X-ray transfer apparatus and method for controlling same

Abstract

The invention provides an X-ray fluoroscopy device and a control method thereof, which are not easily influenced by changes of the surrounding environment and can display a display image with a desired brightness from the start of fluoroscopy. A current for heating a filament is supplied to the filament of the X-ray tube. A tube voltage pulse is applied between the filament and the anode at a set pulse rate. A tube current detector measures a tube current flowing between the filament and the anode after starting applying a tube voltage pulse. On the basis of the value of the tube current measured by the tube current detector, the pulse width control unit finds the time at which the tube current time product during the period in which the tube voltage pulse is applied reaches a preset value. The application of the tube voltage is cut off at the determined timing. As a result, the pulse width of the tube voltage pulse is adjusted for each pulse.

Description

Technical Field

[0001] The present invention relates to an X-ray fluoroscopy apparatus. Background Art

[0002] As one of the methods for fluoroscopic imaging by an X-ray fluoroscopy apparatus, pulsed fluoroscopy is known. In pulsed fluoroscopy, pulsed X-rays are irradiated onto a subject, and the X-rays transmitted through the subject are detected by an X-ray detector, and an image is generated and displayed in real time on a display device. A dynamic X-ray image is displayed by repeating this process at a frequency of 4 to 30 fps (frames per second). The pulsed X-rays are irradiated with a preset tube voltage, tube current, and pulse width. When adjusting the brightness of the image, the tube voltage condition, tube current condition, or pulse width condition (pulse width of about 5 to 20 ms) is changed automatically or manually.

[0003] Patent Document 1 discloses the following: During a specified period from the start of fluoroscopy until the temperature of the filament reaches the temperature in the normal fluoroscopy state, the pulse width of the tube voltage is set to a specified pulse width wider than that in the normal fluoroscopy state.

[0004] Patent Document 1: Japanese Patent Laid-Open No. 2009-289579

[0005] Regarding the tube voltage of the X-ray fluoroscopy apparatus, real-time feedback processing can be performed at high speed, and a required constant tube voltage can be output from the start of fluoroscopy. On the other hand, the tube current depends on the temperature of the filament of the X-ray tube, and in order to make the tube current constant, feedback control of the filament current for heating the filament is required.

[0006] However, the response speed of the filament temperature is as slow as 10 ms or more. And at the start of fluoroscopy, the filament temperature gradually rises. Therefore, feedback control of the tube current of the pulsed X-rays cannot be performed at high speed. This causes poor images at the start of fluoroscopy or a phenomenon of perspective shaking where the brightness fluctuates even when automatic brightness adjustment is performed.

[0007] In the technique of Patent Document 1, since the pulse width of the tube voltage is set to a constant width during a constant time at the start of fluoroscopy, it is necessary to preset this time or the pulse width. The time required for the rise of the filament temperature at the start of transmission or the rise curve varies depending on the environment such as the surrounding temperature, and therefore the technique of Patent Document 1 cannot cope with changes in the surrounding environment. Summary of the Invention

[0008] An object of the present invention is to provide an X-ray fluoroscopy apparatus that is less affected by changes in the surrounding environment and can display a desired brightness of a displayed image from the start of fluoroscopy.

[0009] To achieve the above object, the X-ray fluoroscopy apparatus of the present invention includes: an X-ray tube including a filament as a cathode and an anode; a filament heater that supplies a current for heating the filament; a tube voltage control unit that applies a tube voltage pulse between the filament and the anode at a set pulse rate; a tube current detector; and a pulse width control unit. The tube current detector measures the tube current flowing between the filament and the anode after starting to apply a tube voltage pulse. The pulse width control unit calculates the cut-off time of the tube voltage pulse for making the tube current-time product during the application of the tube voltage pulse reach a preset value based on the value of the tube current measured by the tube current detector, and instructs the tube voltage control unit to cut off the application of the tube voltage at the calculated cut-off time, thereby adjusting the pulse width of the tube voltage pulse for each pulse.

