KR20120010051A - Magnetic-field detecting apparatus having differnetial-magetic-sensor-module - Google Patents

Abstract

PURPOSE: A magnetic field detecting apparatus equipped with a differential magnetism sensor module is provided to measure the difference of magnetic force. CONSTITUTION: A magnetic field detecting apparatus equipped with a differential magnetism sensor module comprises a differential magnetism sensor module(13) and a signal processing module(33). The differential magnetism sensor module comprises a first magnetic sensor(131) and a second magnetic sensor(132). The differential magnetism sensor module outputs the difference output values of the first magnetic sensor and second magnetic sensor as a signal. The signal processing module gets the information about the difference output values of the first magnetic sensor and second magnetic sensor.

Description

Magnetic field detection apparatus having differential magnetic sensor module {Magnetic-field detecting apparatus having differnetial-magetic-sensor-module}

The present invention relates to a magnetic field detection device, and more particularly, by using a differential magnetic sensor module to measure the difference in magnetic field strength in adjacent minute regions in space, even when a strong magnetic field is applied in the direction of response of each magnetic sensor. The present invention relates to a magnetic field detection device capable of measuring a difference in magnetic field strength in an adjacent micro area.

Nondestructive inspection methods using magnetic phenomena are useful inspection methods to detect surface defects in the structure, backside defects or internal defects near the surface. Non-destructive testing methods can be used to detect defects in large plants and structures used in nuclear power, thermal power, and chemical industries.

When measuring the intensity distribution of magnetic field in space or the difference in magnetic field in micro space, measurement of defects in magnetized specimens, non-destructive inspection by eddy currents, detection of metals and mines, inspection of printed circuit boards, inspection of power lines and power connections It can be used for various purposes such as leakage current detection and magnetic pattern inspection.

One of the methods for measuring the intensity distribution of magnetic fields in space or the difference in strength of magnetic fields in micro-space is to measure the intensity of magnetic fields in space corresponding to each position by arranging a large number of magnetic sensors in two or three dimensions. It is.

When the magnetic sensors are arranged in two or three dimensions, the number of wires increases in proportion to the number of sensors, and thus the wiring method for driving and extracting signals of the two-dimensional arrayed magnetic sensors becomes very complicated.

The problem to be solved by the present invention is to measure the difference in magnetic field strength in the adjacent micro-regions in space, and to measure the difference in magnetic field strength in the adjacent micro-regions in space even when a strong magnetic field is applied in the sensitive direction of each magnetic sensor. A magnetic field detection device is provided.

In order to solve the above problems, the present invention includes a first magnetic sensor and a second magnetic sensor for respectively outputting an electrical signal in response to a magnetic field, wherein the output value of the first magnetic sensor and the output value of the second magnetic sensor A differential magnetic sensor module for outputting a difference value as an output signal; And a signal processor configured to filter and amplify the output signal to quantify a difference in magnetic field strength in a space in which the first magnetic sensor and the second magnetic sensor are located. The first magnetic sensor and the second magnetic sensor may include a power source. A first power supply terminal to which Vcc is connected, a second power supply terminal to which ground GND is connected, a first output terminal to output a first output value, and a second output terminal to output a second output value, respectively; The second output terminal of the first magnetic sensor is connected to the first output terminal of the second magnetic sensor, and the first output terminal of the first magnetic sensor and the second output terminal of the second magnetic sensor are the signal processor. It provides a magnetic field detection device characterized in that connected to.

The present invention also provides a differential magnetic sensor array comprising a plurality of differential magnetic sensor modules arranged in M rows * N columns; And a signal processing unit for quantifying a difference in magnetic field strength in a space where the differential magnetic sensor module is located from respective output values of the differential magnetic sensor modules, wherein each of the differential magnetic sensor modules outputs an electrical signal corresponding to the magnetic field strength. And a first magnetic sensor and a second magnetic sensor, wherein the first magnetic sensor and the second magnetic sensor include a first power supply terminal to which a power supply Vcc is connected and a second power supply terminal to which a ground GND is connected. And a first output terminal for outputting a first output value corresponding to the magnetic field strength, and a second output terminal for outputting a second output value corresponding to the magnetic field strength, wherein the second output terminal of the first magnetic sensor includes: And a second output terminal of a second magnetic sensor, wherein the first output terminal of the first magnetic sensor and the first output terminal of the second magnetic sensor are connected to the signal processor. It provides a magnetic field detection apparatus with.

In addition, the present invention includes a first magnetic sensor, a second magnetic sensor, a third magnetic sensor and a fourth magnetic sensor for outputting an electrical signal corresponding to a magnetic field, respectively, wherein the first magnetic sensor and the second magnetic sensor A differential magnetic sensor module for outputting a difference value between the difference value and the difference value between the third magnetic sensor and the fourth magnetic sensor as an output signal; And a signal processor for filtering and amplifying the output signal to quantify a difference in magnetic field strength in a space in which the differential magnetic sensor module is located, wherein the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the third magnetic sensor are quantified. Each of the four magnetic sensors includes a first power supply terminal to which a power supply Vcc is connected, a second power supply terminal to which a ground GND is connected, a first output terminal to output a first output value corresponding to the magnetic field strength, and a magnetic field strength. A second output terminal for outputting a second output value corresponding to the second output terminal, wherein the second output terminal of the first magnetic sensor is connected to the second output terminal of the second magnetic sensor, The second output terminal is connected to the second output terminal of the fourth magnetic sensor, the first output terminal of the second magnetic sensor is connected to the first output terminal of the third magnetic sensor, 1 output Characters and the fourth first output terminal of the magnetic sensor provides a magnetic field detecting device, characterized in that connected to the signal processor.

The present invention also provides a differential magnetic sensor array comprising a plurality of differential magnetic sensor modules arranged in M rows * N columns; And a signal processing unit for quantifying a difference in magnetic field strength in a space where the differential magnetic sensor module is located from respective output values of the differential magnetic sensor modules, wherein each of the differential magnetic sensor modules outputs an electrical signal corresponding to the magnetic field strength. And a first magnetic sensor, a second magnetic sensor, a third magnetic sensor, and a fourth magnetic sensor, wherein each of the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor , A first power terminal connected to the power supply Vcc, a second power supply terminal connected to the ground GND, a first output terminal outputting a first output value corresponding to the magnetic field strength, and a second output value corresponding to the magnetic field strength. A second output terminal for outputting a second output terminal, the second output terminal of the first magnetic sensor is connected to a second output terminal of the second magnetic sensor, and a second output terminal of the third magnetic sensor Is connected to a second output terminal of the fourth magnetic sensor, a first output terminal of the second magnetic sensor is connected to a first output terminal of the third magnetic sensor, and a first output terminal of the first magnetic sensor And a first output terminal of the fourth magnetic sensor is connected to the signal processor.

