JP2017033873A - X-ray high voltage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem of a storage type X-ray high voltage device for supplying power from an electrolytic capacitor at the time of shooting, that the electrolytic capacitor must be charged with a voltage required for shooting, and a standby time is required until completion of the charging, and to provide an X-ray high voltage device capable of shortening the charging time of the capacitor.SOLUTION: In an X-ray high voltage device having a rectifier circuit for rectifying an AC power supply, a charging circuit for converting a DC voltage from the rectifier circuit into a predetermined voltage, and outputting a constant current, an electrolytic capacitor supplied with a voltage by the charging circuit and charged, and an X-ray output circuit receiving a DC power from the electrolytic capacitor, the electrolytic capacitor includes a plurality of capacitors connected in parallel, each having a plurality of switches capable of connecting with the charging circuit and X-ray output circuit and disconnecting therefrom, and the plurality of switches are switched according to the use conditions of the X-ray high voltage device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an energy storage type medical X-ray high voltage apparatus, and more particularly to a medical X-ray high voltage apparatus capable of shortening initial charging and charging time during use.

  In relatively simple medical X-ray high-voltage devices used in clinics and X-ray high-voltage devices for mass screening, so-called energy can be taken by connecting to a household outlet or generator. An accumulation type is known. For example, there has been proposed an apparatus in which a large-capacity electrolytic capacitor is provided as a power source supplied to an inverter, and energy stored in the electrolytic capacitor is used only during photographing that requires a large current.

  Thus, when energy from an electrolytic capacitor is used at the time of photographing that requires a large current, the operator is forced to wait until the voltage necessary for photographing is charged. For example, as described in Japanese Patent Application Laid-Open No. 2009-22672 (Patent Document 1), normally, in such a model, for example, an operation panel for setting and displaying X-ray imaging conditions is being charged. A lamp or the like is displayed so as to indicate that the charging has been completed or that charging has been completed.

JP 2009-22672 A

  Conventionally, X-ray photography can be performed when a charging capacitor is charged to a constant voltage. The time until X-ray imaging becomes possible is determined by the capacitance and current of the capacitor. Here, since the current is limited by the power supply equipment, in practice, the time until X-ray imaging becomes possible is determined by the capacitance of the capacitor. Therefore, in the energy storage type medical X-ray high-voltage apparatus, a standby time is required until the charging capacitor is charged with energy necessary for imaging and becomes a necessary voltage to perform X-ray imaging.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an energy storage type medical X-ray high voltage apparatus that can shorten the charging time of a charging capacitor.

  In order to solve the above-described problems, the present invention, as an example, provides a rectifier circuit that rectifies an AC power source, a charging circuit that converts a DC voltage from the rectifier circuit into a predetermined voltage, and outputs a constant current. An X-ray high voltage device having an electrolytic capacitor charged with voltage applied by a charging circuit and an X-ray output circuit that receives DC power from the electrolytic capacitor, and the electrolytic capacitor is connected to a plurality of capacitors in parallel Each of the plurality of capacitors includes a plurality of switches that can be connected to and opened from the charging circuit and the X-ray output circuit, and the plurality of switches are switched according to the use conditions of the X-ray high-voltage device.

  ADVANTAGE OF THE INVENTION According to this invention, the X-ray high voltage apparatus which can shorten standby time by shortening initial charge time can be provided.

1 is a schematic block diagram of an X-ray high voltage apparatus in Example 1. FIG. It is a sequence diagram from the conventional charge to X-ray imaging. 2 is a sequence diagram from charging to X-ray imaging in Embodiment 1. FIG. 6 is a sequence diagram from charging to X-ray imaging in Embodiment 2. FIG. 6 is a sequence diagram from charging to X-ray imaging in Embodiment 2. FIG. 6 is a sequence diagram from charging to X-ray imaging in Embodiment 2. FIG. It is a schematic block diagram of the X-ray high voltage apparatus in Example 3.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic block diagram showing a basic configuration of an X-ray high voltage apparatus in the present embodiment.

  In FIG. 1, an X-ray high voltage device is a rectifier circuit 2 that rectifies AC power from a power source 1 such as an outlet or a generator, and converts the rectified DC voltage into a predetermined voltage and outputs a constant current. The charging circuit 3 is composed of a step-down chopper circuit, an electrolytic capacitor 4 to which a voltage is applied by the charging circuit 3, and an X-ray output circuit 5 that receives the output of the electrolytic capacitor 4 as an input. Furthermore, the electrolytic capacitor 4 for supplying electric power has a parallel configuration of two capacitors C1 and C2, and switches SC1 and SC2 that can connect and open the capacitors C1 and C2, the charging circuit 3 and the X-ray output circuit 5, respectively. A change-over switch 6 is provided.