[0010] Advantages of the Invention

[0011] According to the present invention, for each X-ray pulse irradiated, the tube current is measured and the pulse width is adjusted. Therefore, it is not affected by changes in the surrounding environment, and an X-ray fluoroscopy image with a desired brightness can be displayed from the start of fluoroscopy. Description of the Drawings

[0012] Figure 1 It is a block diagram showing the structure of the X-ray fluoroscopy apparatus according to Embodiment 1 of the present invention.

[0013] Figure 2 (a) to (f) are diagrams respectively showing examples of the switching times of the average tube current, filament current, filament temperature, tube current, tube voltage, and cumulative time and reading time of the X-ray detector, which are the targets of Embodiment 1.

[0014] Figure 3 It is a flowchart for explaining the operation of the X-ray fluoroscopy apparatus according to Embodiment 1.

[0015] Figure 4 It is a block diagram showing the structure of the X-ray fluoroscopy apparatus according to Embodiment 2.

[0016] Figure 5 It is a flowchart for explaining the operation of the X-ray fluoroscopy apparatus according to Embodiment 2.

[0017] Figure 6 It is a block diagram showing the structure of the X-ray fluoroscopy apparatus according to Embodiment 3.

[0018] Figure 7 (a) to (e) are diagrams respectively showing examples of the average tube current, filament current, filament temperature, tube current, and tube voltage, which are the targets of Embodiment 3.

[0019] Figure 8 It is a flowchart for explaining the operation of the X-ray fluoroscopy apparatus according to Embodiment 3.

[0020] Symbol Explanation

[0021] 101 - Subject, 102 - Tube voltage control unit, 103 - X-ray tube, 103a - Container, 104 - X-ray detector, 106 - Tube current detector, 107 - Filament heater, 109 - Pulse width control unit, 110 - Comparator, 111 - Accumulator, 112 - Control unit, 113 - Anode, 114 - Filament, 115 - Image processing unit, 116 - Display, 117 - Input unit, 132 - Filament control unit, 210 - Arithmetic unit. Detailed Embodiment

[0022] Hereinafter, the X-ray fluoroscopy apparatus according to the embodiment of the present invention will be described with reference to the accompanying drawings.

[0023] The X-ray transmission apparatus according to this embodiment detects the tube current immediately after the start of irradiation for each X-ray pulse irradiated, determines the cut-off time point (pulse width) of the tube voltage pulse that makes the tube current-time product reach a preset value, and cuts off the tube voltage when the cut-off time point is reached. Thus, even during the period from when the filament temperature is in a lower state to when it reaches the target temperature immediately after the start of fluoroscopy, the tube current-time product of each irradiated X-ray pulse can be kept constant.

[0024] When the tube voltage is constant, the tube current-time product roughly corresponds to the time product of the X-ray dose irradiated from the X-ray tube. In pulsed fluoroscopy, the X-rays that reach the X-ray detector with one pulse of X-rays are accumulated and detected and used for generating an image of one frame. Therefore, if the tube current-time product of each pulse is constant, the image brightness can be kept constant and the brightness of the X-ray image can be stabilized.

[0025] Hereinafter, a specific description will be given.

[0026] <<Embodiment 1>>

[0027] Use Figures 1 to 3 The X-ray fluoroscopy apparatus according to Embodiment 1 will be described.

[0028] Figure 1 is a block diagram showing the structure of the X-ray fluoroscopy apparatus according to Embodiment 1. Figure 2 (a) to (f) respectively represent the switching times of the target average tube current, filament current, filament temperature, tube current, tube voltage, and the cumulative time and read time of the X-ray detector. Figure 3 is a flowchart for explaining the operation of the X-ray fluoroscopy apparatus.

