and perform a comparison operation between the filament feedback value and a filament threshold signal output by the central processing unit based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an over-limit signal is output to the central processing unit;

[0009] The central processing unit controls to stop outputting the filament set value according to the over-limit signal;

[0010] The filament protection unit is also used to convert the filament feedback value into an analog feedback value, and input the analog feedback value into the central processing unit;

[0011] The central processing unit is also used to perform a comparison operation based on the analog feedback value and a threshold analog value corresponding to the filament threshold signal. When the analog feedback value is greater than the threshold analog value, it controls to stop outputting the filament set value.

[0012] Optionally, when the central processing unit controls to stop outputting the filament set value, the central processing unit also controls to stop outputting the filament turn-on enable signal.

[0013] Optionally, the filament startup focus switching unit includes a filament startup sub-unit and a filament switching sub-unit;

[0014] The filament startup sub-unit is used to control the operation of the X-ray tube according to the filament set value output by the central processing unit when the central processing unit outputs a filament turn-on enable signal;

[0015] The filament switching sub-unit is used to control the X-ray tube to switch from operating with a large focus filament to operating with a small focus filament, or control the X-ray tube to switch from operating with a small focus filament to operating with a large focus filament when the central processing unit outputs a filament switching signal.

[0016] Optionally, the circuit further includes a switching loop detection unit;

[0017] The switching loop detection unit is used to detect the loop current of the large focus filament loop, and convert the loop current into a detected voltage value and output it to the central processing unit;

[0018] The central processing unit determines whether the filament switching state of the X-ray tube is normal according to the detected voltage value and a preset switching voltage threshold; if it is not normal, an error signal is output and it controls to stop outputting the filament set value.

[0019] Optionally, the filament promoter unit includes: a turn-on control module, a PWM control module, an inverter module, a set value operation module, an integral circuit module, and an integral output value threshold detection module;

[0020] The turn-on control module is configured to convert the filament turn-on enable signal into a turn-on signal and input it to the PWM control module;

[0021] The set value operation module is configured to perform a set value operation on the filament set value to obtain a set voltage value, and output the set voltage value to the integral circuit module;

[0022] The integral circuit module is configured to perform an integral operation based on the set voltage value and the closed-loop feedback voltage value, and input the integral output value to the integral output value threshold detection module;

[0023] The integral output value threshold detection module is configured to transfer the integral output value to the PWM control module when the integral output value does not exceed a preset upper limit value, and feedback a set value overrun signal to the central processing unit when the integral output value is greater than the preset upper limit value; so that the central processing unit controls to stop outputting the filament set value according to the set value overrun signal;

[0024] The PWM control module is configured to generate a drive signal according to the turn-on signal and the integral output value, and the drive signal is used to drive the inverter module to convert the DC input into an AC output to control the operation of the X-ray tube.

[0025] Optionally, the filament switching sub-unit includes: a relay control module and a switching circuit module;

[0026] The relay control module is configured to control the conduction of the first path or the second path of the relay according to the filament switching signal;

[0027] The switching circuit module is configured to control to switch to the large focus filament for operation when the first path is conducted, and control to switch to the small focus filament for operation when the second path is conducted.

[0028] Optionally, the filament protection unit includes: a filament feedback value judgment sub-unit and a filament threshold judgment sub-unit;

[0029] The filament threshold judgment sub-unit is configured to convert the common terminal current value into a filament feedback value, and perform a comparison operation between the filament feedback value and the filament threshold signal output by the central processing unit based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an overrun signal is output to the central processing unit;

[0030] The filament feedback value judgment subunit is used to convert the filament feedback value into an analog feedback value and input the analog feedback value into the central processing unit.

[0031] Optionally, the filament feedback value judgment subunit includes: an operation output module, a proportional modulation module, and a true RMS value conversion module;

[0032] The true RMS value conversion module is used to perform an RMS value conversion on the common terminal current value to obtain a DC voltage value;

[0033] The proportional modulation module is used to convert the DC voltage value into a closed-loop voltage feedback value;

[0034] The operation output module is used to perform an operation on the closed-loop voltage feedback value and output the analog feedback value to the central processing unit, so that the central processing unit performs a comparison operation based on the analog feedback value and the threshold analog value corresponding to the filament threshold signal.

