JP6131832B2 - X-ray generator and X-ray analyzer - Google Patents

Description

  In the present invention, a tube current is generated by applying a tube voltage between a filament and a target that are spaced apart from each other in an X-ray tube, and X-rays are generated by collision of thermoelectrons with the target. The present invention relates to an X-ray generator and an X-ray analyzer to be generated.

  An X-ray tube used in an X-ray analyzer or the like has a period in which it can be normally used, and is replaced with a new X-ray tube when it is time to replace it. About such replacement | exchange time, it can be set as the standard of replacement | exchange by confirming the integrated value of the usage time of a X-ray tube regularly (for example, refer patent document 1 below).

  In other words, the time to replace the conventional X-ray tube is determined by simply comparing the accumulated value of the usage time of the X-ray tube with the usage time guaranteed by the manufacturer as the lifetime of the X-ray tube. In consideration of the state of the X-ray tube and the mode of use, a method for determining the replacement time of the X-ray tube has not been adopted.

Japanese Patent Laid-Open No. 5-283192

  However, depending on the state of the X-ray tube and usage, it may not be possible to use it normally earlier than the usage time guaranteed by the manufacturer as the lifetime of the X-ray tube, or it may be normal beyond the guaranteed usage time. Can be used for

  For this reason, when the replacement is performed only during a guaranteed period, the X-ray tube may not be used normally because the filament is disconnected due to delay in replacement of the X-ray tube. In addition, there is a possibility that the X-ray tube that can still be used is replaced, and there is a problem that the running cost becomes high. As described above, it is difficult to accurately determine the appropriate replacement time of the X-ray tube only by the usage time of the X-ray tube.

  The appropriate replacement time of the X-ray tube as described above varies depending on the state of the filament. In an X-ray tube, a high voltage is applied between a filament and a target that are spaced apart from each other. At this time, a thermoelectron emitted from the filament is caused by passing a current through the filament. Is made to collide with the target and X-rays are generated from the target. As described above, since the filament is heated by passing an electric current through the filament, the filament material evaporates little by little as the X-ray tube is used, and the filament becomes thin gradually and easily breaks.

  Therefore, if the filament state can be grasped, it is possible to determine an appropriate replacement time for the X-ray tube. However, since the filament is disposed in the X-ray tube and cannot be visually confirmed, it is not easy to grasp the state of the filament.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an X-ray generator and an X-ray analyzer that can easily determine an appropriate replacement time of an X-ray tube.

An X-ray generator according to the present invention generates a tube current by applying a tube voltage between a filament and a target that are spaced apart from each other in an X-ray tube, and generates thermoelectrons to the target. An X-ray generator that generates X-rays by collision of the filament, a filament voltage value monitor unit that monitors a voltage value applied to the filament, a filament current value monitor unit that monitors a current value flowing through the filament, A filament resistance value calculating unit that calculates a resistance value in the filament based on a voltage value monitored by the filament voltage value monitoring unit and a current value monitored by the filament current value monitoring unit, and the filament resistance value the resistance value calculated by the calculation unit, and the predetermined threshold determined using the tube current or tube voltage ratio Characterized in that a filament resistance value comparison processing unit for.

  According to such a configuration, the resistance value in the filament is calculated based on the voltage value applied to the filament and the current value flowing through the filament, and the calculated resistance value is compared with a predetermined threshold value. The state of the filament can be grasped. Therefore, it is possible to easily determine an appropriate replacement time for the X-ray tube based on the state of the filament.

  The X-ray generation apparatus may further include a threshold value determination processing unit that determines the threshold value based on an initial value of the resistance value calculated by the filament resistance value calculation unit.

  According to such a configuration, it is possible to determine an appropriate threshold value for each filament by determining the threshold value based on the initial value of the resistance value in the filament. Therefore, it is possible to grasp the state of the filament more accurately using the threshold value and more accurately determine the appropriate replacement time of the X-ray tube.

  When the resistance value calculated by the filament resistance value calculation unit exceeds the threshold value, the X-ray generation device may further include a notification processing unit that notifies that fact.

