JP2006344445A - X-ray tube device and x-ray ct device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray tube device and X-ray CT device using the same capable of reducing power consumption, improving inspection throughput, and reducing power consumption and noise of an air conditioning device in a photographing chamber. <P>SOLUTION: A thermoelectric conversion device 91 converting heat into electric power is arranged at a prescribed part where the heat generated at an anode of the X-ray tube device 9, composed of an X-ray tube 9a housing an anode 9c and a cathode 9b arranged in opposition to the anode in a vacuum container, a tube container housing the X-ray tube filled with insulation oil 9e for cooling, and cable receptacles 9i, 9j for the anode and the cathode in which bushing of a cable impressing high voltage between the anode and the cathode, are inserted, is conducted. The electric power generated by the thermoelectric conversion device is supplied to a focus movement correction device 11 and to an X-ray tube cooling device 14 by power transmission cables 9n, 9o through a low voltage circuit terminal board 9q. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray tube apparatus, and more particularly to an X-ray tube apparatus that effectively uses heat generated by an anode of an X-ray tube apparatus and an X-ray CT apparatus using the same.

In recent years, in X-ray CT systems, “a wide range of scanning is possible in a short time”, “continuous data can be obtained in the direction of the body axis, which enables the generation of 3D images”, and “X-ray detectors” A helical CT called a helical scan or a spiral scan having a multi-slice function having a feature such as "multiple rows of images can be taken at a time and a large number of tomographic images can be taken" has become the mainstream.
This spiral CT is equipped with an X-ray tube device and an X-ray detector on the scanner rotation unit, and continuously rotates the scanner rotation unit, and at the same time, sets the table on which the subject is placed on the body axis of the subject. The X-ray tube device and the X-ray detector are rotated relative to the subject by continuously moving in the direction.

In this way, the spiral CT has to continuously expose X-rays for a long time from the X-ray tube device mounted on the scanner rotating unit. An X-ray tube device is required. However, if the capacity of the X-ray tube device is increased, the heat generated from the anode part of the X-ray tube also increases, thereby increasing the amount of movement of the focal point, which is the X-ray source.
This focal shift is caused by the fact that the rotating anode of the X-ray tube accumulates heat during use and expands due to thermal expansion, as described in Patent Document 1, thereby causing artifacts on the tomographic image. This hinders the improvement of the image quality of the X-ray CT apparatus.

Therefore, as a means for coping with this problem, there has been added a mechanism for moving the X-ray tube apparatus in the tube axis direction of the rotary anode X-ray tube.
This is because the X-ray tube device support base of the X-ray CT device is provided with a mechanism that can move the X-ray tube device in the X-ray tube axis direction by motor drive, and corresponding to the measurement result of the focal shift amount The X-ray tube apparatus is moved in the direction opposite to the direction of focus movement to correct the focus movement amount.
As another example of the coping means, the X-ray detector is moved in the X-ray tube axis direction or the collimator attached to the X-ray CT apparatus is moved in correspondence with the measurement result of the focal movement amount. Some correct the amount of focus movement.

Further, as described in Non-Patent Document 1, if the temperature in the tube container rises due to heat generated from the anode part of the X-ray tube device filled with insulating oil and exceeds the allowable temperature, the insulation In order to prevent the oil insulation performance from deteriorating, measures are taken to forcibly cool the insulation oil using a cooler composed of a radiator (heat radiator) and a pump.
JP 2000-340148 Ishiyaku Shuppan Publishing Co., Ltd .: Medical Radiology Course 13; Radiological Equipment Engineering, 2nd Edition, page 311

As described above, due to the increase in capacity of the X-ray tube apparatus by spiral CT, an X-ray tube focus movement correction device is required, and the cooling capacity of the cooler that cools the X-ray tube apparatus is also required.
Therefore, an increase in the power supply capacity of the X-ray tube focus movement correction device and the power supply of the cooler requires an extra power of several hundred watts, which is one of the causes of a decrease in power efficiency of the entire X-ray CT apparatus. Yes.

