JPH08293395A - X-ray high voltage device - Google Patents

Abstract

PURPOSE: To accurately detect cutoff of a filament or cup touch of the filament by calculating and comparing the resistance of the filament from the filament current to be supplied to the filament of a line pipe and the filament voltage. CONSTITUTION: The filament current is detected by a filament current detecting unit 21, and the detection of the filament voltage is performed by a filament voltage detecting unit 19. The filament resistance value is calculated from the detected filament current value and the voltage value by a dividing unit 35. When the calculated filament resistance value is larger than the preset reference value in cutoff of the filament, a filament cutoff detecting signal is formed. When it is smaller than the calculated reference value in cup touch of the filament, a filament cup touch detecting signal is generated. In this case, the cutoff of the filament of an X-ray tube or the cup touch of the filament can be accurately found through comparators 41, 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray high voltage device for supplying an electron acceleration high voltage and a filament heating current to an X-ray tube which generates X-rays, and more particularly to a filament breakage or X-ray of the X-ray tube. The present invention relates to an X-ray high voltage device capable of detecting a so-called filament cup touch in which a filament comes into contact with a focusing electrode that converges.

[0002]

2. Description of the Related Art Conventionally, there is known an X-ray diagnostic apparatus for photographing and seeing through a subject using X-rays emitted from an X-ray tube. In this X-ray diagnostic apparatus, the focal point of the X-ray tube to be used is fixed depending on the X-ray irradiation condition, and a filament breakage of the X-ray tube or a filament contacting a focusing electrode for converging the X-ray is called a so-called filament cup. If a touch occurred, the diagnosis was abruptly interrupted.

[0003]

However, the conventional X-ray diagnosis does not include means for detecting the filament disconnection of the X-ray tube or the filament cup touch of the X-ray tube. Occasionally, the diagnostic operation was interrupted due to the occurrence of filament cup touch in the wire tube.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an X-ray high voltage apparatus capable of accurately detecting a filament disconnection of the X-ray tube or a filament cup touch of the X-ray tube. And

[0005]

In order to achieve the above object, a first invention of the present application is a filament voltage detecting means for detecting a filament voltage applied to a filament of an X-ray tube for exposing X-rays, and the X-ray detecting means. A filament current detecting means for detecting a filament current supplied to the filament of the filament tube, a filament voltage detected by the filament voltage detecting means, and a resistance of the filament based on the filament current detected by the filament current detecting means. When the resistance of the filament calculated by the calculating means and the preset reference value at the time of filament disconnection is larger than the preset value, a detection signal of the filament disconnection is generated, and when the preset filament cup is touched. Of the filament calculated by the calculating means from the reference value of If better anti smaller is summarized in that and a comparing means for generating a detection signal of the filaments cup touch.

The second invention of the present application is the X-ray high voltage apparatus for supplying a high voltage for electron heating and a current for filament heating to an X-ray tube having at least two filaments for emitting electrons. Filament voltage detecting means for detecting the filament voltage applied to the filament of the X-ray tube, filament current detecting means for detecting the filament current supplied to the filament of the X-ray tube, and filament detected by the filament voltage detecting means A calculating means for calculating the resistance of the filament based on the voltage and the filament current detected by the filament current detecting means, and the resistance of the filament calculated by this calculating means from a preset reference value when the filament is broken. If the value is large, a filament disconnection detection signal is generated and If towards the resistance of the filament, which is calculated by said calculating means from the reference value of the constant filament cup touch is small and summarized in that and a comparing means for generating a detection signal of the filaments cup touch.

Further, a third invention of the present application is the X-ray high voltage apparatus for supplying a high voltage for electron heating and a current for filament heating to an X-ray tube having at least two filaments for emitting electrons. Filament voltage detecting means for detecting the filament voltage applied to the filament of the X-ray tube, filament current detecting means for detecting the filament current supplied to the filament of the X-ray tube, and filament detected by the filament voltage detecting means A calculating means for calculating the resistance of the filament based on the voltage and the filament current detected by the filament current detecting means, and the resistance of the filament calculated by this calculating means from a preset reference value when the filament is broken. If the value is large, a filament disconnection detection signal is generated and When the resistance of the filament calculated by the calculating means is smaller than the determined reference value at the time of filament cup touch, the comparing means for generating the detection signal of the filament cup touch and the detecting signal are generated by the comparing means. At this time, the gist is to have a switching means for switching the filament to be used to a normal filament.

