JPH0678217A - X-ray photographing device - Google Patents

Abstract

PURPOSE:To perform exposure control without using an optical component and to easily change the position and size of an optical detecting part. CONSTITUTION:Crystal oscillators 9e, 9f are selected by a switching relay 9d, and a vertical synchronizing signal and a horizontal synchronizing signal are selected by a selection circuit 11g, and video signals in accordance with the synchronizing signals are inputted to an integration circuit 11c. An output signal integrated at the integration circuit 11c is inputted to a comparator 11e, and it is compared with a reference value from a reference value setting circuit 11d, and the radiation of X-rays is stopped when an integration value arrives at the reference value. Since the exposure control is performed by using a video signal 9i, no optical component is required, which enables the device to be inexpensively comprised. Also, since selection can be performed by using the synchronizing signal, an arbitrary exposure position can be selected. Furthermore, it is possible to accurately perform the exposure control by switching the crystal oscillators 9e, 9f by the switching relay 9d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus for seeing through and photographing an object, and more particularly to an X-ray automatic exposure apparatus for obtaining an appropriate film density.

[0002]

2. Description of the Related Art Conventionally, in an X-ray photographing apparatus for diagnosing digestive organs such as stomach, there is an automatic X-ray exposure control apparatus capable of obtaining a good film blackening degree for improving diagnostic efficiency and diagnostic accuracy. Is required. FIG. 8 is a circuit configuration diagram showing a schematic configuration of an X-ray imaging apparatus including an X-ray automatic exposure control apparatus which has been generally known from the past. 1 is an AC power supply, 2 is a tube voltage adjusting circuit, 3a and 3b are X-rays. X-ray switch for turning radiation on and off, 4 high voltage generating circuit, 5 X-ray tube,
6 is a subject, 7 is an X-ray film, and 8 is a transmission X of the subject 6.
It is an image intensifier (hereinafter referred to as II) that converts a line into visible light.

9 is an I.D. I. The TV camera 10 converts visible light from 8 into a video signal
And a prism to be distributed to the Photomul tube 11a, 1
1a is an I.D. I. 8 is a photomultitube for converting a part of visible light into a photocurrent, 11b is a preamplifier for converting this photocurrent into a voltage and amplifying it, 11c
Is an integrating circuit for integrating the output voltage of the preamplifier 11b, 1
1e indicates that the output voltage of the integrating circuit 11c is the reference value setting circuit 11
A comparison circuit for generating an X-ray cutoff signal 11i when the reference value of d is reached, and 12 is an X-ray emission signal 12a for controlling the X-ray emission and for turning on and off the integration start switch 11f.
Is an X-ray control circuit for generating

In this X-ray imaging apparatus, an X-ray radiation signal 12a is output from the X-ray control circuit 12, and X-ray switches 3a and 3a are provided.
When b is turned on and the integration start switch 11f is turned on at the same time, the voltage adjusted by the tube voltage adjusting circuit 2 is boosted by the high voltage generating circuit 4 and applied to the X-ray tube 5 to generate X-rays. The X-rays are applied to the subject 6, and the X-rays that have passed through the subject 6 expose the X-ray film 7 to light and the I.V. I.
It reaches 8 and is converted into visible light.

The converted visible light is converted into a video signal by the TV camera 9 and displayed on the TV monitor 13, and at the same time, the prism 10 guides it to the photomultiplier tube 11a and converts it into photocurrent. This photocurrent is supplied to the preamplifier 11
After being amplified by b, it is integrated by the integration circuit 11c and the integrated value is input to the comparison circuit 11e. When the integrated value reaches a predetermined value, the X-ray cutoff signal 11i is output from the comparison circuit 11e.
Is output to the X-ray control circuit 12 to block the X-ray.

[0006]

In the conventional X-ray automatic exposure control device described above, the I.D. I. Since the light detection part from is optically fixed by the arrangement of the prism and the photomultiplier tube, the size and position of the light detection part can be easily changed according to the change of the imaging part or the desire of the photographer. There wasn't. Further, optical parts such as prisms and photomultiplier tubes are expensive.

Therefore, an object of the present invention is to perform exposure control without using optical parts and to easily change the position and size of a photodetection site.

