JPS61238047A - X-ray snapshooting device - Google Patents

Abstract

PURPOSE:To perform the stop positioning of a film holder with high precision by detecting the tilt angle of the ceiling plate of a fluoroscopic table by an angle detector, and correcting variation in run load with the gravitational force of the film holder corresponding to the detected tilt angle by a driving control system. CONSTITUTION:The angle detector 62 provided to the fluoroscopic table 61 detects the tilt angle of the ceiling plate 4 at any time any and inputs a tilt angle signal thetax to a microcomputer 63. When an operator presses the snapshooting switch of a console panel, tilting operation is stopped and the film holder 10 enters conveying operation. The output of an encoder is inputted to a speed detector 64 and a position detector 65 to detect the speed and position of the holder 10; and a position signal is compared by a comparator 44 with target displacement thetaref to send the position deviation to an amplifier 42, whose output is sent to a comparator 46, so that a speed command including a corrected gain is outputted. The output of the detector 64, on the other hand, is sent to a comparator 45 through an amplifier 43 and comparator 45 compares the speed command of the comparator 46 with an actual speed from the amplifier 43 to obtain the speed deviation. A motor 11 is driven with a deviation signal to stop the holder 10 with the target displacement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an X-ray speed copying device, and in particular, the present invention relates to an X-ray speed copying device, and in particular, a speed shooting device is controlled by comparing a target displacement and an actual displacement of a film holder to convey the film holder. This invention relates to a cassette-less type X-ray copying apparatus that determines the stop position of a device.

[Background of the invention]

Fig. 3 shows a caseless type X-ray fluoroscopic imaging table according to the present invention (
Hereinafter, a schematic configuration of a fluoroscopic photographing table (hereinafter simply referred to as a fluoroscopic photographing table) is shown. In the fluoroscopic imaging table, a table support frame 2 and an X-ray tube device 3 are supported by a support stand 1, and the table support frame 2 has a top plate 4.
is provided so as to be movable in the vertical and horizontal directions. and,
An X-ray tube device 3 and an imaging system are provided facing each other with the top plate 4 in between. The imaging system includes a cassette-less type X-ray copying apparatus (hereinafter simply referred to as a copying apparatus) 5 that captures an X-ray image on an image storage medium such as film (hereinafter simply referred to as a film), and a cassette-less type X-ray copying apparatus (hereinafter simply referred to as a copying apparatus) 5 for viewing the X-ray image. A photomultiplier tube 6 and an X-ray TV camera 7 that takes a fluorescent image of the photomultiplier tube 6
It consists of. FIG. 4 shows a state in which the top plate of the fluoroscopic photographing table is raised and lowered, and the top plate 4 in FIG. 3 changes from the horizontal position to the standing position.

In the quick copy device 6, a large number of stored unexposed films are taken out one by one and inserted into the film holder 10, and the operator transports the film holder 10 from the standby position F to the imaging position R as appropriate by operating a switch. After the photographing is completed, the film holder 10 is returned to the standby position F, and a series of operations are performed in which the photographed film is taken out from the film holder 10 and stored. The mechanical unit that carries out the operation of transporting the film holder 10 in a series of these operations is called a snapshot drive device, and a schematic configuration of the conventional device and a block diagram of its control system are shown in FIGS. 5 and 6. .

The snapshot drive device uses a DC servo motor 11 as a drive source, and a pulley 13 is attached to its output shaft. pulled pulley 14
Then, the conveyor belt 15 with negligible elongation for transmitting power to the film holder 10 is hooked and rotated, and the conveyor belt 1
5 and the film holder 10 are connected by a connector 16. An encoder 12 is fixed to the rotating shaft of the DC servo motor 11. The encoder 12 generates a pulse signal according to the rotation of the DC servo motor 11, and the signal is measured by a counter not shown, and the value is negatively fed back to the control system to control the transport speed and position of the film holder. is accomplished.

Next, the operation of the film holder 10 will be explained using a block diagram of a conventional control system shown in FIG. In the figure, 11 is the fifth
A DC servo motor similar to the one shown in the figure, 41 is a motor load (film holder, etc.), 42 and 43 are amplifiers, 44 and 45 are comparators, 64 is a speed detector, and 65 is a position detector. In addition, θshiga is the target displacement of the film holder 10 (the moving distance to the target stop position), and θ0 is the actual displacement of the film holder 10.
The displacement of 0 and Tt are the friction torque, gravity, etc. that act on the load 41 (this is referred to as disturbance torque). The film holder 10 has a target displacement θt −L2t with respect to the drive control system.
E is input to the comparator 44. At this time, encoder 1
The output pulses from 2 are sent to the speed detector 64 and the position detector 6.
5 to detect the speed and position of the film holder 10. The position signal of the film holder 10 is compared with the target displacement θ〆,·f by a comparator 44 to obtain a positional deviation, which is input to the amplifier 42, and the amplifier 42 adjusts the positional deviation according to the positional deviation. A speed command is issued, and the signal obtained by the speed detector is input to a comparator 45 via an amplifier 43. A comparator 45 compares the speed command from the amplifier 42 with the actual speed of the film holder from the amplifier 43 to obtain a speed deviation. Then, a pulse signal corresponding to this speed deviation is input to the motor drive circuit to drive and control the DC motor to convey the film holder.

