Pulse voltage generating circuit for X-ray generator and X-ray generator

Abstract

The present application relates to the field of X-rays, and specifically to a pulse voltage generating circuit for an X-ray generator and an X-ray generator, comprising: a first power switching device group; a first pulse voltage transmission branch, a first end of which is connected between the first power switching device and the second power switching device, and a second end of which is used to connect to the first core wire of the cathode high-voltage line of the tube; a second power switching device group; a second pulse voltage transmission branch, a first end of which is connected between the third power switching device and the fourth power switching device, and a second end of which is used to connect to the second core wire of the cathode high-voltage line of the tube; and a switch module, a first end of which is connected between the first transformer and the first power switching device group, a second end of which is used to connect to the common line of the cathode high-voltage line of the tube, and a third end of which is connected to a main control unit. The configuration of the switch module can simultaneously realize both flying focus control and grid control, reducing costs and simplifying the X-ray generator.

Description

Technical Field

[0001] The present application relates to the field of X-rays, and in particular to a pulse voltage generating circuit for an X-ray generator and an X-ray generator. Background Art

[0002] X-ray generators are widely used in medical products such as direct digital X-ray radiography systems (Digital Radiography, DR), electronic computed tomography systems (Computed Tomography, CT), and digital subtraction angiography systems (Digital Subtraction Angiography, DSA). High-voltage generators are the core components of X-ray generators.

[0003] like Figure 1 As shown, it shows a pulse voltage generating circuit for realizing flying focus control of an X-ray generator in the prior art. The pulse voltage generating circuit includes a first power switch device group and a second power switch device group. The first power switch device group includes a first power switch device 101 and a second power switch device 102 connected in series, and the second power switch device group includes a third power switch device 103 and a fourth power switch device 104 connected in series. The first power switch device group and the second power switch device group are connected in parallel to the first transformer ( Figure 1 Not shown) and the second transformer ( Figure 1 Main control unit ( Figure 1 The first and second transformers (not shown) are connected to the first and second transformers, respectively, to control the voltages output to the first and second transformers. The first core of the high-voltage cathode wire of the bulb is connected between the first power switch 101 and the second power switch 102, and the second core of the high-voltage cathode wire of the bulb is connected between the third power switch 103 and the fourth power switch 104.

[0004] This pulse voltage generating circuit can only realize flying focus control when used in an X-ray generator. For an X-ray generator that needs to realize a gate control function, an additional pulse generating circuit that can realize the gate control function needs to be added, thereby increasing the cost and making the X-ray generator complicated. Summary of the Invention

[0005] In order to solve one of the above technical deficiencies, the present application provides a pulse voltage generating circuit and an X-ray generator for an X-ray generator in an embodiment. The technical solution is as follows:

[0006] According to a first aspect of an embodiment of the present application, a pulse voltage generating circuit for an X-ray generator is provided. The X-ray tube includes a high voltage generator and a tube. The circuit includes:

[0007] a first power switch device group, comprising a first power switch device and a second power switch device, wherein the first power switch device and the second power switch device are connected in series; wherein a first end of the first power switch device group is used to be connected to a first transformer of a high-voltage generator, and a second end of the first power switch device group is used to be connected to a second transformer of the high-voltage generator;

[0008] A first pulse voltage transmission branch, having a first end connected between the first power switch device and the second power switch device, and a second end connected to a first core wire of the cathode high-voltage wire of the bulb;

[0009] A second power switch device group includes a third power switch device and a fourth power switch device, wherein the third power switch device and the fourth power switch device are connected in series; wherein the second power switch device group is connected in parallel with the first power switch device group;

[0010] A second pulse voltage transmission branch, a first end of which is connected between the third power switch device and the fourth power switch device, and a second end of which is used to be connected to the second core wire of the cathode high-voltage wire of the bulb;

[0011] The switch module has a first end connected between the first transformer and the first power switch device group, a second end used to be connected to the common line of the cathode high-voltage line of the bulb, and a third end connected to the main control unit.

[0012] Optionally, the switch module includes:

[0013] The first MOS tube has a gate connected to the main control unit, a source connected between the first transformer and the first power switch device group, and a drain connected to the common line of the cathode high-voltage line of the bulb.

[0014] Optionally, the switch module further includes:

[0015] The second MOS tube has a gate connected to the main control unit, a drain connected to the drain of the first MOS tube, and a source connected to the common line of the cathode high voltage line of the bulb.

[0016] Optionally, the switch module further includes: a third diode, a cathode of which is connected to the drain of the first MOS tube, and an anode of which is used to be connected to a common line of the cathode high-voltage line of the tube.