[0008]

To achieve the above object, a high voltage generating circuit for applying a high voltage to an X-ray tube and an I.V. for converting an X-ray image from an object into an optical image. I. A camera for converting the optical image into a video signal, a television monitor for displaying the video signal as an image, the optical image into an electric signal, integrating the electric signal, and integrating the integrated value and a reference value. And an X-ray automatic exposure control device that outputs an X-ray emission stop signal to the X-ray control circuit when the values match, and an X-ray control circuit that controls the high voltage generation circuit by the output of the comparison circuit. In an X-ray imaging apparatus having
The X-ray automatic exposure control device includes a scanning signal generating circuit for generating a scanning signal for extracting a video signal from the camera and a vertical synchronizing signal and a horizontal synchronizing signal, and an oscillator for generating the scanning signal. An amplifier circuit for amplifying the video signal taken out from the camera, a selection signal for arbitrarily selecting the vertical synchronization signal and the horizontal synchronization signal and selecting a video signal corresponding to this selection signal, and a selection signal selected by this selection signal The X-ray automatic exposure control device has a plurality of oscillators having different frequencies, and a plurality of oscillators having different frequencies, in addition to the configuration of an integrating circuit for integrating a video signal and a comparing circuit for comparing an output of the integrating circuit with a reference value. It is provided with a switching device for selectively switching the oscillator of.

[0009]

[Operation] I. I. The optical image from the image is projected by the camera, converted into a video signal by the scanning signal from the scanning signal generation circuit, amplified by the amplification circuit, and output to the television monitor. At this time, the vertical synchronizing signal and the horizontal synchronizing signal from the scanning signal generating circuit are selected by the selecting circuit, and the video signal corresponding to the selected vertical synchronizing signal and the horizontal synchronizing signal is input to the integrating circuit. The output signal integrated by the integration circuit is input to the comparison circuit and compared with the reference value from the reference value setting circuit. When the integrated value reaches the reference value in this comparison circuit, the X-ray cutoff signal is transmitted to the X-ray control circuit and the X-ray emission is stopped. The switch also selects a plurality of oscillators to change the speed of the scanning signal, the so-called number of scanning lines.

As a result, an optical component such as a prism is not required, and the light detecting portion can be arbitrarily selected. further,
The exposure control can be accurately performed by switching the generation speed of the scanning signal.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a block diagram showing a schematic configuration of an X-ray imaging apparatus of the present invention, FIG. 2 is a circuit diagram showing a configuration example of a selection circuit, FIG. 3 is a diagram showing operation waveforms of FIG. 2, and FIG. 4 is a selection of FIG. FIG. 5 is a diagram showing the exposure position selected by the circuit, FIG. 5 is a circuit diagram showing a second configuration example of the selection circuit, FIG. 6 is a diagram showing the exposure position selected by the selection circuit of FIG. 5, and FIG. 3 is a diagram in which the crystal oscillator of FIG. 1 is an AC power supply, 2 is a tube voltage adjusting circuit, 3a and 3b are X-ray switches, 4 is a high voltage generating circuit, 5
Is an X-ray tube, 6 is a subject, 7 is an X film, and 8 is an I.D. I.
Is.

9a is an I.D. I. A CCD camera that converts the output light from 8 into a video signal, an amplification circuit 9b that amplifies the video signal from the CCD camera 9a, and a CCD camera 9c.
The vertical synchronizing signal 9 is generated to the amplifying circuit 9b and the selecting circuit 11g while generating the scanning signal for extracting the video signal from a.
g, a scanning signal generating circuit for outputting a horizontal synchronizing signal 9h, 9
d is a switching relay for switching the crystal oscillators 9e and 9f, and 9
e is a crystal oscillator that determines the frequency of the scanning signal for photographing, 9
f is a crystal oscillator that determines the frequency of the scanning signal for fluoroscopy, 9
g is a vertical synchronization signal synchronized with the vertical scanning signal from the scanning signal generation circuit 9c, 9h is a horizontal synchronization signal synchronized with the horizontal scanning signal from the scanning signal generation circuit 9c, and 9i.
Is a video signal amplified by the amplifier circuit 9b.

Reference numeral 11c is an integrating circuit for integrating the video signal 9i, 11d is a reference value setting circuit for setting a reference value, and 11e.
Is the integrated value from the integrating circuit 11c and the reference value setting circuit 11d
A comparison circuit for comparing the reference value from 1), 11f is an integration start switch for controlling the operation of the integration circuit 11c, 11g is a selection circuit for selecting the vertical synchronization signal 9g and the horizontal synchronization signal 9h, and 11h is an output of the selection circuit 11g An analog switch for outputting the corresponding video signal 9i to the integrating circuit 11c, 1
1i is an X-ray cutoff signal output from the comparison circuit 11e, 1
2 is an X-ray control circuit that controls the high voltage generation circuit 4, the integration start switch 11f, and the changeover relay 9d; 12a is an X-ray emission signal that controls the high voltage generation circuit 4; 12b is a changeover relay 9d and the integration start switch 11f. Shooting signal to control,
A television monitor 13 displays the video signal 9i from the amplifier circuit 9b.