In addition, since it is necessary to grasp the current amount of focal movement in order to correct the focal movement of the X-ray tube device, there is no subject or no invalid exposure even if there is a subject. X-rays are exposed with a shutter (hereinafter referred to as pre-exposure), and the X-ray detector that detects the X-ray beam calculates the amount of focal movement from the amount of movement of the X-ray beam. Detected.
For this reason, the preliminary exposure described above is required, which reduces the throughput of the X-ray CT examination.

  Further, the exhaust heat from the cooler that cools the X-ray tube apparatus causes a temperature rise inside the X-ray CT apparatus, so that the air-conditioning capacity of the imaging room is increased in order to bring the imaging room to a predetermined temperature due to this temperature increase This leads to an increase in power consumption and noise of the air conditioner.

  An object of the present invention has been made in view of the above problems, and is an X-ray tube apparatus capable of reducing power consumption, improving inspection throughput, reducing power consumption of an air conditioner in a radiographing room, and reducing noise. And an X-ray CT apparatus using the same.

The present invention has been made based on the idea of converting the heat generated in the anode part of the X-ray tube device into electric power and effectively using this electric power. The above object is achieved by the following means.
(1) An X-ray tube in which an anode and a cathode disposed opposite to the anode are accommodated in a vacuum envelope, and a tube container for accommodating the X-ray tube filled with cooling insulating oil And an anode and a cathode cable receptacle for inserting a cable bushing for applying a high voltage between the anode and the cathode. Thermoelectric conversion means for converting the power into electric power.
(2) The thermoelectric conversion means includes a thermoelectric conversion element made of a thermoelectric material formed of a material containing at least one element of Bi, Te, Sb, and Se as a main component, and the thermoelectric conversion element One surface is composed of a heat absorbing portion that absorbs heat generated by the anode, and a heat radiating portion that dissipates heat absorbed by the heat absorbing portion on the other surface of the heat absorbing portion.
(3) Piezoelectric means using a piezoelectric element for moving the X-ray tube in a direction opposite to the focal direction of the anode target is provided between the tube container and a vacuum envelope near the cathode of the X-ray tube, The electric power generated by the thermoelectric conversion means is input to the piezoelectric means to correct the focal shift amount of the X-ray tube.
(4) An electric transmission means for transmitting the electric power generated by the thermoelectric conversion means to the outside through one of the anode and cathode cable receptacles is provided.
(5) A cooling means for cooling the insulating oil is further provided, and electric power transmitted from the electric transmission means is used as a power source of the cooling means.
(6) The cooling means is further provided with control means for controlling the cooling power according to the amount of heat generated by the anode from the correlation between the electric power generated by the thermoelectric conversion means and the cooling power required for the insulating oil. .

As described above, thermoelectric conversion means for converting heat generated from the anode of the X-ray tube into electric power is provided in the X-ray tube device, and the converted electric power is converted into an X-ray diagnostic imaging device using the X-ray tube device, By using it as a power source for elements constituting the X-ray CT apparatus (for example, electric power for focus movement correction by piezoelectric means, insulating oil cooling means, etc.), the power consumption of the entire system is reduced and the efficiency is improved.
Further, by providing the piezoelectric means inside the X-ray tube apparatus, it is possible to obtain an X-ray tube apparatus that does not require correction of the focal shift amount.
Furthermore, since the control means for controlling the cooling power according to the heat generation amount of the anode is provided, the X-ray tube can be efficiently cooled.
The effect is particularly great in an X-ray tube apparatus having a rotating anode.

(7) An X-ray generation unit and an X-ray detection unit are disposed opposite to each other with the subject sandwiched between a rotation member having an opening for arranging the subject, and the rotation member is rotated around the subject to rotate the X An X-ray CT apparatus that irradiates the subject with X-rays from a ray generation means, detects X-rays transmitted through the subject with the X-ray detection means, and obtains a tomographic image of the subject from the detection signal Therefore, the X-ray tube device according to any one of (3) to (6) is used as the X-ray generation means.
(8) The power transmitted by the power transmission means is used as a component of the X-ray CT system.
(9) It has a focus movement amount correction means for moving the X-ray tube device in accordance with an X-ray focus movement amount generated from the anode target, and a power source of the focus movement amount correction means is supplied from the electric transmission means. Use electricity.
(10) The focus movement amount correction means is a correction means using a piezoelectric element, and the correction means is inserted between the fixed portion provided on the rotating member and the X-ray tube device, and the electric transmission from the electric transmission means. Electric power is used as a power source for the correction means.
(11) Further, the driving force according to the amount of heat generated by the anode from the correlation between the electric power generated by the thermoelectric conversion unit and the driving force required for the focal movement correction unit is applied to the focal movement correction unit. Control means for controlling was provided.
(12) A rotating anode X-ray tube device is used as the X-ray tube device in order to be compatible with spiral scanning.

