JP2002065656A - X ray ct device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide all the necessary electric power to the rotary side of an X-ray computerized tomography device without mechanical contact to facilitate the maintenance of an electric power supply means from the static side to the rotary side, and at the same time, to provide a highly reliable X-ray CT device that is low in loss rate and little in high-frequency noise. SOLUTION: An X-ray tube and an X-ray detector are placed oppositely to each other with a subject body placed between them. To a high-voltage generation circuit which is required to generate X-rays from the above X-ray tube, an anode rotation driving circuit of the X-ray tube and circuits such as a filament heating one of the X-ray tube, and a control power-source circuit which controls these circuits installed in a scanner's rotary unit which turns around the subject body, electric power is supplied by an electromagnetic induction transmission means. The electromagnetic induction transmission means is composed of a first coil which is arranged around a fixed frame of the scanner's rotary unit combines with a plurality of second coils that are arranged around a rotation frame of the scanner's rotary unit and oppositely to the first coil. A commercial electric power or an alternative current voltage that is roughly same in frequency with that of the commercial electric power is inputted to the first coil. The voltage of the second coils that is induced by an electromagnetic induction action is made equal to the electric power voltage of the circuits installed in the scanner's rotary unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus which emits X-rays to a diagnosis site of a subject, detects a transmitted X-ray image thereof, reconstructs a tomographic image, and displays the image as an image. An X-ray CT apparatus which has a means for supplying power from a power supply to the X-ray tube side in a scanner rotating unit which rotates at an angle, and which can facilitate maintenance and inspection of the power supply means and improve reliability. .

[0002]

2. Description of the Related Art An X-ray CT apparatus irradiates a subject with a fan-shaped X-ray beam from an X-ray tube and detects X-rays transmitted through the subject at a position facing the X-ray tube. The detected data is subjected to image processing to obtain a tomographic image of the subject.

The X-ray detector is composed of a group of hundreds of detection elements arranged in an arc shape, and is arranged opposite to an X-ray tube with a subject interposed therebetween. X-ray passages are formed in a number corresponding to the number of radially distributed X-ray tubes, and the X-ray tube and the detector are integrally rotated at least 180 degrees around the object to transmit the X-rays of the object at a certain angle. Is detected.

In recent years, this X-ray CT apparatus has been described as "scanning a wide range in a short time", "obtaining continuous data in the body axis direction, and thereby enabling generation of a three-dimensional image". Due to its characteristics, spiral CT called helical scan or spiral scan has rapidly spread.

In the spiral CT, the time required for multi-layer imaging over a wide range is greatly reduced by actively moving the imaging position during imaging, thereby enabling three-dimensional CT imaging. .

In the spiral CT having such characteristics, the X-ray tube is moved to the subject by moving the table on which the subject is placed in the body axis direction at the same time as the fixed scanner body performs the continuous rotation scan. A relatively spiral motion is performed. As described above, since the helical scan changes the shooting position in parallel with the continuous rotation scan during shooting, the entire shooting time is reduced. In addition, since scanning is continuously performed also in the body axis direction during imaging, three-dimensional data is collected.

In order to realize the spiral scan, it is necessary to continuously rotate the scanner rotating unit. For this purpose, means for continuously supplying power to the X-ray tube mounted on the scanner rotating unit is required. Is required. As this means, a power supply mechanism comprising a slip ring and a brush is used, and a high voltage (hereinafter, this voltage is referred to as a tube voltage) is applied to the X-ray tube together with the X-ray tube to the scanner rotating section. And a power supply for generating required X-rays from the X-ray tube via the power supply mechanism. Since the high-voltage generator is mounted on the scanner turntable and rotated at a high speed, it is desirable that the high-voltage generator be as light as possible. For this reason, as the X-ray high-voltage device, an inverter-type X-ray high-voltage device capable of reducing the size and weight of the high-voltage transformer of the high-voltage generator and reducing the pulsation of the tube voltage is used.