According to the present invention, the differential magnetic sensor module can be used to measure the difference in magnetic field strength in adjacent microregions in space, and even when a strong magnetic field is applied in the sensitive direction of each magnetic sensor, the magnetic field strength in adjacent microregions in space The difference can be measured.

In addition, according to the present invention, by using a differential magnetic sensor array in which a plurality of differential magnetic sensor modules are arranged in a matrix form, it is possible to quickly measure the difference in intensity of magnetic fields in adjacent microspaces in a large area.

In addition, according to the present invention, by placing all the switches of the switching unit outside the magnetic sensor arrangement, each magnetic sensor can be arranged more densely and the number of wires can be minimized in the area where each magnetic sensor is arranged. .

1 is a block diagram showing a magnetic sensor and a magnetic field detection device having the same.
FIG. 2 illustrates a magnetic field detection device including the magnetic sensor array in which the magnetic sensors of FIG. 1 are arranged in a matrix form. FIG.
3 is a view showing a differential magnetic sensor module and a magnetic field detection device having the same according to the present invention.
4 is a view showing a differential magnetic sensor array and a magnetic field detection device having the same according to the present invention.
5 is a view showing a differential magnetic sensor module and a magnetic field detection device having the same according to the present invention.
Figure 6 illustrates a differential magnetic sensor array and a magnetic field detection device having the same according to the present invention.
7 is a view showing a differential magnetic sensor module and a magnetic field detection device having the same according to the present invention.
8 illustrates a differential magnetic sensor array and a magnetic field detection device having the same according to the present invention.
9 is a view showing a magnetic field detection device according to the present invention.
10 is a detailed view of a signal processor.
FIG. 11 is a view showing experimental results according to the magnetic sensor arrangement of FIG. 2. FIG.
FIG. 12 is a diagram illustrating a distribution of differences in magnetic field strength in a minute region in the horizontal axis direction in FIG. 11. FIG.
FIG. 13 is a view showing experimental results according to the differential magnetic sensor arrangement of FIG. 4. FIG.
FIG. 14 is a view showing experimental results when a magnetic field is applied in a direction in which a magnetic sensor is sensed in the arrangement of FIG. 2.
FIG. 15 is a view showing an experimental result when a magnetic field is applied in the direction of induction of the magnetic sensor in the arrangement of FIGS. 4 to 8.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a view showing a magnetic sensor and a magnetic field detection device having the same.

As shown in FIG. 1, the magnetic field detection device 60 may include a magnetic sensor 10 and a signal processor 30, and may further include a switch 20.

The magnetic sensor 10 includes a first power terminal a, a second power terminal c, a first output terminal d, and a second output terminal b. The first power supply terminal (a) is connected to the first power supply (Vcc) and the second power supply terminal (c) is connected to the second power supply (GND) which is ground, and the first output terminal (d) and the second output terminal ( b) outputs a first output voltage V1 + and a second output voltage V1-, respectively.

The switch 20 includes a first switch SW1 and a second switch SW1 ′, and a first switch SW1 is connected between the first power supply terminal a and the first power supply Vcc, and The second switch SW1 ′ is connected between the power supply terminal c and the ground GND. The switch 20 plays a role of initiating and terminating the driving of the magnetic sensor 10, and for the magnetic sensors positioned in each row and column when the plurality of magnetic sensors 10 are arranged in a matrix form. Start and end the drive.

When the first power supply Vcc is applied to the first power supply terminal a of the magnetic sensor 10 and the second power supply GND (ground) is connected to the second power supply terminal c, the magnetic sensor 10 is magnetic. The electrical signal corresponding to the intensity of the magnetic field incident on the sensor 10 is output to the signal processor 30 through the first output terminal d and the second output terminal b. When the electric field and the magnetic field are orthogonal in the magnetic sensor 10, a voltage difference occurs between the first output terminal d and the second output terminal b.

That is, when the switches SW1 and SW1 'are driven, Vcc and GND are input to the a terminal and the c terminal of the magnetic sensor 10. In addition, a voltage corresponding to V1 + is output to the first output terminal b and V1- is output to the second output terminal d in proportion to the strength of the magnetic field input to the magnetic sensor 10. The signal processor 30 may quantitatively measure the intensity of the magnetic field in the space where the magnetic sensor 10 is located by detecting electrical signals of V1 + and V1-.

In the present invention, the magnetic sensor includes a hall sensor, a magneto-resistive sensor (MR sensor) sensor, a giant magneto resistive sensor (GMR sensor), and a giant magneto impedance sensor. , GMI sensor).

To detect the magnetic field using the single magnetic sensor 10, the magnetic field generated in the object 60 may be detected while moving precisely on a plane parallel to the object under test (not shown). In such a method, the magnetic sensor 10 must be moved to scan the entire subject 60. As described above, when a single magnetic sensor 10 is used, the magnetic sensor 10 must be moved on the object under test.

On the other hand, as will be described later, by arranging the plurality of magnetic sensors 10 in a matrix form, the magnetic field can be detected quickly over a large area. In addition, when a differential magnetic sensor array is used, the magnetic field is applied to the object under test without moving the magnetic sensor. The magnetic field may be detected. By detecting the magnetic field of the subject using the magnetic sensor, the magnetic sensor array and the differential magnetic sensor array according to the present invention, the internal structure of the subject can be inspected in a non-destructive manner without destroying the subject. Defects, such as a crack which may exist inside a to-be-measured object, can be detected.

FIG. 2 is a diagram illustrating a magnetic field detection device including a magnetic sensor array in which the magnetic sensors of FIG. 1 are arranged in a matrix form.

The magnetic field detecting apparatus according to FIG. 2 includes a magnetic sensor array 110, switching units 211 and 212, and a signal processor (not shown).

The magnetic sensor array 110 according to FIG. 2 is in the form of a matrix of M rows * N columns (4 rows * 4 columns in FIG. 2, but embodiments of the present invention are not limited thereto and can be arranged in various types of rows and columns). Magnetic sensors 1101-1116 are arranged. The first power supply terminal a of each of the magnetic sensors arranged in the m (m is 1 to M) rows is connected to the first power supply Vcc through the same power supply line, and the m (m is 1 to M) rows are arranged. The second power supply terminals b of the respective magnetic sensors are connected to the second power supply GND through the same power supply line. The first output terminal d of each of the magnetic sensors arranged in the n (n is 1 to N) columns outputs an electrical signal Vn + through the same output line, and the n (n is 1 to N) The second output terminal d of the magnetic sensors outputs an electrical signal Vn− through the same output line.