[0029] As Figure 1As shown, the X-ray fluoroscopy apparatus is configured to include an X-ray tube 103, an X-ray detector 104, a filament heater 107, a tube voltage control unit 102, a tube current detector 106, a pulse width control unit 109, a control unit 112, an image processing unit 115, a display 116, and an input unit 117.

[0030] The X-ray tube 103 has a structure in which a filament 114 as a cathode and an anode 113 are enclosed in a container 103a. In the container 103a, the region through which the X-rays emitted from the anode 113 pass is made of a material that transmits X-rays. And although not shown, a drive unit for rotating the anode 113 is connected to the anode 113.

[0031] The filament heater 107 is connected to both ends of the filament 114, and the filament heater 107 supplies current to the filament 114 and heats it. Thermoelectrons are released from the heated filament 114.

[0032] The tube voltage control unit 102 applies a tube voltage pulse between the filament 114 and the anode 113 at a set pulse rate. Thereby, the thermoelectrons released from the filament reach the anode 113, and X-rays are released from the anode 113. The released X-rays irradiate the subject 101 disposed between the X-ray detector 104 and the X-ray tube 103. The X-rays passing through the subject 101 are detected by the X-ray detector 104.

[0033] The timing at which the tube voltage control unit 102 starts applying the tube voltage pulse (the rising time of the tube voltage pulse) and the timing at which it ends applying the tube voltage pulse (the falling of the tube voltage pulse) are indicated by respectively outputting timer signals Ton and Toff from the pulse width control unit 109 to the tube voltage control unit 102. The tube voltage control unit 102 applies the tube voltage pulse by starting and cutting off the application of the tube voltage pulse according to this timer signal.

[0034] In this way, a tube voltage pulse is applied between the filament 114 and the anode 113, and thermoelectrons reach the anode 113 from the filament 114, whereby a tube current flows between the anode 113 and the filament 114. A tube current detector 106 is disposed in the wiring between the filament 114 and the tube voltage control unit 102, and the tube current is detected. The tube current detector 106 can be of any structure, but for example, a structure that detects the tube current by detecting the magnetic field formed by the tube current flowing in the wiring can be used. The tube current detector 106 can also be disposed in the wiring between the anode 113 and the tube voltage control unit 102.

[0035] The pulse width control unit 109 is configured to include an integrator 111 and a comparator 110. The comparator 110 outputs a timer signal Ton indicating the start of applying a tube voltage pulse to the tube voltage control unit 102 at a pulse rate set by the control unit 112. When the comparator 110 outputs the start-applying timer signal Ton, the integrator 111 integrates the tube current measured by the tube current detector 106 and calculates the tube current-time product (mAs / Frame). The comparator 110 determines whether the value of the tube current-time product calculated by the integrator 111 has reached the target tube current-time product value received from the control unit 112. If it has reached, the comparator 110 outputs a timer signal Toff indicating the end of the application of the tube voltage pulse.

[0036] The input unit 117 receives input of desired fluoroscopy conditions (target tube voltage value, target average tube current value (reference Figure 2 (a)), pulse rate) from the user.

[0037] The X-ray detector 104 includes a plurality of two-dimensionally arranged X-ray detection elements and a reading circuit. The X-ray detection elements detect the incident X-rays and convert them into detection signals. The reading circuit is a circuit for reading the detection signals of the X-ray detection elements. For example, a flat panel detector (FPD) can be used as the X-ray detector 104.

[0038] In the X-ray detector 104, as Figure 2 shown in (f), a reading time and a detection integration time are preset within one cycle of the pulse rate. For example, the reading time is a preset constant time, and the remaining time of one cycle of the pulse rate is set as the integration time. The X-ray detection elements integrate and detect the incident X-rays during the integration time and convert them into detection signals. The reading circuit reads the detection signals integrated and detected during the integration time within the reading time of the same cycle as the integration time and outputs them to the image processing unit 115.