[0035] Optionally, the filament threshold judgment subunit includes: a threshold control module, a threshold detection module, and a threshold error reporting module;

[0036] The threshold control module is used to perform an operation on the filament threshold signal to obtain a threshold voltage;

[0037] The threshold detection module is used to perform a comparison operation between the DC voltage value input from the true RMS value conversion module and the threshold voltage, and output an overlimit signal to the threshold error reporting module when the DC voltage value is greater than the threshold voltage;

[0038] The threshold error reporting module is used to output the overlimit signal to the central processing unit.

[0039] In a second aspect, the present application provides an X-ray machine, including an X-ray tube and the filament protection circuit of the X-ray tube according to any one of the first aspect.

[0040] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: The filament protection circuit of the X-ray tube provided by the embodiment of the present application includes: a central processing unit, a filament startup focus switching unit, a filament current sampling unit, and a filament protection unit; wherein, the filament startup focus switching unit is used to control the operation of the X-ray tube according to the filament set value output by the central processing unit when the central processing unit outputs a filament turn-on enable signal; the X-ray tube includes a large focus filament and a small focus filament; the filament current sampling unit is used to collect the common terminal current value of the large focus filament and the small focus filament and output it to the filament protection unit; the filament protection unit is used to convert the common terminal current value into a filament feedback value, and compare and operate the filament feedback value with the filament threshold signal output by the central processing unit based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an overlimit signal is output to the central processing unit; the central processing unit controls to stop outputting the filament set value according to the overlimit signal; the filament protection unit is also used to convert the filament feedback value into an analog feedback value and input the analog feedback value into the central processing unit; the central processing unit is also used to compare and operate the analog feedback value with the threshold analog value corresponding to the filament threshold signal. When the analog feedback value is greater than the threshold analog value, it controls to stop outputting the filament set value.

[0041] This circuit can collect the common terminal current value of the large focus filament and the small focus filament, convert the common terminal current value into a filament feedback value through the filament protection unit, and compare and operate the filament feedback value with the filament threshold signal output by the central processing unit based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an overlimit signal is output to the central processing unit, causing the central processing unit to stop outputting the filament set value, thereby protecting the filament at the hardware level. Moreover, the filament protection unit can also convert the filament feedback value into an analog feedback value and input the analog feedback value into the central processing unit. The central processing unit can compare and operate the analog feedback value with the threshold analog value corresponding to the filament threshold signal. When the analog feedback value is greater than the threshold analog value, it controls to stop outputting the filament set value, thereby protecting the filament at the software level. Since the filament set value that controls the operation of the X-ray tube can be restricted simultaneously at the hardware and software levels, the large focus filament and the small focus filament of the X-ray tube can be effectively protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings here are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0043] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, unless otherwise stated, the drawings in the figures do not constitute a scale limitation.

[0045] Figure 1 Schematic diagram of the filament protection circuit of an X-ray tube provided by an embodiment of the present application;

[0046] Figure 2 Schematic diagram of the filament protection circuit of an X-ray tube provided by another embodiment of the present application;

[0047] Figure 3 Schematic diagram of the filament protection circuit of an X-ray tube provided by another embodiment of the present application;

[0048] Figure 4 Schematic diagram of the filament protection circuit of an X-ray tube provided by another embodiment of the present application. Detailed implementation manners

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0050] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0051] To solve the technical problem of how to effectively protect the filament of an X-ray tube in the prior art, the present application provides a filament protection circuit for an X-ray tube and an X-ray machine, which can limit the filament set value for controlling the operation of the X-ray tube at both the hardware and software levels, and can effectively protect the large-focus filament and the small-focus filament of the X-ray tube.

[0052] The first embodiment of the present application provides a filament protection circuit for an X-ray tube, as Figure 1 , the circuit at least includes a central processing unit 101, a filament start focus switching unit 102, a filament current sampling unit 103, and a filament protection unit 104.