[0008]

In the X-ray high voltage apparatus according to the first aspect of the present invention, the filament voltage detected by the filament voltage detecting means for detecting the filament voltage applied to the filament of the X-ray tube that exposes the X-ray, and the X-ray The resistance of the filament is calculated based on the filament current detected by the filament current detecting means for detecting the filament current supplied to the filament of the wire tube. Then, when the calculated resistance of the filament is larger than the preset reference value at the time of filament disconnection, a detection signal of the filament disconnection is generated, and is calculated from the preset reference value at the time of filament cup touch. When the resistance of the filament is smaller, the detection signal of the filament cup touch is generated.

An X-ray high voltage apparatus according to the second invention of the present application is an X-ray high voltage apparatus for supplying a high voltage for electron heating and a filament heating current to an X-ray tube having at least two filaments for emitting electrons. In, the filament voltage detected by the filament voltage detecting means for detecting the filament voltage applied to the filament of the X-ray tube,
The filament resistance is calculated based on the filament current detected by the filament current detecting means for detecting the filament current supplied to the filament of the X-ray tube. Then, when the calculated resistance of the filament is larger than the preset reference value at the time of filament disconnection, a detection signal of the filament disconnection is generated, and is calculated from the preset reference value at the time of filament cup touch. When the resistance of the filament is smaller, the detection signal of the filament cup touch is generated.

An X-ray high voltage apparatus according to the third invention of the present application is an X-ray high voltage apparatus for supplying a high voltage for electron heating and a current for filament heating to an X-ray tube having at least two filaments for emitting electrons. In, the filament voltage detected by the filament voltage detecting means for detecting the filament voltage applied to the filament of the X-ray tube,
The filament resistance is calculated based on the filament current detected by the filament current detecting means for detecting the filament current applied to the filament of the X-ray tube. Then, when the calculated resistance of the filament is larger than the preset reference value at the time of filament disconnection, a detection signal of the filament disconnection is generated, and is calculated from the preset reference value at the time of filament cup touch. If the resistance of the filament is smaller, a filament cup touch detection signal is generated, and when this detection signal is generated, the filament to be used is switched to a normal filament.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an X-ray high voltage device according to the present invention. In the present embodiment, an example will be described in which an X-ray tube including a small focus filament having a small X-ray focus and a large focus filament having a large X-ray focus is used.

As shown in FIG. 1, an X-ray high voltage apparatus 1 of this embodiment is an AC power supply 3, a rectifying / smoothing circuit 5 for converting an AC voltage supplied from the AC power supply 3 into a DC, and a rectifying / smoothing circuit 5. D that converts the DC voltage output from the
The C / DC converter 7, an inverter circuit 9 for converting the DC voltage converted by the DC / DC converter 7 into an AC voltage, and the AC voltage converted by the inverter circuit 9 are distributed to two filaments of the X-ray tube 11. The focus switching unit 13, the small focus filament transformer 15 and the large focus filament transformer 17 that transform the output voltage of the focus switching unit 13, the filament voltage detection unit 19 that detects the output voltage of the DC / DC converter 7, and the small It has a filament current detector 21 for detecting the primary current of the focus filament transformer 15 or the large-focus filament transformer 17, and a filament heating controller 23 for detecting filament disconnection and filament cup-touch of the X-ray tube 11.

The filament voltage detector 19 is composed of a voltage divider composed of two resistors 25 as shown in FIG. 2, for example. The filament current detector 21 is composed of a current transformer 27 as shown in FIG. 3, a rectifier circuit including four diodes 29 and one capacitor 31, for example. Neither the filament voltage detection unit 19 nor the filament current detection unit 21 directly detects the filament voltage and the filament current, but the winding ratio of the small-focus filament transformer 15 and the large-focus filament transformer 17 and the voltage divider. The filament voltage from the voltage division ratio, and the filament transformer for small focus 1
5, the filament current can be obtained from the winding ratio of the filament transformer 17 for large focus and the conversion ratio of the current transformer 27.