The switching units 211 and 212 start and end the driving of the respective magnetic sensors 1101 to 1116 in the magnetic sensor array 110. To this end, the switching units 211 and 21 may include a first switch 211 and each magnetic sensor 1101 to 1116 transferring the first power source Vcc to the first power supply terminal a of each of the magnetic sensors 1101 to 1116. And a second switch 212 that transfers the second power source GND to the second power source terminal c).

The first switch 211 includes the same number of switches as the number of rows in order to drive the magnetic sensor for each row. Similarly, the second switch 212 also has the same number of switches as the number of rows in order to drive the magnetic sensor for each row. Since the magnetic sensor array 110 of FIG. 2 has four rows, in the case of FIG. 2, the first switch 211 includes four switches SW1a, SW2a, SW3a, and SW4a. It is also composed of four switches SW1b, SW2b, SW3b, SW4b. When a switch is turned on, power is supplied to all magnetic sensors belonging to the row connected to that switch. Since the magnetic sensor is driven only when both the first power source Vcc and the second power source GND are applied, the switches belonging to the same row in the first switch and the second switch 211 and 212 must be controlled to be turned on at the same time.

In the first switch 211, SW1a transfers the first power source Vcc to each of the first power terminals a of the magnetic sensors 1101 to 1104 in one row, and SW1b is the magnetic sensors 1101 to 1 in one row. The second power source GND is transferred to each of the second power source terminals c of 1104. SW2a delivers the first power source Vcc to each of the first power supply terminals a of the two rows of magnetic sensors 1105-1108, and SW2b is each second power source of the magnetic sensors 1101-1104 in two rows. The second power source GND is transferred to the terminals c. The switches SW3a, SW3b, SW4a, and SW4b are also connected similarly to the above.

In FIG. 2, the magnetic sensors arranged in the m row are the magnetic sensors disposed in the m row with the switches SWma and SWmb connected to the magnetic sensors of the m row turned on. When the power supply Vg is applied, the magnetic sensors arranged in the m row respectively output electrical signals corresponding to the strength of the magnetic field incident on the respective magnetic sensors.

For example, the magnetic sensors 1101 to 1104 arranged in a row may provide an electrical signal corresponding to the strength of the magnetic field incident on the magnetic sensors 1101 to 1104 when the switch SW1a and the switch SW1b are turned on. Output through each output line. When the switch SW1a and the switch SW1b are turned on, the magnetic sensor 1101 disposed in one column of one row outputs V1 + and V1-, which are output values corresponding to the magnetic field strength, as electrical signals, and the magnets arranged in two columns of one row. The sensor 1102 outputs V2 + and V2-, which are output values corresponding to the magnetic field strength, as electrical signals. On the other hand, the magnetic sensors 1103 and 1104 arranged in three columns of one row and four columns of one row output V3 + and V3-, V4 + and V4-, respectively.

The output lines Vn + and Vn− are connected to the signal processor 30. The signal processor 30 quantitatively detects a magnetic field corresponding to the position of each magnetic sensor 1101 to 1116 in the magnetic sensor array by analyzing the electrical signals transmitted through the respective output lines Vn + and Vn−.

Since the first output terminal d and the second output terminal b of the magnetic sensors arranged in the same column are connected to the same output line, respectively, they belong to different rows in the first switch and the second switch 211 and 212. The switch must be controlled so that it is not turned on at the same time.

3 is a view showing a differential magnetic sensor module and a magnetic field detection device having the same according to the present invention.

Referring to FIG. 3, the magnetic field detecting apparatus according to the present invention may include a differential magnetic sensor module 13 and a signal processor 30, and may further include a switching unit 23.

As shown in FIG. 3, the differential magnetic sensor module 13 according to the present invention comprises a pair of magnetic sensors, and includes a first magnetic sensor 131 and a second magnetic sensor 132.

The first magnetic sensor 131 and the second magnetic sensor 132 have a first power terminal (a), a second power terminal (c), a first output terminal (d) and a second output terminal (b), respectively. do.

In the first magnetic sensor 131 and the second magnetic sensor 132, the first power supply terminal a is connected to the first power supply Vcc and the second power supply terminal c is the grounded second power supply GND. Connected with Meanwhile, the second output terminal b of the first magnetic sensor 131 is connected to the second output terminal b of the second magnetic sensor 132.

The first output terminal d of the first magnetic sensor 131 is connected to the signal processor 33 and outputs a first output voltage V1 +. The first output terminal d of the second magnetic sensor 132 is connected to the signal processor 33 and outputs a second output voltage V1-.

The switching unit 23 serves to supply power to the differential magnetic sensor module 13, and includes a first switch SW1 and a second switch SW1 ′. The first switch SW1 is positioned between the first power source Vcc and the first power terminal a of each of the magnetic sensors 131 and 132, and the second switch SW1 ′ is connected to the second power source GND. It is located between the 2nd power supply terminals c of each magnetic sensor 131.132.

By arranging and wiring a pair of magnetic sensors 131 and 132 as shown in FIG. 3, it is possible to measure the difference in intensity of magnetic fields in adjacent areas in space. That is, when SW1 and SW1 'are driven in FIG. 3, power is supplied to each of the power terminals a and c of the magnetic sensors 131 and 132 by Vcc and GND. Accordingly, in the left magnetic sensor 131 and the right magnetic sensor 132, the first output terminal (d) and the second output terminal (b) respectively output an electrical signal proportional to the strength of the magnetic field. At this time, when the second output terminal b of the left magnetic sensor 131 and the second output terminal b of the right magnetic sensor 132 are connected to each other, the first output terminal d of the left magnetic sensor 131 is connected. And electrical signals corresponding to V1 + and V1-, respectively, are output from the first output terminal d of the right magnetic sensor 132. This electrical signal is independent of the strength of the magnetic field incident on the left magnetic sensor 131 and the right magnetic sensor 132, respectively, and is proportional to the difference in the relative magnetic field strengths of the two magnetic sensors 131 and 132. That is, the differential magnetic sensor module 13 of FIG. 3 outputs, as an electric signal, a difference in intensity of a magnetic field in an adjacent micro space, that is, a space in which two magnetic sensors 131 and 132 are located.

The signal processor 33 is connected to the first output terminal d of the first magnetic sensor 131 and the first output terminal d of the second magnetic sensor 132, and is formed of the differential magnetic sensor module 13. The first output voltage V1 + and the second output voltage V1- are received.

