JPH0112400Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tube current time product display circuit for an X-ray control device.

The tube current time product display circuit of the X-ray control device is a circuit that integrates the tube current flowing between the anode and cathode of the X-ray tube by the time the tube current flows, and displays the integrated value. In reality, conventional tube current time product display circuits convert tube current into voltage, then integrate it over time using a Miller integration circuit, and simply display the integrated output using a meter or the like. Although this allows the time-integrated value of the tube current that actually flows to be displayed on a meter or the like, it has various problems.

That is, in the tube current time product display circuit of the conventional X-ray control device as described above, in consideration of continuous imaging, the charge stored in the mirror integration circuit is discharged immediately after the X-ray radiation signal disappears. I need to prepare for the next shoot. Otherwise, the time-integrated value of the tube current from the next imaging will be integrated in the mirror integration circuit, making it impossible to accurately display the integrated value of the tube current for each X-ray imaging. Therefore,
The tube current time product display circuit of the conventional X-ray control device is
As soon as the X-ray radiation signal disappears after the imaging is completed, the display of the tube current integral value is reset, which has the disadvantage that it is difficult to confirm the value after the imaging is completed. In particular, in rapid photography, the X-ray radiation signal disappears almost as soon as the photography ends, so the above-mentioned drawbacks are likely to occur.Furthermore, in the case of continuous photography, the output of the mirror integration circuit is used as the meter needle for displaying the tube current integral value. cannot follow due to mechanical inertia,
Another disadvantage was that the needle oscillated in the intermediate display scale range between the peak value and zero.

The present invention was devised in view of the shortcomings of the conventional tube current time product display circuit of the X-ray control device. The purpose is to provide a product display circuit.

The tube current time product display circuit of the present invention is as follows. That is, the integrating circuit integrates the tube current of the X-ray tube, which has been converted into a voltage signal, only during the output period of the X-ray radiation signal instructed by the control circuit, and the obtained integrated signal is sent to the first sample-and-hold circuit. output to the input terminal of This integrating circuit is immediately reset by a command from the control circuit after the output period of the X-ray radiation signal has elapsed.

The above-mentioned sample-and-hold circuit is such that when a high-level signal (first signal) is input to the second input terminal, the sample mode is set, and the second input terminal is set to the sample mode.
The hold mode is set when, for example, a low level signal (second signal) is input to the input terminal of the sample mode.
In the hold mode, the signal that has already been input to the first input terminal in the sample mode is held and output. In this device, the sample-and-hold circuit is set to sample mode during the period in which the X-ray radiation signal is output by the function of the control circuit, takes in the output of the integrating circuit during this period, and outputs it to the display circuit. . In addition, after the X-ray radiation signal disappears, the control circuit operates to set the camera to hold mode for a certain period of time, and during this period, the integrated value of the tube current at the time of the previous image taken in the sample mode is retained. Output. Further, after the above-mentioned fixed period has elapsed, the control circuit immediately sets the sample mode to prepare for the next photographing. moreover,
In continuous shooting with quick shooting intervals, if the next shooting is started before the above-mentioned fixed period has elapsed, the control circuit will set the sample mode at the same time as shooting starts, and the output of the integrating circuit will be taken in.
Output to the display circuit.

As described above, the control circuit that controls the integrating circuit and the sample and hold circuit is as follows. That is, the integration circuit is instructed to perform integration only while the X-ray radiation signal is being output, and immediately after the X-ray radiation signal disappears, the integration circuit is instructed to reset. In addition, for the sample and hold circuit, the above-mentioned high level signal (the first signal ) to set the sample mode, and then output the
The low level signal (second signal) is output to the second input terminal of the sample hold circuit until the radiation signal is output, whichever is earlier, and the hold mode is set. be.

According to this invention, during general photography, the sample and hold circuit is set to hold mode for a certain period of time after the end of photography, so that the previous tube current integral value is displayed for a certain period of time after the end of photography. . In addition, during continuous shooting, the sample hold circuit is set to hold mode after the end of shooting until before the start of the next shot, so the previous tube current integral value is displayed after the end of shooting until the start of the next shot. .