The X-ray CT apparatus configured as described above uses the electric power converted by the thermoelectric conversion means as the power source of the X-ray tube focus shift correction device and the cooling device of the X-ray tube device. The overall power consumption is less and the power usage efficiency is improved.
In this case, the cathode filament heating device and the X-ray tube device of the X-ray tube device can be used in addition to using the electric power obtained by the conversion as the power source of the X-ray tube focal point movement correcting means and the X-ray tube device cooling device. Further, the power utilization efficiency of the X-ray CT apparatus can be further improved by using it as a power source for system components such as the anode rotation drive apparatus.

In addition, since the control means for controlling the focal movement amount and the cooling power according to the calorific value of the anode is provided, the focal movement correction and the X-ray tube can be efficiently cooled.
Further, by providing the focus movement control means, it is possible to finely control the focus movement correction in real time, so that it is not necessary to measure the current focus movement amount used in the prior art, and a preliminary X for that purpose. X-ray CT inspection throughput can be improved by eliminating the need for radiation exposure.

Furthermore, since the anode of the X-ray tube device is cooled by the thermoelectric conversion device means, it becomes possible to reduce the cooling capacity of the X-ray tube cooling device, and the noise of this cooling device is reduced, and the X-ray CT device. Therefore, the air conditioning capacity of the air conditioner in the photographing room can be reduced.
Furthermore, by using an X-ray tube device having piezoelectric means inside the X-ray tube device, there is no need to provide a focus movement correction means outside the X-ray tube device, so the X-ray CT device is simpler. And cheap.
In particular, the use of a rotating anode X-ray tube device for the X-ray tube device has a great effect.

According to the present invention, by providing means for converting heat generated at the anode of the X-ray tube device into electric power, the following effects can be obtained.
(1) By using the converted electric power as a power source for elements constituting the X-ray CT apparatus such as the X-ray tube focus shift correction device and the X-ray tube cooling device, the entire X-ray CT system can be used. Less power is consumed and power efficiency is improved.
(2) Since the focus shift correction can be controlled in real time and finely by the control means provided in the focus shift correction device, it is not necessary to measure the focus shift amount, and preliminary X-ray exposure for that purpose is also unnecessary. As a result, the throughput of the X-ray CT examination is improved.
(3) Since the anode of the X-ray tube device is cooled by the thermoelectric conversion device means, the cooling capacity of the X-ray tube cooling device can be reduced, and the noise of the cooling device is reduced, and the X-ray CT device Therefore, the air conditioning capability of the air conditioner in the photo studio is also reduced, and as a result, the noise in the photo studio and the power supply capacity of the air conditioner can be reduced.
(4) Since the piezoelectric means is provided inside the X-ray tube apparatus, and the focus movement correction is performed by the piezoelectric means, it is not necessary to provide the focus movement correction means outside the X-ray tube apparatus. Can be simpler and cheaper.

Hereinafter, preferred embodiments of an X-ray tube apparatus and an X-ray CT apparatus using the same according to the present invention will be described in detail with reference to the drawings.
The X-ray CT apparatus includes a scanner gantry, a table on which a subject is placed, and a console with a built-in image processing apparatus.
An opening for inserting a subject is provided at the center of the scanner gantry, and a table is disposed on the front surface of the scanner gantry.
The height of the table is configured to be electrically adjustable, and a top plate on which the subject is placed is provided on the upper surface of the table, and the top plate is used to position the subject at the imaging position. It is configured so that it can slide electrically with respect to the tree.
On the console, an input device such as a keyboard and a mouse, and a monitor as a display device that displays various information such as patient information and imaging conditions and a tomographic image taken, are arranged inside the console. A control device for controlling the image processing apparatus and the entire system is accommodated and connected to the scanner gantry and table, and these scanner gantry and table are controlled by the control device.