  A normal sequence from charging to X-ray imaging will be described with reference to FIG. The basic configuration of the conventional X-ray high voltage apparatus is one capacitor in which the electrolytic capacitor 4 is not divided in FIG. 1, and there is no changeover switch 6, and the electrolytic capacitor 4 is the charging circuit 3 and the X-ray output circuit. 5 will be described below on the premise of this configuration.

  In FIG. 2, when the power of the X-ray high-voltage device is turned on (ON), electric power is supplied to the rectifier circuit 2 from the motor generator (herein, the power source will be described as the motor generator). The charging circuit 3 composed of a step-down chopper circuit receives the DC voltage rectified by the rectifying circuit 2 as an input and starts operating. The charging circuit 3 is controlled to supply a current that does not exceed the power capacity of the generator. The electrolytic capacitor 4 is charged by the current supplied by the charging circuit 3, and the voltage applied to the electrolytic capacitor 4 increases. This capacitor voltage rises to about 280 V (capacitor voltage target value VR12) when the voltage of the generator / generator is 200 V or 50 Hz, for example, but X-rays permitting X-ray imaging that is a threshold lower than that voltage. The photographing permission reference value VR11 is reached. When this VR11 voltage is reached, the X-ray imaging permission signal is turned on, and X-ray imaging is possible. When X-ray imaging is possible and the operator performs X-ray imaging (imaging signal ON), the electric power stored in the electrolytic capacitor is consumed, so that the capacitor voltage of the electrolytic capacitor decreases. When the voltage drops, the charging circuit starts operating again, and the voltage of the electrolytic capacitor starts to rise.

  When charging and X-ray imaging are repeated in such a sequence, a certain waiting time is required until the voltage rises to the X-ray imaging permission reference value VR11 after initial charging or after high-power X-ray imaging. The standby time is determined by the current supplied from the charging circuit and the capacitance of the electrolytic capacitor. For example, the initial charging requires a standby time of several tens of seconds to 1 minute.

  In this embodiment, in order to shorten such a standby time, the configuration shown in FIG. 1 is provided, and the sequence from the charging to the X-ray imaging will be described with reference to FIG.

  In FIG. 3, the X-ray high voltage apparatus is powered on and the charging circuit starts operating. First, charging is started for C1 of C1 and C2 connected in parallel with the electrolytic capacitor 4. That is, the switch SC1 is turned ON (short circuit), the charging circuit 3 is connected to the capacitor C1, and charging of the capacitor C1 is started. Here, the capacitor C1 is set to ½ of the total capacitance of the electrolytic capacitor 4 in FIG. Therefore, the capacitor voltage of the capacitor C1 rises to the voltage VR11 of the X-ray imaging permission reference value in a time ½ that of FIG. Here, when the X-ray imaging conditions are such that the tube voltage, which is the voltage applied to the X-ray tube, is a high tube voltage and excludes large power, X-ray imaging is permitted, and X-ray imaging permission using the power from the capacitor C1 is permitted. The signal 1 is turned on to enable X-ray imaging. When the X-ray imaging is not performed, the switch SC1 is turned off (opened), the switch SC2 to the uncharged capacitor C2 is turned on (short circuit), and charging of the capacitor C2 is started. When the voltage of C2 reaches the voltage VR21 of the X-ray imaging permission reference value, the X-ray imaging permission signal 2 using the power from the capacitor C2 is turned ON. When both the X-ray permission signals of the capacitors C1 and C2 are in the ON state, X-ray imaging can be performed under all X-ray conditions, for example, high tube voltage and high power conditions. In this way, by switching the switches SC1 and SC2 so that the capacitors C1 and C2 are alternately charged up to the voltage of the X-ray imaging permission reference value, the waiting time for charging time with a small-capacitance capacitor can be shortened.

  In other words, the tube voltage required for the X-ray high-voltage device differs depending on the part to be imaged. When a relatively low tube voltage is sufficient, imaging can be performed with a charging voltage with a small-capacitance capacitor, thus shortening the waiting time for charging time. In addition, when a high tube voltage is required, shooting can be performed by using both capacitors C1 and C2, and the waiting time during charging can be shortened while accommodating various shooting conditions.

  In the embodiment, the electrolytic capacitor 4 is described as a parallel configuration of two capacitors C1 and C2. However, a configuration in which a plurality of capacitors are connected in parallel may be used, and the changeover switch 6 is charged by each of the plurality of capacitors. A plurality of switches that can be connected to and opened from the circuit 3 and the X-ray output circuit 5 may be used.

As described above, in this embodiment, a rectifier circuit that rectifies an AC power source, a charging circuit that converts a DC voltage from the rectifier circuit into a predetermined voltage and outputs a constant current, and a voltage applied by the charging circuit are charged. An X-ray high voltage apparatus having an electrolytic capacitor and an X-ray output circuit that receives DC power from the electrolytic capacitor, the electrolytic capacitor having a plurality of capacitors connected in parallel, Is equipped with a plurality of switches that can be connected to and opened from the charging circuit and the X-ray output circuit, and switches the plurality of switches according to the usage conditions of the X-ray high-voltage device. Thus, it is possible to provide an X-ray high voltage device that can shorten the standby time.