[0053] Among them, the filament start focus switching unit 102 is used to control the operation of the X-ray tube according to the filament set value output by the central processing unit 101 when the central processing unit 101 outputs a filament turn-on enable signal; the X-ray tube includes a large-focus filament and a small-focus filament. The filament current sampling unit 103 is used to collect the common terminal current value of the large-focus filament and the small-focus filament and output it to the filament protection unit 104. The filament protection unit 104 is used to convert the common terminal current value into a filament feedback value, and compare and calculate the filament feedback value with the filament threshold signal output by the central processing unit 101 based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an over-limit signal is output to the central processing unit 101. The central processing unit 101 controls to stop outputting the filament set value according to the over-limit signal. The filament protection unit 104 is also used to convert the filament feedback value into an analog feedback value and input the analog feedback value into the central processing unit 101. The central processing unit 101 is also used to compare and calculate according to the analog feedback value and the threshold analog value corresponding to the filament threshold signal. When the analog feedback value is greater than the threshold analog value, it controls to stop outputting the filament set value.

[0054] This circuit can collect the common terminal current values of the large focus filament and the small focus filament, convert the common terminal current values into filament feedback values through the filament protection unit, and perform a comparison operation on the filament feedback values and the filament threshold signals output by the central processing unit based on the filament set values. When the filament feedback value is greater than the filament threshold signal, an overlimit signal is output to the central processing unit, causing the central processing unit to stop outputting the filament set values, thereby protecting the filament at the hardware level. Moreover, the filament protection unit can also convert the filament feedback values into analog feedback values and input the analog feedback values into the central processing unit. The central processing unit can perform a comparison operation based on the analog feedback values and the threshold analog values corresponding to the filament threshold signals. When the analog feedback value is greater than the threshold analog value, it controls the stop of outputting the filament set values, thereby protecting the filament at the software level. Since the filament set values that control the operation of the X-ray tube can be restricted simultaneously at the hardware and software levels, the large focus filament and the small focus filament of the X-ray tube can be effectively protected.

[0055] In one embodiment, when the central processing unit 101 controls the stop of outputting the filament set values, the central processing unit 101 also controls the stop of outputting the filament turn-on enable signal.

[0056] In this embodiment, while the central processing unit 101 controls the stop of outputting the filament set values, it also controls the stop of outputting the filament turn-on enable signal, which can ensure that the X-ray tube stops working when the central processing unit 101 receives the overlimit signal or when the central processing unit 101 determines that the analog feedback value is greater than the threshold analog value, protecting the safe use of the filament.

[0057] In one embodiment, a schematic structural diagram of a filament protection circuit for an X-ray tube is as Figure 2 , and the circuit further includes a switching loop detection unit 105.

[0058] The switching loop detection unit 105 is used to detect the loop current of the large focus filament loop and convert the loop current into a detected voltage value and output it to the central processing unit 101; the central processing unit 101 determines whether the filament switching state of the X-ray tube is normal according to the detected voltage value and a preset switching voltage threshold; if it is not normal, an error signal is output and the control stops outputting the filament set values.

[0059] In this embodiment, the switching circuit detection unit 105 can detect the circuit current of the large-focus filament circuit, so that the central processing unit 101 can judge whether the filament switching state of the X-ray tube is normal according to the detected voltage value and the preset switching voltage threshold. For example, if the filament switching signal indicates switching to the small-focus filament, the detected circuit current should be 0 or approaching 0, and the detected voltage value converted by the switching circuit detection unit 105 should be lower than the preset switching voltage threshold. If it is lower, the filament switching state is normal. If the detected voltage value is higher than the preset switching voltage threshold, the filament switching state is abnormal. At this time, an error signal is output and the output of the filament setting value is controlled to stop. If the filament switching signal indicates switching to the large-focus filament, for example, the detected circuit current is 1A, the corresponding converted detected voltage value should be greater than the preset switching voltage threshold. If the detected voltage value is greater than the preset switching voltage threshold at this time, the state is normal. If the detected voltage value is lower than the preset switching voltage threshold, the filament switching state is abnormal. At this time, an error signal is output and the output of the filament setting value is controlled to stop. By detecting the circuit current of the large-focus filament circuit through the switching circuit detection unit 105, it is possible to detect whether the switching state of the large and small filaments is normal, thus realizing the protection of the large and small focus filaments, especially protecting the use safety of the small focus filament.