[0039] The image processing unit 115 receives the detection signals integrated and detected by the X-ray detection elements within one cycle of the pulse rate from the reading circuit, generates one X-ray image, and displays it on the display 116. Thus, one X-ray image is displayed on the display 116 for each cycle of the pulse rate. By repeating this operation at a frequency of the pulse rate (e.g., 4 to 30 fps), an X-ray image of a dynamic image is displayed.

[0040] In the control unit 112, the target tube voltage value (kV), the target average tube current value (mA), and the pulse rate (fps) are received from the input unit 117, and the target tube voltage value is set in the tube voltage control unit 102. Further, the control unit 112 sets a preset filament current value in the filament heater 107. Moreover, the control unit 112 calculates the value of the tube current-time product as the target based on the target average tube current value and the pulse rate. The control unit 112 sets the calculated tube current-time product and the pulse rate in the comparator 110 of the pulse width control unit 109.

[0041] Furthermore, the image processing unit 115 may be configured to have a known automatic adjustment function that obtains the target tube voltage value, the target average tube current value, and the pulse rate based on the luminance value of the generated X-ray image by a preset mathematical formula or the like. When the automatic adjustment function is enabled, the control unit 112 is configured to receive the target tube voltage value, the target average tube current value, and the pulse rate from the image processing unit 115.

[0042] Hereinafter, Figure 3 the operation of the X-ray fluoroscopy apparatus according to the present embodiment will be described using

[0043] <Step S11>

[0044] If the control unit 112 receives an instruction to start fluoroscopy from the input unit 117, the control unit 112 receives the target tube voltage value (kV), the target average tube current value (mA) (see Figure 2 (a)), and the pulse rate (fps) from the input unit 117 or the image processing unit 115.

[0045] <Step S12>

[0046] The control unit 112 outputs the target tube voltage value (kV) to the tube voltage control unit 102 and sets it.

[0047] <Step S13>

[0048] The control unit 112 obtains the filament current value (If) based on the target tube voltage value (kV) and the target average tube current value (mA), referring to a preset table or calculation formula, and outputs it to the filament heater 107. The filament heater 107 supplies the current of the filament current value (If) received from the control unit 112 to the filament 114 and starts heating ( Figure 2 (b)).

[0049] The temperature of the filament 114 gradually rises from the time point when the filament current starts (see Figure 2 (c)). The filament 114 emits thermoelectrons from the time point when the filament current starts to be supplied, but the amount of thermoelectrons emitted depends on the filament temperature.

[0050] <Step S14>

[0051] The control unit 112 calculates the value of the tube current time product (mAs / Frame) as the target based on the target average tube current value and the pulse rate. The tube current time product as the target is output to the pulse width control unit 109 together with the pulse rate for setting.

[0052] <Step S15>

[0053] The pulse width control unit 109 outputs the timer signal Ton to the tube voltage control unit 102. The tube voltage control unit 102 starts applying the tube voltage at the moment when the timer signal Ton is received (refer to Figure 2 (e)).

[0054] As a result, the thermoelectrons of the filament 114 reach the anode 113, and the tube current flows between the anode 113 and the filament 114 ( Figure 2 (d)). And X-rays are emitted from the anode 113.

[0055] <Step S16>

[0056] The tube current detector 106 detects the tube current (mA) flowing in the wiring between the filament 114 and the tube voltage control unit 102, and outputs it to the accumulator 111 of the pulse width control unit 109.

[0057] <Step S17>

[0058] The accumulator 111 of the pulse width control unit 109 calculates the tube current time product by accumulating the tube current received from the tube current detector 106. When the tube current time product calculated by the accumulator 111 reaches the tube current time product (mAs / Frame) as the target set by the control unit 112, the comparator 110 outputs the timer signal Toff to the tube voltage control unit 102 and instructs to instantaneously cut off the tube voltage.

[0059] However, before the tube current time product calculated by the accumulator 111 reaches the tube current time product (mAs / Frame) as the target set by the control unit 112, when it becomes the end time of the cumulative time of the X-ray detector 104 within one cycle, at this time point, the comparator 110 outputs the timer signal Toff to the tube voltage control unit 102 ( Figure 2 (f)).