However, a conventional X-ray CT apparatus using such a power supply mechanism using a slip ring and a brush is a method for supplying power by mechanical sliding contact between the slip ring and the brush. When a large current flows through the contact portion, wear and corrosion occur at the contact portion. That is, the high-voltage transformer mounted on the scanner rotating unit generates a high voltage of more than one hundred tens of kV on the output side, and a sufficient insulation distance is provided internally for insulation from the input side. Yes, several μH
There is a leakage inductance of .about.tens of .mu.H. Further, the current flowing through the slip ring and the brush reaches about 400 A at the maximum. In such a state, when a small gap is generated between the slip ring and the brush provided on the scanner fixing unit when the scanner rotating unit rotates,
The current tends to continue to flow under the influence of the leakage inductance, and an arc is generated in the gap, which may locally increase the temperature. The high temperature may cause wear and corrosion of the slip ring and the brush. Therefore, it is necessary to periodically perform maintenance and inspection such as polishing of the slip ring and replacement of the brush. And cost. In addition, this problem is becoming more and more serious in recent years, because a market has demanded a higher-speed scanning X-ray CT apparatus for the purpose of effectively diagnosing organs such as the heart, which are moving rapidly. .

To cope with such a problem, Japanese Unexamined Patent Publication No. Hei 7-204192 discloses a method utilizing an electromagnetic induction action for supplying electric power from a power supply to the X-ray tube side in a non-contact manner without mechanical sliding contact. Issue. This is connected to the output side of the inverter circuit of the above-mentioned inverter type X-ray high-voltage device and provided as a means for supplying electric power from the power supply to the X-ray tube provided in the scanner rotating unit and at the periphery of the fixed frame of the scanner rotating unit. The first winding is disposed on the second winding, and the second winding is disposed on the periphery of the rotating frame of the scanner rotating unit facing the first winding and connected to the input side of the high-voltage transformer. And an electromagnetic induction power transmitting means formed by combining the above windings.

Japanese Patent Laid-Open No. 9-313473 discloses an X-ray CT apparatus using non-contact transmission means utilizing optical communication in which a light emitting element and a light receiving element are combined as means for transmitting a detection signal from an X-ray detector to an image processing apparatus. Issue. Thus, a high voltage can be supplied to the X-ray tube in a non-contact manner, and an X-ray detection signal can be transmitted to the image processing apparatus. Wear and corrosion can be prevented, maintenance and inspection can be facilitated, and the reliability of the entire apparatus can be improved.

[0011]

However, Japanese Patent Application Laid-Open No. 7-204192 lacks consideration for the following problems.

(1) The power is supplied from the power supply to the X-ray tube side by transmitting a high-frequency AC voltage, which is the output voltage of an inverter circuit arranged on the stationary side (fixed side) of the scanner, to the electromagnetic induction power transmitting means. Therefore, it is necessary to consider radiation noise and induction noise caused by high-frequency current flowing through the first winding and the second winding of the electromagnetic induction power transmitting means.

The radiation noise is proportional to the value of the current flowing through the first and second windings, and the induction noise is also proportional to the frequency. Therefore, the frequency of radiation and induction noise generated by the current flowing through the winding in the electromagnetic induction means is high, and the noise may increase in proportion to this frequency. For this reason, a malfunction of the X-ray CT apparatus and a malfunction of other devices may be caused, and a countermeasure for preventing the malfunction is required.

(2) Since the electromagnetic induction power transmitting means operates on the same principle as the rotary transformer, an eddy current flows through the iron core in proportion to the frequency of the current flowing through the first winding and the second winding. As a result, eddy current loss is generated, and the eddy current loss is proportional to the square of the frequency of the eddy current. On the other hand, the hysteresis loss due to the hysteresis characteristic of the iron core increases in proportion to the number of reciprocations on the hysteresis curve, that is, the frequency. Therefore, iron loss consisting of eddy current loss and hysteresis loss is
Since the higher the frequency of the current flowing through the winding in the electromagnetic induction power transmission means, the higher the frequency, the lower the frequency, the better.

(3) In the prior art of Japanese Patent Application Laid-Open No. 7-204192, only a high voltage generating circuit for generating X-rays is described, and a filament heating circuit for heating a filament of the X-ray tube, an X-ray tube No mention is made of power supply to the various circuits other than the high voltage generation circuit required for X-ray generation, such as the X-ray tube anode rotation drive circuit for rotating the anode.