  According to such a configuration, when the calculated resistance value in the filament exceeds the threshold value, it is possible to notify the appropriate replacement time of the X-ray tube by notifying that effect. By exchanging the X-ray tube based on such notification, it is possible to prevent the replacement time from being delayed and the filament from being disconnected, or the replacement time from being too early to increase the running cost.

Moreover, the X-ray generator according to the present invention generates a tube current by applying a tube voltage between a filament and a target that are spaced apart from each other in an X-ray tube, and supplies the tube current to the target. An X-ray generator that generates X-rays by collision of thermoelectrons, a filament voltage value monitor unit that monitors a voltage value applied to the filament, and a filament current value monitor unit that monitors a current value flowing through the filament A filament resistance value calculation unit that calculates a resistance value in the filament based on a voltage value monitored by the filament voltage value monitoring unit and a current value monitored by the filament current value monitoring unit; and the filament A history storage unit that stores a history of resistance values calculated by the resistance value calculation unit, and the history storage unit Based on the history of the resistance being憶, a change rate calculating section for calculating a change rate of the resistance value, the rate of change of the resistance value calculated by the change rate calculating section, with a tube current or tube voltage And a change rate comparison processing unit for comparing with the determined predetermined threshold value.

  According to such a configuration, the resistance value in the filament is calculated based on the voltage value applied to the filament and the current value flowing through the filament, and the resistance value calculated from the history of the calculated resistance value is calculated. By comparing the rate of change with a predetermined threshold, the state of the filament can be grasped. Therefore, it is possible to easily determine an appropriate replacement time for the X-ray tube based on the state of the filament.

  The X-ray generation apparatus may further include a threshold value determination processing unit that determines the threshold value based on an initial value of the change rate of the resistance value calculated by the change rate calculation unit.

  According to such a configuration, it is possible to determine an appropriate threshold value for each filament by determining the threshold value based on the initial value of the rate of change of the resistance value in the filament. Therefore, it is possible to grasp the state of the filament more accurately using the threshold value and more accurately determine the appropriate replacement time of the X-ray tube.

  The X-ray generation apparatus may further include a notification processing unit that notifies that when the change rate of the resistance value calculated by the change rate calculation unit exceeds the threshold value.

  According to such a configuration, when the calculated change rate of the resistance value in the filament exceeds the threshold value, it is possible to notify the appropriate replacement time of the X-ray tube by notifying that effect. . By exchanging the X-ray tube based on such notification, it is possible to prevent the replacement time from being delayed and the filament from being disconnected, or the replacement time from being too early to increase the running cost.

  The X-ray analyzer according to the present invention is characterized in that analysis is performed using X-rays generated by the X-ray generator.

  According to such a configuration, it is possible to provide an X-ray analyzer that can easily determine an appropriate replacement time of the X-ray tube. In particular, in an X-ray analyzer, it is important to grasp the state of the filament because analysis cannot be performed accurately unless the tube current is stabilized. Therefore, by adopting a configuration that can easily grasp the state of the filament as in the present invention, analysis can be performed with high accuracy.

  According to the present invention, it is possible to grasp the state of the filament from the resistance value of the filament or the rate of change of the resistance value, and easily determine the appropriate replacement time of the X-ray tube based on the state of the filament.

It is the schematic which showed the structural example of the X-ray generator which concerns on one Embodiment of this invention. It is the block diagram which showed the specific structure of the X-ray generator of FIG. It is the flowchart which showed an example of the process at the time of calculating the resistance value of a filament by the control part of FIG. It is the block diagram which showed the specific structure of the X-ray generator which concerns on another embodiment of this invention. 6 is a flowchart showing an example of processing when calculating a rate of change in the resistance value of the filament by the control unit in FIG. 4.

  FIG. 1 is a schematic diagram showing a configuration example of an X-ray generator according to an embodiment of the present invention. This X-ray generator includes a filament 11 and a target 12 in an X-ray tube 1. The target 12 can be formed of, for example, Cu, Cr, Mo, Al, Ag, or Au.