[0060] The tube voltage control unit 102 cuts off the tube voltage at the moment when the timer signal Toff is received, and ends the application of one tube voltage pulse ( Figure 2 (e)).

[0061] <Step S18>

[0062] After the cumulative time within one cycle of the X-ray detector 104 ends, during the read time, the detection signal of the X-ray detection element is read and output to the image processing unit 115 ( Figure 2 (f)). The image processing unit 115 generates an X-ray image for one frame and displays it on the display 116.

[0063] The control unit 112 returns to step S14 at the start of the next cycle of the pulse rate. When the condition of the target average tube current value is changed, the tube current-time product as the target is changed, and the application of the tube voltage pulse for the next cycle is started. Until an instruction to end fluoroscopy is input from the input unit 117, steps S14 to S18 are repeated.

[0064] Each time it is repeated, the pulse width of the tube voltage pulse is controlled so that the tube current-time product reaches the target tube current-time product. Therefore, the brightness of the image generated in step S18 can be kept constant.

[0065] Thus, even when the temperature rise curve of the filament 114 changes due to environmental changes such as the surrounding temperature, a display image with the desired brightness can be displayed from the start of fluoroscopy.

[0066] <<Embodiment 2>>

[0067] Use Figures 4 to 5 The X-ray fluoroscopy apparatus according to Embodiment 2 will be described.

[0068] Figure 4 is a block diagram showing the structure of the X-ray fluoroscopy apparatus according to Embodiment 2. Figure 5 is a flow chart for explaining the operation of the X-ray fluoroscopy apparatus.

[0069] Regarding the X-ray fluoroscopy apparatus according to Embodiment 2, the structure of the pulse width control unit 109 is different from that of the X-ray fluoroscopy apparatus according to Embodiment 1. Since other structures are the same as those in Embodiment 1, the description thereof is omitted.

[0070] The pulse width control unit 109 according to Embodiment 2 includes an arithmetic unit 210. The arithmetic unit 210 calculates the cut-off time of the tube voltage pulse based on the tube current measured by the tube current detector 106 immediately after the application of the tube voltage pulse starts. Specifically, the arithmetic unit 210 divides the target tube current-time product received by the control unit 112 by the tube current detected by the tube current detector 106, and calculates the time (pulse width) required to reach the target tube current-time product. The arithmetic unit 210 outputs a timer signal Toff to the tube voltage control unit 102 to cut off the tube voltage pulse at the calculated time.

[0071] Use Figure 5The operation of the X-ray fluoroscopy apparatus according to Embodiment 2 will be described.

[0072] <Steps S11 to S15>

[0073] Steps S11 to S15 are performed in the same manner as Steps S11 to S15 of Embodiment 1. As a result, the pulse width control unit 109 outputs a timer signal Ton to the tube voltage control unit 102, and the tube voltage control unit 102 starts applying the tube voltage at the moment when the timer signal Ton is received.

[0074] <Step S21>

[0075] The tube current detector 106 measures the tube current (mA) flowing in the wiring between the filament 114 and the tube voltage control unit 102 and outputs it to the pulse width control unit 109. The arithmetic unit 210 of the pulse width control unit 109 divides the target tube current time product received from the control unit 112 in Step S14 by the tube current detected by the tube current detector 106 and calculates the time (pulse width) to reach the target tube current time product.

[0076] <Step S22>

[0077] The arithmetic unit 210 of the pulse width control unit 109 outputs a timer signal Toff to the tube voltage control unit 102. The timer signal Toff indicates that the tube voltage is to be cut off at the time point that becomes the pulse width obtained in Step S21 from the time point when the tube voltage pulse starts to be applied by outputting the timer signal Ton in Step S15.