The differential magnetic sensor module 13 according to the present invention connects the second output terminal b of the first magnetic sensor 131 and the second output terminal b of the second magnetic sensor 132 with each other, and consequently, The value corresponding to the difference between the output values of the first magnetic sensor 131 and the second magnetic sensor 132 is output in the form of the first output voltage V1 + and the second output voltage V1-.

4 is a diagram illustrating a differential magnetic sensor array and a magnetic field detection device having the same according to the present invention.

The magnetic field detecting apparatus according to the present invention includes a differential magnetic sensor array 130, switching units 231 and 232, and a signal processor (not shown).

First, in the differential magnetic sensor array 130 according to the present invention, the differential magnetic sensor modules 13_1 to 13_12 same as those of FIG. 3 are M rows * N columns (4 rows * 3 columns in FIG. 4, but embodiments of the present invention are limited thereto). Can be arranged in a variety of rows and columns). Since the differential magnetic sensor modules 13_1 to 13_12 of FIG. 4 are the same as those of the differential magnetic sensor module 13 of FIG. 3, redundant description thereof will be omitted.

In the differential magnetic sensor array 130 according to the present invention, the first power terminals a of all the magnetic sensors included in each of the differential magnetic sensor modules arranged in columns n (n is 1 to N) are connected to one power line. The second power terminals b of all the magnetic sensors included in each differential magnetic sensor module arranged in the n (n is 1 to N) columns are connected to the first power supply Vcc through 2 Connected to power supply (GND). On the other hand, in each of the differential magnetic sensor modules 13_1 to 13_12, the second output terminals b of the left magnetic sensors 1301 to 1324 are odd magnetic sensors that are even in the right magnetic sensors 1301 to 1324. Is connected to the second output terminal (b). The first output terminals d of the left magnetic sensors 1301 to 1324 are odd in each of the differential magnetic sensor modules arranged in the row m (m is 1 to M), and the electrical signals ( Vm +) and the first output terminals d of the right magnetic sensors 1301 to 1324 are even in each of the differential magnetic sensor modules arranged in the row m (m is 1 to M), and the same output line Outputs an electrical signal (Vn-).

Each output line of the differential magnetic sensor modules 13_1 to 13_12 is connected to the signal processor 33, and output values V1 +, V2 +, V3 +, V4 +, V1-, of the differential magnetic sensor modules 13_1 to 13_12. V2-, V3- and V4- are transmitted to the signal processor 33, respectively.

The switching units 231 and 232 start and end the driving of the respective magnetic sensors 1301 to 1324 in the magnetic sensor array 130. To this end, the switching units 231 and 232 may include a first switch 231 and each magnetic sensor 1302 to 1324 for transmitting the first power Vcc to the first power terminal a of each of the magnetic sensors 1301 to 1324. And a second switch 232 for transmitting the second power source GND to the second power source terminal c).

The first switch 231 includes the same number of switches as the number of rows in order to drive the magnetic sensor for each row. Similarly, the second switch 212 also includes the same number of switches as the number of rows to drive the magnetic sensor for each row. Since the magnetic sensor array 130 of FIG. 4 is composed of three rows, in FIG. 4, the first switch 231 is composed of three switches SW1, SW2, and SW3, and the second switch 232 is also three switches. (SW1 ', SW2', SW3 '). When any one of the three switches is turned on, power (Vcc, GND) is applied to all magnetic sensors included in the differential magnetic sensor module belonging to the column connected to the turned on switch. Since the magnetic sensor is driven when both the first power source Vcc and the second power source GND are applied, the switches belonging to the same row in the first switch and the second switch 231 and 232 must be controlled to be turned on at the same time. For example, when trying to drive the differential magnetic sensor modules 13_1, 13_4, 13_7, and 13_10 belonging to the first row, SW1 and SW1 ′ must be controlled to be turned on.

The switch SW1 connected to the first row of the first switch 231 is connected to the first power terminals a of all magnetic sensors included in the differential magnetic sensor modules 13_1, 13_4, 13_7, and 13_10 of the first row. (SWc ') connected to the first row in the second switch 232 and connected to the second switch 232, each second of every magnetic sensor included in the differential magnetic sensor modules 13_1, 13_4, 13_7, and 13_10 of the first row. The second power supply GND is connected to the power supply terminals c. On the other hand, the switches SW2, SW2 ', SW3, and SW3' are similarly connected.

The switches belonging to the same column in the first switch 231 and the second switch 232 are controlled to be turned on and off at the same time. For example, SW1 and SW1 'are controlled to be turned on and off at the same time, SW2 and SW2' are controlled to be turned on and off at the same time, and SW3 and SW3 'should be controlled to be turned on and off at the same time.

On the other hand, the output values V1 +, V2 +, V3 +, V4 +, V1-, V2-, V3-, and V4- output from the respective output lines of the respective differential magnetic sensor modules 13_1 to 13_12 are not equal to each other. In order to identify the output, the switches must be controlled so that they are not turned on simultaneously in two rows. When the switch driving the differential magnetic sensor modules of one row is turned on, the switch driving the differential magnetic sensor modules of another row must be controlled to be turned off.

For example, when SW1 and SW1 ', which are switches for driving the differential magnetic sensor modules 13_1, 13_4, 13_7, and 13_10 of the first row, are turned on, the remaining switches SW2, SW2', SW3, and SW3 'are turned on. Will remain off. Since the switches for driving the differential magnetic sensor modules of the respective rows are controlled to be periodically turned on / off in order, the difference in the relative magnetic field strength in the space in which the differential magnetic sensor array 130 is located can be quickly detected.

On the other hand, in the present invention, all the switches SW1 to SW3 and SW1 'to SW3' of the switching units 231 and 232 are preferably located outside the differential magnetic sensor array 130, whereby each magnetic sensor The fields 1301 to 1324 may be arranged more densely, and the number of wires may be minimized in the region in which the magnetic sensors 1301 to 1324 are arranged.

In this arrangement, SW1 and SW1 ', SW2 and SW2', SW3 and SW3 'are sequentially switched and driven, and output values of V1 + and V1-, V2 + and V2-, V3 + and V3-, and V4 + and V4- are signaled. By measuring in parallel by the processing unit 33, the difference in the intensity of the magnetic field on the adjacent microspace in a large area can be quickly measured. According to this principle, the differential magnetic sensor module is arranged two-dimensionally so as to have more rows and columns as well as the four-row * three-column differential magnetic sensor modules 13_1 to 13_12 of FIG. The difference in intensity of the magnetic field can be measured.