  The filament 11 and the target 12 are arranged in the X-ray tube 1 at a distance from each other. A high voltage of about 50 kV, for example, is applied as a tube voltage between the filament 11 and the target 12 by the X-ray power source 2 including the filament cable 21 and the high voltage cable 22. Thereby, as indicated by an arrow in FIG. 1, thermoelectrons are emitted from the filament 11 toward the target 12, and the thermoelectrons collide with the target 12 to generate X-rays.

  At this time, a tube current is generated in the high-voltage cable 22, and the tube current can be detected by the ammeter 23. A voltage is applied to the filament 11 via the filament cable 21. By controlling the voltage applied to the filament 11 so that the tube current detected by the ammeter 23 is constant, a current corresponding to the voltage flows through the filament 11. That is, when X-rays are generated, even if the tube current is constant, the voltage value applied to the filament 11 and the current value flowing through the filament 11 vary depending on the tube voltage and the state of the filament 11.

  FIG. 2 is a block diagram showing a specific configuration of the X-ray generator of FIG. In addition to the above-described X-ray tube 1 and X-ray power supply 2, the X-ray generator includes a control unit 3, a storage unit 4, a display unit 5, and the like. Although not shown in FIG. 2, the X-ray generation apparatus may be provided with an operation unit for a user to perform an input operation related to the operation of the X-ray generation apparatus.

  The X-ray power source 2 includes a filament voltage value monitor unit 24 and a filament current value monitor unit 25. The filament voltage value monitor unit 24 monitors the voltage value applied to the filament 11 by the filament cable 21. On the other hand, the filament current value monitor unit 25 monitors the current value flowing through the filament cable 21.

  The control unit 3 includes a CPU (Central Processing Unit), for example, and controls the operation of the X-ray generator. The control unit 3 in the present embodiment functions as a filament resistance value calculation unit 31, a filament resistance value comparison processing unit 32, a threshold determination processing unit 33, a notification processing unit 34, and the like when the CPU executes a program.

  The filament resistance value calculation unit 31 performs a process of calculating a resistance value in the filament 11 based on the voltage value monitored by the filament voltage value monitor unit 24 and the current value monitored by the filament current value monitor unit 25. . Specifically, the resistance value in the filament 11 can be calculated by dividing the voltage value monitored by the filament voltage value monitor unit 24 by the current value monitored by the filament current value monitor unit 25.

  The calculation of the resistance value of the filament 11 as described above may be automatically performed at predetermined time intervals such as once a day or once a week. The configuration may be such that it is performed by the user operating the operation unit. A plurality of calculated resistance values of the filament 11 can be stored as a history in the storage unit 4 together with information on the usage time of the X-ray tube 1, for example. That is, the storage unit 4 functions as a history storage unit that stores a history of the resistance value of the filament 11 calculated by the filament resistance value calculation unit 31. The storage unit 4 can be configured by, for example, a hard disk or a RAM (Random Access Memory).

  The filament resistance value comparison processing unit 32 performs processing for comparing the resistance value calculated by the filament resistance value calculation unit 31 with a predetermined threshold value. In the present embodiment, the threshold value is determined by the threshold value determination processing unit 33. However, the threshold value may be a predetermined value.

  The resistance value of the filament 11 increases as the integrated value of the usage time of the X-ray tube 1 increases. The threshold value determination processing unit 33 determines, for example, a value that is slightly smaller than the resistance value at which the filament 11 is expected to be disconnected as the threshold value. By determining such a value as a threshold value and comparing the threshold value with the resistance value calculated by the filament resistance value calculation unit 31, the replacement time of the X-ray tube 1 can be predicted.

  In the present embodiment, the threshold value is determined based on the initial value of the resistance value of the filament 11 stored in the storage unit 4. That is, the initial value of the resistance value of the filament 11 is different for each X-ray tube 1, and if the initial value of the resistance value of the filament 11 is different, an appropriate threshold value is changed. The threshold value is determined. For example, an initial value is calculated from the resistance value of the first filament 11 at which the use of the X-ray tube 1 is started or the resistance value of the filament 11 within a predetermined period after the start of use, and the initial value is set to a predetermined value. A value obtained by multiplying the ratio can be determined as a threshold value.