[0078] However, when the pulse width calculated by the arithmetic unit 210 in Step S21 is greater than the integration time of the X-ray detector 104, a timer signal Toff indicating that the tube voltage is to be cut off at the end of the integration time is output to the tube voltage control unit 102.

[0079] The tube voltage control unit 102 cuts off the tube voltage at the time indicated by the timer signal Toff, and ends the application of one tube voltage pulse. As a result, the time product of the tube current flowing in the X-ray tube 103 can be adjusted to the target tube current time product.

[0080] <Step S18>

[0081] The X-ray detector 104 reads the detection signal of the X-ray detection element during the reading time and outputs it to the image processing unit 115. The image processing unit 115 generates one frame of X-ray image and displays it on the display 116.

[0082] The control unit 112 returns to Step S14 at the start of the next cycle of the pulse rate and repeats Steps S14 to S18.

[0083] Each time it repeats, the pulse width of the tube voltage pulse is controlled so that the tube current time product reaches the target tube current time product, and thus the brightness of the image generated in step S18 can be kept constant.

[0084] The X-ray fluoroscope of Embodiment 2 calculates the pulse width by calculation, and thus has the advantage that the structure of the pulse width control unit 109 can be simplified compared with the X-ray fluoroscope of Embodiment 1. Other effects are the same as those of Embodiment 1.

[0085] <<Embodiment 3>>

[0086] Use Figures 6 to 8 The X-ray fluoroscope of Embodiment 3 will be described.

[0087] Figure 6 is a block diagram showing the structure of the X-ray fluoroscope of Embodiment 3. Figure 7 (a) to (d) respectively represent the target average tube current, filament current, filament temperature, tube current, and tube voltage. Figure 8 is a flow chart explaining the operation of the X-ray fluoroscope.

[0088] In the X-ray fluoroscope of Embodiment 1, as Figure 2 shown in (a) and (b), the structure is as follows: Even when the user or the image processing unit 115 changes the target average tube current value, the filament current is set to a preset constant current value. In the X-ray fluoroscope of Embodiment 3, the filament current value is also controlled according to the target average tube current value set by the user. Thereby, while keeping the tube current time product constant, the pulse width of the tube voltage pulse can be kept substantially constant, and thus the operation can be performed in a wider range of X-ray conditions. However, due to the rise time of the tube voltage or control delay, etc., it is difficult to perform stable control at a pulse width below a certain level, so it needs to be set to a pulse width above a specified value. And the pulse width needs to be set to exceed Figure 2 the pulse width of the cumulative time shown in (f).

[0089] Therefore, the device structure of the X-ray fluoroscope of Embodiment 3 is the same as that of the Figure 1 X-ray fluoroscope of Embodiment 1, but a filament control unit 132 for controlling the filament heater 107 is provided in the control unit 112. In this regard, the device of Embodiment 3 is different from that of Embodiment 1.

[0090] The filament control unit 132 receives the target average tube current value from the connected input unit 117 or the image processing unit 115, determines the filament current value to be supplied to the filament 114 based on the received target average tube current value, and outputs it to the filament heater 107.

[0091] Thereby, as Figure 7 shown in (b), the filament current value is changed.

[0092] Hereinafter, the operation of the X-ray fluoroscopy apparatus according to the third embodiment will be described using Figure 8 the following procedure.

[0093] <Step S11 - S12>

[0094] In steps S11 - S12, in the same manner as in the first embodiment, the control unit 112 receives the target tube voltage value (kV), the target average tube current value (mA) (refer to Figure 7 (a)), and the pulse rate (fps), and outputs the target tube voltage value (kV) to the tube voltage control unit 102 for setting.

[0095] <Step S31>

[0096] The control unit 112 obtains the filament current value (If) based on the target tube voltage value and the target average tube current value (mA) received in step S11, referring to a preset table or calculation formula, and outputs it to the filament heater 107. The filament heater 107 supplies the current of the filament current value (If) received from the control unit 112 to the filament 114 and starts heating ( Figure 7 (b)).