[0060] In one embodiment, a schematic structural diagram of a filament protection circuit of an X-ray tube is as Figure 3 , and the filament start focus switching unit 102 includes a filament start sub-unit 201 and a filament switching sub-unit 202. The filament protection unit 104 includes: a filament feedback value judgment sub-unit 203 and a filament threshold judgment sub-unit 204.

[0061] In this embodiment, the filament start sub-unit 201 is used to control the operation of the X-ray tube according to the filament setting value output by the central processing unit 101 when the central processing unit 101 outputs a filament turn-on enable signal; the filament switching sub-unit 202 is used to control the X-ray tube to switch from operating with the large-focus filament to operating with the small-focus filament, or to control the X-ray tube to switch from operating with the small-focus filament to operating with the large-focus filament when the central processing unit 101 outputs a filament switching signal.

[0062] The filament threshold judgment sub-unit 204 is used to convert the common terminal current value into a filament feedback value, and perform a comparison operation between the filament feedback value and the filament threshold signal output by the central processing unit 101 based on the filament setting value. When the filament feedback value is greater than the filament threshold signal, an over-limit signal is output to the central processing unit 101; the filament feedback value judgment sub-unit 203 is used to convert the filament feedback value into an analog quantity feedback value and input the analog quantity feedback value into the central processing unit 101.

[0063] In this embodiment, the filament starter unit 201 is responsible for controlling the operation of the X-ray tube when receiving the filament turn-on enable signal and the filament set value from the central processing unit 101. The filament switching sub-unit 202 is responsible for switching between the large and small focus filaments when the central processing unit 101 outputs a filament switching signal. The filament threshold judgment sub-unit 204 compares and calculates the filament feedback value and the filament threshold signal in a hardware manner (such as a comparator, etc.) to achieve the safety protection of the filament. The filament feedback value judgment sub-unit 203 converts the filament feedback value into an analog feedback value and inputs it into the central processing unit 101. The central processing unit 101 realizes the safety protection of the filament in a software manner through the built-in software logic comparison, improving the usage safety of the large and small focus filaments.

[0064] In one embodiment, a schematic structural diagram of a filament protection circuit for an X-ray tube is as Figure 4 , the filament starter unit 201 includes: a turn-on control module 301, a PWM (pulse width modulation) control module 302, an inverter module 303, a set value operation module 304, an integral circuit module 305, and an integral output value threshold detection module 306. The filament switching sub-unit 202 includes: a relay control module 307 and a switching circuit module 308. The filament feedback value judgment sub-unit 203 includes: an operation output module 309, a proportional modulation module 310, and a true RMS conversion module 311. The filament threshold judgment sub-unit 204 includes: a threshold control module 312, a threshold detection module 313, and a threshold error reporting module 314.

[0065] In this embodiment, the turn-on control module 301 is used to convert the filament turn-on enable signal into a turn-on signal and input it to the PWM control module 302; the set value operation module 304 is used to perform set value operation on the filament set value to obtain a set voltage value and output the set voltage value to the integral circuit module 305; the integral circuit module 305 is used to perform integral operation based on the set voltage value and the closed-loop feedback voltage value and input the integral output value to the integral output value threshold detection module 306; the integral output value threshold detection module 306 is used to transfer the integral output value to the PWM control module 302 when the integral output value does not exceed the preset upper limit value, and feedback a set value overrun signal to the central processing unit 101 when the integral output value is greater than the preset upper limit value; so that the central processing unit 101 controls to stop outputting the filament set value according to the set value overrun signal; the PWM control module 302 is used to generate a drive signal according to the turn-on signal and the integral output value, and the drive signal is used to drive the inverter module 303 to convert the DC input into an AC output to control the operation of the X-ray tube.

[0066] The relay control module 307 is used to control the conduction of the first path or the second path of the relay according to the filament switching signal; the switching circuit module 308 is used to control the switching to the large focus filament for operation when the first path is conducting, and control the switching to the small focus filament for operation when the second path is conducting.