5 is a view showing a magnetic field detection device having a differential magnetic sensor module according to the present invention, Figure 6 is a view illustrating a differential magnetic sensor array and a magnetic field detection device having the same according to the present invention.

Referring to FIG. 5, the differential magnetic sensor module 14 according to the present invention has the same wiring connection scheme as that of the differential magnetic sensor module 13 of FIG. 3, but the terminals of the magnetic sensors 141 and 142 are each a. , b, c, d) is a different embodiment.

In addition, although the differential magnetic sensor array 140 of FIG. 6 has the same wiring connection method as that of the differential magnetic sensor array 130 of FIG. 4, the terminals a, b, c, and d of the magnetic sensors 1401-1424 are shown. ) Is a different embodiment.

In FIGS. 5 and 6, the differential magnetic sensor module 14 and the differential magnetic sensor array 140 may include the differential magnetic sensor module 13 and the differential magnetic sensor array 130 and components and functions thereof. The same description will be omitted since it is the same.

As such, the terminals included in the respective magnetic sensors in the differential magnetic sensor module 13 and 14 and the differential magnetic sensor array 130 and 140 according to the present invention are not limited to the embodiments of FIGS. The terminals may be connected in various forms between each terminal, the power line, and the output line.

7 is a view showing a differential magnetic sensor module and a magnetic field detection device having the same according to the present invention.

Referring to FIG. 7, the magnetic field detecting apparatus according to the present invention may include a differential magnetic sensor module 15 and a signal processor 35, and may further include a switching unit 25.

As shown in FIG. 7, the differential magnetic sensor module 15 according to the present invention includes four magnetic sensors, and includes a first magnetic sensor 151, a second magnetic sensor 152, a third magnetic sensor 153, and a first magnetic sensor. Four magnetic sensors 154. Each of the first to fourth magnetic sensors 151 to 154 includes a first power terminal a, a second power terminal c, a first output terminal d, and a second output terminal b. .

In the first to fourth magnetic sensors 151 to 154, all of the first power terminals a are connected to the first power source Vcc through power lines connected to one, and all of the second power terminals c are connected to each other. The second power source GND is connected to the ground through a power line connected to one. The second output terminal b of the first magnetic sensor 151 is connected to the second output terminal b of the second magnetic sensor 152 and the second output terminal b of the third magnetic sensor 153. ) Is connected to the second output terminal b of the fourth magnetic sensor 152. The first output terminal d of the second magnetic sensor 152 is connected to the first output terminal d of the third magnetic sensor 153.

The first output terminal d of the first magnetic sensor 151 is connected to the signal processor 33 and outputs a first output voltage V1 +. The first output terminal d of the fourth magnetic sensor 132 is connected to the signal processor 35 and outputs a second output voltage V1-.

The switching unit 25 serves to supply power to each of the magnetic sensors 151 to 154 included in the differential magnetic sensor module 15, and the first power source Vcc and each of the magnetic sensors 151 to 154. The second switch located between the first switch SW1 and the second power source GND positioned between the first power terminal a and the second power terminal c of each of the magnetic sensors 151 to 154. (SW1 ').

When four magnetic sensors 151 to 154 are arranged and wired as shown in FIG. In the differential magnetic sensor module 15 of FIG. 7, the terminal arrangement and the wiring connection of the upper two magnetic sensors 151 and 152 and the lower two magnetic sensors 153 and 154 are connected to the differential magnetic sensor module 13 of FIG. 3. similar. However, the differential magnetic sensor module 15 of FIG. 7 connects the first output terminal d of the upper right magnetic sensor 152 and the first output terminal d of the lower left 153 to each other, resulting in the upper magnetic. The difference between the magnetic field strength difference in the sensors 151 and 152 and the magnetic field strength difference in the lower magnetic sensors 153 and 154 is output in the form of the first output voltage V1 + and the second output voltage V1-. .

That is, the differential magnetic sensor module 15 according to the exemplary embodiment of FIG. 7 may include a difference value between the output values of the first magnetic sensor 151 and the second magnetic sensor 152, and the third magnetic sensor 153 and the fourth magnetic sensor. The difference value of the difference value of the output value of (153) is output as an output value.

8 shows a magnetic field detection device having a differential magnetic sensor arrangement in accordance with the present invention.

The magnetic field detecting apparatus according to the present invention includes a differential magnetic sensor array 150, switching units 251 and 252, and a signal processor (not shown).

In the differential magnetic sensor array 150 according to the present invention, the differential magnetic sensor modules 15_1 to 15_6 of FIG. 7 are M rows * N columns (2 rows * 3 columns in FIG. 8, but embodiments of the present invention are not limited thereto). Can be arranged in rows and columns of various forms).

Since the differential magnetic sensor modules 15_1 to 15_6 of FIG. 8 have the same function as that of the differential magnetic sensor module 15 of FIG. 7, the arrangement of the terminals, and the connection method of the wirings, overlapping description thereof will be omitted. Meanwhile, in the differential magnetic sensor array 150 of FIG. 8, terminal arrangement, connection between terminals, and connection between each terminal and a power line and an output line of the magnetic sensors 1501 to 1524 existing in each module 15_1 to 15_6 are illustrated in FIG. It is not limited to the embodiment of 8 and can be modified in various forms.

In the differential magnetic sensor array 150 according to the present invention, the first power terminals a of all the magnetic sensors included in each of the differential magnetic sensor modules arranged in columns n (n is 1 to N) are connected to one power line. The second power terminals b of all the magnetic sensors included in each differential magnetic sensor module arranged in the n (n is 1 to N) columns are connected to the first power supply Vcc through 2 Connected to power supply (GND). The first output terminals d of the upper left magnetic sensor are connected to the same output line in each of the differential magnetic sensor modules arranged in the row m (m is 1 to M) to output an electrical signal Vm +, and m ( m is 1 to M), and in each of the differential magnetic sensor modules arranged in the row, the first output terminals d of the lower right magnetic sensor (the magnetic sensor even in 1301 to 1324) are connected to the same output line, so that the electrical signal Vn Output-)

Meanwhile, in each of the differential magnetic sensor modules 15_1 to 15_6, the second output terminal b of the upper left magnetic sensors 1501, 1505, 1509, 1513, 1517, and 1521 may have the upper right magnetic sensors 1502, 1506, and the like. 1510, 1514, 1518, and 1522 are connected to the second output terminal b, and the second output terminal b of the lower left magnetic sensors 1503, 1507, 1511, 1515, 1519, and 1523 are upper right magnetic. The second output terminals b of the sensors 1504, 1508, 1512, 1516, 1520, and 1524 are connected to each other.