FIG. 1 is a diagram showing a configuration of a scanner gantry of an X-ray CT apparatus in which an X-ray generation apparatus using an X-ray tube apparatus according to the present invention and an X-ray detection apparatus are mounted on a scanner rotating unit.
In FIG. 1, a scanner gantry 1 includes a scanner fixing unit (not shown) and a scanner rotating unit. The scanner rotating unit includes a rotating member 2, an X-ray generator 3, an X-ray detecting device 4, and a scanner rotating unit. A rotating unit control device 5 for controlling the inside of the unit is mounted.

The X-ray generation device 3 includes an X-ray generation X-ray tube device 9 that irradiates a subject (not shown) inserted into the opening 8 and placed at the imaging position, and an X-ray tube device 9 Consists of a collimator 10 that limits the ray beam to the irradiation field of the subject, and a focus movement correction device 11 that corrects the focal movement amount of the X-ray tube device 9, and the X-ray control signal from the X-ray control device 12 Corresponding high voltage is generated by the high voltage generator 13, and this high voltage is applied between the anode and the cathode of the X-ray tube device 9 and the X-ray corresponding to the X-ray control signal from the X-ray tube device 9 Is generated.
The X-ray control device 12 includes a filament heating device that heats a filament that is a cathode of the X-ray tube device 9, and the X-ray generation device 3 rotates the anode of the X-ray tube device 9. An anode driving device (not shown) is included.
In addition, an X-ray tube cooling device 14 is mounted on the rotating member 2, whereby the X-ray tube device 9 is cooled and suppressed to a predetermined temperature or lower.

  The X-ray detection device 4 is disposed at a position facing the X-ray generation device 3 with the subject interposed therebetween, and an X-ray detector 15 that detects X-rays transmitted through the subject, and this X-ray detection And an amplifier 16 that amplifies the electric signal output from the device 15, and each is fixed to the rotating member 2.

  In the scanner gantry 1 having such a configuration, the correction of the focal shift due to the heat generated from the anode portion of the X-ray tube is provided separately from the X-ray detector 15 by performing preliminary exposure before starting imaging. The focal movement detector detects the focal movement amount from the movement amount of the position of the X-ray beam, and moves the X-ray tube device 9 by the focal movement correction device 11 in the opposite direction to the focal movement by this movement amount. To correct.

FIG. 2 is a structural diagram of the first embodiment of the X-ray tube apparatus 9 according to the present invention in the X-ray generator 3 of the X-ray CT apparatus.
2 also shows an X-ray cooler 14 for cooling the X-ray tube apparatus.

  The X-ray tube 9a of the X-ray tube device 9 includes a cathode 9b that emits thermoelectrons from a heated filament, an anode target 9c that receives electrons to generate X-rays, and a rotating anode 9d that rotates the target 9c. Are housed in a vacuum envelope and fixed by an anode support 9f and a cathode support 9g of the tube container of the X-ray tube device 9 filled with a cooling insulating oil 9e.

Near the center of the inside of the X-ray tube device 9, a radiation port 9h made of an epoxy resin with good X-ray filterability is attached, and an anode cable receptacle 9i and a cathode cable receptacle 9j are provided at both ends, A cable bushing extending from the high voltage generator 13 is inserted here.
Lead wires extend from the anode cable receptacle 9i and cathode cable receptacle 9j to the anode end of the X-ray tube 9a and the stem of the cathode end side glass bulb (not shown), and a high voltage is applied.
The anode side is energized with a single cable, while the cathode side is used with a plurality of cables insulated from each other, such as filaments and other common terminals.
An unillustrated stator winding is wound around the rotating anode stator 9k that rotates the anode, and electric power is supplied through a low-voltage circuit terminal plate (not shown) provided on the anode support 9f. The stator winding is used at ground potential.
In the case of a large-capacity, high-input X-ray tube device such as the X-ray CT device, the insulating oil 9e exceeds the allowable temperature only by heat radiation from the X-ray tube device 9, so a radiator (heat radiator) and a pump Cooling is forcibly performed using an X-ray tube cooling device 14 constituted by:

  In the X-ray tube device 9 having such a configuration, the present invention converts heat generated in the anode target 9c of the X-ray tube 9a into electric power by the thermoelectric conversion device 9l, and the converted electric power is, for example, the focus movement correction This is used for the power source of the components of the X-ray CT apparatus such as the apparatus 11.