[0067] The true effective value conversion module 311 is used to convert the common terminal current value into an effective value to obtain a DC voltage value; the proportional modulation module 310 is used to convert the DC voltage value into a closed-loop voltage feedback value; the operation output module 309 is used to perform operations on the closed-loop voltage feedback value and output an analog feedback value to the central processing unit 101, so that the central processing unit 101 performs a comparison operation based on the analog feedback value and the threshold analog value corresponding to the filament threshold signal.

[0068] The threshold control module 312 is used to perform operations on the filament threshold signal to obtain a threshold voltage; the threshold detection module 313 is used to perform a comparison operation between the DC voltage value input from the true effective value conversion module 311 and the threshold voltage, and output an overlimit signal to the threshold error reporting module 314 when the DC voltage value is greater than the threshold voltage; the threshold error reporting module 314 is used to output the overlimit signal to the central processing unit 101.

[0069] In this embodiment, the central processing unit 101 includes multiple input / output ports, such as FILON, FSET_FUALT, FILMENT_SET, FILMENT_SELECT, FILMENT_AD, FILMENT_OVER, FILMENT_threshold, and FILMENT_FOUS_CHECK.

[0070] Among them, FILON is used to output a filament turn-on enable signal. FSET_FUALT is used to input a set value overlimit signal. FILMENT_SET is used to output a filament set value (i.e., the voltage value set for the filament). FILMENT_SELECT is used to output a filament switching signal for switching between the large and small foci of the filament. FILMENT_AD is used to input the analog feedback value of the filament current after true effective processing. FILMENT_OVER is used to input an overlimit signal. FILMENT_threshold is used to output the threshold voltage of the filament, which is given by the central processing unit 101. If the filament current is too large and the feedback value after true effective value conversion is greater than this filament threshold, an error will be prompted. FILMENT_FOUS_CHECK is used to input the detection voltage value converted from the loop current.

[0071] In this embodiment, the functions of each component are as follows:

[0072] The turn-on control module 301: Control output of the turn-on command;

[0073] PWM control module 302: starts to work according to the turn-on signal, performs PWM (pulse width modulation) according to the control voltage, and outputs two sets of drive signals to the inverter module 303;

[0074] Inverter module 303, which can be, for example, an H-bridge DC inverter module. The H-bridge DC inverter module converts 36 VDC into high-frequency alternating current under the control of two-way PWM drive signals;

[0075] Set value operation module 304: controls the input of the filament set value and outputs the set voltage value;

[0076] Integral circuit module 305: performs integration based on the set voltage value and the closed-loop feedback voltage value and outputs an integral signal (i.e., the integral output value);

[0077] Integral output value threshold detection module 306: transmits the integral signal and performs threshold detection on the integral output value. If it exceeds the preset upper limit value, it outputs a threshold detection error signal (i.e., the set value overrun signal);

[0078] Relay control module 307: controls the relay to conduct the large focus output branch or the small focus output branch according to the filament switching signal of the large and small foci;

[0079] Switching circuit module 308: that is, the relay switching circuit, conducts the large focus output branch or the small focus output branch under the action of the relay control module 307;

[0080] Filament current sampling unit 103: performs current transformer isolation sampling on the common terminal current value output by the large and small foci;

[0081] True RMS conversion module 311: converts the sampled filament current (common terminal current value) into an effective value;

[0082] Proportion circuit (proportion modulation module 310): performs proportion adaptation on the current effective value, outputs the closed-loop feedback voltage value, and outputs it to the operation output module 309;

[0083] Operation output module 309: performs operations on the feedback value and outputs the analog quantity feedback value to the central processing unit 101;

[0084] Threshold control module 312: calculates and gives a threshold voltage according to the given filament threshold signal;

[0085] Threshold detection module 313: performs a comparison operation on the DC voltage value output by the true RMS and the threshold voltage, and outputs a threshold error signal (such as an overrun signal) when it is over the limit;

[0086] Threshold error reporting module 314: outputs an error report for the threshold error signal;

[0087] Switching circuit detection unit 105: Detect the loop current of the large focus filament circuit, convert the loop current into a detected voltage value and output it. If it has been switched to the large focus branch, the detected voltage value of the switching circuit should be greater than a software threshold (preset switching voltage threshold). If it is less than the threshold, an error will be reported. Similarly, if it has been switched to the small focus branch, the detected voltage value of the switching circuit should be less than a software threshold. If it is greater than the threshold, an error will be reported.

