JPH02245750A - Quick photographing controller for x-ray fluoroscopic photographing stand - Google Patents

Abstract

PURPOSE:To achieve speedy positioning in a prescribed stop position by providing a quick photographing controller for a X-ray fluoroscopic photographing stand with a servo command control means for issuing a servo command whereby a film holder is stopped in a regular stop position, after issuing a servo command whereby the film holder is slowed down or temporarily stopped in the prescribed position on this side of the regular stop position. CONSTITUTION:The quick photographing controller for the X-ray fluoroscopic photographing stand is provided with the servo command control means 2 for issuing the servo command S2 whereby the film holder is temporarily stopped in the prescribed position on this side of the regular stop position and the servo command S1 whereby it is stopped in the regular stop position. The present position of the film holder is followed and detected by a follower potentiometer 1. After the film holder is temporarily stopped by issuing the temporary stop position command S2 in the prescribed position on this side of the regular stop position, the servo command S1 whereby the film holder is stopped in the regular position is issued; accordingly, the influence of the inertia of the film holder, etc., is minimized, and the amount of overshoot in the regular stop position is considerably reduced. Thus, speedy positioning in the prescribed stop position an be achieved without requiring a cushioning member.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a servo system to move a film holder back and forth between a preparation position for film feeding and an imaging position for X-ray imaging. The present invention relates to a quick-shooting control device for an X-ray fluoroscopy table.

[Prior Art] Conventionally, in this type of device, the film holder receives servo commands (stop position It was only a matter of giving commands.

[Problem to be solved by the invention]

As described above, the conventional device simply issues a servo command for the stop position, and therefore has the following problems. That is, when the film holder stops, overshoot occurs due to the inertia of the film holder itself and the motor for moving the film holder. For this reason, positioning to the stop position cannot be performed quickly, and especially due to the mechanical structure of the snapshot device.

If there is a dead end in front of the stop position (which usually corresponds to the preparation position), there is a risk that the film holder will collide with the dead end due to the overshoot, causing parts such as the film holder to be destroyed. Therefore, it has been considered to provide a buffer member such as a damper or a spring at the dead end point, but in this case, when the film holder stops,
Servo system.

There were problems such as electrical oscillations due to lack of electrical balance, heat generation in the servo circuit elements, and vibration (hunting) in the mechanical components of the servo system.

An object of the present invention is to minimize the amount of overshoot of the film holder when the film holder is stopped, and therefore to prevent the film holder from colliding with the dead end due to overshoot when there is a dead end in front of the stop position due to the mechanical structure. This can be prevented, and the fixed positioning to the stop position can be quickly performed without providing a buffer member to prevent this.

It is an object of the present invention to provide a quick-shooting control device for an X-ray fluoroscopic imaging table that can solve all the problems caused by providing a buffer member.

[Means for Solving the Problem] The above object is to provide X-ray fluoroscopic imaging in which a servo system is used to move a film holder back and forth between a preparation position for film supply and an imaging position for X-ray imaging. In the quick-shooting control device of the camera, when the film holder is stopped at least at the preparation position, after giving a servo command to decelerate or temporarily stop the film holder at a predetermined position before the normal stop position, the film holder is returned to the normal stop position. This is achieved by providing a servo command control means for giving servo commands of .

[For production]

The servo command control means decelerates or temporarily stops the film holder before the regular stop position (for example, about 20 nn before) to reduce the inertia of the film holder, etc.
The amount of overshoot of the film holder is significantly reduced (for example, the overshoot amount of about 3111111 in the conventional technology is reduced to about 1 mm in the present invention). Therefore, especially when there is a dead end in front of the stop position, the amount of overshoot of the film holder due to overshoot is reduced. Collision with a dead end is prevented, and the vehicle can be quickly positioned at the stop position without providing a buffer member to prevent this, and all problems caused by providing a buffer member are eliminated. Become.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit diagram showing one embodiment of a quick-shooting control device for an X-ray fluoroscopic imaging table according to the present invention, and numeral 1 in the figure is a follow-up potentiometer for detecting the position of a film holder (not shown).

Reference numeral 2 denotes a servo command control means, which gives a servo command to temporarily stop the film holder (not shown) at a predetermined position before the regular stop position when the film holder (not shown) is stopped at at least a semi-position.

Give the servo command for the regular stop position. This servo command control means 2 here includes a DC voltage source +Veal to +V.
cc3 (Veal (Vcc2 (Vcc3)) and switches 5W-8W3. Among these, switch SW1 is configured to issue a servo command (Veal) to stop the film holder at the normal stop position when the film holder is stopped at the preparation position. This is a relay contact for giving a preparation position command signal (SZ).Switch SW2 is a servo that temporarily stops the film holder at a predetermined position before the normal stop position when the film holder is stopped at the preparation position. It is a relay contact for giving a command (- time stop position command) SZ.Switch SW3 is a servo command (photographing position command signal) S3 to stop the film holder at the photographing position (regular stop position) of the film holder. This switch SW3 is a relay contact for suppressing the photographic push button switch (not shown) and turning ON/OFF.
, turns off when shooting is completed.