The drive control system described above feeds back the actual displacement θ0 of the film holder, compares the deviation between the target displacement θj'*:f' and the actual displacement θ0, and moves the film holder until the deviation becomes O. This is a commonly used servo system.

However, in a device like this device in which the posture of the device changes in various ways, such as horizontal or standing, there is a large difference in disturbance torque Tt between the various postures, and the control system described above cannot control the disturbance torque Tt. I can't get enough of it. That is, the target displacement θr@
f and the actual displacement θ. This results in a positional deviation Δθ between the two. This means that the stop position of the film holder at the photographing position R or the standby position F varies, and as a result, an X-ray image that should be taken on the film may be missing on the film, which may impede diagnosis, or Problems may occur when transferring the film between the film holder and the film take-out section (as shown), and an improvement has been desired.

The relationship between the tilting angle of the top plate and the stop position deviation Δθ of the film holder is expressed as shown in Figure 8, and the tilting angle and the positional deviation Δθ show an approximately proportional relationship, and the tilting angle is absolute. If the values are the same, it indicates that the amount of positional deviation is almost the same.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned needs, and it is possible to perform the stop positioning of the film holder with high precision without being affected by the tilting angle of the top plate of the fluoroscopic imaging table, and also has a simple configuration. The purpose of the present invention is to provide a cassette-less type X-ray copying device.

[Summary of the invention]

A feature of the present invention for achieving the above object is that, in order to control the snapshot drive device, an angle detector detects the tilting angle of the top plate of the fluoroscopic photographing table, and a film corresponding to the tilting angle is detected. The present invention is provided with means for causing the drive control system to correct fluctuations in running load due to the gravity of the cage.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing an example of a control circuit of a snapshot device for a fluoroscopic imaging stand according to the present invention. In FIG. 1, the same parts as in FIG. 6 are given the same reference numerals. Reference numeral 61 denotes a main body of the fluoroscopic imaging table, 62 an angle detector for detecting the tilting angle of the top plate of the fluoroscopic imaging table, and 63 a correction means for causing the drive control system to correct fluctuations in running load of the film holder. It is a nine-microcomputer equipped with an arithmetic unit 63a, a storage device 63b, and the like. In this embodiment, the storage device 6
Target displacement θ in 3b! 9. Each control constant and an arithmetic expression for obtaining the correction gain of the control circuit are memorized. The calculation device 63a uses the calculation formula in the storage device 63b and the tilting angle signal of the top plate from the angle detector 62 to calculate the influence of the gravity component on the film holder (driving load fluctuation) caused by the tilting and raising of the top plate. Calculate the gain for correction in the drive control system.

Next, the operation of this control circuit will be explained. An angle detector 62 provided on the fluoroscopic photographing table main body 61 sequentially detects the tilting angle of the top plate, and inputs a tilting angle signal θx of the top plate to the microcomputer 63.

Here, the ninth target displacement θFJ for conveyance of the film holder is set and input for quick copying. The setting and input of this target displacement θ14 is performed by operating selection switches on the operation panel (shown in the diagram), such as switches for selecting the film size to be used and for selecting the imaging field (full-scale imaging or divided imaging). .

Then, when the operator presses the quick-shooting switch on the operation panel, the fluoroscopic photographing table stops raising and lowering the top plate, and the film holder 10 starts the conveying operation. In response to the tilting angle signal θX of the top plate at this time, the microcomputer 63 calculates the positional deviation amount Δθ at the stop position of the film holder 10 shown in FIG. 7 from the input tilting angle signal θX, and The next correction gain is calculated to obtain the optimum gain to be given to the control system. The optimal gain at this top tilting angle is obtained by adding and subtracting this correction gain and the t-specific gain given to the amplifier 42, and the refined calculation formula for obtaining the optimal gain is formula (A). Shown below.

G = G, r,, + G□・θX...
(a) G: Optimal gain/Ga rof' Gain of amplifier 42 G#x: Correction gain coefficient θ,: Raising/tilting angle of the top plate Here, G, x/θX are in the arithmetic unit 63a This is the correction gain calculated from the tilting angle signal, and is G #rsf
is the inherent gain of the amplifier 42 in the control system.

The target displacement θref is input to the comparator 44. At this time, the output pulse from the encoder 12 is input to the speed detector 64 and the position detector 65 to detect the speed and position of the film holder 10, and the position signal is input to the comparator. At 44, a comparison calculation is made with the target displacement θrat to obtain a positional deviation, which is input to the amplifier 42. The amplifier 42 issues a speed command according to the positional deviation.