Generally, the X-ray generation efficiency of an X-ray tube device is very low, 99% or more is heat, and an X-ray tube device with an output of 100 kW emits 99 kW of thermal energy.
Rotating the thermoelectric conversion device 9l using a thermoelectric conversion element made of a thermoelectric material made of a material containing at least one element of Bi, Te, Sb, and Se as a main component. It adheres to the support 9p provided at the end of the anode 9d and converts the heat generated at the anode into electric power.

  Although not shown, the thermoelectric conversion device 9l has one end surface of the thermoelectric conversion element made of the thermoelectric material in contact with the outer surface of the support 9p, and an endothermic portion that absorbs heat generated in the anode target 9c, The other end of the thermoelectric conversion element is connected to the other surface of the heat absorbing part, and a heat radiating part that radiates the heat absorbed by the heat absorbing part is provided, and the thermoelectric conversion element causes a temperature difference between the heat absorbing part and the heat radiating part. In this configuration, an electromotive force is generated to generate power.

Although the conversion efficiency of the thermoelectric conversion element of this thermoelectric conversion device 9l is as low as several percent, if the thermal energy discharged from the X-ray tube device is 99 kW, several percent of this thermal energy is converted into electric power, It can generate about several kW of power.
The generated power of several kW is used as a power source for the components of the X-ray CT apparatus. For example, the focal point movement correction device 11 that requires several tens of watts or about several hundred watts of power is used. It is used as a power source for the necessary X-ray tube cooling device 14 and other devices.

  In the embodiment of FIG. 2 described above, the electric power generated by the thermoelectric conversion device 9l is taken outside the X-ray tube device 9 via a low-voltage circuit terminal plate 9q (lead receptacle cannot be used for high voltage) by a lead wire 9m. However, power is supplied to the focus movement correction device 11 and the X-ray tube cooling device 14 through the transmission lines 9n and 9o, respectively.

Note that since the internal temperature of the X-ray tube device 9 is very high, sufficient consideration must be given to the heat resistance of the thermoelectric conversion element.
In this regard, the temperature distribution of the X-ray tube 9a is highest at the anode target 9c and reaches 1000 ° C., but is about 150 ° C. at the support 9p for fixing the thermoelectric conversion device 9l. Since the melting point of the simple substance is 271 ° C for Bi, 449 ° C for Te, 630 ° C for Sb, and 220 ° C for Se, sufficient heat resistance can be secured.

  Further, although an example in which the entire X-ray tube apparatus is moved as the focus movement correction unit has been described, the present invention is not limited to this, and is different from the focus movement correction apparatus 11 according to the measurement result of the focus movement amount. Even when means for moving the X-ray detector as the coping means in the X-ray tube axis direction or means for moving the collimator attached to the X-ray CT apparatus can be used as a drive power source for these means.

By configuring as described above, the power of the focus movement correction device 11 (drive motor and control device not shown) and the power of the X-ray tube cooling device 11 are provided in the scanner rotation unit of the X-ray CT apparatus. There is no need to supply from an external power source.
Further, since the heat generated by the anode target 9c is absorbed by the thermoelectric conversion device 9l by an amount corresponding to the power generation of the thermoelectric conversion device 9l and the rotary anode 9d of the X-ray tube device 9 is cooled, the focal shift amount Becomes smaller.
Therefore, the amount of focus movement correction by the focus movement correction apparatus 11 can be reduced, and the correction capability of the focus movement correction apparatus 11 can be reduced.
Further, similarly to the above, since the rotary anode 9d of the X-ray tube device 9 is cooled by the thermoelectric conversion device 9l, the cooling capacity of the X-ray tube cooler 14 can be reduced. The necessary electric power, the noise of the cooler 14, and the exhaust heat from the X-ray CT apparatus are also reduced.
As a result, by applying the X-ray tube apparatus according to the first embodiment of the present invention to the X-ray CT apparatus, it becomes possible to reduce power consumption, cost, and noise of the entire X-ray CT apparatus.

