JPH01206598A - High voltage power supply for x-ray generating device - Google Patents

Abstract

PURPOSE:To separate a high voltage control part from a high voltage generating part, prevent electromagnetic obstacle, and ensure stability by converting a command voltage into an optical pulse, transmitting to the high voltage generating part side via photo-conductive path, applying reversely converting treatment, and thereby reproducing the command voltage. CONSTITUTION:A command voltage a (and b) generated by a high voltage control part 14 is first converted into a signal c (c') with a frequency proportional to the voltage, and further into an optical pulse d (d') having the frequency of signal c (c'). The pulse d (d') is sent to the high voltage generating part 16 side via a photo- conductive path. On this generating part 16 side, the pulse d (d') is converted photoelectrically to obtain a signal g (g'), which is frequency-electrically converted so as to reproduce the original command voltage h (h'). On the basis of this command voltage h (h') the generating part 16 generates as objective impression voltage and supply current, which is impressed on and supplied to an X-ray bulb 10. Accordingly the control part 14 and generating part 16 are perfectly separated in electrical terms by the photo-conductive path. Thereby no electromagnetic obstacle likely to be generated by the generating part 16 will be transmitted, and operators for the control part 14 are free of high voltage to ensure their safety.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-voltage power supply device for an X-ray generator, and in particular,
The present invention relates to a high voltage power supply device characterized by a method of transmitting a command signal from a control section to a high voltage generation section.

[Prior Art] As shown in FIG. 3, an X-ray generator includes an X-ray tube 10 and a high-voltage power supply 12 for applying a high voltage thereto. The high-voltage power supply device 12 further includes a high-voltage control section 14 that generates a command signal corresponding to the applied voltage and supplied current to the X-ray tube 10, and a high-voltage control section 14 that generates a command signal corresponding to the applied voltage and supplied current to the X-ray tube 10, and a high-voltage control section 14 that generates a command signal corresponding to the applied voltage and supplied current to the It consists of a high voltage generating section 16 that applies and supplies to the bulb 10. The command signals include an applied voltage command voltage a corresponding to the applied voltage (in kV units) and a supply current command voltage S corresponding to the supplied current (in mA units).

[Problems to be Solved by the Invention] This type of high-voltage power supply device performs high-speed switching with large power in the high-voltage generating section, which causes electromagnetic interference. This electromagnetic interference can be transmitted through electrical wiring and affect the high voltage control section. In recent years, high voltage 761
A microcomputer has been installed in the 1111 section to control the voltage and current of the X-ray tube based on external signals, and the high voltage control section has come to be digitally controlled. The electromagnetic interference described above is thought to have an adverse effect on such microcomputer control, and there is a need to prevent this.

In addition, the high voltage control section is equipped with an operation panel for manually setting the applied voltage and supply current to the X-ray tube, but from the standpoint of operator safety, the high voltage is not generated. It would be safer if the high voltage generator and the operation panel could be electrically separated completely.

In view of the above points, an object of the present invention is to provide an X-ray generator that completely electrically separates a high voltage control section and a high voltage generation section to prevent electromagnetic interference and ensure safety. The purpose of the present invention is to provide a high voltage power supply device.

[Means for Solving the Problems] In order to achieve the above object, a high voltage power supply device according to the present invention has the following components.

(a) A high voltage control section that generates an applied voltage command voltage and a supply current command voltage corresponding to the applied voltage and supply current to the X-ray tube.

(b) A voltage-frequency converter that generates an electrical signal with a frequency proportional to the magnitudes of the applied voltage command voltage and the supply current command voltage.

(c) an electrical-optical converter that converts the electrical signal into an optical signal;

(d) An optical transmission line for transmitting the optical signal.

(e) An optical-to-electrical converter that converts the optical signal from the optical transmission line into an electrical signal.

(f) A frequency-voltage converter that converts the electrical signal from the optical-to-electrical converter into an applied voltage command voltage and a supply current command voltage whose magnitude is proportional to the frequency of the electrical signal.

(0) A high voltage generation unit that applies and supplies an applied voltage and a supply current corresponding to the applied voltage command voltage and supply current command voltage from the frequency-voltage converter to the X-ray tube.

[Action] High voltage! The two types of command voltages generated in the IJ m section are first converted into electrical signals with frequencies proportional to the voltages,
Roughly, electricity is converted into light. In other words, it becomes a light pulse having a frequency proportional to the magnitude of the command voltage. This optical pulse is sent to the high voltage generator side via an optical transmission line such as an optical fiber.

On the high voltage generator side, this optical pulse is subjected to optical-to-electrical conversion and roughly frequency-to-voltage conversion to reproduce the original command voltage. Based on this command voltage, the high voltage generator generates a target applied voltage and supply current, and applies and supplies them to the X-ray tube. Therefore, the high voltage control section and the high voltage generation section are completely electrically separated by the optical transmission line.

[Example] Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block circuit diagram of one embodiment of the present invention. The X-ray generator shown in this figure consists of an X-ray tube 10 and a high-voltage power supply that extends from a high-voltage control section 14 to a high-voltage generation section 16. The high voltage control section 14 outputs an applied voltage command voltage a and a supply current command voltage S as command signals.