This speed command is processed by the comparator 46 using the correction gain G□・
θX is added and a new speed command is issued. On the other hand, the signal obtained by the lotus degree detector passes through an amplifier 43 and a comparator 45.
is input to. The comparator 45 compares and calculates the speed command from the comparator 46 and the actual speed of the film holder 10 from the amplifier 43 to obtain a speed deviation. Then, a pulse signal corresponding to this speed deviation is input to the motor drive circuit to drive and control the DC servo motor 11 to transport the film holder 10, and while the actual displacement θ0 is negatively fed back, the target displacement is θrsf is compared with 00, and the film holder is stopped at the target displacement θref.

FIG. 9 shows the relationship between the tilting angle θX of the top plate and the correction gain coefficients G and z. According to this, when the tilting angle θX of the top plate is between 0° (horizontal position) and +90° (standing position), the film holder does not reach the target position due to the influence of gravity, so the correction gain is added, and , 0° (standing position) to −90° (reverse tilted position), since the target position is exceeded, it is understood that it is sufficient to subtract the correction gain.

As described above, this embodiment includes an angle detector that detects the tilting angle of the top plate of the fluoroscopic imaging platform, and a gain for correcting the gravitational component according to the tilting angle of the top plate detected by this angle detector. Equipped with an arithmetic unit for calculations and a storage device for storing data such as tilting angle data, the film holder is positioned by inputting the target position into the control system. This can be done with high precision without being affected by the tilt angle. The above is the first embodiment.

Next, a second embodiment of the present invention will be explained with reference to FIG.

In this embodiment, the gain of the amplifier 42 and the correction gain are added and subtracted in advance to obtain the tilting angle θX of the top plate and the corresponding optimum gain Gx.
is stored in the storage device as a table.
When performing quick copying, data on the tilting angle of the top board is input to the microcomputer 63, a gain corresponding to the tilting angle is read out from the storage device 63b, and a gain corresponding to the tilting angle is read out from the storage device 63b. The arithmetic unit 63a also outputs a speed command to control the transport position of the film holder. According to this embodiment, since the microcomputer 63 also serves as the amplifier 42 in the first embodiment, there is an effect that the configuration of the control system is simplified.

Note that the detailed description of the present invention has been made based on an example in which the transport direction of the film holder is set in the longitudinal direction of the top plate of a fluoroscopic photographing table; It is also possible to apply this method to the case where the container is transported in a direction perpendicular to the top plate.

〔Effect of the invention〕

As described above, according to the present invention, even if the running load fluctuation occurs in the film holder in the snapshot device due to a change in the tilting angle of the top plate of the fluoroscopic imaging platform, the drive control system is not affected by the fluctuation. can be easily configured, and as a result, there is an effect that the stop positioning of the film holder can be performed with high precision.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a first embodiment of a copying drive control circuit for a cassette-less type X-ray copying apparatus of the present invention, Fig. 2 is a block diagram of a second embodiment, and Figs. 3 and 4 are transparent views. A diagram showing the schematic configuration of the photographing stand together with the tilt angle of the top plate, Figure 5 is a configuration diagram of the snapshot drive device, Figure 6 is a block diagram of the control system of the conventional device, and Figure 7 is the snapshot direction of Figure 5. is facing the direction of gravity, Figure 8 is a relationship diagram between the tilting angle of the top plate and the amount of deviation in the stop position of the film holder, and Figure 9 is a diagram showing the relationship between the tilting angle of the top plate and the correction gain coefficient. It is. DESCRIPTION OF SYMBOLS 10... Film holder, 11... DC servo motor, 12... Encoder, 41... Motor load, 4
2゜43...Amplifier, 44-46...Comparator, 62
...Angle detector, 63...Microcomputer,
63a... Arithmetic device, 63b... Storage device, 64.
...Speed detector, Figure 12 Figure 2 Figure 3 Figure 4 Circle Figure 3 Figure 6

Claims (1)

[Scope of Claims] 1. The film holder is placed on an X-ray fluoroscopy table for X-ray examination of the subject by raising and lowering the top plate, and determines the transport position of the film holder by comparing the target displacement and the actual displacement. In an X-ray rapid imaging apparatus equipped with a drive control system that performs An X-ray snapshot apparatus, characterized in that it is provided with means for causing the drive control system to correct fluctuations in running load due to gravity of the film holder. 2. The correction means comprises a calculation device for calculating a gravity component correction gain to be applied to the drive control system, and a storage device for storing the target displacement and calculation command data. The X-ray photographic device according to scope 1. 3. The correction means comprises a storage device that stores an optimal gain for the drive control system corresponding to the tilting angle of the top plate, and a device that reads out the optimal gain. X-ray photographic device.