FIG. 3 is a diagram showing a second embodiment of the present invention in which the electric power generated by the thermoelectric conversion device of the X-ray tube device is used for the focal movement correction device.
As described above, in the X-ray tube device 9, the greater the heat generated by the anode target 9c, the greater the focal shift amount, so the driving force required for the focal shift correction device 11 also increases.
Further, the greater the heat generated by the anode target 9c, the greater the power generated by the thermoelectric conversion device 9l.
Accordingly, since the electric power generated by the thermoelectric conversion device 9l increases as the focal point movement amount increases, the electric power generated by the thermoelectric conversion device 9l is controlled in accordance with the driving force required for the focal point movement correction device 11. It ’s fine.

FIG. 3 provides a focal point movement control unit 11a based on this idea, thereby obtaining a focal point movement correction control signal according to the electric power generated by the thermoelectric conversion device 9l, and using this correction control signal, the focal point movement correction device 11 The drive motor (not shown) is controlled.
That is, the focal point movement control unit 11a obtains a correlation between the electric power generated by the thermoelectric conversion device 9l and the driving force required for the focal point movement correction device 11, and is necessary for the heat generation amount of the rotary anode 9d from this correlation. The driving force of the focal point movement correction device 11 is controlled.

The correlation between the electric power generated by the thermoelectric conversion device 9l and the driving force required for the focal movement correction device 11 is as follows:
(1) Relationship between the amount of heat generated by the rotating anode and the amount of focus movement
(2) Relationship between the amount of heat generated by the rotating anode that absorbs heat at the heat absorbing portion of the thermoelectric converter and the amount of heat released from the heat radiating portion of the thermoelectric converter
(3) Relationship between the electromotive force due to the temperature difference between the heat absorbing part and the heat radiating part and the amount of focal movement
(4) Since it can be obtained from the relationship between the electromotive force of the thermoelectric conversion device and the driving force required for the focus movement correction device, this is provided in the focus movement control unit 11a, and the power generation of the thermoelectric conversion device is based on these relationships. The correction control signal corresponding to the power to be obtained is obtained, and the driving force of the focus movement correction apparatus is controlled by this signal.
In the embodiment of FIG. 3, the electric power generated by the thermoelectric conversion device 9l is illustrated as being directly supplied to the focal movement correction device 11 and the focal movement control unit 11a, but this is a simplified illustration. Actually, as shown in FIG. 2, power is supplied through the transmission line 9n via the low voltage circuit terminal plate 9q.

Thus, by providing the focal point movement control unit 11a, the focal point movement correction can be finely controlled in real time.
Therefore, it is not necessary to measure the current focal shift amount, and preliminary X-ray exposure for that purpose is not necessary, so that the throughput of X-ray CT inspection can be improved.

FIG. 4 is a diagram showing a third embodiment of the present invention in which electric power generated by the thermoelectric conversion device of the X-ray tube device is used for focus movement correction.
This is because the focus movement correction device 17 using a piezoelectric element is used for focus movement correction. A fixing portion 18 for fixing the focus movement correction device 17 is provided on the scanner rotation portion, and the fixing portion 18 and the X-ray tube device 9 are provided. The focal point movement correction device 17 is inserted between the cathode side and the vicinity thereof.
The piezoelectric element of the focus movement correction device 17 expands / contracts according to the electric power generated by the thermoelectric conversion device 9l, and pressure is generated, and the X-ray tube device 9 is moved in the direction opposite to the focus movement direction to move the focus. Correct the amount.
Note that the fixing of the piezoelectric device 17 is not limited to the fixing unit 18 of the scanner rotation unit corresponding to the cathode side of the X-ray tube device 9, and the X-ray tube device 9 can be moved in a direction in which focal movement can be corrected It may be fixed at any position as long as it is fixed at a position.
Thus, by using a piezoelectric element for the focus movement correction apparatus, the focus movement correction apparatus can be configured with a simpler mechanism than that using the motor of the first embodiment.