Two signal transmission systems exist to transmit these two types of command voltages to the high voltage generation section 16. Since these two signal transmission systems basically have the same configuration, the signal transmission system for the applied voltage command voltage a will be mainly explained.

The applied voltage command voltage a output from the high voltage control section 14 is applied to a voltage-frequency converter 18, an electric-to-optical converter 20, an optical-
The signal is transmitted to the high voltage generator 16 via an electrical converter 22 and a frequency-voltage converter 24.

The electrical-optical converter 20 and the optical-electrical converter 22 are connected by an optical fiber.

Next, the operation of this embodiment will be explained. FIG. 2 is a timing chart for applied voltage command voltage a. For the applied voltage command voltage a, the magnitude difference of the voltage becomes signal information. This applied voltage command voltage a is applied to the voltage-frequency converter 18
Then, an electric signal C with a frequency proportional to the magnitude of the command voltage a
is converted to In this embodiment, this electrical signal C is made into a pulse signal that switches between two positive voltages, strong and weak. In this electrical signal C, the difference in frequency becomes signal information. This electrical signal C is converted into an optical pulse signal d by an electrical-optical converter 20. LE as the electrical-optical converter 20
D is used, and an optical pulse signal d having two different levels of emitted light intensity is 1q. This optical pulse signal d is
It is sent via an optical fiber to an optical-to-electrical converter 22, where it is converted into an electrical signal q. A phototransistor is used as the optical-to-electrical converter 22, and an electrical signal with two voltage levels is obtained. This electrical signal is binarized by a comparator to obtain an electrical pulse signal @q.

This electric pulse signal q is converted into a voltage by the frequency-voltage converter 24 and the applied voltage command voltage q is obtained. This voltage is the same as the original applied voltage command voltage a. At 16, a high voltage corresponding to this applied voltage signal is generated, and this is applied to the X-ray tube 10.

The supply current command voltage is also processed in exactly the same way and is transmitted to the high voltage generation section 16. Then, the target supply current is supplied to the X-ray tube 10.

As the two types of command voltages, voltages in the range of DC O to IOV are used, and the converted frequency is O to 100kHz.
A range of values of 2 is used.

In the above embodiment, an analog value was used as the applied voltage command voltage a, but a digital signal (a binary coded value corresponding to the applied voltage) may also be used, and in this case, the digital signal can be directly converted into Just convert it to frequency.

In the present invention, when transmitting a command signal from a high voltage control section to a high voltage generation section, a predetermined conversion process is performed to electrically separate the high voltage control section and the high voltage generation section. Conversely, it is also possible to send a signal from the high voltage generation section to the high voltage il control section. For example, the actual voltage and current of the X-ray tube may be displayed on the control panel of the high voltage control section.

In this case, it is necessary to transmit information regarding these voltages and currents from the high voltage generation section to the high voltage control section. For such purposes, a normal isolation amplifier can be used since very high precision is not required. If high precision is required, conversion processing similar to that of the present invention may be performed.

[Effects of the Invention] As explained above, the present invention converts the command voltage generated in the high voltage control section into a frequency, roughly converts it into an optical pulse, and transmits this to the high voltage generation section side through an optical transmission line. Since the command voltage is transmitted and recirculated by performing the reverse conversion process, the high voltage control section and the high voltage generation section can be electrically completely separated by the optical transmission line. Therefore, electromagnetic interference generated in the high voltage generation section will not be transmitted through the electrical wiring and affect the high voltage control section. In general, the high voltage control section is electrically isolated from the high voltage, ensuring operator safety.

Further, by extending the optical transmission line, the high voltage control section and the high voltage generation section can be separated by a long distance, and the high voltage generation section can be remotely connected. With conventional high-voltage power supplies that transmit command voltage to the high-voltage generator via electrical wiring, if the electrical wiring is extended,
This is undesirable because it causes a voltage drop and the electrical wiring becomes an antenna.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a timing chart of this embodiment, and FIG. 3 is a block circuit diagram of a conventional example. 10...X-ray tube 14...High voltage control section 16...High voltage generation section 18...Voltage-frequency converter 20...Electricity-optical converter 22...Optical-electrical conversion Figure 2 shows the frequency-voltage converter time.

Claims (1)

[Claims] (1) A high-voltage power supply device for an X-ray generator having the following components: (a) A high voltage control unit that generates an applied voltage command voltage and a supply current command voltage corresponding to the applied voltage and supply current to the X-ray tube. (b) A voltage-frequency converter that generates an electrical signal with a frequency proportional to the magnitudes of the applied voltage command voltage and the supply current command voltage. (c) an electrical-optical converter that converts the electrical signal into an optical signal; (d) An optical transmission line for transmitting the optical signal. (e) An optical-to-electrical converter that converts the optical signal from the optical transmission line into an electrical signal. (f) A frequency-voltage converter that converts the electrical signal from the optical-to-electrical converter into an applied voltage command voltage and a supply current command voltage whose magnitude is proportional to the frequency of the electrical signal. (g) A high voltage generation unit that applies and supplies an applied voltage and a supply current corresponding to the applied voltage command voltage and supply current command voltage from the frequency-voltage converter to the X-ray tube.