[0016] For this reason, since power does not function as an X-ray CT apparatus without power supply to the various circuits, power supply to these circuits is also a major problem. In this case, it is conceivable to use the same power supply method as that of the related art by mechanical sliding contact between the slip ring and the brush for supplying power to the various circuits, but the power required for the various circuits is much higher than that of the high voltage generation circuit. Although it is small, current of several tens of amperes flows, so that the problem of wear and corrosion still remains in this method.

(4) Further, since the control of the tube voltage of the X-ray CT apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-204192 is performed by the inverter circuit on the fixed side of the scanner rotating unit, this inverter is used. Since the output voltage of the circuit, that is, the voltage supplied to the primary side of the high voltage transformer mounted on the rotating side of the scanner rotating unit changes according to the tube voltage, it can be used as a power supply source for the various circuits. Can not. Therefore, since it is necessary to separately provide the electromagnetic induction power transmitting means for each of the above circuits, the entire system becomes more complicated,
The rise in costs and the increase in size and weight will be significant.

Therefore, an object of the present invention is to supply all necessary power to the rotating side of the X-ray CT apparatus without mechanical contact, and to facilitate maintenance and inspection of the power supply means from the stationary side to the rotating side. Another object of the present invention is to provide a highly reliable X-ray CT apparatus with low loss and low high-frequency noise.

[0019]

The above object is achieved by the following means.

(1) An X-ray tube that emits X-rays, an X-ray detector that detects a transmitted X-ray dose distribution emitted from the X-ray tube and transmitted through a subject, and amplifies the detection signal; A scanner rotating unit for rotating the X-ray detector around the subject with the X-ray detector facing the X-ray detector, an image processing apparatus for processing an output signal from the X-ray detector and reconstructing a tomographic image of a diagnostic site An image display device that receives an output signal from the image processing device and displays a tomographic image, the first volume being disposed on a periphery of a fixed frame of the scanner rotating unit. A commercial power supply or a frequency substantially equal to the commercial power supply frequency by an electromagnetic induction power transmitting means comprising a combination of a wire and a second winding arranged on the periphery of the rotating frame of the scanner rotating unit so as to face the first winding. The power from the AC power source with the same frequency Supply to the circuit mounted in the unit.

(2) The electromagnetic induction power transmitting means winds the first winding around a ring-shaped iron core arranged on the periphery of a fixed frame of the scanner rotating section, and rotates the plurality of second windings around the scanner rotating section. So that the magnetic flux generated in the first windings interlinks with the plurality of second windings through the respective iron cores. Constitute.

(3) An output voltage of an arbitrary one of the plurality of second windings of the electromagnetic induction power transmitting means is input to the tube voltage control means, and the output voltage of the second winding is selected from the plurality of second windings. The output voltages of the remaining windings are supplied to circuits other than the tube voltage control means mounted on the scanner rotating unit.

(4) An output voltage of an arbitrary one of the plurality of second windings of the electromagnetic induction power transmitting means is input to the tube voltage control means, and the remaining windings of the second winding are inputted. And an insulation transformer for generating a plurality of types of output voltages insulated from the circuit. The output voltage of the insulation transformer is supplied to circuits other than the tube voltage control means mounted on the scanner rotating unit.

As described above, the electromagnetic induction power transmitting means transmits the power of the commercial power supply frequency or a frequency near the commercial power supply frequency, so that the first winding and the second winding of the electromagnetic induction power transmitting means are used. , The frequency of the current flowing through the power supply can be reduced, thereby enabling power transmission with low electromagnetic noise and loss. Also, since the output voltage of the electromagnetic induction power transmitting means is supplied to a circuit mounted on the scanner rotating unit other than the high voltage generating circuit, it is possible to supply electric power to all circuits mounted on the scanner in a non-contact manner. The maintenance and inspection of the means for supplying power from the power supply to the circuit mounted on the scanner rotating unit is facilitated, and a highly reliable X-ray CT apparatus can be provided.

