JP2001074852A - Image display device using magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize an induction magnetic field from an object, to be detected, which is placed in a wide-area magnetic field and to display the object, to be detected, or the like on a two-dimensional image display device. SOLUTION: This image display device is composed of a wide-area magnetic field generator by an exciting coil. The image display device is composed of a receiver in which an array magnetic sensor 2 having many directional sensor elements is arranged in a magnetic field generated by the generator and which receives a magnetic signal from the sensor. The image display device is composed of a two-dimensional image display device in which the distribution state and the approximate shape of a metal to be detected are displayed two- dimensionally on the basis of its reception intensity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus using a magnetic sensor which can be applied to a metal object inspection apparatus used for baggage inspection at airports and the like for crime prevention. The present invention relates to an image display device using a magnetic sensor capable of recognizing an induced magnetic field from a detected object and displaying a detected object or the like on a two-dimensional image display device.

[0002]

2. Description of the Related Art A conventional magnetic sensor generates an AC magnetic field, receives an induced voltage of a metal from the magnetic field, and detects the presence or absence of a metal object in baggage. Also, X
A method of detecting the presence of a metal object using a wire and a transmission type nondestructive inspection device or the like is well known.

[0003]

However, in the system using the magnetic sensor, it is difficult to recognize the shape, and there are many detection malfunctions other than the detection target, and the detection performance is poor. In the case of transmission type non-destructive inspection equipment using X-rays, the use of X-rays irradiated to the human body in excess of the allowable radiation capacity is restricted by law. Must be used, and there is a very inconvenient point in use. Also, the X-ray baggage inspection apparatus used at airports and the like has a large shape in view of safety and is shielded with lead or the like, so that it is heavy and inconvenient when used.

[0004] In view of the above, the present invention provides a wide-area magnetic field generator using an excitation coil, a plurality of array-like magnetic sensor elements having directivity in the generated magnetic field, and a receiver for receiving a magnetic signal from this element. And a two-dimensional image display device for arbitrarily changing the directivity of the receiver and displaying the distribution state and schematic shape of the detected metal in two dimensions based on the received intensity, thereby enabling the shape of the detected object or the like to be accurately displayed. An object of the present invention is to solve the above problems by providing an image display device using a sensor.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a wide-area magnetic field generator using an exciting coil and an array magnetic sensor having a large number of directional sensor elements in the generated magnetic field. A receiver for receiving the
An image display device using a magnetic sensor, comprising: a two-dimensional image display device that two-dimensionally displays a distribution state and a rough shape of a detected metal from reception intensity. The array magnetic sensor is a magnetic sensor element. An image display device using a magnetic sensor characterized by being arranged in a large number in a planar manner, wherein the receiver uses a magnetic sensor characterized by comprising a plurality of receivers having directivity An image display device using a magnetic sensor, wherein the directivity can be arbitrarily switched.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a two-dimensional image display device using a magnetic sensor according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a two-dimensional image display device, and FIG. 2 is a configuration diagram of an array magnetic sensor. 1 in the figure
Is a loop coil for generating a wide area magnetic field, 2 is a magnetic sensor means,
Reference numeral 3 denotes a signal processing unit for processing a signal from the sensor unit, and reference numeral 4 denotes an image display unit.

The wide-area magnetic field generating loop coil 1 has a conventionally known configuration, and a detailed description thereof will be omitted. The magnetic sensor means 2 includes a magnetic sensor 2a, a sensor signal balance device 2b having a known configuration for receiving a signal from the sensor, and an A / D / D / A converter 2c. Is configured as a printed circuit board-shaped array magnetic sensor in which a plurality of sensor elements 20 are arranged in a predetermined area as shown in FIG. 2, and a sensor signal balance device 2b balances a measurement signal from the magnetic sensor. Performs the function of making adjustments. For example, assuming that the detection target is in a bag of a normal size (35 × 40 × 8 cm), the number of sensor elements of the array magnetic sensor is about 15 in length and about 20 in width, and a pitch of about 3 cm each. Need to be installed at It is desirable that the distance between the bag and the sensor is in contact.

The signal processing means 3 comprises a conventionally known data processing device (noise processing device or the like) 3a and a data analysis device 3b. The signal processing means 3 comprises a magnetic field generating an excitation magnetic field from a detection result and a conductor of the detection object. It has a function of processing the phase shift of the returning magnetic field and selectively extracting only the returning magnetic field from the conductor of the detection object. Further, the image processing means 4 includes a known image conversion device 4a, a two-dimensional image display device (monitor) 4b, and an image recording device 4c, and has a function of displaying a signal from the signal processing device 3 as an image and an image recording function. ing. Note that the image recording device can be omitted as necessary.