Hereinafter, the present invention will be further described in detail with reference to embodiments shown in the accompanying drawings.

The attached drawing shows an embodiment of a tube current time product display circuit for an X-ray control device according to the present invention.
First, normal general shooting (not continuous shooting) will be explained. In the accompanying drawings, a tube current flows through resistors R1 and R2 connected between terminals N and NE of a high-voltage neutral circuit (not shown) of an X-ray apparatus, and the tube current is converted into a voltage signal. When an X-ray radiation signal XS indicating that imaging is in progress is being output, current flows through the relay coil L, so that the relay a contact La is closed. Therefore, the above voltage signal is applied to relay A contact La and variable resistor VR1.
The signal is inputted to the Miller integration circuit 1 via. Since the voltage signal is input to the Miller integration circuit 1 only during the output of the X-ray radiation signal XS, the Miller integration circuit 1 executes time integration based on the voltage signal proportional to the tube current during that time. The output of the Miller integration circuit 1 is input to a sample and hold IC 2.
Here, when a high level signal is input to the sample and hold IC2 at its terminal T2,
When the sample mode is set to capture the signal input to terminal T1 and output it as is, and a low level signal is input to terminal T2,
It is configured to be set to a hold mode in which a signal that has already been taken in is held and output during the sample mode. In this embodiment, a high-level signal is input to the terminal T2 when either the photocoupler PC1 or PC2 is on.

While the X-ray radiation signal XS is being output, the photocoupler PC1 is in the on state, so a high level signal is input to the terminal T2 of the sample and hold IC2, and the sample and hold IC2 is set to sample mode. . Therefore, the output signal of the Miller integration circuit 1 is taken into the sample and hold IC 2 via the terminal 1 and output.
The output of the sample and hold IC2 is input to the display circuit 3 via the resistor 6 and variable resistor VR2, and the integrated value of the tube current is displayed on the display circuit 3.

When the imaging is finished and the X-ray radiation signal XS disappears,
Miller integrating circuit 1 is reset as follows.
That is, since no current flows through the coil L, the relay B contact Lb in the Miller integrating circuit 1 is closed,
The charge accumulated in the capacitor C1 is discharged via the resistor R3 and the relay b contact Lb. As a result, the Miller integration circuit 1 is reset. At the same time as the Miller integration circuit 1 is reset, the X-ray radiation signal
Due to the disappearance of XS, the photocoupler PC1 is turned off. Therefore, the sample hold IC
A low level signal is input to terminal T2 of 2,
The sample and hold IC2 is set to sample mode. Therefore, after the photographing is completed, the sample and hold IC 2 holds and outputs the output of the mirror integrating circuit 1 that was taken in during the previous photographing, regardless of whether the mirror integrating circuit 1 is reset. Therefore, even if the mirror integration circuit 1 is reset after photographing is completed, the display circuit 3 does not immediately set the display to zero, but instead displays the integrated value of the tube current at the time of the previous photograph.

On the other hand, when imaging ends and the X-ray radiation signal XS disappears, the transistor Tr1 is turned off and charging of the capacitor C2 is started via the resistors R4 and R5. When the positive potential of the capacitor C2 reaches the Zener voltage of the Zener diode ZD, the transistor Tr2 is turned on. As a result, the photocoupler PC2 is turned on, and a high level signal is again input to the terminal T2 of the sample and hold IC2. Therefore, for sample hold
IC2 is set to sample mode again.
Thereafter, the sample and hold IC2 becomes ready to capture the signal input to the terminal T1 in preparation for the next photographing, and at this time, the Miller integration circuit 1 has already been reset to zero output as described above. , the display of the display circuit 3 is also reset to zero. Therefore, according to this embodiment, the time period from when the X-ray radiation signal XS disappears until the charging voltage of the capacitor C2 reaches a constant value (the Zener voltage of the Zener diode ZD) is used for sample and hold purposes.
The previous integral value of the X-ray tube current is held and output in the IC2, and during this time the previous integral value of the X-ray tube current is displayed on the display circuit 3 via the resistor R6 and the variable resistor VR2. Furthermore, this display time can be arbitrarily determined based on the capacitance of the capacitor C2, the resistance values of the resistors R4 and R5, etc.