  The storage unit 4 stores values such as tube current and tube voltage when the resistance value is calculated in association with the resistance value of the filament 11 calculated by the filament resistance value calculation unit 31. Good. In this case, the threshold value determination processing unit 33 may determine the threshold value using not only the resistance value of the filament 11 but also values such as tube current and tube voltage. For example, if the relationship between the resistance value of the filament 11 and the usage time of the X-ray tube 1 is stored in the storage unit 4 in association with the value of the tube current or tube voltage, the value of the tube current or tube voltage is obtained. Based on the resistance value of the corresponding filament 11, the threshold value can be determined more accurately.

  When the resistance value calculated by the filament resistance value calculation unit 31 exceeds the threshold value, the notification processing unit 34 performs processing to notify that effect. In the present embodiment, by displaying on the display unit 5 that the X-ray tube 1 is at the replacement time, the user can be notified of the replacement time of the X-ray tube 1. However, the notification by the notification processing unit 34 is not limited to the display on the display unit 5 and may be configured to be performed by other modes such as voice.

  FIG. 3 is a flowchart showing an example of processing when the resistance value of the filament 11 is calculated by the control unit 3 of FIG. When calculating the resistance value of the filament 11, first, the voltage value applied to the filament 11 is acquired from the filament voltage value monitor unit 24 (step S101), and the current value flowing through the filament 11 is the filament current value. Obtained from the monitor unit 25 (step S102).

  Thereafter, the resistance value of the filament 11 is calculated based on the acquired voltage value and current value (step S103), and the calculated resistance value of the filament 11 is stored in the storage unit 4 (step S104). If the calculated resistance value of the filament 11 exceeds the threshold value (Yes in step S105), the fact is displayed on the display unit 5 to indicate to the user the time to replace the X-ray tube 1. Notification is made (step S106).

  As described above, in the present embodiment, the resistance value in the filament 11 is calculated based on the voltage value applied to the filament 11 and the current value flowing through the filament 11, and the calculated resistance value is set to a predetermined threshold value. By comparing with, the state of the filament 11 can be grasped. Therefore, it is possible to easily determine an appropriate replacement time for the X-ray tube 1 based on the state of the filament 11.

  In particular, in the present embodiment, an appropriate threshold value can be determined for each filament 11 by determining the threshold value based on the initial value of the resistance value in the filament 11. Therefore, the state of the filament 11 can be grasped more accurately using the threshold value, and an appropriate replacement time of the X-ray tube 1 can be judged more accurately.

  Moreover, in this embodiment, when the calculated resistance value in the filament 11 exceeds the threshold value, an appropriate replacement time of the X-ray tube 1 can be notified by notifying that effect. By exchanging the X-ray tube 1 based on such notification, it is possible to prevent the filament 11 from being disconnected due to the replacement time being delayed, or the running cost from being increased due to the replacement time being too early. .

  FIG. 4 is a block diagram showing a specific configuration of an X-ray generator according to another embodiment of the present invention. In this embodiment, only the configuration of the control unit 3 is different from that of the above embodiment, and the other configurations are the same as those of the above embodiment. Is omitted.

  The control unit 3 in the present embodiment, as the CPU executes a program, as a filament resistance value calculation unit 35, a change rate calculation unit 36, a change rate comparison processing unit 37, a threshold value determination processing unit 38, a notification processing unit 39, and the like. Function.

  Similar to the filament resistance value calculation unit 31 in the above embodiment, the filament resistance value calculation unit 35 sets the voltage value monitored by the filament voltage value monitor unit 24 and the current value monitored by the filament current value monitor unit 25. Based on this, a process of calculating a resistance value in the filament 11 is performed. A plurality of calculated resistance values of the filament 11 can be stored as a history in the storage unit 4 together with information on the usage time of the X-ray tube 1, for example.

  The change rate calculation unit 36 performs a process of calculating the change rate of the resistance value based on the resistance value history of the filament 11 stored in the storage unit 4. For example, the increase amount of the resistance value per unit time can be calculated as the rate of change based on the relationship between the resistance value of the filament 11 stored in the storage unit 4 and the usage time of the X-ray tube 1.