FIG. 3 shows an overall schematic configuration diagram of a two-dimensional image display device using the magnetic sensor. The magnetic sensor means 2 on which the magnetic sensor elements are arranged is erected at a substantially right angle from a mounting table 5 on which a detection object is mounted, and the test object 6 can be mounted on the mounting table 5. . Also, a wide-area magnetic field generation loop coil (not shown) capable of generating a magnetic field toward the detection object is arranged at a predetermined position,
The magnetic sensor means 2 is connected to a two-dimensional image display device.

The operation of the two-dimensional image display device having the above configuration will be described. First, when an AC power supply or a pulse-like voltage is applied to the wide-area magnetic field generating loop coil in a state where the detection object is mounted on the mounting table 5, a magnetic field proportional to the current flowing through the loop coil is emitted from the loop coil. Detected object (such as knife) made of a conductor (metal, etc.) in this magnetic field
Is present, the detection object is excited in an alternating current or a pulse. When the detection object itself is excited as described above, an induced current flows, and a magnetic field is generated from the detection object.

Although the generated magnetic field is detected by the magnetic sensor means 2 for detecting the magnetic field, the magnetic field for detecting the magnetic field is included in the strong magnetic field generated from the wide-area magnetic field generating loop coil in the above state. Since the sensor means is provided, it is difficult to detect a weak magnetic field from the detected object. Therefore, if the phase shift between the magnetic field generated by the exciting magnetic field and the magnetic field returned from the conductor of the detection object is processed by the signal processing unit 3,
Only the magnetic field returning from the conductor of the detection object can be selectively received. Thereafter, the signal from the signal processing means 3 is transmitted to the two-dimensional image display device, and the image is processed by a known technical means. When performing two-dimensional image processing, by providing a plurality of directional receivers in which a wide-area magnetic field generator and a loop coil are arranged in an array on the same plane, an object detected by each receiver can be used. Can be detected. At this time, the signal strength of the receiver becomes larger as the magnetic field detection sensor is closer to the detection metal,
A weak signal from each of the receivers is amplified, and the shape of the detected object can be displayed two-dimensionally on an image display device corresponding to the arrangement of the sensors. Thus, a knife or the like existing in the detection object can be easily detected.

While one embodiment of the present invention has been described above, the present invention can be embodied in any other form without departing from its spirit or main characteristics. Therefore, the above-described embodiment is merely an example in all aspects and should not be interpreted in a limited manner.

[0013]

As described above in detail, the present invention uses a printed circuit board-shaped array-type magnetic sensor as compared with the conventional transmission-type sensor, so that the power-saving device is small and lightweight. And it is harmless to the human body. Since the obtained upper part is input to a personal computer to be imaged and displayed on a display, it is possible to visually confirm and find dangerous goods and weapons present in the bag. Since this device uses magnetism that is harmless to the human body, there is no restriction on the place of use such as an X-ray device. An X-ray apparatus requires a national qualification such as a chief X-ray operator, but this apparatus does not require a qualification and can be used by anyone. Also, if the baggage contents are inspected at schools or the like to prevent dangerous materials from being brought in, the privacy of the individual may be violated because the contents of the bag are taken out by many students. When carrying out a property inspection or the like with a time limit by using the method, it is possible to reliably limit the bringing in of dangerous goods.
It is possible to select and detect dangerous substances using a certain amount of metal and weapons such as knives in a container such as a bag, thereby respecting the privacy of individuals. When this device is used as a device to detect the condition of reinforcing bars in a concrete wall, the condition of the reinforcing bars in the wall is visualized and displayed. Excellent effects can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a two-dimensional image display device according to the present invention.

FIG. 2 is a configuration diagram of a magnetic sensor.

FIG. 3 shows an overall schematic configuration diagram of a two-dimensional image display device using a magnetic sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Loop coil for wide area magnetic field generation 2 Magnetic sensor means 2a Magnetic sensor 2b Sensor signal balance device 2c A / D, D / A converter 3 Signal processing means 3a Data processing device 3b Data analysis device 4 Image display means 4a Image conversion device 4b 2D image display device 4c Image recording device 5 Mounting table 6 Inspection object

Claims (4)

[Claims] 1. A wide-area magnetic field generator using an exciting coil, an array magnetic sensor having a large number of directional sensor elements in the generated magnetic field, and a receiver for receiving a magnetic signal from the sensor; An image display device using a magnetic sensor, comprising: a two-dimensional image display device that two-dimensionally displays a distribution state and a schematic shape of a detection metal. 2. The image display device using a magnetic sensor according to claim 1, wherein the array magnetic sensor is configured by arranging a large number of magnetic sensor elements in a plane and vertically and horizontally. 3. The image display device using a magnetic sensor according to claim 1, wherein the receiver comprises a plurality of receivers having directivity. 4. The image display device using a magnetic sensor according to claim 3, wherein the directivity can be arbitrarily switched.