Metal detector

Patent metadata

Field	Value
Publication number	US-12189077-B2
Application number	US-202017776882-A
Country	US
Kind code	B2
Filing date	Feb 27, 2020
Priority date	Nov 20, 2019
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

Provided is a metal detector capable of quickly and accurately ascertaining a noise generating situation. A metal detector generates a magnetic field in an inspection region and detects a change in the magnetic field in the inspection region to detect a foreign substance in an inspection object passing through the inspection region. The metal detector measures the change in the magnetic field of the inspection region while changing an inspection frequency, performs frequency analysis of the measurement result, and displays an obtained frequency distribution diagram on the display unit as a noise diagnosis result. In the frequency distribution diagram, target foreign substance reference lines are displayed.

First claim

What is claimed is:

1. A device for detecting metal in an inspection region comprising
a magnetic field generation unit,
a magnetic field detection unit,
a control unit, and
a monitor,

wherein:
the magnetic field generation unit generates a magnetic field in the inspection region;
the magnetic field detection unit detects a magnetic field fluctuation in the inspection region;
the control unit comprises a transmission signal setting unit, a reception signal processing unit, a noise diagnosis unit, and a capacitor setting unit;

and wherein:
the control unit:
measures a change in the magnetic field in the inspection region while changing a frequency in a frequency range including the inspection frequency without fixing the frequency at the inspection frequency, and
displays a frequency distribution diagram obtained by performing frequency analysis of a measurement result on a monitor as a noise diagnosis result.

2. The device for detecting metal according to claim 1 , wherein a reference line serving as a reference for inspection of the foreign substance is displayed in the frequency distribution diagram.

3. The device for detecting metal according to claim 2 , wherein a plurality of the reference lines is displayed in accordance with a type and size of the foreign substance.

4. The device for detecting metal according to claim 1 , wherein a set frequency line is displayed at a position corresponding to a set value of an inspection frequency for generating a magnetic field in the inspection region in the frequency distribution diagram.

5. The device for detecting metal according to claim 1 , wherein a noise diagnosis button is displayed on the monitor during detection processing of the foreign substance and the noise diagnosis result is displayed by pressing the noise diagnosis button.

6. The device for detecting metal according to claim 1 , wherein a plurality of the frequency distribution diagrams is acquired and displayed by changing the inspection frequency over a plurality of ranges.

7. The device for detecting metal according to claim 1 , wherein the frequency analysis is performed using a zoom FFT.

8. The device for detecting metal according to claim 2 , wherein a set frequency line is displayed at a position corresponding to a set value of an inspection frequency for generating a magnetic field in the inspection region in the frequency distribution diagram.

9. The device for detecting metal according to claim 2 , wherein a noise diagnosis button is displayed on the monitor during detection processing of the foreign substance and the noise diagnosis result is displayed by pressing the noise diagnosis button.

10. The device for detecting metal according to claim 2 , wherein a plurality of the frequency distribution diagrams is acquired and displayed by changing the inspection frequency over a plurality of ranges.

11. The device for detecting metal according to claim 2 , wherein the frequency analysis is performed using a zoom FFT.

12. A device for detecting metal in an inspection region comprising
a magnetic field generation unit,
a magnetic field detection unit,
a control unit, and
a monitor,

wherein:
the magnetic field generation unit generates a magnetic field in the inspection region at a fixed inspection frequency;
the magnetic field detection unit detects a change in the magnetic field in the inspection region at the fixed inspection frequency to detect a metal in the inspection region; and
the control unit comprises a transmission signal setting unit, a reception signal processing unit, a noise diagnosis unit, and a capacitor setting unit,

and wherein:
the control unit:
is configured to be able to set a plurality of inspection frequencies;
sets a frequency range including the inspection frequency for each of the inspection frequencies;
measures the change in the magnetic field of the inspection region while changing the frequency in each of the set frequency range without fixing the frequency at the inspection frequency;
displays a plurality of frequency distribution diagrams obtained on the basis of a measurement result of the change in the magnetic field of the inspection region on a monitor as a noise diagnosis result; and
receives setting of the inspection frequency.

13. The device for detecting metal according to claim 12 , wherein a set frequency line is displayed at a position corresponding to a set value of an inspection frequency for generating a magnetic field in the inspection region in the frequency distribution diagram.

14. The device for detecting metal according to claim 13 , wherein a noise diagnosis button is displayed on the monitor during detection processing of the foreign substance and the noise diagnosis result is displayed by pressing the noise diagnosis button.

15. The device for detecting metal according to claim 14 , wherein a plurality of the frequency distribution diagrams is acquired and displayed by changing the inspection frequency over a plurality of ranges.

16. The device for detecting metal according to claim 13 , wherein a plurality of the frequency distribution diagrams is acquired and displayed by changing the inspection frequency over a plurality of ranges.

17. The device for detecting metal according to claim 13 , wherein the frequency analysis is performed using a zoom FFT.

18. The device for detecting metal according to claim 12 , wherein a noise diagnosis button is displayed on the monitor during detection processing of the foreign substance and the noise diagnosis result is displayed by pressing the noise diagnosis button.

19. The device for detecting metal according to claim 12 , wherein a plurality of the frequency distribution diagrams is acquired and displayed by changing the inspection frequency over a plurality of ranges.

20. The device for detecting metal according to claim 12 , wherein the frequency analysis is performed using a zoom FFT.

Assignees

• A&D Co Ltd

Inventors

• Murata Yutaka
• Kurosaki Nobuyuki
• Nishimura Yuji
• MIZUKAWA Hisanobu
• Tsunemi Hiroaki

Classifications

• G01V2003/086

  Processing · CPC title

• G01V3/101

  by measuring the impedance of the search coil; by measuring features of a resonant circuit comprising the search coil (measuring impedance or characteristics derived therefrom G01R27/00, e.g. quality factor G01R27/26) · CPC title

• G01V3/083 Primary

  Controlled source electromagnetic [CSEM] surveying · CPC title

• G01V3/10 Primary

  using induction coils · CPC title