[0017] Optionally, the switch module includes: a relay, an input end of which is connected between the first transformer and the first power switching device group of the high-voltage generator, an output end of which is used to be connected to the common line of the cathode high-voltage line of the bulb, and a control end of which is connected to the main control unit.

[0018] Optionally, the circuit further includes: a load branch, one end of which is connected between the first transformer and the first power switch device group of the high-voltage generator, and the other end of which is used to be connected to the common line of the cathode high-voltage line of the bulb.

[0019] Optionally, the load branch includes a third resistor.

[0020] Optionally, the circuit further includes: a fourth diode, an anode of which is connected to the second end of the first power switch device group, and a cathode of which is connected to the second transformer of the high voltage generator.

[0021] According to a second aspect of an embodiment of the present application, an X-ray generator is provided, comprising: a tube; a high-voltage generator; and the above-mentioned pulse voltage generating circuit.

[0022] According to a third aspect of an embodiment of the present application, there is provided an X-ray generator control method, which is applied to the above-mentioned X-ray generator, and the method includes:

[0023] Determining a control mode of the X-ray generator; wherein the control mode includes flying focus control and grid control;

[0024] When it is determined that the control mode is flying focus control, the main control unit drives the switch module to disconnect, and sends a first switch signal to the first power switch device and the fourth power switch device, and sends a second switch signal to the second power switch device and the third power switch device; wherein the first switch signal and the second switch signal have the same pulse width and pulse period, and opposite pulse amplitudes;

[0025] When it is determined that the control mode is gate control, the main control unit drives the switch module to turn on, and sends a third switch signal to the first power switch device and the third power switch device, and sends a fourth switch signal to the second power switch device and the fourth power switch device; wherein the pulse width and pulse period of the third switch signal and the fourth switch signal are the same, and the pulse amplitudes are opposite.

[0026] By adopting the pulse voltage generating circuit for the X-ray generator provided in the embodiment of the present application and the setting of the switch module, the pulse generating circuit can enable the X-ray tube to simultaneously realize two control modes: flying focus control and grid control, thereby reducing costs and simplifying the X-ray generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0028] Figure 1 A pulse voltage generating circuit for realizing flying focus control in the prior art;

[0029] Figure 2 A pulse voltage generating circuit provided in an embodiment of the present application;

[0030] Figure 3 for Figure 1 Waveform diagram produced when a pulse generating circuit fails;

[0031] Figure 4 A structural block diagram of an X-ray generator provided in an embodiment of the present application;

[0032] Figure 5 for Figure 4 Waveform diagram for realizing flying focus control;

[0033] Figure 6 for Figure 4 Waveform diagram for realizing gate control in ;

[0034] Figure 7 for Figure 2 Schematic diagram of the structure of the control module;

[0035] Figure 8 Flowchart of the X-ray generator control method. DETAILED DESCRIPTION

[0036] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0037] In the description of this application, it should be understood that the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0038] In this application, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or mutual communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0039] Example 1

[0040] The X-ray generator includes a high voltage generator and a tube. The high voltage generator generates a high voltage to enable the tube to generate X-rays. Figure 1 The X-ray generator shown implements a pulse voltage generating circuit for flying focus control. The inventors have found that this circuit can only implement flying focus control in the X-ray generator. For an X-ray generator that needs to implement a gate control function, it is necessary to add a pulse generating circuit that can implement the gate control function, which increases the cost and makes the X-ray generator complex.

[0041] Furthermore, the first power switch device group is connected in parallel with the second power switch device group, the first end 105 of the first power switch device group can be connected to the first transformer (not shown) of the high voltage generator, and the second end 106 of the first power switch device group can be connected to the second transformer (not shown) of the high voltage generator. When the voltage of the second end 106 of the first power switch device group is greater than the voltage of the first end 105 of the first power switch device group, the first power switch device group and the second power switch device group are directly connected, and the current will flow from the second end 106 of the first power switch device group to the first end 105 of the first power switch device group, and the entire circuit will not work properly. Figure 3 As shown, when the voltage difference between the first end 105 of the first power switch device group and the second end 106 of the first power switch device group is large, the greater the switching frequency of the power switch device, the slower the rising edge of the pulse output waveform, which cannot meet the actual clinical application requirements.