Next, the filament heating controller 23 is provided, and the filament disconnection detector 33 detects the filament disconnection and the filament cup touch of the X-ray tube 11.
An example of the configuration will be described with reference to FIG. As shown in FIG. 4, the filament breakage detection unit 33 includes a divider 35, two reference voltage setting devices 37 and 39, and two voltage comparators 41 and 4.
And 3.

The divider 35 is a filament voltage detector 1
9 and the output voltage IF of the filament current detection unit 21 are input, and the output voltage EF of the filament voltage detection unit 19 / the output voltage IF of the filament current detection unit 21 is input.
(EF / IF) is output. Therefore, the output of the divider 35 represents the magnitude of the resistance of the filament.

In the reference voltage setting unit 37, a voltage higher than the output voltage of the divider 35 in a normal state, for example, a voltage twice as high as that in a normal state is set. The voltage comparator 41 includes a divider 35.
Of the output voltage of the reference voltage setting device 37,
When the output voltage of the divider 35 is higher than the output voltage of the reference voltage setting unit 37, the filament disconnection detection signal F1 is output.

When the filament of the X-ray tube 11 is normal,
Since the output voltage of the divider 35 is lower than the output voltage of the reference voltage setting unit 37, the voltage comparator 41 does not output the filament disconnection detection signal F1. However, when the filament of the X-ray tube 11 is broken, the resistance of the filament becomes extremely large. Therefore, the voltage comparator 41 outputs the filament disconnection detection signal F1. In the reference voltage setting unit 39, a voltage lower than the output voltage of the divider 35 in the normal state, for example, 0.7 times the voltage in the normal state is set. Voltage comparator 43
Compares the output voltage of the divider 35 with the output voltage of the reference voltage setting unit 39, and when the output voltage of the divider 35 is lower than the output voltage of the reference voltage setting unit 39, outputs the filament cup touch detection signal F2. .

Next, a configuration example of the focus switching unit 13 will be described with reference to FIG. As shown in FIG. 5, the focus switching unit 13
Are OR gates 51 and 53, two D flip-flops 55 and 57, a NOR gate 59, and an AND gate 6
1 and inverters 63 and 65, and a power-on reset circuit 67.

The D flip-flops 55 and 57 have a power source O.
At the time of N, it is reset by the power-on reset circuit 67. Therefore, each output terminal Q becomes LOW level (hereinafter referred to as "L"). When the filament of the X-ray tube 11 is in a normal state, the filament disconnection detection signal F1 and the filament cup touch signal F2 are both "L", so that the output terminals Q of the D flip-flops 55 and 57 are both "L".

Therefore, the focus switching signal FC output from the control means (not shown) for setting the tube voltage, the tube current, the exposure time, etc. passes through the AND gate 61 and the OR gate 53, and the relay coils 13a, 13b for switching the focus.
Operate. When the focus switching signal FC is "L", the relay coils 13a and 13b bring the inverter circuit 9 and the filament transformer 17 for large focus into conduction. Further, when the focus switching signal FC is at a HIGH level (hereinafter referred to as "H"), the relay coils 13a and 13b bring the inverter circuit 9 and the small focus filament transformer 15 side into conduction.

Here, when a filament having a small focus is selected (when the focus switching signal FC is "H"), when the filament disconnection or the filament cup touch is detected, the output of the OR gate 51 is "H". Becomes Therefore, the output terminals Q of the D flip-flops 55 and 57 function to hold the input terminal D at that time. Therefore, the output terminal Q of the D flip-flop 55 is "H", and the output terminal Q of the D flip-flop 57 is inverted by the inverter 63 and becomes "L".

When the output terminal Q of the D flip-flop 55 becomes "H", the output of the NOR gate 59 becomes "L".
Then, the focus switching signal FC is blocked by the AND gate 61. On the other hand, since the output terminal Q of the D flip-flop 57 is "L", the output of the OR gate 53 is "L", and the relay coils 13a and 13b have the focus switching signal F.
The inverter circuit 9 and the large-focus filament transformer 17 are electrically connected regardless of C. The inverter 65 is OR
The output of the gate 53 is inverted, and the output of the OR gate 53 is amplified to operate the relay coils 13a and 13b.