The switch SW2 is turned ON when the switch SW3 is turned OFF (photographing is completed), and is turned OFF when the film holder is temporarily stopped. Switch SWI is set when switch SW2 is OFF.
F (stop when film holder) turns ONL, turns OFF when the film holder stops at the ready position (normal stop position ffi).

3 is voltage inversion OP amplifier, 4 is impedance conversion O
5 is an addition/subtraction OP amplifier, 6 is a DC motor for moving the film holder, and 7 is a servo system gain resistor.

Further, R1-R3 are resistors.

Next, the operation of the above-mentioned device of the present invention will be explained.

The current position of the film holder is tracked and detected by a tracking potentiometer 1. This verification voltage is inverted by the voltage inverting OP amplifier 3 and becomes negative (or positive) f? ! It is output as pressure.

On the other hand, the stop position (regular stop position) of the film holder is selected by the servo commands (position command signals) St, S3, and the servo commands (position command signals) St,
S3 is a plus (or minus) fl! whose impedance has been converted by the impedance converting ○P amplifier 4! It is output as pressure.

The stop position command voltage from the servo commands (position command signals) S1 and S3 and the film holder current position detection voltage from the follow-up potentiometer 1 are input to the inverting input terminal of the addition/subtraction OP amplifier 5. If the stop position command voltage is greater than the film holder current position detection voltage, the OP amplifier 5
A negative (or positive) voltage is output from , and the film holder moves to the photographing position. Conversely, if the pressure is smaller, plus (or minus) ft pressure is output, and the film holder moves to the preparation position. In either case, when the film holder arrives at the stop command position (preparation position or shooting position), the output of the OP amplifier 5 becomes Ov, the film holder movement motor 6 stops, and the film holder completes its movement and reaches its position. Stop at.

Although the above is not particularly different from the conventional device, it differs from the conventional device in the following points. That is, when the film holder stops, the film holder always overshoots due to inertia. Therefore, especially if there is a dead end in front of the stop position (usually the preparation position) due to the mechanical configuration of the snapshot device, if you try to stop just before the dead end, you will overshoot and collide with the dead end. However, the impact may destroy parts such as the film holder. In the present invention, the stiffness is replaced with the normal stopping position I! (Here, the preparation position g1) is temporarily stopped, for example, about 20 vagina before. That is, when the film holder is stopped at the preparation position, a servo command (minus stop position command) S2 is given to temporarily stop the film holder at a predetermined position before the normal stop position, and the film holder is temporarily stopped at a predetermined position before the normal stop position. After the film holder is stopped (the output of the ○P amplifier 5 becomes ○■), a servo command (preparation position command signal) St is given to stop the film holder at the normal stop position, thereby greatly reducing the influence of the inertia of the film holder, etc. This is what I did.

As a result, the amount of overshoot at the normal stop position of the film holder is extremely small (for example, conventionally 3 mm
Therefore, when there is a dead end in front of the stop position, such as at the preparation position, the film holder is prevented from colliding with the dead end due to overshoot. The fixed positioning to the stop position is performed quickly without providing a buffer member to prevent this, and the problem caused by providing a buffer member (when the film holder is stopped, the servo system is not electrically balanced). This eliminates all problems (such as electrical vibration without vibration, heat generation in the servo circuit elements, and hunting in the mechanical components of the servo system).

In the above embodiment, the servo command control means 2 is used.

The film holder is configured to temporarily stop at a predetermined position before the normal stop position only when the film holder is stopped at the mW position, but the film holder is also temporarily stopped when stopped at the shooting position. It may be configured to stop at. Instead of a temporary stop, it may be configured to decelerate.

〔Effect of the invention〕

As explained above, according to the present invention, the amount of overshoot of the film holder can be minimized when the film holder is stopped. Collision with a dead end can be prevented, and the vehicle can be quickly positioned at the stop position without providing a buffer member to prevent this, and all problems caused by providing a buffer member can be solved. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Follow-up potentiometer, 2... Servo command control means, 3... Voltage inversion OP amplifier, 4... OP amplifier for impedance conversion, 5... QP fan for addition/subtraction. 6... Film holder movement motor, 7... Gain resistor, R1-R3... Resistor. patent applicant

Claims (1)

[Claims] 1. In a quick-shooting control device for an X-ray fluoroscopy table in which a servo system is used to move the film holder back and forth between a preparation position for supplying film and an imaging position for taking X-ray images, at least one of the film holders is A servo command control means is provided for giving a servo command for decelerating or temporarily stopping the film holder at a predetermined position before the regular stop position when stopping at the preparation position, and then giving a servo command for the regular stop position. A quick-shooting control device for an X-ray fluoroscopic imaging table.