[0097] <Steps S14 - S18>

[0098] In the X-ray fluoroscopy apparatus according to the third embodiment, steps S14 - S18 are performed in the same manner as steps S14 - S18 in the first embodiment.

[0099] In the third embodiment, after step S18 ends, the control unit 112 returns to step S31 and repeats steps S31, S14 - S18. In step S31, when the condition of the target average tube current value is changed, the filament current value is changed.

[0100] Thereby, even when the temperature rise curve of the filament 114 changes due to environmental changes such as the surrounding temperature, a display image with the desired brightness can be displayed from the start of fluoroscopy.

Claims

1. An X-ray fluoroscopy device, characterized in that: The invention comprises: an X-ray tube including a filament as a cathode and an anode; a filament heater for supplying a current for heating the filament; a tube voltage control unit for applying a tube voltage pulse between the filament and the anode at a set pulse rate; a tube current detector; and a pulse width control unit. The tube current detector measures the tube current flowing between the filament and the anode after the tube voltage pulse starts to be applied. The pulse width control unit determines a cut-off timing of the tube voltage pulse so that the tube current-time product during application of the tube voltage pulse reaches a preset value based on the value of the tube current measured by the tube current detector, and instructs the tube voltage control unit to cut off the application of the tube voltage at the determined cut-off timing, thereby adjusting the pulse width of the tube voltage pulse for each pulse.

2. The X-ray transmission device according to claim 1, characterized in that: The pulse width control unit includes an accumulator, The integrator calculates the time product of the tube current measured by the tube current detector according to the time when the tube voltage control unit starts applying one tube voltage pulse. The pulse width control unit instructs the tube voltage control unit to cut off application of the tube voltage when the time product of the tube current reaches the preset value.

3. The X-ray fluoroscopy device according to claim 1, characterized in that: The pulse width control unit obtains a cutoff timing of the tube voltage pulse by calculation based on the tube current measured by the tube current detector, and instructs the tube voltage control unit to cut off application of the tube voltage at the obtained cutoff timing.

4. The X-ray fluoroscopy device according to claim 1, characterized in that: It also has an X-ray detector and an image processing unit. The X-ray detector comprises: an X-ray detection element for detecting X-rays emitted from the X-ray tube and passing through the subject and converting the detected X-rays into detection signals; and a reading circuit for reading the detection signals of the X-ray detection element. In the X-ray detector, the detection accumulation time and the reading time are preset within the pulse rate cycle. The X-ray detection element accumulates and detects the X-rays reaching the detection element within the accumulation time and converts the X-rays into the detection signal. The reading circuit reads the detection signal accumulated and detected within the accumulation time within the reading time, and outputs the detection signal to the image processing unit. When the integrated time ends before the cut-off time, the pulse width control unit instructs the tube voltage control unit to cut off the application of the tube voltage at the time when the integrated time ends.

5. The X-ray fluoroscopy device according to claim 1, characterized in that: It also includes a filament control unit for controlling the filament heater. The filament control unit receives a target tube current value from a connected input unit or an image processing unit, determines a filament current value supplied to the filament according to the received target tube current value, and outputs the filament current value to the filament heater. The filament heater supplies the filament current of the filament current value received from the control unit to the filament.

6. A control method for an X-ray fluoroscopy device, the X-ray fluoroscopy device comprising an X-ray tube including a filament as a cathode and an anode and a filament heater for supplying a current for heating the filament, wherein pulse fluoroscopy is performed by applying a tube voltage pulse between the filament and the anode at a set pulse rate, wherein: After the application of a tube voltage pulse is started, the tube current flowing between the filament and the anode is measured, Based on the measured value of the tube current, a cut-off timing of the tube voltage pulse is determined so that the tube current-time product during the application of the tube voltage pulse reaches a preset value, and the pulse width of the tube voltage pulse is adjusted for each pulse by cutting off the application of the tube voltage at the determined cut-off timing.

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