First, the operation of this embodiment will be described. The X-ray emission signal 12 is generated by the X-ray control circuit 12 so that X-rays are generated.
a is transmitted to the X-ray switches 3a and 3b. Then, the X-rays generated by the X-ray tube 5 are transmitted through the subject 6 and the X-ray film 7, and the I.D. I. Enter in 8. I. I. 8, the X-ray image is converted into an optical image, the CCD camera 9a receives the light, and the scanning signal generation circuit 9
The scanning signal is received by c and output to the amplifier circuit 9b.
At this time, the switching relay 9 is used by the X-ray control circuit 12 at the time of photographing.
When d is switched to the crystal oscillator 9e, the crystal signal is switched to the crystal oscillator 9f at the time of fluoroscopy to generate a scanning signal from the scanning signal generating circuit 9c, about 300 sheets are scanned per second at the time of photographing, and about 60 sheets are scanned per second at the time of fluoroscopy. Is done.

In the amplifier circuit 9b, the vertical synchronizing signal 9g and the horizontal synchronizing signal 9h are inputted from the scanning signal generating circuit 9c and the CCD is inputted.
The output from the camera 9a is amplified to output the video signal 9i. The video signal 9i is displayed on the television monitor 13 and input to the analog switch 11h operated by the selection circuit 11g. The analog switch 11h integrates the video signal 9i corresponding to the vertical synchronizing signal 9g and the horizontal synchronizing signal 9h selected by the selecting circuit 11g into an integration start switch 11f.
Output to.

The integration start switch 11f is the X-ray control circuit 1
The photographing signal 12b from 2 is received and opened / closed. When the integration open / close switch 11f is closed, the selected video signal 9i is input to the integration circuit 11c. The comparison circuit 11e is the integration circuit 1
The integrated value from 1c is compared with the reference value set by the reference value setting circuit 11d, and when the integrated value reaches the reference value, the X-ray cutoff signal 11i is transmitted to the X-ray control circuit 12, and the X-ray control circuit 12 Transmits an X-ray emission signal 12a for stopping the generation of X-rays.

Next, a first embodiment of the selection circuit 11g is shown in FIG.
4 to FIG. Reference numeral 14 is a monostable multivibrator (hereinafter referred to as MM), 15 is an output signal of the MM 14, and 16 is an AND circuit for calculating the logical sum of the output signals 15b and 15d. In the selection circuit 11g, the vertical synchronizing signal 9g is selected by the MMs 14a and MM14b for the vertical exposure position, and the horizontal synchronizing signal 9h is selected by the MMs 14c and MM.
The exposure position in the horizontal direction is selected by 14d, the vertical and horizontal selection signals are logically operated by the AND circuit 16, and the result is used as the exposure position in the analog switch 11h.
And the video signal 9i is selected.

Further, when this operation is represented by a waveform, as shown in FIG. 3, the vertical synchronizing signal generating circuit shown in (b) corresponds to the vertical video signal shown in (a) of the scanning signal generating circuit 9c in the vertical direction. Generate 9g and input to MM14a. And
The output signal 15a of the MM 14a shown in FIG.
To output the vertical video selection signal shown in (d).

Similarly in the horizontal direction, the scanning signal generating circuit 9c generates the horizontal synchronizing signal 9h shown in (f) corresponding to the horizontal video signal shown in (e) and inputs it to the MM 14c. Then, the output signal 15c of the MM 14c shown in (g) is converted to MM
14d and outputs the horizontal video selection signal shown in (h). When this result is calculated by the AND circuit 16, FIG.
The selected position as shown in is obtained. When changing the selection position by the selection circuit 11g, an arbitrary exposure position can be selected by adjusting the voltage of the MM14.

