Magnetic sensor device

Patent metadata

Field	Value
Publication number	US-9234947-B2
Application number	US-201113812680-A
Country	US
Kind code	B2
Filing date	Jul 28, 2011
Priority date	Jul 30, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

By providing a first magnet and a second magnet on wall surfaces of a hollow section where paper money is conveyed such that different magnetic poles face each other, a gradient magnetic field is formed wherein both a magnetic field component in an opposing direction to the magnets and a magnetic field component in a conveyance direction of the paper money include a zero point. An AMR element is provided between the paper money and the first magnet. The AMR element is enclosed by a multi-layered substrate and covered with resin. The AMR element is provided in an area where the magnetic field intensity is weak, which is where the magnetic field intensity in the gradient magnetic field in the conveyance direction is near zero. The paper money passes through an area where the magnetic field intensity of the gradient magnetic field is strong.

First claim

The invention claimed is:

1. A magnetic sensor device, comprising:
a housing that includes a first slit, which is an insert opening for a test object, a hollow section, which is a conveyance path for the test object that has been inserted through the first slit, and a second slit, which is an output opening for the test object that was conveyed through the hollow section;
a first magnet that is provided in the hollow section and that is arranged such that magnetic poles thereof alternate along a conveyance direction of the test object;
a second magnet that is provided in the hollow section in a position that faces the first magnet on an opposite side of the conveyance path, and having magnetic poles arranged along the conveyance direction in an opposite polarity to the magnetic poles of the first magnet, the first and second magnets forming a continuous gradient magnetic field along the conveyance direction;
a magnetoresistive element provided between the test object and the first magnet and that has an output terminal, the magnetoresistive element being configured to change a resistance value thereof based on a magnetic component of the test object that passes through the gradient magnetic field;
a substrate that encloses the magnetoresistive element and outputs the change in resistance value from the output terminal of the magnetoresistive element; and
an electrical connector that electrically connects a pad of the substrate and the output terminal of the magnetoresistive element;
wherein
the magnetoresistive element is provided in an area where the magnetic field intensity is weak, which is where the magnetic field intensity in the gradient magnetic field is near zero; and
the test object passes through an area where the magnetic field intensity of the gradient magnetic field is stronger than the area where the magnetic field intensity is weak.

2. The magnetic sensor device according to claim 1 , further comprising resin that covers the magnetoresistive element and electrical connector so as not protrude from a surface of the substrate.

3. The magnetic sensor device according to claim 1 , wherein
the magnetoresistive element is such that a first rectangular-shaped resistor pattern and a second rectangular-shaped resistor pattern each having one side located in a direction parallel to the conveyance direction are connected in series, and
a connection point between the first rectangular-shaped resistor pattern and the second rectangular-shaped resistor pattern that are connected in series is connected to the output terminal.

4. The magnetic sensor device according to claim 3 , wherein
the first resistor pattern is arranged such that a long side of the rectangular shape extends in a direction that is orthogonal to conveyance direction, and
the second resistor pattern is arranged such that a long side of the rectangular shape extends in the conveyance direction.

5. The magnetic sensor device according to claim 3 , wherein
the first resistor pattern and the second resistor pattern both have a meandering shape.

6. The magnetic sensor device according to claim 1 , wherein
a plurality of magnetoresistive elements and substrates are arranged in an array in a direction that is orthogonal to the conveyance direction; and
each substrate outputs a change in resistance value from an output terminal of a respective magnetoresistive element.

7. The magnetic sensor device according to claim 1 , wherein
a first yoke that includes a pair of magnetic bodies is provided on both side surfaces in the conveyance direction of the first magnet; and
a second yoke that includes a pair of magnetic bodies is provided on both side surfaces in the conveyance direction of the second magnet.

8. A magnetic sensor device, comprising:
a housing that includes a first slit, which is an insert opening for a test object, a hollow section, which is a conveyance path for the test object that has been inserted through the first slit, and a second slit, which is an output opening for the test object that was conveyed through the hollow section;
a first magnet that is provided in the hollow section and that is arranged such that magnetic poles thereof alternate along a conveyance direction of the test object;
a second magnet that is provided in the hollow section in a position that faces the first magnet on an opposite side of the conveyance path, and having magnetic poles arranged along the conveyance direction in an opposite polarity to the magnetic poles of the first magnet, the first and second magnets forming a gradient magnetic field, wherein the magnetic field component in the opposing direction to the first magnet and the magnetic field component in the conveyance direction both include a zero point;
a magnetoresistive element provided between the test object and the first magnet and that has an output terminal, the magnetoresistive element being configured to change a resistance value thereof based on a magnetic component of the test object that passes through the gradient magnetic field;
a substrate that encloses the magnetoresistive element and outputs the change in resistance value from the output terminal of the magnetoresistive element; and
an electrical connector that electrically connects a pad of the substrate and the output terminal of the magnetoresistive element;
wherein
the magnetoresistive element is provided in an area where magnetic field intensity is weak, which is where the magnetic field intensity in the conveyance direction of the gradient magnetic field is near zero; and
the test object passes through an area where the magnetic field intensity of the gradient magnetic field is stronger than the area where the magnetic field intensity is weak.

9. The magnetic sensor device according to claim 8 , further comprising resin that covers the magnetoresistive element and electrical connector so as not protrude from a surface of the substrate.

10. The magnetic sensor device according to claim 8 , wherein
the magnetoresistive element is such that a first rectangular-shaped resistor pattern and a second rectangular-shaped resistor pattern each having one side located in a direction parallel to the conveyance direction and are connected in series, and
a connection point between the first rectangular-shaped resistor pattern and the second rectangular-shaped resistor pattern that are connected in series is connected to the output terminal.

11. The magnetic sensor device according to claim 10 , wherein
a first of the two resistive elements is arranged such that a length thereof extends in a direction that is orthogonal to conveyance direction, and
a second of the two resistive elements is arranged such that a length thereof extends in the conveyance direction.

12. The magnetic sensor device according to claim 10 , wherein
the two resistive elements are patterns that have a meandering shape.

13. A magnetic sensor device, comprising:
a housing that includes a first slit, which is an insert opening for a test object, a hollow section, which is a conveyance path for the test object that has been inserted through the first slit, and a second slit, which is an output opening for the test object that was conveyed through the hollow section;
a first magnet that is provided in the hollow section and that is arranged such that magnetic poles thereof alternate along a conveyance direction of the test object;
a second magnet that is provided in the hollow section in a position that faces the first magnet on an opposite side of the conveyance path, and having magnetic poles arranged along the conveyance direction in an opposite polarity to the magneti

Assignees

• Ogomi Tomokazu
• Shirahana Ryoji
• Shoji Toshiaki
• Musha Takeshi
• Inoue Jin
• Okada Masaaki
• Mitsubishi Electric Corp

Inventors

• Ogomi Tomokazu
• Shirahana Ryoji
• Shoji Toshiaki
• Musha Takeshi
• Inoue Jin
• Okada Masaaki

Classifications

• G01R33/09 Primary

  Magnetoresistive devices · CPC title

• G01R33/091 Primary

  Constructional adaptation of the sensor to specific applications · CPC title

• G01R33/096

  anisotropic magnetoresistance sensors · CPC title

• G01R33/02

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G07D7/04

  Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint (G07D7/01 takes precedence) · CPC title