  In this embodiment, an example in which the order of charging the divided charging capacitors is optimized will be described.

  In the first embodiment, as described with reference to FIG. 3, the sequence in which the capacitors C1 and C2 are alternately charged up to the voltage of the X-ray imaging permission reference value has been described. However, in this embodiment, the capacitor voltage of the capacitors C1 and C2 And charging was started from the capacitor with the higher capacitor voltage.

  4, 5 and 6 show sequence diagrams from charging to X-ray imaging in this embodiment. 4 shows that the capacitor voltages of the capacitors C1 and C2 are the same, FIG. 5 shows that the capacitor voltage of the capacitor C1 is higher than the capacitor voltage of the capacitor C2, and FIG. 6 shows that the capacitor voltage of the capacitor C2 is higher than the capacitor voltage of the capacitor C1. The sequence diagram in the case is shown. The circuit configuration in this embodiment is the same as that in the first embodiment shown in FIG. That is, the switches SC1 and SC2 are connected in series with capacitors C1 and C2 (= 0.5 × total capacitance C0) obtained by dividing the capacitance into two, and the switches operate independently.

  First, the case where the capacitor voltages of the capacitors C1 and C2 are the same will be described with reference to FIG. As shown in FIG. 4, first, the capacitor voltages VC1 and VC2 of the capacitors C1 and C2 are compared. In this case, since both are 0V, the charging operation of the capacitor C1 starts, and the voltage of C1 reaches the target voltage VR12. When it rises, it stops charging C1 and opens SC1. Thereafter, charging of C2 is started. This is the same sequence as in the first embodiment in which the capacitors C1 and C2 are alternately charged to the voltage of the X-ray imaging permission reference value.

  Next, the case where the capacitor voltage of the capacitor C1 is higher than the capacitor voltage of the capacitor C2 will be described with reference to FIG. As shown in FIG. 5, for example, after powering on the X-ray high voltage device, first, similarly to FIG. 4, the voltages of the capacitors C1 and C2 are equal, the charging operation of the capacitor C1 is started, and the voltage of the capacitor C1 becomes the target voltage. When the voltage rises to the upper limit, charging of the capacitor C1 is stopped and the switch SC1 is opened. Here, when X-ray imaging is performed before the charging of the capacitor C2 is started, the voltage of the capacitor C1 drops and the X-ray imaging permission signal is turned from ON to OFF. Here, the voltage of the capacitor C1 and the voltage of the capacitor C2 are compared. When the voltage of the capacitor C1 is high, charging starts from the capacitor C1, and when the voltage of the capacitor C1 rises to the target voltage VR12, charging of the capacitor C1 is stopped. Release SC1. Thereafter, charging of the capacitor C2 is started.

  Thus, by detecting and comparing the voltages of the capacitors C1 and C2, and starting charging from the direction where a higher voltage is applied, the charging standby time for the capacitor can be further reduced.

  Next, a case where the capacitor voltage of the capacitor C2 is higher than the capacitor voltage of the capacitor C1 will be described with reference to FIG. As shown in FIG. 6, after the power is turned on, the capacitors C1 and C2 are charged in order as in FIG. 4, and then the SC1 connected in series with the capacitor C1 in FIG. X-ray imaging is performed using the energy of the capacitor C1. After that, when the imaging signal is turned on before charging of the capacitor C1 is started, this time, X-ray imaging is performed using the energy of the capacitor C2. When the voltage of the capacitor C2 is higher than the voltage of the capacitor C1 at the time when the two X-rays are finished, charging is started from the capacitor C2. After that, it is the same as other sequences.

  Thus, by detecting and comparing the voltages of the capacitors C1 and C2, and starting charging from the direction where a higher voltage is applied, the charging standby time for the capacitor can be further reduced.

  In this embodiment, a case where the present invention is applied to a fluoroscopic imaging apparatus will be described.

  FIG. 7 is a schematic block diagram of the X-ray high voltage apparatus in the present embodiment. 7 differs from FIG. 1 in the first embodiment in that FIG. 1 shows that an electrolytic capacitor 4 for supplying power has a parallel configuration of two capacitors C1 and C2, and the capacitors C1 and C2 are connected to the charging circuit 3 and In contrast to having the changeover switch 6 composed of the switches SC1 and SC2 to be connected to and opened from the X-ray output circuit 5, in this embodiment, an electrolytic capacitor 7 in which three capacitors are arranged in parallel, and the respective capacitors are provided. The switch 8 includes a switch 8 that is connected to and opened from the charging circuit 3 and the X-ray output circuit 5. Other configurations are the same as those in FIG.