The selection circuit 11g shown in FIGS.
The second embodiment of Reference numeral 19 is a counter IC for counting the number of divisions of the vertical video signal, 20 is a counter IC for counting the number of divisions of the horizontal video signal, 21 is an oscillator for determining the number of horizontal divisions, and 22 is a memory 23. A switching IC for switching data input, 23 is a memory for storing data of the microcomputer 24 or the counter ICs 19, 20, and 24 is a microcomputer for selecting an arbitrary exposure position. First, the counter IC1
When the vertical synchronizing signal 9g is input to 9 for resetting and the horizontal synchronizing signal 9h is input to the counter IC 19, the number of divisions of the video signal in the vertical direction is counted.

Further, the horizontal synchronizing signal 9h is a counter IC.
The frequency signal from the oscillator 21 is input to count the number of divisions of the video signal in the horizontal direction.
The data divided in the vertical and horizontal directions is switched IC2
2 is stored in the memory 23. And the switching IC2
3 is switched to the microcomputer 24 side, an arbitrary exposure position is selected and stored in the memory 23. The stored exposure position is transmitted to the analog switch 11h and the video signal 9
Select i.

As described above, since the exposure control is performed by using the video signal 9i from the CCD camera 9a, the cost can be reduced because the optical parts are not used. Moreover, since the selection is performed using the synchronizing signal of the scanning signal, an arbitrary exposure position can be selected. Further, the oscillator for generating the scanning signal is divided into a photographing crystal oscillator 9e and a see-through crystal oscillator 9f, and the taking crystal oscillator 9e has a frequency several times that of the see-through crystal oscillator 9f. Accurate exposure control is possible.

[0023]

According to the present invention, since the image signal from the camera is used for the exposure control, the exposure can be controlled without using the optical parts such as the prism and the photomultitube, and the apparatus can be made inexpensive. Further, since the exposure position is selected using the vertical synchronizing signal and the horizontal synchronizing signal of the scanning signal, any position can be selected. In addition, because we have installed multiple oscillators with different frequencies to switch selectively with the switch,
The number of scans of the camera can be changed and the exposure control can be made accurate.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a selection circuit.

FIG. 3 is a diagram showing operation waveforms in FIG.

FIG. 4 is a diagram showing an exposure position selected by a selection circuit of FIG.

FIG. 5 is a diagram showing a second configuration example of a selection circuit.

6 is a diagram showing an exposure position selected by the selection circuit of FIG.

FIG. 7 is a diagram in which the crystal oscillator of FIG. 1 is integrated.

FIG. 8 is a block diagram showing a schematic configuration of a conventional X-ray imaging apparatus.

[Explanation of symbols]

 9a CCD camera 9b Amplifying circuit 9c Scan signal generating circuit 9d Switching relay 9e Crystal oscillator 9f Crystal oscillator 9g Vertical synchronizing signal 9h Horizontal synchronizing signal 9i Video signal 11c Integration circuit 11d Reference value setting circuit 11e Comparison circuit 11f Integration start switch 11g Selection circuit 11h Analog switch 11i X-ray cutoff signal 12 X-ray control device 12a X-ray emission signal 12b Imaging signal 14 MM (monostable multivibrator) 15 Output signal 16 AND circuit 19 Counter IC 20 Counter IC 21 Oscillator 22 Switching IC 23 Memory 24 Microcomputer

Claims (2)

[Claims] 1. A high voltage generating circuit for applying a high voltage to an X-ray tube, an image intensifier for converting an X-ray image from a subject into an optical image, and a camera for converting the optical image into a video signal. , A television monitor that displays the video signal as an image, and the optical image is converted into an electrical signal, the electrical signal is integrated, the integrated value is compared with a reference value, and X-rays are obtained when those values match. In an X-ray imaging apparatus having an X-ray automatic exposure control device that outputs an X-ray emission stop signal to a control circuit, and an X-ray control circuit that controls the high voltage generation circuit by the output of the comparison circuit, An exposure control device, a scanning signal generating circuit for generating a scanning signal for extracting a video signal from the camera and a vertical synchronizing signal and a horizontal synchronizing signal, an oscillator for generating the scanning signal, An amplifier circuit for amplifying the video signal extracted from the camera, a selection signal for arbitrarily selecting the vertical synchronization signal and the horizontal synchronization signal and selecting a video signal corresponding to this selection signal, and a video signal selected by this selection signal X is constituted by an integrator circuit for integrating and an comparator circuit for comparing the output of the integrator circuit with a reference value.
X-ray equipment. 2. The X-ray imaging apparatus according to claim 1, further comprising a plurality of oscillators of the X-ray automatic exposure control device having different frequencies, and a switching device for selectively switching the plurality of oscillators. apparatus.