[0088] In the above embodiments of the present application, the filament set value and the filament feedback value are in a closed loop. Corresponding threshold voltages can be given according to different filament set values, and a hardware circuit is used to ensure that different filament set values will not overflow. At the same time, the analog feedback value can also be compared with the threshold analog quantity corresponding to the filament threshold signal in the central processing unit 101 to ensure the safety of the filament from both software and hardware aspects. In addition, in the embodiments of the present application, while ensuring the execution of the filament switching signal, the loop current of the large focus filament circuit is sampled by an independent switching circuit detection unit to determine the correctness and reliability of the large and small focus filament switching, achieving better safety performance. In addition, the embodiments of the present application also perform limit detection on the filament set value. By determining the upper limit of the filament set value, the output upper limit is limited, further protecting the filament and improving safety.

[0089] Based on the same inventive concept, the second embodiment of the present application provides an X-ray machine, including an X-ray tube and the filament protection circuit of the X-ray tube described in any one of the first embodiments.

[0090] In the X-ray machine of this embodiment, since the filament protection circuit can collect the common terminal current value of the large focus filament and the small focus filament, convert the common terminal current value into a filament feedback value through the filament protection unit, and compare and calculate the filament feedback value with the filament threshold signal output by the central processing unit based on the filament set value. When the filament feedback value is greater than the filament threshold signal, an overlimit signal is output to the central processing unit to stop the central processing unit from outputting the filament set value, thereby protecting the filament at the hardware level. Moreover, the filament protection unit can also convert the filament feedback value into an analog feedback value and input the analog feedback value into the central processing unit. The central processing unit can perform comparison and calculation according to the analog feedback value and the threshold analog quantity corresponding to the filament threshold signal. When the analog feedback value is greater than the threshold analog quantity, it controls to stop outputting the filament set value, thereby protecting the filament at the software level. Since the filament set value that controls the operation of the X-ray tube can be limited at both the hardware and software levels, the large focus filament and the small focus filament of the X-ray tube can be effectively protected, improving the safety of the X-ray machine.

[0091] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0092] It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present application and are not used to limit the present application. In the description, the suffixes such as "module", "component", or "unit" used to denote elements are only for the convenience of describing the present application and have no specific meaning in themselves. Therefore, "module", "component", or "unit" can be used interchangeably.

[0093] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A filament protection circuit for an X-ray tube, characterized in that: The circuit comprises: a central processing unit, a filament start focus switching unit, a filament current sampling unit, and a filament protection unit; Wherein, the filament start focus switching unit is used to control the operation of the X-ray tube according to the filament setting value output by the central processing unit when the central processing unit outputs the filament start enable signal; the X-ray tube includes a large focus filament and a small focus filament; The filament current sampling unit is used to collect the common terminal current value of the large-focus filament and the small-focus filament and output it to the filament protection unit; The filament protection unit is used to convert the common terminal current value into a filament feedback value, and compare the filament feedback value with the filament threshold signal output by the central processing unit based on the filament setting value, and output an over-limit signal to the central processing unit when the filament feedback value is greater than the filament threshold signal; The central processing unit controls to stop outputting the filament setting value according to the over-limit signal; The filament protection unit is also used to convert the filament feedback value into an analog feedback value, and input the analog feedback value into the central processing unit; The central processing unit is further used to perform a comparison operation based on the analog quantity feedback value and a threshold analog quantity corresponding to the filament threshold signal, and to control the filament setting value to be stopped from being output when the analog quantity feedback value is greater than the threshold analog quantity.

2. The circuit according to claim 1, characterized in that When the central processing unit controls to stop outputting the filament setting value, the central processing unit also controls to stop outputting the filament opening enable signal.