[0025]

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

FIG. 1 is a block diagram of the overall configuration showing a first embodiment of the X-ray CT apparatus according to the present invention. This X-ray C
The T device emits X-rays to the diagnostic site of the subject and transmits the X-rays.
As shown in FIG. 1, it is connected to a commercial AC power supply unit 1 and supplies electric power to a scanner rotating unit 5 in a non-contact manner, as shown in FIG. -204192, a known electromagnetic induction power transmitting means 4, a high voltage generating circuit 520 for generating a DC high voltage, and an X for applying an output voltage of the high voltage generating circuit 520 to emit X-rays. The X-ray tube 560 and the X-ray tube 560
A filament heating circuit 530 for heating the cathode filament 562, an anode rotation drive circuit 510 for supplying electric power to an anode rotation mechanism for rotating the rotating anode 563 of the X-ray tube 560, and an X-ray tube 520. An X-ray detection unit 7 that detects a transmitted X-ray dose distribution transmitted through the sample 6 and amplifies the detection signal; the filament heating circuit 530, the anode rotation driving circuit 510, and the X-ray detection unit 7
Power supply circuit 540 that supplies power to a circuit that controls
And an insulating transformer 570 that insulates the output voltage of the electromagnetic induction power transmitting means 4 and uses the AC power of the anode rotation drive circuit 510, the filament heating circuit 530, and the control power supply circuit 540.
The X-ray tube 560 and the X-ray detection unit 7 are opposed to each other with the object 6 interposed therebetween, and the X-ray tube 560 is mounted on the scanner rotation unit 5 for rotating these around the object 6. Issuer 703 for converting the output signal from the X-ray detector 7 into light, a light receiving element 704 mounted on a scanner fixing unit for converting the light into an electric signal, and processing the output electric signal of the light receiving element 704. The image processing apparatus 11 is configured to reconstruct a tomographic image of a diagnosis site by inputting an output signal from the image processing apparatus 11 and to display a tomographic image.

An AC voltage of the commercial frequency of the AC power supply 1 is input to a first winding 401 of the electromagnetic induction power transmitting means 4,
The voltage induced in the second winding 402 of the electromagnetic induction power transmitting means 4 is supplied to various circuits mounted on the scanner rotating unit 5.

The high voltage generating circuit 520 includes a converter circuit 52 for converting an AC voltage having a commercial frequency induced in the second winding 402 of the electromagnetic induction power transmitting means 4 into a DC voltage.
1, a capacitor 522 for smoothing the output voltage of the converter circuit 521, an inverter circuit 523 for converting the DC voltage to a high-frequency AC voltage, a high-voltage transformer 524 for boosting the output voltage of the inverter circuit 523,
And a high-voltage rectifier 525 for rectifying the output voltage to convert it into a DC high voltage. The DC high voltage converted by the high-voltage rectifier 525 is applied between the anode and the cathode of the X-ray tube 560.

The control of the tube voltage applied between the anode and the cathode of the X-ray tube 560 makes the voltage induced in the second winding 402 of the electromagnetic induction power transmitting means 4 constant, and the inverter circuit 5
22 and the converter circuit 521.

The anode rotation driving circuit 510 of the X-ray tube includes a three-phase stator coil 561 of the anode rotation driving mechanism of the X-ray tube 560 in order to reduce the load on the anode target of the X-ray tube 560 during X-ray emission. A circuit for supplying an AC voltage, which converts the voltage of the secondary winding 571 of the insulating transformer 570 induced in the second winding 402 of the electromagnetic induction power transmitting means 4 and insulated by the insulating transformer 570 into a converter circuit At 511, the voltage is converted into a DC voltage, the DC voltage is smoothed by a smoothing capacitor 512, and this voltage is converted into a three-phase AC voltage having a frequency set by an inverter circuit 513.
To rotate the anode of the X-ray tube 560 at a predetermined rotation speed.

The filament heating circuit 530 supplies an electric current (hereinafter, this electric current is referred to as a tube current) between the anode and the cathode of the X-ray tube to generate a required amount of X-ray irradiation.
The circuit for heating the filament of the wire tube converts the voltage of the secondary winding 572 of the insulating transformer 570 into a converter circuit 531.
To a DC voltage, which is smoothed by a smoothing capacitor 532, and this voltage is converted to a single-phase AC voltage of a predetermined frequency by an inverter circuit 533, and this voltage is converted to a heating transformer 535.
To the filament 562 of the X-ray tube 560 to heat the filament to a predetermined temperature.

The control power supply circuit 540 includes the high voltage generation circuit 5
20, an anode rotation drive circuit 510, a filament heating circuit 530, and other circuits mounted on the scanner rotation unit.
70 is a circuit for converting the voltage of the secondary winding 573 into a DC voltage by a rectifier circuit (not shown).

