JPH0355131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positioning method and apparatus for positioning a pair of objects, such as an X-ray irradiation head and an X-ray film in an X-ray imaging device, on a desired straight line. .

That is, to explain the above-mentioned X-ray imaging device using a dental X-ray imaging device as an example, instead of performing panoramic X-ray imaging of the whole jaw, it performs X-ray imaging of two or three specified teeth. In this type, a film is set inside the oral cavity, and the film is exposed to X-rays from the outside to take pictures and use for diagnosis. In this case, the positioning of the film and the Because it relied on intuition, it was easy for the film to be misaligned, and not only would the film come off from the X-ray irradiation field, exposing unnecessary areas to X-rays, but the target tooth would not be photographed on the film, resulting in a so-called cone cut. The problem is that the radiation dose to the human body is further increased due to the need for re-imaging, and conversely, in order to suppress this cone cup, the irradiation field of X-rays must be expanded, and unnecessary radiation exposure is This is causing a problem with radiation exposure.

Also, in machine tools, for the workpiece,
When cutting, etc. is added to a specific part,
Some require precise positioning of a specific part and the cutting tool, and require complex control devices such as numerical control.

In view of such difficulties, the present invention provides the above-mentioned example
To provide a device capable of precisely positioning both objects by a simple method and configuration when there are two objects to be positioned, not limited to a line imaging device or a machine tool.

Hereinafter, the details of the present invention will be explained based on the drawings. In FIGS. 1 and 2, a magnetic generation source M made of a magnet or an electromagnet is placed at a certain point on the coordinates, and the center of the magnetic generation source M is placed at a certain point on the coordinates. A rotationally symmetrical magnetic field is formed around the axis m. Corresponding to this, a movable object A is provided, and this movable object A has its central axis a.
Four magnetic detection sensors S... are arranged at equal intervals in the circumferential direction around the , and the distance r from the central axis a of each magnetic detection sensor S is the same, so that the magnetic sensitive axis of these sensors S... is the central axis. If they are made to be mutually symmetrical with respect to a, then if we move two-dimensionally or three-dimensionally with respect to the magnetic source M to a position where the magnetic detection outputs of these sensors S... show the same coincidence,
At points showing the same value, the central axes a and m of the movable object A and the magnetic source M are positioned so that they are coaxial. In other words, in the coaxial state, the distance from the magnetic source M to each magnetic detection sensor S is the same, and each sensor is placed in an area with the same magnetic field strength of the axially symmetrical magnetic field formed by the magnetic source M. The outputs naturally match.

Therefore, after extracting the peak value of the output of each sensor S by the peak hold circuit 1, these output peak values are passed through the comparison amplifier circuit 2 and displayed as a comparison value by the display means 3, and while looking at this displayed value. Move movable object A manually or move movable object A
By moving the driving means 4 of the movable object A to automatically control the feeding of the movable object A, the central axes a,
m matches are obtained. Furthermore, if the movable object A is moved forward and backward with respect to the magnetic source M from this coaxial matching state, the relative relationship between the magnetic source M and the movable object A can be adjusted by increasing or decreasing the output value of each magnetic detection sensor S. Distance can be controlled. Magnetic source M
is provided inside or on the back of one of the objects made of non-ferromagnetic material so as to form a rotationally symmetrical magnetic field around the central axis of the object's positioning, and the magnetic generation source M and the magnetic detection sensor are replaced. When the movable object A and the movable object A are positioned coaxially, the positions of the one object and the movable object A are inevitably determined such that the positioning center axes of both objects are coaxial. 15 is an oscillator, and 16 is a driver for driving the sensor. A power source is not shown.

In addition, although four magnetic detection sensors S are used in FIGS. 1 and 2, three may be arranged at equal intervals as shown in FIG. When the direction of movement of A is restricted by the guide member 5 so that it only moves parallel to the magnetic source M in one direction, it is also possible to use two pieces distributed in the direction of movement.

Also, as shown in Fig. 5, a fixed magnetic source M
On the other hand, it can also be used to move the movable object A from the chain line to the position shown by the solid line by applying a rotational force to the movable object A.

FIG. 6 shows an application example of a method of coaxially aligning two movable objects A and A' by positioning the two movable objects A and A' from opposite directions with respect to a single magnetic source M. After this positioning, the magnetic source M
If this is removed, these objects can be easily mated and connected by linear coaxial movement of both movable objects A and A'.

Furthermore, if the object B to which the magnetic generation source M is attached is shaped like a saucer with respect to the movable object A, as shown in FIG.
Object A can be fitted inside this object B.

In this way, the range of use and application is extremely wide.

As the magnetic detection sensor, a magnetic modulation type sensor, a Hall element, a magnetoresistive element, a SQUID, etc. are used.

FIG. 8 shows an embodiment in which the present invention is applied to a dental X-ray imaging apparatus, in which a magnet M is attached to a film F by an appropriate means.
is attached, and this film F is positioned inside the irradiation target tooth 6. At this time, the magnet center m is positioned to match the film center. On the other hand, three or four magnetic detection sensors S... are installed on the outer periphery of the tip of the X-ray irradiation tube 7 along the central axis of the X-ray irradiation tube 6 (X-ray central axis).
They are attached at equal intervals around m. In this way, from the state where the film F is positioned inside the patient's irradiation target tooth 6 as described above, the X-ray irradiation tube 7 is moved so that the output values of each magnetic detection sensor S... all match. By operating, when this coincides, the film center and magnet center m and the central axis m of the X-point irradiation tube 7,
In other words, coaxial alignment with the X-ray central axis is observed, and therefore, when X-ray photography is performed, the film F is completely contained within the X-ray irradiation field, and the irradiation target tooth 6 is photographed without causing a cone cut. can.