Output lines of the differential magnetic sensor modules 15_1 to 15_6 are connected to the signal processor 33 and simultaneously signal output values V1 +, V2 +, V1- and V2- of the differential magnetic sensor modules 15_1 to 15_6. Transfer to the processing unit 33.

The switching units 251 and 252 start and end the driving of the respective magnetic sensors 1501 to 1524 in the differential magnetic sensor array 150. To this end, the switching units 251 and 252 may include the first switch 251 and the respective magnetic sensors 1501 to 1524 that transmit the first power source Vcc to the first power terminal a of each of the magnetic sensors 1501 to 1524. And a second switch 232 for transmitting the second power source GND to the second power source terminal c).

In order to sequentially drive the differential magnetic sensor modules 15_1 to 15_6 for each column, the first switch 251 includes switches SW1, SW2, and SW3 provided for each column, and similarly, the second switch. The switch 252 also includes switches SW1 ', SW2', and SW3 'provided for each column. That is, the first switch 251 and the second switch 252 are each provided with the same number of switches as the number of columns to drive the magnetic sensor for each column.

On the other hand, the switches provided in each row should be controlled to turn on / off at the same time, and at the same time, the switches should not be turned on in two different rows.

For example, SW1 and SW1 'are controlled to be turned on and off at the same time, SW2 and SW2' are controlled to be turned on and off at the same time, and SW3 and SW3 'should be controlled to be turned on and off at the same time.

In addition, when a switch connected to one column is turned on, the switch connected to the other column should be turned off. If SW1 and SW1 'are turned on, SW2, SW2', SW3, SW3 'should be turned off.

9 is a view illustrating a magnetic field detection apparatus according to the present invention.

The magnetic field detecting apparatus 600 according to the present invention includes a differential magnetic sensor 100, a switching unit 200, a signal processing unit 300, and a control unit 400, and further includes a magnetic field applying unit 500. can do.

The differential magnetic sensor 100 includes the differential magnetic sensor modules 13, 14, 15 of FIGS. 3, 5, and 7 and the differential magnetic sensor arrays 130, 140, 150 of FIGS. 4, 6, and 8. Can be either. The differential magnetic sensor 100 outputs the difference in magnetic field strength in space to the magnetized measuring object 70 as an output value.

The signal processor 300 obtains information on the magnetic field strength difference in the space where the differential magnetic sensor 100 is located, based on the output value of the differential magnetic sensor 100. When the differential magnetic sensor module is arranged in a matrix form as illustrated in FIGS. 4, 6, and 8, the differential magnetic sensor 100 may output a plurality of output values according to the number of rows.

For example, when the differential magnetic sensor 100 is configured as a differential magnetic sensor module having 5 rows * N columns, V1 + to V5 + and V1- to V5- may be output. The signal processor 300 receives a plurality of output values in parallel and quantifies the difference in magnetic field strength in the space in which the magnetic sensors arranged in each row are located.

On the other hand, the magnetic field detection device 600 according to the present invention may further include a magnetic field applying unit 500 to magnetize the object to be measured 70. The magnetic field applying unit 500 magnetizes the object under test 70 using alternating current or direct current.

The switching unit 200 includes a switch for driving the respective magnetic sensors included in the differential magnetic sensor 100. All the switches included in the switching unit 200 are preferably located outside the differential magnetic sensor 100. The switching unit 200 is positioned between the first power source Vcc and the differential magnetic sensor 100, and is also located between the second power source GND and the differential magnetic sensor 100. The switching unit 200 transfers the first power source Vcc and the second power source GND to respective magnetic sensors included in the differential magnetic sensor 100.

The controller 400 controls the switching operation of the switching unit 200 and the operation of the signal processing unit 300. In addition, the controller 400 transmits the information on the operation state of each switch included in the switching unit 200 to the signal processing unit 300. 3, 5, and 7, when there is only one differential magnetic sensor module, the control of the switching unit 200 is not essential, but the differential magnetic sensor modules are arranged in a matrix form as shown in FIGS. 4, 6, and 8. In the operation of each switch and the signal processor must be sequentially controlled by the controller 400.

For example, according to the differential magnetic sensor array 150 of FIG. 8, the controller 400 may control the switches such that the differential magnetic sensor modules 15_1 to 15_6 are sequentially driven in the horizontal direction. To this end, the controller 400 turns on SW1 and SW1 'to drive the differential magnetic sensor modules 15_1 and 15_4 located in the first row. When the differential magnetic sensor modules 15_1 and 15_4 located in the first column are driven, the differential magnetic sensor modules 15_1 and 15_4 located in the first column output V1 +, V1-, V2 + and V2- as output values, and the output values V1 +. , V1-, V2 +, and V2- are transmitted to the signal processor 300. Meanwhile, the controller 400 notifies the signal processor 300 that the switch of the first column is turned on. Accordingly, the signal processor 300 processes an operation on the output values V1 +, V1-, V2 +, and V2- to determine the difference in magnetic field strength in the space where the differential magnetic sensor modules 15_1 and 15_4 located in the first column are located. Quantify and store the quantified data.

Then, the controller 400 turns off the SW1 and SW1 'and turns on the SW2 and SW2' to drive the differential magnetic sensor modules 15_2 and 15_5 located in the second column. As described above, when the differential magnetic sensor modules 15_2 and 15_5 located in the second column are driven, the differential magnetic sensor modules 15_2 and 15_5 located in the second column output V1 +, V1-, V2 + and V2- as output values. The output values V1 +, V1-, V2 +, and V2- are transmitted to the signal processor 300. The controller 400 notifies the signal processor 300 that the switch of the second column is turned on, and accordingly, the signal processor 300 processes arithmetic operations on the output values V1 +, V1-, V2 +, and V2-. Quantifying the difference in the magnetic field strength in the space where each differential magnetic sensor module (15_2, 15_5) is located, and stores the quantified data.

Then, in the same manner as described above, the controller 400 turns off the SW2 and SW2 'and turns on the SW3 and the SW3' to drive the differential magnetic sensor modules 15_3 and 15_6 located in the third column. After the above process, the signal processor 300 may acquire and store information on the difference in magnetic field strength in all spaces occupied by the differential magnetic sensor array 150.

The differential magnetic sensor arrays 130 and 140 of FIGS. 4 and 6 are also controlled similarly to the above.

10 is a diagram illustrating in detail a signal processor.