The X-ray tube 560 is connected to the anode driving circuit 510.
Is supplied, the anode rotates, the filament 562 is heated by the heating circuit 530, and a DC high voltage is applied from the high voltage generation circuit 520 to emit X-rays toward the subject 6. It radiates.

Then, the X-ray transmitted through the subject is X-ray
The light enters the line detection unit 7. The X-ray detector 7 detects the transmitted X-ray dose distribution radiated from the X-ray tube 560 and transmitted through the subject, and amplifies the detection signal. The detector 701 detects the transmitted X-ray dose distribution. And a preamplifier 702 for amplifying the detection signal from the detector 701. The detection signal detected and amplified by the X-ray detection unit 7 is converted into light by the light emitting element 703, and this light signal is converted into an electric signal by the light receiving element 704 mounted on the scanner fixing unit. Is input to the image processing device 11 to reconstruct a tomographic image of the diagnosis site, and the reconstructed tomographic image is displayed on the image display device 12.

As described above, in the scanner rotating unit 5 of the X-ray CT apparatus, in addition to the high voltage generating circuit 520, the X-ray tube 560 and the X-ray detecting unit 7, the anode driving circuit 510, the filament heating circuit 530 , And a control power supply circuit 540, and supplies power to the respective circuits in a non-contact manner by the electromagnetic induction power transmitting means 4.

FIG. 2 shows a specific structure of the electromagnetic induction power transmitting means 4. FIG. 2A is a cross-sectional view illustrating an arrangement relationship between a fixed frame 55 provided on the scanner stationary side and a rotating frame 52 provided on the scanner rotating unit 5. FIG. 2 (b)
It is the perspective view which expanded the part of the electromagnetic induction power transmission means 4 enclosed with the broken line of FIG. Inner circumference of fixed frame 55 and rotating frame 52
A first iron core 404 and a second iron core 405 are arranged facing each other on the outer periphery of. A first winding 401 connected to the commercial frequency AC power supply 1 is fixed to a groove provided in the first iron core 404. The high-voltage generating circuit 520 and the insulating transformer 570
Is fixed to the second winding 402 connected to the input side.
Thus, when an AC current from the AC power supply 1 of the commercial frequency flows through the first winding 401, as shown in FIG. 2B, the first winding 401, the second winding 402, Core 404 and the second iron core 405 constitute a shell-type transformer, and a magnetic flux φ is generated. The magnetic flux φ interlinks with the second winding 402 to induce a voltage in the second winding 402, and the voltage is induced from the second winding 402 to the high voltage generating circuit 520 and the insulating transformer 570 shown in FIG. An AC voltage can be supplied.

Here, when the current flowing through the first winding 401 and the second winding 402 is a high-frequency AC current as disclosed in Japanese Patent Application Laid-Open No. 7-204192, the generated noise Is high, the magnitude increases in proportion to the frequency, and the eddy current loss and the iron loss due to hysteresis generated in the first iron core 404 and the second iron core 405 also increase.

Since these noises and losses are detrimental to the X-ray CT apparatus and may cause a reduction in reliability, it is desirable that these are small. Accordingly, the present invention provides a first winding 401 and a second winding 40
2. Since the current flowing through 2 is low at the commercial frequency, the high-frequency noise and loss are small, and are suitable for an X-ray CT apparatus that detects a weak X-ray detection signal and reconstructs an image using the detection signal. And leads to improved reliability.

In the embodiment of FIG. 1, the commercial frequency AC power supply 1 is a single-phase AC power supply, but it may be a three-phase AC power supply. FIG. 3 shows a specific example of the structure of the electromagnetic induction power transmitting means 4 in this case. In FIG. 3, a first iron core 404 fixed to the stationary side of the X-ray CT apparatus and provided on the inner periphery of the fixed frame is provided.
a and a second iron core 405a fixed to the scanner rotating unit and provided on the outer periphery of the rotating frame, constitutes an outer iron type three-phase transformer iron core. The first winding 401 connected to the u-phase, v-phase, and w-phase of the three-phase AC power supply is provided in a groove provided in the first iron core 404a.
u, 401v, and 401w are respectively fixed, and a high-voltage generation circuit 520 is provided in a groove provided in the second iron core 405a.
And the second windings 402u, 402v, 402w connected to the input side of the insulating transformer 570 are fixed.