  The change rate comparison processing unit 37 performs a process of comparing the change rate of the resistance value of the filament 11 calculated by the change rate calculating unit 36 with a predetermined threshold value. In the present embodiment, the threshold value determination processing unit 38 determines the threshold value. However, the threshold value may be a predetermined value.

  The rate of change of the resistance value of the filament 11 increases rapidly as the filament 11 breaks near. The threshold value determination processing unit 38 determines, for example, a value that is slightly larger than the rate of change of the resistance value at the start of use of the X-ray tube 1 as the threshold value. It is possible to predict the replacement time of the X-ray tube 1 by determining such a value as a threshold value and comparing the threshold value with the change rate of the resistance value of the filament 11 calculated by the change rate calculation unit 36. it can.

  In the present embodiment, the threshold value is determined based on the initial value of the change rate of the resistance value calculated by the change rate calculation unit 36. That is, the initial value of the resistance value change rate differs for each X-ray tube 1, and if the initial value of the resistance value change rate is different, an appropriate threshold value also changes. The threshold value is determined. For example, the initial value is calculated from the rate of change of the resistance value of the first filament 11 where the use of the X-ray tube 1 is started, or the rate of change of the resistance value of the filament 11 within a predetermined period after the start of use, A value obtained by multiplying the initial value by a predetermined ratio can be determined as the threshold value.

  Note that the storage unit 4 stores values such as tube current and tube voltage when the resistance value is calculated in association with the resistance value of the filament 11 calculated by the filament resistance value calculation unit 35. Good. In this case, the threshold value determination processing unit 38 may determine the threshold value using not only the resistance value of the filament 11 but also values such as tube current and tube voltage. For example, if the relationship between the resistance value of the filament 11 and the usage time of the X-ray tube 1 is stored in the storage unit 4 in association with the value of the tube current or tube voltage, the value of the tube current or tube voltage is obtained. Based on the change rate of the resistance value of the corresponding filament 11, the threshold value can be determined with higher accuracy.

  When the change rate of the resistance value of the filament 11 calculated by the change rate calculation unit 36 exceeds the threshold value, the notification processing unit 39 performs a process of notifying that effect. In the present embodiment, by displaying on the display unit 5 that the X-ray tube 1 is at the replacement time, the user can be notified of the replacement time of the X-ray tube 1. However, the notification by the notification processing unit 39 is not limited to the display on the display unit 5 and may be configured to be performed by other modes such as voice.

  FIG. 5 is a flowchart showing an example of processing when the control unit 3 in FIG. 4 calculates the rate of change in the resistance value of the filament 11. When calculating the rate of change of the resistance value of the filament 11, first, the voltage value applied to the filament 11 is acquired from the filament voltage value monitor unit 24 (step S 201), and the current value flowing through the filament 11 is determined. It is acquired from the filament current value monitor unit 25 (step S202).

  Thereafter, the resistance value of the filament 11 is calculated based on the acquired voltage value and current value (step S203), and the calculated resistance value of the filament 11 is stored in the storage unit 4 (step S204). Then, the rate of change of the resistance value is calculated based on the calculated history of the resistance value of the filament 11 (step S205). If the rate of change exceeds the threshold value (Yes in step S206), this is indicated. By displaying on the display unit 5, the user is notified of the replacement time of the X-ray tube 1 (step S207).

  As described above, in the present embodiment, the resistance value in the filament 11 is calculated based on the voltage value applied to the filament 11 and the current value flowing through the filament 11, and is calculated from the history of the calculated resistance value. The state of the filament 11 can be grasped by comparing the change rate of the resistance value to be a predetermined threshold value. Therefore, it is possible to easily determine an appropriate replacement time for the X-ray tube 1 based on the state of the filament 11.

  In particular, in the present embodiment, an appropriate threshold value can be determined for each filament 11 by determining the threshold value based on the initial value of the change rate of the resistance value in the filament 11. Therefore, the state of the filament 11 can be grasped more accurately using the threshold value, and an appropriate replacement time of the X-ray tube 1 can be judged more accurately.