FIG. 5 is a diagram showing a fourth embodiment of the present invention in which electric power generated by the thermoelectric conversion device of the X-ray tube device is used for focus movement correction.
This is to correct the focal movement by moving the X-ray tube 9a in the X-ray tube device 9 by attaching the piezoelectric device 19 by a piezoelectric element to the fixed portion 20 provided inside the X-ray tube device 9. The electric power generated by the thermoelectric conversion device 9l of the X-ray tube device 9 is used as a power source of pressure generated by the piezoelectric device 19, and the X-ray tube 9a itself is moved in the direction opposite to the focal point movement by the pressure generated thereby. Focus movement correction is performed.
With this configuration, the entire X-ray tube apparatus 9 is not moved as in the first, second, and third embodiments, but only the X-ray tube 9a is moved to perform focus movement correction. It is not necessary to provide a focus movement correction means outside the tube device 9, and the focus movement correction means and the space and wiring required for this means are not required. Therefore, the scanner rotating portion can be made light and simple.

FIG. 6 shows a fifth embodiment of the present invention which is another embodiment in which the electric power generated by the thermoelectric conversion device of the X-ray tube device in the first embodiment of FIG. 2 is used for the X-ray tube cooling device 14. FIG.
As shown in the embodiment of FIG. 2 above, assuming that the power generated by the thermoelectric conversion device 9l of the X-ray tube device 9 is the input power of the X-ray tube cooling device 14, the amount of heat generated by the rotary anode 9d of the X-ray tube device 9 Accordingly, the cooling power output from the X-ray tube cooling device 14 also varies, and the cooling power of the X-ray tube cooler 14 increases as the heating value of the rotary anode 9d increases.
Therefore, in order to efficiently cool the X-ray tube device 9, the power generated by the thermoelectric conversion device 9l may be controlled in accordance with the cooling power required for the X-ray tube cooling device 14.

  The fifth embodiment of the present invention shown in FIG. 6 is provided with a cooling control unit 14a based on this idea, thereby correcting the cooling power of the X-ray tube cooler 14 according to the power generated by the thermoelectric conversion device 9l. A control signal is obtained, and the heat dissipation power and pumping force of an X-ray tube cooler (not shown) constituted by a radiator (radiator) and a pump are controlled by this correction control signal.

  That is, the cooling control unit 14a obtains a correlation between the electric power generated by the thermoelectric conversion device 9l and the cooling power required for the X-ray tube cooling device 14, and from this correlation, it is necessary for the heat generation amount of the rotating anode 9d. The cooling power of the X-ray tube cooling device 14 is controlled.

The correlation between the electric power generated by the thermoelectric conversion device 9l and the cooling power required for the X-ray tube cooling device 14 is
(1) Relationship between the amount of heat generated by the rotating anode 9d of the X-ray tube device 9 and the temperature of the rotating anode 9d
(2) Relationship between the temperature of the rotating anode 9d and the cooling power required for the X-ray tube cooler 14
(3) Since it can be determined from the relationship between the cooling power and the electric power generated by the thermoelectric converter, the cooling control unit 11a is provided with these correlations, and thus the cooling corresponding to the electric power generated by the thermoelectric converter 9l. A correction control signal is obtained, and the cooling power of the X-ray tube cooling device 14 is controlled by this control signal.
Thus, by providing the cooling control unit 11a, the X-ray tube cooler 14 can be controlled more finely.
In the embodiment of FIG. 6, the electric power generated by the thermoelectric conversion device 9l is illustrated as being directly supplied to the X-ray tube cooling device 14 and the cooling control unit 14a, but this is a simplified illustration, and actually As shown in FIG. 2, power is supplied through the transmission line 9o via the low voltage circuit terminal plate 9q.

  According to the present embodiment, an external power source for the X-ray tube cooler 14 is not required, and the cooling of the rotating anode is automatically controlled according to the amount of heat generated by the rotating anode 9d of the X-ray tube device 9. Is possible.