When a filament having a large focal point is selected (when the focus switching signal FC is "L"), when a filament break or a filament cup touch is detected, the output terminal Q of the D flip-flop 55 becomes " The output terminal Q of the L "and D flip-flops 57 becomes" H ". Also in this case, the output of the NOR gate 59 becomes "L" and the focus switching signal FC is blocked by the AND gate 61. On the other hand, since the output of the OR gate 53 becomes "H",
The relay coils 13a and 13b electrically connect the inverter circuit 9 and the small focus filament transformer 15 regardless of the focus switching signal FC.

If a filament break or filament cup touch occurs while using the small focus and the focus is switched to the large focus, the resolution of the obtained image is reduced by the larger focus size, but the diagnosis should be continued. You can Also, when filament breakage or filament cup touch occurs when using the large focus, and when switching to the small focus, the tube current cannot supply the same large current as the large focus because the tube current has a small focus size. By extending the exposure time, it is possible to obtain an image similar to a large focus.

When the filament heating control section 23 outputs the filament disconnection detection signal F1 and the filament cup touch detection signal F2, the control means (not shown) receives them and uses sound, light, characters, graphic symbols and the like. The operator is informed of the abnormality of the X-ray tube 11.

As described above, in the X-ray high voltage apparatus 1 of this embodiment, the resistance of the filament is obtained from the output voltage EF of the filament voltage detecting section 19 and the output voltage IF of the filament current detecting section 21, and X is determined based on this. Detects filament breakage or filament cup touch of the wire tube 11,
When the filament of the wire tube 11 is normal, the focus is switched by the focus switching signal FC, and when the filament disconnection or the filament cup touch is detected, the focus is switched to the normal filament side regardless of the focus switching signal FC. Therefore, the filament disconnection or filament cup touch of the X-ray tube 11 can be accurately detected, and the diagnosis can be continued even if the filament disconnection or filament cup touch occurs.

In the X-ray high voltage apparatus 1 of this embodiment, D
One C / DC converter 7 and one inverter circuit 9 are provided, but the present invention is not limited to this, and as shown in FIG. 6, a DC / DC converter 7 and an inverter circuit are separately provided for small focus and large focus. 9 may be provided. In this case, the focus switching unit 13 becomes unnecessary, and the focus switching is performed by the filament heating control unit 23 or the control means (not shown) for setting the tube voltage, the tube current, the exposure time, etc., to output the output of the DC / DC converter 7. This is done by controlling the value.

Further, the focus switching unit 13 of the X-ray high voltage apparatus 1 of this embodiment is composed of a digital circuit, but the invention is not limited to this, and a computing means such as a CPU is used to form the filament of the X-ray tube 11. If the focus is normal, the focus switching signal F
The focus may be switched by C, and when a filament disconnection or a filament cup touch is detected, control may be performed such that the focus is switched to a normal filament side regardless of the focus switching signal FC. In this case, the output voltage EF of the filament voltage detection unit 19 and the output voltage IF of the filament current are converted into digital signals by an AD converter and then read by the arithmetic means.

Further, in the X-ray high voltage apparatus 1 of this embodiment, when the filament disconnection or the filament cup touch is detected, the focus switching signal FC is not used,
Although the focus is switched to the normal filament side, the focus is not limited to this and the operator may switch the focus of the X-ray tube 11 using a console (not shown).

Further, in the X-ray high voltage apparatus 1 of the present embodiment, the case where it is applied to the X-ray tube 11 having two filaments has been described as an example, but the present invention is not limited to this, and three or more filaments are provided. It can also be applied to X-ray tubes. Further, it can be applied to an X-ray tube having only one filament. In this case, since there is only one filament, when filament disconnection or filament cup touch is detected, only the operation of notifying the operator of the abnormality of the filament of the X-ray tube 11 by using sound, light, characters, graphic symbols, etc. However, since the above filaments can be known immediately after they are generated, the backup operation can be quickly performed.