In FIG. 10, the differential magnetic sensor 100 includes the differential magnetic sensor modules 13, 14, and 15 of FIGS. 3, 5, and 7, and the differential magnetic sensor array of FIGS. 4, 6, and 8, as described with reference to FIG. 9. It may be any one of the 130, 140, 150. When the differential magnetic sensor module is arranged in a matrix form as illustrated in FIGS. 4, 6, and 8, the differential magnetic sensor 100 may output a plurality of output values according to the number of rows.

The signal processor 300 obtains information on the magnetic field strength difference in the space where the differential magnetic sensor 100 is located from the electrical signals V + and V− output from the differential magnetic sensor 100. To this end, the signal processor 300 includes an analog to dogital converter (AD converter) 330 for converting output values output from the differential magnetic sensor 100 into a digital signal, and processes the digital signal to process the differential magnetic. The apparatus 100 may further include a data processor 340 for obtaining information about a difference in magnetic field strength in a space where the sensor 100 is located.

As described with reference to FIG. 9, the signal processing unit 300 receives information about an operation state of each switch included in the switching unit 200 from the control unit 400. Accordingly, the signal processor 300 may identify output devices output from the differential magnetic sensor 100 and which differential magnetic sensor modules are digital signals corresponding to the output values.

The data processor 340 may store and calculate an output signal of the AD converter 330 to obtain information about a magnetic field strength difference quantitatively quantified in space, and image a distribution of magnetic field strength differences in space based thereon. have.

In addition, the data processing unit 340 may easily distinguish the distribution of the magnetic field strength difference in the space by coloring the representation of the distribution of the magnetic field strength difference in the space in various colors according to each intensity difference.

On the other hand, the signal processor 300 is a filter 310 for filtering the electrical signals (V +, V-) output from the differential magnetic sensor 100 to remove the noise and the amplifier 320 for amplifying the filtered electrical signal. It may further include.

Since an alternating current or direct current may be used to apply the magnetic field to the object under test 70, a high pass filter and a low pass filter according to power and noise characteristics used for applying the magnetic field. Various filters can be used, such as filters and band pass filters. In addition, the signal processor 300 may further include a smoothing circuit (not shown) to maintain the pulse current at a constant voltage.

Hereinafter, the experimental results derived by actually manufacturing the above embodiments will be described as drawings.

FIG. 11 is a diagram illustrating an experiment result according to the magnetic sensor arrangement of FIG. 2.

FIG. 11 illustrates an example of a magnetic image in which the intensity distribution of a magnetic field formed by a circular permanent magnet having a diameter of 15 mm is measured by a magnetic sensor array having the arrangement of FIG. 2. Each hemispherical shape on the left and right sides corresponds to the north pole and south pole of the circular permanent magnet. According to the arrangement by the arrangement of the magnetic sensors of FIG. 2, a total of 1024 magnetic sensors were arranged and wired in a matrix manner of 32 rows by 32 columns at 0.78 mm intervals. The spacing between the magnetic sensors and the number of rows and columns are not illustrative of the limitations of the present invention as an example.

FIG. 12 is a diagram illustrating a difference distribution of magnetic field intensities in the minute region in the horizontal axis direction in FIG. 11.

FIG. 12 illustrates a result of calculating a difference in magnetic field strength for each of the minute regions adjacent to the horizontal axis in the magnetic field intensity distribution of FIG. 11. Referring to FIG. 12, it can be seen that the difference in magnetic field strength is more clearly shown at the place where the change of the magnetic field is sharp (for example, the boundary between air and magnetic pole and the boundary between N pole and S pole).

FIG. 13 is a diagram illustrating an experiment result according to the differential magnetic sensor arrangement of FIG. 4, and FIG. 14 is a diagram illustrating an experiment result when a magnetic field is applied in the direction of response of the magnetic sensor in the arrangement method of FIG. 2. 4 to 8 are diagrams showing experimental results when a magnetic field is applied in the direction of response of the magnetic sensor.

FIG. 13 shows an example of a magnetic image obtained by measuring the intensity distribution of a magnetic field formed by a circular permanent magnet having a diameter of 15 mm by the differential magnetic sensor array having the arrangement of FIG. 4.

In a manner similar to the arrangement of FIG. 4, a total of 2,048 magnetic sensors were spaced 0.52 mm in the horizontal axis and 0.78 mm in the vertical axis, and were arranged and wired in a matrix manner of 32 rows * 64 columns. Two magnetic sensors adjacent in the horizontal axis direction were connected in the form of the differential magnetic sensor modules of FIGS. 3 and 4 to arrange and wire 32 rows * 32 columns of data. Here, the distance between the magnetic sensors and the number of rows and columns are merely examples for understanding, and do not represent a limitation of the present invention.

The result of FIG. 13 is similar to the result of calculating and calculating a difference of measured values between adjacent magnetic sensors in the horizontal axis direction of FIG. 12. Therefore, when the magnetic sensor is arranged as shown in FIG. 4, it can be seen that a desired result can be obtained without a separate calculation process.

As shown in FIGS. 4 to 8, the method of arranging the magnetic sensors and connecting the wirings is advantageous when the intensity of the external magnetic field is in the same direction as the magnetic response direction of each magnetic sensor, and also when measuring the difference between the adjacent magnetic field intensities.

In one example, the magnetic sensor is sensitive to the strength of the magnetic field in a direction perpendicular to the magnetic sensor. Therefore, according to the arrangement | positioning system of the form like FIG. 2, the magnetic field of the normal direction of a figure surface becomes a sensitive sensitive direction. As a result, when a strong magnetic field is applied in the normal direction of the drawing plane, when a difference in intensity of the magnetic field in the adjacent microscopic area in the space is to be measured, the desired value is obtained as in the result of FIG. In other words, it is not possible to measure the difference in the strength of the magnetic field in the adjacent minute region in space.

However, when the differential magnetic sensor module and the differential magnetic sensor array according to the arrangement method and the wiring method of FIGS. 4 to 8 are used, even when a strong magnetic field is applied in the response direction of the magnetic sensor (normal direction in the drawing plane), unlike FIG. It can be seen from FIG. 15 that the difference in the intensity of the magnetic field in the adjacent minute regions in space can be measured.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the scope of protection of the present invention should be construed in accordance with the following claims, and all technical ideas within the scope of equivalents and equivalents thereof should be construed as being covered by the scope of the present invention.