  First, the operation of the fluoroscopic apparatus will be briefly described. The fluoroscopic apparatus is an apparatus that can perform fluoroscopy, which is an X-ray condition of relatively low output, and X-ray imaging of medium output and high output. The X-ray condition of fluoroscopy is, for example, a tube voltage of 125 kV and a tube current of about 4 mA. However, in fluoroscopy, an X-ray image is captured as a moving image, so the X-ray is output for a long time, and may be output from several minutes to several tens of minutes.

  Because of such usage conditions, electric power is supplied from both the generator / generator as a power source and a large-capacity electrolytic capacitor, and a low-capacity electrolytic capacitor is sufficient in perspective.

  Therefore, in this embodiment, as shown in FIG. 7, the electrolytic capacitor 7 is configured in parallel with capacitors C1, C2, and C3, the capacitors C1 and C2 are used for photographing, and the capacitor C3 is used for fluoroscopy. Further, the capacitor C3 is constituted by an electrolytic capacitor having a lower capacity than the capacitor C1 (= C2). In addition, there is a change-over switch 8 comprising switches SC1, SC2 and SC3 for connecting and opening the capacitors C1, C2 and C3 with the charging circuit 3 and the X-ray output circuit 5, respectively. Thereby, the time for charging C3 to the voltage required for fluoroscopy can be shortened. Further, at the time of photographing, the switch SC3 connected to C3 is opened so that the voltage of the electrolytic capacitor used for fluoroscopy does not decrease. Accordingly, it is possible to start fluoroscopy immediately after imaging by switching the switch SC3 to ON (short circuit) in synchronization with the fluoroscopic imaging device operating as fluoroscopy.

  In this way, the capacity of the electrolytic capacitor is different from the capacitors C1 and C2 used at the time of photographing and the capacitor C3 used at the time of fluoroscopy. However, the waiting time during charging can be shortened.

  In this embodiment, a specific example of a switch for connecting and opening a capacitor in parallel with a charging circuit and an X-ray output circuit will be described.

  In the first to third embodiments, a switch for switching each capacitor in parallel configuration is not particularly specified, but in this embodiment, a configuration using a semiconductor switch is used.

  By using a semiconductor switch, for example, it can be applied to X-ray imaging in which several images are repeated per second, such as continuous imaging. There are X-ray conditions for continuous imaging from medium power to high power, but the imaging time is as short as several tens of ms. Therefore, continuous shooting is possible by configuring a plurality of relatively low-capacitance capacitors for continuous shooting and semiconductor changeover switches in parallel.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Power supply, 2 ... Rectification circuit, 3 ... Charging circuit, 4, 7 ... Electrolytic capacitor, 5 ... X-ray output circuit, 6, 8 ... Changeover switch, C1, C2 ... Capacitor, C3 ... Capacitor for see-through, SC1, SC2 , SC3 ... switch

Claims (5)

A rectifying circuit for rectifying an AC power supply; a charging circuit for converting a DC voltage from the rectifying circuit into a predetermined voltage and outputting a constant current; an electrolytic capacitor to which a voltage is applied and charged by the charging circuit; An X-ray high voltage apparatus having an X-ray output circuit that receives DC power from a capacitor,
The electrolytic capacitor has a plurality of capacitors connected in parallel,
Each of the plurality of capacitors includes a plurality of switches that can be connected to and opened from the charging circuit and the X-ray output circuit,
An X-ray high voltage apparatus, wherein the plurality of switches are switched according to a use condition of the X-ray high voltage apparatus. The X-ray high voltage apparatus according to claim 1,
The electrolytic capacitor has two capacitors connected in parallel,
The plurality of switches are two switches in which each of the two capacitors can be connected to and opened from the charging circuit and the X-ray output circuit,
An X-ray high-voltage apparatus, wherein the two switches are switched so that the two capacitors are alternately charged to a reference voltage required for X-ray imaging. The X-ray high voltage apparatus according to claim 1,
An X-ray high-voltage apparatus characterized by comparing the capacitor voltages of the plurality of capacitors and switching the plurality of switches so as to start charging the capacitor to which a high voltage is applied. The X-ray high voltage apparatus according to any one of claims 1 to 3,
The plurality of capacitors are capacitors for X-ray photography and fluoroscopy,
Synchronously with the operation of the X-ray high-voltage device for fluoroscopy, the X-ray imaging and fluoroscopy capacitors are connected to the charging circuit and the X-ray output circuit, and the plurality of switches that can be opened are switched. An X-ray high voltage apparatus characterized by the above. The X-ray high voltage apparatus according to any one of claims 1 to 4,
An X-ray high-voltage apparatus characterized in that the plurality of switches are constituted by semiconductor switches.

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