[0042] In response to the above problems, Figure 2 and Figure 4As shown, an embodiment of the present application provides a pulse voltage generation circuit 10 for an X-ray generator. The pulse voltage generation circuit 10 includes a first power switch group, a first pulse voltage transmission branch, a second power switch group, a second pulse voltage transmission branch, and a switch module. The first power switch group is connected in parallel with the second power switch group. The first power switch group includes a first power switch 101 and a second power switch 102, while the second power switch group includes a third power switch 103 and a fourth power switch 104. The first power switch 101 and the second power switch 102 are connected in series, while the third power switch 103 and the fourth power switch 104 are connected in series. A high-voltage generator 30 includes a transformer 301 and a main control unit 302. The transformer 301 includes a first transformer and a second transformer. The transformer 301 is connected to the main control unit 302, which controls the voltage output to the first and second transformers. The first terminal 105 of the first power switch group can be connected to the first transformer, and the second terminal 106 of the first power switch group can be connected to the second transformer. Among them, the first control end 1011 of the first power switch device 101 is connected to the main control unit 302, the second control end 1021 of the second power switch device 102 is connected to the main control unit 302, the third control end 1031 of the third power switch device 103 is connected to the main control unit 302, and the fourth control end 1041 of the fourth power switch device 104 is connected to the main control unit 302, so as to control the on and off of the first power switch device 101, the second power switch device 102, the third power switch device 103 and the fourth power switch device 104, and the first power switch device 101, the second power switch device 102, the third power switch device 103 and the fourth power switch device 104 can be MOS tubes.

[0043] The first end of the first pulse voltage transmission branch is connected between the first power switch 101 and the second power switch 102. The second end 107 of the first pulse voltage transmission branch can be connected to the first core wire G1 of the cathode high-voltage line of the bulb 20. A first resistor R1 can be provided on the first pulse voltage transmission branch. In some embodiments, a first diode D1 can also be included. The anode of the first diode D1 can be connected between the first resistor R1 and the first core wire G1 of the cathode high-voltage line of the bulb 20, and the cathode of the first diode D1 can be connected to the common line C of the cathode high-voltage line of the bulb 20. The first end of the second pulse voltage transmission branch is connected between the third power switch 103 and the fourth power switch 104. The second end 108 of the second pulse voltage transmission branch can be connected to the second core wire G2 of the cathode high-voltage line of the bulb 20. A second resistor R2 can be provided on the second pulse voltage transmission branch. In some embodiments, a second diode D2 can also be included. The anode of the second diode D2 can be connected between the second resistor R2 and the second core wire G2 of the cathode high-voltage line of the bulb 20, and the second diode D2 can be connected to the common line C of the cathode high-voltage line of the bulb 20. After the main control unit 302 controls the voltage output to the first transformer and the second transformer, the pulse voltage is transmitted to the first core wire G1 of the cathode high-voltage wire of the bulb 20 through the first pulse voltage transmission branch, and the pulse voltage is transmitted to the second core wire G2 of the cathode high-voltage wire of the bulb 20 through the second pulse voltage transmission branch.

[0044] The first end of the switch module is connected between the first transformer and the first power switch device group of the high-voltage generator, the second end of the switch module can be connected to the common line C of the cathode high-voltage line of the tube 20, and the third end of the switch module is connected to the main control unit 302. When the X-ray generator needs to realize flying focus control, the main control unit 302 controls the switch module to disconnect, and repeatedly controls the first power switch device 101 and the fourth power switch device 104 to switch between disconnection and conduction through the switching signal, and controls the second power switch device 102 and the third power switch device 103 to switch between conduction and disconnection. When the first power switch device 101 and the fourth power switch device 104 are disconnected, the second power switch device 102 and the third power switch device 103 are turned on; when the first power switch device 101 and the fourth power switch device 104 are turned on, the second power switch device 102 and the third power switch device 103 are disconnected. Figure 5 The figure shows the waveform of the flying focus control output. The two voltage values ​​have equal amplitude and frequency, but opposite phases. By applying these two pulse voltages of equal amplitude, frequency, and opposite phases to the grid, the X-ray generator causes the cathode electrons of the tube to periodically bombard different positions on the anode target surface, thus achieving the flying focus function.

[0045] When the X-ray generator needs to implement gate control, the main control unit 302 controls the switch module to turn on, repeatedly controls the first power switch device 101 and the third power switch device 103 to switch between off and on through the switch signal, and controls the second power switch device 102 and the fourth power switch device 104 to switch between on and off. When the first power switch device 101 and the third power switch device 103 are off, the second power switch device 102 and the fourth power switch device 104 are on; when the first power switch device 101 and the third power switch device 103 are on, the second power switch device 102 and the fourth power switch device 104 are off. Figure 6 As shown in Figure 1, this is the waveform of the gate control output, with equal voltage amplitude, frequency, and phase. For each X-ray tube voltage value, there is a corresponding limit voltage. When the gate voltage is greater than or equal to the limit voltage, electrons emitted from the cathode cannot reach the anode, resulting in rapid cutoff, and thus rapid X-ray cutoff. When the gate voltage is less than this limit voltage, the pulse voltage amplitude can be controlled to achieve rapid control of the focal spot size.