  In the above embodiment, an X-ray tube device provided with thermoelectric conversion means for converting thermal energy generated in the anode part of the X-ray tube into electric energy, and this X-ray tube device is used for an X-ray CT device, and the conversion is performed. However, the present invention is not limited to these, and the filament of the X-ray tube is described as a power source and a control power source for the X-ray tube device focus movement correction device and the X-ray tube cooling device. Power supply for peripheral elements of the X-ray tube device such as a filament heating device for heating the anode and an anode rotation drive device for rotating the anode of the X-ray tube, and peripheral elements of the X-ray CT device and X-ray diagnostic device using the power source It can also be used for power supplies and other effects.

Furthermore, although the example applied to the large-capacity rotary anode X-ray tube apparatus in which the anode is rotated has been described for the X-ray tube apparatus of the above embodiment, the present invention can also be applied to a fixed anode X-ray tube apparatus.
Further, the X-ray tube apparatus of the above embodiment has been described with respect to an example in which the X-ray tube apparatus is applied to a neutral grounding type that applies an anode and a high voltage to the cathode, but an anode grounding X-ray tube that applies a high voltage only to the cathode It can also be applied to devices.

The figure which shows the structure of the scanner gantry of the X-ray CT apparatus which mounts the X-ray generator and X-ray detector which used the X-ray tube apparatus by this invention in the scanner rotation part. The figure which shows the structure of 1st Embodiment of the X-ray tube apparatus and X-ray cooling device by this invention. The figure which shows the 2nd Embodiment of this invention which provided the focus movement control part in the focus movement correction apparatus. The figure which shows the 3rd Embodiment of this invention using the focus movement correction apparatus by a piezoelectric element for focus movement correction. The figure which shows the 4th Embodiment of this invention which provides the piezoelectric device by a piezoelectric element inside an X-ray tube apparatus, and moves an X-ray tube and correct | amends a focus movement. The figure which shows the 5th Embodiment of this invention which provided the cooling control part in the X-ray tube cooling device.

Explanation of symbols

  1 Scanner gantry, 2 Rotating member, 3 X-ray generator, 4 X-ray detector, 9 X-ray tube device, 9a X-ray tube, 9b Cathode, 9c Anode target, 9d Rotating anode, 9e Insulating oil, 9f Anode support Body, 9g cathode support, 9i anode cable receptacle, 9j cathode cable receptacle, 9l thermoelectric converter, 9m lead wire, 9n, 9o power transmission line, 9p support, 9q low voltage circuit terminal board, 10 collimator, 11 focus Movement correction device, 11a Focus movement control unit, 14 X-ray tube cooling device, 14a Cooling control unit, 17 Focus movement correction device using piezoelectric element, 19 Piezoelectric device using piezoelectric element

Claims (4)

  An X-ray tube containing an anode and a cathode disposed opposite to the anode in a vacuum envelope, a tube container containing the X-ray tube filled with a cooling insulating oil, An X-ray tube apparatus including an anode and a cathode cable receptacle for inserting a cable bushing for applying a high voltage between an anode and a cathode, wherein the heat generated in the anode is transferred to a predetermined portion. An X-ray tube apparatus characterized by comprising thermoelectric conversion means for converting the power into electric power.   2. The thermoelectric conversion device according to claim 1, wherein the thermoelectric conversion means includes a thermoelectric conversion element made of a thermoelectric material formed of a material containing at least one element of Bi, Te, Sb, and Se as a main component. X is characterized in that one surface of the element is composed of a heat absorbing portion that absorbs heat generated by the anode, and a heat radiating portion that dissipates heat absorbed by the heat absorbing portion on the other surface of the heat absorbing portion. Tube device.   The electric power generated by the thermoelectric conversion means is provided in the tube container according to claim 1 or 2, and a power transmission means is provided for transmitting the electric power to the outside through the low voltage circuit terminal board. X-ray tube device.   An X-ray generation unit and an X-ray detection unit are arranged opposite to each other with a subject interposed between a rotation member having an opening for arranging the subject, and the rotation member is rotated around the subject to generate the X-ray generation unit. An X-ray CT apparatus that irradiates the subject with X-rays, detects X-rays transmitted through the subject with the X-ray detection means, and obtains a tomographic image of the subject from the detection signal; An X-ray CT apparatus, wherein the X-ray generation means includes the X-ray tube apparatus according to any one of claims 1 to 3.

Images