The first windings 401u, 401v, 401w
When a three-phase alternating current of a commercial frequency flows through the first core 4
A magnetic flux φ is generated in a shell-type three-phase transformer core composed of the core 04a and the second core 405a. The magnetic flux φ links with the second windings 402u, 402v, 402w, and a three-phase AC voltage having the same frequency as the commercial frequency is induced in the second windings 402u, 402v, 402w. An AC power supply is used as a power supply for each circuit mounted on the scanner rotating unit 5.

In this case, the high voltage generation circuit 52 shown in FIG.
0 converter circuit 521 is a three-phase full-wave rectifier circuit, and a three-phase transformer is used as the isolation transformer 570. The converter circuit 511 of the anode drive circuit 510, the converter circuit 511 of the filament heating circuit 530, and the control power supply circuit 54
The zero converter circuit (not shown) may be a three-phase full-wave rectifier circuit.

As shown in FIG. 3, if the winding direction of the first winding 401v connected to the v-phase of the commercial frequency AC power supply is reversely wound with respect to the other first windings 401u and 401w. The magnetic flux of the intermediate yoke 407 of each phase has a phase of 120 °.
Since the difference is the sum and the magnitude of the magnetic flux is equal to that of the other portions, it is not necessary to particularly double the cross-sectional area. Further, the insulation transformer 570 includes the second windings 402u and 402u.
A single-phase transformer may be used as long as a voltage between any two phases of the three-phase AC voltages induced in v and 402w is used.

Further, the present invention may have various embodiments as follows.

(1) In the embodiment shown in FIG. 1, the second winding on the rotating side of the scanner is connected in parallel with the high voltage generating circuit 520 and the insulating transformer 570, and the output of the insulating transformer is increased. Although the power supply is used for each circuit other than the voltage generation circuit 520, the present invention is not limited to this method. For example, two second windings of the electromagnetic induction power transmitting means 4 are provided, and a voltage induced in one of them is used as a power supply voltage of the high voltage generation circuit 520, and a voltage induced in the other winding is provided. May be the power supply voltage of the insulating transformer 570.

(2) In the above (1), the insulation transformer 5
A method may be used in which a plurality of second windings of the electromagnetic induction power transmitting means 4 are provided, and power is supplied to each circuit from these second windings.

(3) High voltage generating circuit 52 shown in FIG.
0, the internal configuration of the anode drive circuit 510 and the filament heating circuit 530 is not limited to the above embodiment. Respectively,
Any configuration is possible as long as tube voltage control, anode drive, and filament heating control are possible.

(4) In the embodiment shown in FIG. 1, the AC power of the commercial frequency is directly input to the electromagnetic induction power transmitting means 4. However, the present invention is not limited to this. The voltage may be boosted by a step-up transformer, and the boosted voltage of the commercial frequency may be transmitted by the electromagnetic induction power transmitting means 4.

(5) Although the case where the AC power supply unit 1 of the above embodiment is a single-phase AC power supply and a three-phase AC power supply has been described, the present invention can also be applied to a DC power supply using a battery.
In this case, the battery voltage may be converted into a single-phase or three-phase AC voltage having the same frequency as the commercial power supply frequency by an inverter circuit, and the converted voltage may be input to the electromagnetic induction power transmitting means 4.

(6) The frequency of power transmission by the electromagnetic induction power transmission means 4 has been described as an example in which the frequency of the commercial power supply is used in terms of electromagnetic noise and loss. The power may be higher or lower than the power supply frequency, and an optimum frequency may be selected and transmitted. In this case, the inverter circuit generates and transmits the AC voltage having the optimum frequency.

[0050]

As described above, according to the present invention, the electromagnetic induction power transmission means is employed as the power supply means from the scanner stationary side to the rotation side in the X-ray CT apparatus, and the power transmission frequency of the electromagnetic induction power transmission means is changed to the commercial power supply. By providing a frequency near the frequency and supplying the output voltage of the electromagnetic induction power transmitting means to a circuit mounted on the scanner rotating unit other than the high voltage generating circuit, the following effects can be obtained.