[0046] In summary, the setting of the switch module and the use of the pulse generating circuit can enable the X-ray tube to simultaneously realize two control modes: flying focus control and grid control, thereby reducing costs and simplifying the X-ray generator.

[0047] In one or more embodiments, Figure 2 and Figure 4 As shown, the switch module includes a first MOS transistor 110. The gate of the first MOS transistor 110 is connected to the main control unit 302. The source of the first MOS transistor 110 is connected between the first transformer and the first power switch device group. The drain 1101 of the first MOS transistor 110 can be connected to the common line C of the cathode high-voltage line of the bulb 20. The main control unit 302 can control the conduction and disconnection of the first MOS transistor 110 to achieve flying focus control and gate control of the pulse voltage generating circuit.

[0048] In one or more embodiments, Figure 2 and Figure 4 As shown, the switch module may further include a third diode D3. The cathode of the third diode D3 is connected to the drain of the first MOS tube 110, and the anode of the third diode D3 may be connected to the common line C of the cathode high voltage line of the bulb 20. In some embodiments, as Figure 7 As shown, the switch module may further include a second MOS transistor 109. The gate of the second MOS transistor 109 is connected to the main control unit 302, the drain of the second MOS transistor 109 is connected to the drain of the first MOS transistor 110, and the source of the second MOS transistor 109 may be connected to the common line C of the cathode high voltage line of the bulb 20.

[0049] In one or more embodiments, the switch module includes a relay, a solid-state switch, or an IGBT (not shown). When the switch module includes a relay, the input end of the relay is connected between the first transformer and the first power switch device group of the high-voltage generator, the output end of the relay can be connected to the common line of the cathode high-voltage line of the bulb, and the control end of the relay is connected to the main control unit.

[0050] In one or more embodiments, Figure 2 and Figure 4 As shown, the pulse generation circuit further includes a load branch. One end of the load branch is connected between the first transformer and the first power switching device group of the high-voltage generator, and the other end of the load branch can be connected to the common line C of the cathode high-voltage line of the bulb 20. A third resistor R3 can be provided on the load branch. The resistance of the third resistor R3 can be between 100 kilo-ohms and 1 megohm to enhance the stability of the pulse output.

[0051] In one or more embodiments, Figure 2 As shown, the pulse generation circuit further includes a fourth diode D4. The anode of the fourth diode D4 is connected to the second terminal of the first power switch group, and the cathode of the fourth diode D4 can be connected to the second transformer of the high-voltage generator. This prevents the risk of a direct current between the first and second power switch groups when the voltage at the second terminal 106 of the first power switch group is greater than the voltage at the first terminal 105 of the first power switch group, thereby improving the safety of the entire circuit.

[0052] Example 2

[0053] This embodiment provides an X-ray generator. Figure 4 As shown, the device comprises a tube 20, a high-voltage generator 30, and the pulse voltage generating circuit 10 of Example 1. The pulse voltage generating circuit 10 is connected to the tube 20 and the high-voltage generator 30, respectively, to generate a pulse voltage and output it to the tube 20, thereby generating X-rays and achieving both flying focus and grid control. It should be noted that the high-voltage generator 30 also includes an input filter, a pre-charge and rectification section, a high-frequency inverter, a high-frequency transformer, a high-voltage rectifier, a filament driver, a rotating anode driver, a grid control power supply, a main control unit, etc., which are not detailed here.

[0054] This embodiment also provides an X-ray generator control method for controlling an X-ray generator including the pulse generating circuit of embodiment 1. Figure 8 As shown, the X-ray generator control method includes the following steps (S101-S103):

[0055] S101. Determine a control mode of an X-ray generator.

[0056] The control modes of the X-ray generator include flying focus control and grid control. When the control mode of the X-ray generator is flying focus control, step S102 is executed; when the control mode of the X-ray generator is grid control, step S103 is executed.

[0057] S102 : The main control unit drives the switch module to disconnect, and sends a first switch signal to the first power switch device and the fourth power switch device, and sends a second switch signal to the second power switch device and the third power switch device.