[0031]

As described above, according to the present invention, the resistance of the filament is obtained from the filament current supplied to the filament of the X-ray tube and the filament voltage applied to the filament of the X-ray tube. Based on the resistance of the filament, it is possible to accurately detect the filament disconnection or the filament cup touch of the X-ray tube.

Further, when the present invention is applied to an X-ray tube having at least two filaments, the filament disconnection or filament cup touch of the X-ray tube can be accurately detected, so that the filament disconnection of the X-ray tube can be detected during diagnosis. Alternatively, when the filament cup touch is detected, the filament to be used can be switched to the normal filament.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an X-ray high voltage device according to the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a filament voltage detection unit.

FIG. 3 is a circuit diagram showing a configuration example of a filament current detection unit.

FIG. 4 is a circuit diagram showing a configuration example of a filament breakage detection unit.

FIG. 5 is a circuit diagram showing a configuration example of a focus switching unit.

FIG. 6: DC / DC separately for small focus and large focus
It is a block diagram which shows the X-ray high-voltage apparatus provided with the converter and the inverter circuit.

[Explanation of symbols]

 1 X-ray high-voltage device 3 AC power supply 5 Rectifying / smoothing circuit 7 DC / DC converter 9 Inverter circuit 11 X-ray tube 13 Focus switching section 13a, 13b Relay coil 15 Filament transformer for small focus 17 Filament transformer for large focus 19 Filament voltage detection Part 21 Filament current detection part 23 Filament heating control part 25 Resistance 27 Current transformer 29 Diode 31 Capacitor 33 Filament disconnection detection part 35 Divider 37,39 Reference voltage setting device 41,43 Voltage comparator 51,53 OR gate 55,57 D Flip-flop 59 NOR gate 61 AND gate 63, 65 Inverter 67 Power-on reset circuit

Claims (3)

[Claims] 1. A filament voltage detecting means for detecting a filament voltage applied to a filament of an X-ray tube for exposing X-rays, and a filament current detecting means for detecting a filament current supplied to the filament of the X-ray tube. A calculation means for calculating the resistance of the filament based on the filament voltage detected by the filament voltage detection means and the filament current detected by the filament current detection means; and a preset reference value when the filament is broken. When the filament resistance calculated by the calculating means is larger, a filament disconnection detection signal is generated, and the filament resistance calculated by the calculating means is larger than the preset reference value at the time of filament cup touch. If it is small, the filament cup touch detection signal X-ray high-voltage device having a comparison means for generating a signal. 2. An X-ray high voltage apparatus for supplying a high voltage for heating an electron and a current for heating a filament to an X-ray tube having at least two filaments for emitting electrons, which is applied to a filament of the X-ray tube. Filament voltage detecting means for detecting a filament voltage, a filament current detecting means for detecting a filament current supplied to the filament of the X-ray tube, a filament voltage detected by the filament voltage detecting means, and a filament current detecting means. Calculating means for calculating the resistance of the filament based on the filament current detected by the means, and if the resistance of the filament calculated by this calculating means is larger than a preset reference value when the filament is broken, Generates a detection signal and presets the filament X-ray high voltage device if the reference value at the cup touch smaller for resistance to computed filaments by said calculating means is characterized by having a comparing means for generating a detection signal of the filaments cup touch. 3. An X-ray high voltage apparatus for supplying a high voltage for electron heating and a current for filament heating to an X-ray tube having at least two filaments for emitting electrons, which is applied to the filament of said X-ray tube. Filament voltage detecting means for detecting a filament voltage, a filament current detecting means for detecting a filament current supplied to the filament of the X-ray tube, a filament voltage detected by the filament voltage detecting means, and a filament current detecting means. Calculating means for calculating the resistance of the filament based on the filament current detected by the means, and if the resistance of the filament calculated by this calculating means is larger than a preset reference value when the filament is broken, Generates a detection signal and presets the filament When the resistance of the filament calculated by the calculating means is smaller than the reference value at the time of cup touch, the comparing means generates a detection signal of the filament cup touch, and when the detecting signal is generated by the comparing means, it is used. An X-ray high-voltage device having a switching means for switching a filament to a normal filament.