3. The circuit according to claim 1, characterized in that The filament start focus switching unit includes a filament start subunit and a filament switch subunit; The filament starter subunit is used to control the operation of the X-ray tube according to the filament setting value output by the central processing unit when the central processing unit outputs a filament start enable signal; The filament switching subunit is used to control the X-ray tube to switch from large-focus filament operation to small-focus filament operation, or to control the X-ray tube to switch from small-focus filament operation to large-focus filament operation when the central processing unit outputs a filament switching signal.

4. The circuit according to claim 3, characterized in that The circuit also includes a switching loop detection unit; The switching circuit detection unit is used to detect the circuit current of the large-focus filament circuit, and convert the circuit current into a detection voltage value and output it to the central processing unit; The central processing unit determines whether the filament switching state of the X-ray tube is normal according to the detection voltage value and the preset switching voltage threshold; if it is abnormal, an error signal is output and the output of the filament setting value is stopped.

5. The circuit according to claim 3, characterized in that The filament starter unit includes: an opening control module, a PWM control module, an inverter module, a set value calculation module, an integration circuit module and an integration output value threshold detection module; The on control module is used to convert the filament on enable signal into an on signal and input it into the PWM control module; The set value operation module is used to perform set value operation on the filament set value to obtain a set voltage value, and output the set voltage value to the integration circuit module; The integration circuit module is used to perform integration operation according to the set voltage value and the closed-loop feedback voltage value, and input the integration output value into the integration output value threshold detection module; The integral output value threshold detection module is used to transmit the integral output value to the PWM control module when the integral output value does not exceed the preset upper limit value, and to feed back a set value over-limit signal to the central processing unit when the integral output value is greater than the preset upper limit value; so that the central processing unit controls to stop outputting the filament set value according to the set value over-limit signal; The PWM control module is used to generate a driving signal according to the opening signal and the integrated output value, and the driving signal is used to drive the inverter module to convert the DC input into AC output to control the operation of the X-ray tube.

6. The circuit according to claim 3, characterized in that The filament switching subunit comprises: a relay control module and a switching circuit module; The relay control module is used to control the first path or the second path of the conducting relay according to the filament switching signal; The switching circuit module is used to control switching to the large-focus filament operation when the first path is turned on, and to control switching to the small-focus filament operation when the second path is turned on.

7. The circuit according to claim 1, characterized in that The filament protection unit comprises: a filament feedback value judgment subunit and a filament threshold value judgment subunit; The filament threshold judgment subunit is used to convert the common terminal current value into a filament feedback value, and compare the filament feedback value with the filament threshold signal output by the central processing unit based on the filament setting value, and output an over-limit signal to the central processing unit when the filament feedback value is greater than the filament threshold signal; The filament feedback value determination subunit is used to convert the filament feedback value into an analog feedback value, and input the analog feedback value into the central processing unit.

8. The circuit according to claim 7, characterized in that The filament feedback value judgment subunit includes: an operation output module, a proportional modulation module and a true effective value conversion module; The true effective value conversion module is used to convert the common terminal current value into an effective value to obtain a DC voltage value; The proportional modulation module is used to convert the DC voltage value into a closed-loop voltage feedback value; The operation output module is used to operate the closed-loop voltage feedback value and output an analog feedback value to the central processing unit, so that the central processing unit performs a comparison operation based on the analog feedback value and the threshold analog value corresponding to the filament threshold signal.

9. The circuit according to claim 8, characterized in that The filament threshold judgment subunit includes: a threshold control module, a threshold detection module and a threshold error reporting module; The threshold control module is used to calculate the filament threshold signal to obtain a threshold voltage; The threshold detection module is used to compare the DC voltage value input from the true effective value conversion module with the threshold voltage, and output an over-limit signal to the threshold error reporting module when the DC voltage value is greater than the threshold voltage; The threshold error reporting module is used to output the over-limit signal to the central processing unit.

10. An X-ray machine, characterized in that: The invention comprises an X-ray tube and a filament protection circuit of the X-ray tube according to any one of claims 1 to 9.

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