Next, the operation in continuous shooting will be explained. In the case of continuous imaging, the next imaging is executed after the previous imaging is completed and the X-ray radiation signal disappears, but before the photocoupler PC2 is turned on. In this case, the X-ray radiation signal associated with the next imaging
At the same time that XS is output, the photocoupler PC1 is turned on, and a high level signal is input to the terminal T2 of the sample and hold IC2. Therefore, the sample-and-hold IC2 switches to the sample mode, and the output of the Miller integration circuit 1, which is input to the terminal T1 of the sample-and-hold IC2, is taken into the sample-and-hold IC2 and output. Here, as described above, the capacitor C1 in the mirror integrating circuit 1 is discharged every time the photographing is completed.
Since the mirror integration circuit 1 is reset each time a photograph is completed, the display of the display circuit 3 is reset to zero once and then displays the integrated value of the tube current for the next photograph.

Therefore, in the case of continuous shooting, due to the action of photocoupler PC1, at the timing of starting shooting,
The sample and hold IC2 is switched from the hold mode to the hold mode. As a result, the sample and hold IC2 takes in the output of the Miller integration circuit 1 and displays it on the display circuit 3 via the resistor R6 and the variable resistor VR2. In this case, as described above, since the mirror integration circuit 1 is reset each time a photograph is completed, the previous integral value is not integrated into the current integral value. Therefore, even in continuous imaging, an accurate tube current integral value can be displayed for each imaging.

As is clear from the above description, the tube current time product display circuit of the present invention uses an integrating circuit that is kept in a reset state during periods other than the X-ray radiation period to generate a voltage signal proportional to the tube current of the X-ray tube. Time-integrate over the X-ray radiation period, and calculate the integral value during the X-ray radiation period and
The data is displayed on a display circuit via a sample hold circuit which is placed in a sample mode until the end of radiation.

Therefore, according to the present invention, during general radiography, it is possible to display the time product of tube current for a certain period of time after the end of radiography. Furthermore, in continuous imaging, it becomes possible to accurately display the time product of tube current.

[Brief explanation of the drawing]

The accompanying drawing is a circuit diagram showing an embodiment of the tube current time product display circuit of the X-ray control device of the present invention. 1... Miller integration circuit, 2... Sample and hold IC, 3... Display circuit, C1, C2... Capacitor, R1, R2, R3, R4, R5, R6...
...Resistor, VR1, VR2...Variable resistor, L...Coil, PC1, PC2...Photocoupler, TR1,
TR2...Transistor, ZD...Zener diode.

Claims (1)

[Claims for Utility Model Registration] The tube current of the X-ray tube converted into a voltage signal is integrated only for a period instructed by a control circuit, and the obtained integral signal is input to the first input terminal of a sample-and-hold circuit. an integrating circuit that outputs an output signal and is immediately reset by an instruction from the control circuit after the above-mentioned period has elapsed; and an integrating circuit that is set to sample mode when the first signal is input to the second input terminal and outputs the second signal to the second input terminal. When a signal is input, the hold mode is set, and the integral signal input to the first input terminal in the sample mode is captured and output, and in the hold mode, the integrated signal input to the first input terminal during the sample mode is set to the hold mode. A sample and hold circuit holds and outputs the integral signal, and the integration circuit instructs the integration circuit to perform integration only during the period when the X-ray radiation signal is output, and resets the integration circuit immediately after the X-ray radiation signal disappears. instruct,
Furthermore, the period during which the X-ray radiation signal is output or
After a certain period of time has elapsed after the radiation signal disappears, the first signal is input to the second input terminal of the sample hold circuit.
of the sample and hold circuit for a certain period after the X-ray radiation signal disappears, or until the next X-ray radiation signal is output after the X-ray radiation signal disappears, whichever is earlier an X-ray control device comprising: a control circuit that outputs the second signal to the second input terminal; and a display circuit that displays the tube current time product according to the output of the sample and hold circuit. Tube current time product display circuit.