FIG. 9 shows a cutting machine to which the present invention is applied, in which a workpiece 9 made of a non-ferromagnetic material is placed on a processing table 8, and a magnet M is placed below a cutting part 9a of the workpiece 9. It is pasted. Drill 1 is directly above it.
A cutting tool holder 11 equipped with a drill bit 10 is provided, and magnetic detection sensors S . Then, the output of each magnetic detection sensor S... is taken out via the comparator 12, and the comparison value is input to the control device 13, so that the comparison value is zero, that is, the output of the magnetic detection sensor S... matches. The machining table 8 is fed via the servo motor 14 to position the cutting part directly below the drill 10, and from this state the drill 10 is lowered to perform the required cutting.

Figure 10 is a circuit diagram when digitally processing sensor output, 17 is a timing control,
18 and 20 are waveform shaping circuits, 19 is an analog multiplexer, 21 is an A/D converter, 22 is a memory, 23 is a motor driver circuit, 24 is a motor, 25 is a display driver circuit, and 26 is a display means. .

In addition, in the explanation so far, a plurality of sensors S are fixedly provided, but as shown in FIG. 11, a single sensor S' is rotated around the object A,
For example, the outputs of the rotating sensors S' may be taken out and compared at each fixed position of the sensor S as shown in FIG. Therefore, in FIG. 11, 27 indicates a circuit for rotationally driving the sensor S'.

As described above, the present invention allows two objects to be precisely and easily positioned by a simple combination of a magnetic generation source and a magnetic detection sensor.

In particular, since the present invention uses a magnetic circuit for positioning, there may be non-ferromagnetic objects (such as plastic, aluminum, etc.) between the objects to be positioned.
Positioning can be performed even when a human body or the like is involved, and it is suitable for application to processing and transportation after object recognition, industrial robots, radiation equipment for diagnosis and treatment, and the like.

[Brief explanation of drawings]

Figures 1 and 2 are operation diagrams for explaining the principle of the method of the present invention, Figures 3 to 7 are operation diagrams for explaining applied usage, respectively, and Figure 8 is a dental FIG. 9 is a schematic diagram showing the configuration of an embodiment in which the present invention is applied to a line imaging device, FIG. 9 is a schematic diagram showing the configuration of an embodiment applied to a machine tool, FIG. 10 is an example of a circuit configuration, and FIG. FIG. 3 is a circuit diagram for explaining an application example. (Explanation of symbols), A, A'B, F, 7, 9, 11
...Object, M...Magnetic source, S, S'...Magnetic detection sensor, a, m...Positioning center, 2,12
. . . Comparison circuit, 3 . . . Display means, 4 . . . Driving means.

Claims (1)

[Scope of Claims] 1. A magnetic generation source that forms a rotationally symmetrical magnetic field around the central axis of positioning of two objects that are to be positioned relative to each other is provided inside or on the back of one of the objects made of a non-ferromagnetic material. At the same time, the other object is provided with magnetic detection sensors at a plurality of equidistant positions within the same plane perpendicular to the positioning center axis of the other object. Attach it so that it is symmetrical, or
Alternatively, one magnetic detection sensor is provided so as to move sequentially over the plurality of positions, and the output of the magnetic detection sensor sensitive to the magnetic field at each of the above positions is extracted as a peak value by a peak hold circuit, and these outputs are matched. A method of positioning objects relative to each other in a direction in which the two objects are moved relative to each other so that the positioning center axes of both objects are coaxial. 2 A device for positioning two objects so that their central axes are coaxial with each other, and forming a rotationally symmetrical magnetic field around the positioning central axis of one of the objects, inside or on the back of one of the objects made of non-ferromagnetic material. A magnetic generation source is provided on the other object, and magnetic detection sensors are installed on the other object at a plurality of equidistant positions within the same plane perpendicular to the positioning center axis of the object. At the same time, one or both of the two objects is a movable object, and each output of the magnetic detection sensor is taken out as a peak value by a peak hold circuit, and these outputs are compared. A device for positioning objects with respect to each other, comprising: a circuit; and a comparison output thereof is input to a display means and/or a drive means for the movable object. 3 A device for positioning two objects so that their central axes are coaxial with each other, and forming a rotationally symmetrical magnetic field around the positioning central axis of one of the objects inside or on the back of one of the objects made of non-ferromagnetic material. A magnetic generation source is provided, and the other object is provided with a magnetic detection sensor that moves over a plurality of equidistant positions in the same plane perpendicular to the central positioning axis of the object, and either one or both of the objects is a movable object, and a comparison circuit that extracts the output of the magnetic detection sensor at each of the above positions as a peak value by a peak hold circuit and compares each of these outputs, and a display means or/and a comparison circuit that compares the outputs of the magnetic detection sensor at each position of the above movable object. A device for positioning objects relative to each other configured to input to a driving means.