[0058] The first and second switching signals have the same pulse width and pulse period, but opposite pulse amplitudes. When the switching signal is high, the power switch is on; when the switching signal is low, the power switch is off. The first switching signal causes the first and fourth power switches to have the same on / off state, while the second switching signal causes the second and third power switches to have the same on / off state. The on / off states of the first and fourth power switches are opposite to those of the second and third power switches, thus achieving non-focus control.

[0059] S103 : The main control unit drives the switch module to turn on, and sends a third switch signal to the first power switch device and the third power switch device, and sends a fourth switch signal to the second power switch device and the fourth power switch device.

[0060] The third and fourth switching signals have the same pulse width and pulse period, but opposite pulse amplitudes. The third switching signal causes the first and third power switches to have the same on / off state, while the second switching signal causes the second and fourth power switches to have the same on / off state. The on / off states of the first and third power switches are opposite to those of the second and fourth power switches, thereby achieving gate control.

[0061] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A pulse voltage generating circuit for an X-ray generator, wherein the X-ray tube comprises a high voltage generator and a tube, characterized in that: The circuit comprises: a first power switch device group, comprising a first power switch device and a second power switch device, wherein the first power switch device and the second power switch device are connected in series; wherein a first end of the first power switch device group is used to be connected to a first transformer of a high-voltage generator, and a second end of the first power switch device group is used to be connected to a second transformer of the high-voltage generator; A first pulse voltage transmission branch, having a first end connected between the first power switch device and the second power switch device, and a second end connected to a first core wire of the cathode high-voltage wire of the bulb; A second power switch device group includes a third power switch device and a fourth power switch device, wherein the third power switch device and the fourth power switch device are connected in series; wherein the second power switch device group is connected in parallel with the first power switch device group; A second pulse voltage transmission branch, a first end of which is connected between the third power switch device and the fourth power switch device, and a second end of which is used to be connected to the second core wire of the cathode high-voltage wire of the bulb; The switch module has a first end connected between the first transformer and the first power switch device group, a second end used to be connected to the common line of the cathode high-voltage line of the bulb, and a third end connected to the main control unit.

2. The circuit according to claim 1, wherein The switch module includes: The first MOS tube has a gate connected to the main control unit, a source connected between the first transformer and the first power switch device group, and a drain connected to the common line of the cathode high-voltage line of the bulb.

3. The circuit according to claim 2, wherein: The switch module further includes: The second MOS tube has a gate connected to the main control unit, a drain connected to the drain of the first MOS tube, and a source connected to the common line of the cathode high voltage line of the bulb.

4. The circuit according to claim 2, wherein: The switch module further includes: The third diode has a cathode connected to the drain of the first MOS tube, and an anode connected to the common line of the cathode high-voltage line of the tube.

5. The circuit according to claim 1, wherein The switch module includes: The relay has an input end connected between the first transformer and the first power switch device group of the high-voltage generator, an output end used to be connected to the common line of the cathode high-voltage line of the bulb, and a control end connected to the main control unit.

6. The circuit according to any one of claims 1 to 5, characterized in that: The circuit further comprises: The load branch has one end connected between the first transformer and the first power switch device group of the high voltage generator, and the other end used to be connected to the common line of the cathode high voltage line of the bulb.

7. The circuit according to claim 6, wherein: The load branch includes a third resistor.

8. The circuit according to any one of claims 1 to 7, wherein: The circuit further comprises: A fourth diode has an anode connected to the second end of the first power switch device group, and a cathode connected to the second transformer of the high voltage generator.

9. An X-ray generator, characterized in that: The X-ray generator comprises: Ball tube; A high voltage generator; and a pulse voltage generating circuit as described in any one of claims 1-8.

10. An X-ray generator control method, applied to the X-ray generator according to claim 9, characterized in that: The method comprises: Determining a control mode of the X-ray generator; wherein the control mode includes flying focus control and grid control; When it is determined that the control mode is flying focus control, the main control unit drives the switch module to disconnect, and sends a first switch signal to the first power switch device and the fourth power switch device, and sends a second switch signal to the second power switch device and the third power switch device; wherein the first switch signal and the second switch signal have the same pulse width and pulse period, and opposite pulse amplitudes; When it is determined that the control mode is gate control, the main control unit drives the switch module to turn on, and sends a third switch signal to the first power switch device and the third power switch device, and sends a fourth switch signal to the second power switch device and the fourth power switch device; wherein the pulse width and pulse period of the third switch signal and the fourth switch signal are the same, and the pulse amplitudes are opposite.

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