  Moreover, in this embodiment, when the calculated change rate of the resistance value in the filament 11 exceeds the threshold value, it is possible to notify the appropriate replacement time of the X-ray tube 1 by notifying that effect. it can. By exchanging the X-ray tube 1 based on such notification, it is possible to prevent the filament 11 from being disconnected due to the replacement time being delayed, or the running cost from being increased due to the replacement time being too early. .

  When the X-ray generator according to the present invention as exemplified in the above embodiment is applied to an X-ray analyzer, analysis can be performed using X-rays generated by the X-ray generator. In this case, it is possible to provide an X-ray analyzer that can easily determine an appropriate replacement time of the X-ray tube 1. In particular, in an X-ray analyzer, it is important to grasp the state of the filament 11 because analysis cannot be performed with accuracy unless the tube current is stabilized. Therefore, by adopting a configuration in which the state of the filament 11 can be easily grasped as in the above embodiment, analysis can be performed with high accuracy.

  However, the X-ray generator according to the present invention is not limited to the X-ray analyzer, and can be applied to various other devices such as a medical device such as an X-ray device.

DESCRIPTION OF SYMBOLS 1 X-ray tube 2 X-ray power supply 3 Control part 4 Memory | storage part 5 Display part 11 Filament 12 Target 21 Filament cable 22 High voltage cable 23 Ammeter 24 Filament voltage value monitor part 25 Filament current value monitor part 31 Filament resistance value calculation part 32 Filament resistance value comparison processing unit 33 Threshold determination processing unit 34 Notification processing unit 35 Filament resistance value calculation unit 36 Change rate calculation unit 37 Change rate comparison processing unit 38 Threshold determination processing unit 39 Notification processing unit

Claims (7)

X-rays that generate a tube current by applying a tube voltage between a filament and a target that are spaced apart from each other in an X-ray tube, and generate X-rays by the impact of thermoelectrons on the target A generator,
A filament voltage value monitoring unit for monitoring a voltage value applied to the filament;
A filament current value monitor unit for monitoring a current value flowing through the filament;
A filament resistance value calculating unit that calculates a resistance value in the filament based on a voltage value monitored by the filament voltage value monitoring unit and a current value monitored by the filament current value monitoring unit;
An X-ray generation apparatus comprising: a filament resistance value comparison processing unit that compares a resistance value calculated by the filament resistance value calculation unit with a predetermined threshold value determined using a tube current or a tube voltage .   The X-ray generation apparatus according to claim 1, further comprising a threshold value determination processing unit that determines the threshold value based on an initial value of a resistance value calculated by the filament resistance value calculation unit.   3. The X-ray generation according to claim 1, further comprising a notification processing unit that notifies the fact when the resistance value calculated by the filament resistance value calculation unit exceeds the threshold value. 4. apparatus. X-rays that generate a tube current by applying a tube voltage between a filament and a target that are spaced apart from each other in an X-ray tube, and generate X-rays by the impact of thermoelectrons on the target A generator,
A filament voltage value monitoring unit for monitoring a voltage value applied to the filament;
A filament current value monitor unit for monitoring a current value flowing through the filament;
A filament resistance value calculating unit that calculates a resistance value in the filament based on a voltage value monitored by the filament voltage value monitoring unit and a current value monitored by the filament current value monitoring unit;
A history storage unit for storing a history of resistance values calculated by the filament resistance value calculation unit;
Based on the history of resistance values stored in the history storage unit, a change rate calculation unit that calculates a change rate of the resistance value;
X-ray generation characterized by comprising: a rate-of-change comparison processing unit that compares the rate of change of the resistance value calculated by the rate-of-change calculating unit with a predetermined threshold value determined using tube current or tube voltage apparatus.   The X-ray generation apparatus according to claim 4, further comprising a threshold value determination processing unit that determines the threshold value based on an initial value of the change rate of the resistance value calculated by the change rate calculation unit.   6. The X according to claim 4 or 5, further comprising a notification processing unit for notifying that when the change rate of the resistance value calculated by the change rate calculation unit exceeds the threshold value. Line generator.   An X-ray analyzer that performs analysis using X-rays generated by the X-ray generator according to claim 1.

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