Switching unit 20 Signal processing unit 30 Control unit 400
Magnetic field applying unit 500 filter 310 amplification unit 320
AD converter 330

Claims (14)

A differential magnetic sensor comprising a first magnetic sensor and a second magnetic sensor respectively outputting an electric signal corresponding to a magnetic field, and outputting a difference value between an output value of the first magnetic sensor and an output value of the second magnetic sensor as an output signal; module; And
A signal processor for filtering and amplifying the output signal to obtain information about a difference in magnetic field strength in a space where the first magnetic sensor and the second magnetic sensor are located;
Each of the first magnetic sensor and the second magnetic sensor outputs a first power terminal connected to a power supply Vcc, a second power supply terminal connected to a ground GND, and a first output value corresponding to a magnetic field strength. A first output terminal and a second output terminal for outputting a second output value corresponding to the magnetic field strength, respectively,
The second output terminal of the first magnetic sensor is connected to the second output terminal of the second magnetic sensor, and the first output terminal of the first magnetic sensor and the first output terminal of the second magnetic sensor are the signal processor. Magnetic field detection device characterized in that connected with. A differential magnetic sensor arrangement in which a plurality of differential magnetic sensor modules are arranged in M rows * N columns; And
A signal processor configured to obtain information on a difference in magnetic field strength in a space in which the differential magnetic sensor module is located from respective output values of the differential magnetic sensor modules;
Each of the differential magnetic sensor modules includes a first magnetic sensor and a second magnetic sensor, respectively, which output electrical signals corresponding to magnetic field strengths,
Each of the first magnetic sensor and the second magnetic sensor outputs a first power terminal connected to a power supply Vcc, a second power supply terminal connected to a ground GND, and a first output value corresponding to a magnetic field strength. A first output terminal and a second output terminal for outputting a second output value corresponding to the magnetic field strength, respectively,
The second output terminal of the first magnetic sensor is connected to the second output terminal of the second magnetic sensor, and the first output terminal of the first magnetic sensor and the first output terminal of the second magnetic sensor are the signal processor. Magnetic field detection device characterized in that connected with. The magnetic field detection device of claim 2, wherein
N first switches disposed in each column of the N columns and connected between the first power terminal of the first magnetic sensor and the second magnetic sensor included in the differential magnetic sensor module disposed in each column and the power source; And
N second switches disposed in each column of the N columns and connected between the first power sensor and the second power terminal of the second magnetic sensor included in the differential magnetic sensor module disposed in each column, and the ground. Magnetic field detection device, characterized in that. The magnetic field detection device of claim 3, wherein
And a controller configured to control a switching operation of the first switch and the second switch and to provide information about the switching operation of the first switch and the second switch to the signal processor. . The method of claim 4, wherein the control unit
Magnetic field detection device, characterized in that for controlling the switches arranged in each row to turn on sequentially and periodically in the order of the columns. The method of claim 4 or 5, wherein the control unit
The first field and the second switch located in the n ((n is a natural number of 1 ~ N)) is turned on at the same time, the magnetic field detection device, characterized in that for controlling the switches in the other rows except the n column. The method of claim 2, wherein the signal processing unit
And an analog-to-digital converter for converting output values of the differential magnetic sensor modules into a digital signal, and using the digital signal to quantify a distribution of a difference in magnetic field strength in a space where the differential magnetic sensor array is located. . And a first magnetic sensor, a second magnetic sensor, a third magnetic sensor, and a fourth magnetic sensor, each of which outputs an electrical signal corresponding to a magnetic field, wherein the difference value between the first magnetic sensor and the second magnetic sensor A differential magnetic sensor module for outputting a difference value between the difference between the third magnetic sensor and the fourth magnetic sensor as an output signal; And
A signal processor for filtering and amplifying the output signal to obtain information about a difference in magnetic field strength in a space where the differential magnetic sensor module is located;
Each of the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor may include a first power terminal connected to a power supply Vcc and a second power supply terminal connected to a ground GND. A first output terminal for outputting a first output value corresponding to the magnetic field strength, and a second output terminal for outputting a second output value corresponding to the magnetic field strength, respectively.
A second output terminal of the first magnetic sensor is connected to a second output terminal of the second magnetic sensor, a second output terminal of the third magnetic sensor is connected to a second output terminal of the fourth magnetic sensor, The first output terminal of the second magnetic sensor is connected to the first output terminal of the third magnetic sensor
And a first output terminal of the first magnetic sensor and a first output terminal of the fourth magnetic sensor are connected to the signal processor. A differential magnetic sensor arrangement in which a plurality of differential magnetic sensor modules are arranged in M rows * N columns; And
A signal processor configured to obtain information on a difference in magnetic field strength in a space in which the differential magnetic sensor module is located from respective output values of the differential magnetic sensor modules;
Each of the differential magnetic sensor modules includes a first magnetic sensor, a second magnetic sensor, a third magnetic sensor, and a fourth magnetic sensor for outputting an electrical signal corresponding to magnetic field strength,
Each of the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor may include a first power terminal connected to a power supply Vcc and a second power supply terminal connected to a ground GND. A first output terminal for outputting a first output value corresponding to the magnetic field strength, and a second output terminal for outputting a second output value corresponding to the magnetic field strength, respectively.
A second output terminal of the first magnetic sensor is connected to a second output terminal of the second magnetic sensor, a second output terminal of the third magnetic sensor is connected to a second output terminal of the fourth magnetic sensor, The first output terminal of the second magnetic sensor is connected to the first output terminal of the third magnetic sensor,
And a first output terminal of the first magnetic sensor and a first output terminal of the fourth magnetic sensor are connected to the signal processor. The magnetic field detection device of claim 9, wherein
N first switches arranged in each column of the N columns and connected between the first power terminals of the first to fourth magnetic sensors included in the differential magnetic sensor module disposed in each column and the power source; And
It is disposed in each column of the N column, and further comprises N second switches connected between the second power terminal and the ground of the first magnetic sensor to the fourth magnetic sensor included in the differential magnetic sensor module disposed in each column Magnetic field detection device, characterized in that. The magnetic field detection device of claim 10, wherein
And a controller configured to control a switching operation of the first switch and the second switch and to provide information about the switching operation of the first switch and the second switch to the signal processor. . The method of claim 11, wherein the control unit
Magnetic field detection device, characterized in that for controlling the switches arranged in each row to turn on sequentially and periodically in the order of the columns. The method of claim 11 or 12, wherein the control unit
The first field and the second switch located in the n (n is a natural number of 1 ~ N) is turned on at the same time, the switch in the other columns except for the n column is controlled to turn off the magnetic field detection device. The method of claim 9, wherein the signal processing unit
And an analog-to-digital converter for converting output values of the differential magnetic sensor modules into a digital signal, and using the digital signal to quantify a distribution of a difference in magnetic field strength in a space where the differential magnetic sensor array is located. .

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