(1) Power transmission with small electromagnetic wave noise and loss becomes possible. (2) Power can be supplied to the high-voltage generation circuit, anode drive circuit, filament heating / heat recovery circuit, and other control power supply circuits mounted on the scanner rotating unit. (3) According to the above (1) and (2), the maintenance and inspection work of the means for supplying power from the power supply to the circuit mounted on the scanner rotating unit is facilitated, and the reliability of the X-ray CT apparatus is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an overall configuration showing a first embodiment of an X-ray CT apparatus according to the present invention.

FIG. 2 is a specific structural diagram of the electromagnetic induction power transmitting means according to the present invention.

FIG. 3 is a structural diagram of an electromagnetic induction power transmitting unit when transmitting power from a three-phase power supply according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 AC power supply, 4 electromagnetic induction power transmitting means, 5 scanner rotating unit, 52 rotating frame, 55 fixed frame, 401, 401
u, 401v, 401w First winding, 402, 402
u, 402v, 402w Second winding, 404, 404
a First core, 405, 405a Second core, 4
07 Intermediate yoke, 510 Anode drive circuit 520 High voltage generation circuit, 530 Filament heating circuit, 540 Control power supply circuit 511, 521, 531
Converter circuit, 512, 522, 532 Smoothing capacitor, 513, 523, 533 Inverter circuit, 52
4 High voltage transformer 525 High voltage rectifier, 535 Heating transformer, 560 X-ray tube, 561 X-ray tube Anode drive mechanism stator coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiichi Chabata 1-1-1 Uchikanda, Chiyoda-ku, Tokyo Inside Hitachi Medical Corporation (72) Inventor Kazuhiko Sakamoto 1-11-1 Uchikanda, Chiyoda-ku, Tokyo No. Hitachi Medical Corporation (72) Inventor Hiroshi Takano 1-1-14 Uchikanda, Chiyoda-ku, Tokyo F-term (reference) 4C093 AA22 BA03 BA09 CA06 CA35 CA36 EC41 EC43 EC60

Claims (4)

[Claims] An X-ray tube that emits X-rays, an X-ray detector that detects a transmitted X-ray dose distribution emitted from the X-ray tube and transmitted through a subject, and amplifies the detection signal; A scanner rotating unit that rotates the tube and the X-ray detecting unit around the subject in opposition to each other, an image processing device that processes an output signal from the X-ray detecting unit to reconstruct a tomographic image of a diagnostic site, An image display device that receives an output signal from the image processing device and displays a tomographic image, the X-ray CT device comprising: a first winding disposed on a periphery of a fixed frame of the scanner rotating unit; And a second winding disposed in opposition to the first winding on the periphery of the rotating frame of the scanner rotating unit, by electromagnetic induction power transmission means, a commercial power supply or a frequency substantially equal to the commercial power supply frequency. The power from the AC power supply with the same frequency is An X-ray CT apparatus characterized in that the apparatus is supplied to a circuit mounted in the apparatus. 2. The electromagnetic induction power transmission means, wherein the first winding is wound around a ring-shaped iron core arranged on the periphery of a fixed frame of the scanner rotating unit, and a plurality of second windings are wound on the scanner rotating unit. The magnetic flux generated in the first winding is linked to a plurality of second windings via the respective iron cores by being wound around a ring-shaped iron core arranged on the periphery of the rotating frame. The X-ray CT apparatus according to claim 1, wherein: 3. An output voltage of an arbitrary one of the plurality of second windings of the electromagnetic induction power transmitting means is input to the tube voltage control means, and a remaining one of the plurality of second windings is provided. The X-ray CT apparatus according to claim 1, wherein the output voltage of the winding is supplied to a circuit other than the tube voltage control means mounted on the scanner rotating unit. 4. An output voltage of an arbitrary one of the plurality of second windings of the electromagnetic induction power transmitting means is input to the tube voltage control means, and an output voltage of the remaining windings of the second winding is input to the tube voltage control means. An insulation transformer for generating a plurality of types of output voltages by insulation, and supplying an output voltage of the insulation transformer to a circuit other than the tube voltage control means mounted on the scanner rotating unit. Item 7. An X-ray CT apparatus according to Item 1.