Magnetic field generator, control method for magnetic field generator, and magnetic recording medium processing device

Patent metadata

Field	Value
Publication number	US-10402597-B2
Application number	US-201515323158-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	Jul 1, 2014
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A magnetic field generator may include a magnetic field generation part including a resonance part including an inductor and a capacitor connected with each other, and which is structured so that an AC current is flowed between the inductor and the capacitor by charging electric charge to the capacitor and discharging the electric charge to generate a magnetic field by a resonance; a current direction monitoring section structured to monitor a direction of a current flowing through the inductor of the magnetic field generation part; and a judging section structured to control a timing for charging in the magnetic field generation part depending on the direction of the current flowing through the inductor which is obtained by monitoring of the current direction monitoring section.

First claim

The invention claimed is:

1. A magnetic field generator comprising:
a magnetic field generation part comprising a resonance part comprising an inductor and a capacitor connected with each other and which is structured so that an AC current is flowed between the inductor and the capacitor by charging electric charge to the capacitor and discharging the electric charge to generate a magnetic field by a resonance;
a current direction monitoring section structured to monitor a direction of a current flowing through the inductor of the magnetic field generation part; and
a judging section structured to control a timing for charging in the magnetic field generation part depending on the direction of the current flowing through the inductor which is obtained by monitoring of the current direction monitoring section.

2. The magnetic field generator according to claim 1 , wherein
the inductor is alternately flowed with a first direction current flowing from one end side to the other end side and a second direction current from the other end side to the one end side, and
the judging section comprises:
a current direction judging section which configured to judge whether the current flowing through the inductor is switched to the first direction current or not based on a monitoring result of the current direction monitoring section; and
an operation instructing section configured to drive and control to charge the magnetic field generation part based on that the current flowing through the inductor is switched to the first direction current.

3. The magnetic field generator according to claim 2 , wherein
the judging section comprises a time judging section configured to judge whether a resonance time previously set has elapsed or not after the charging is stopped, and
the operation instructing section is configured to confirm that the resonance time has elapsed and that the current flowing through the inductor is switched to the first direction current and drives and controls to charge the magnetic field generation part.

4. The magnetic field generator according to claim 3 , wherein
the time judging section of the judging section is configured to judge whether a monitoring time previously set has elapsed or not after the resonance time has elapsed, and
the operation instructing section is configured to drive and control to charge the magnetic field generation part when the monitoring time has elapsed and the current flowing through the inductor is not switched to the first direction current.

5. The magnetic field generator according to claim 3 , wherein
the time judging section of the judging section is configured to judge whether a charge time previously set has elapsed or not, and
the operation instructing section is configured to start a resonance after the charge time has elapsed when the current flowing through the inductor is switched to the first direction current within the charge time based on a monitoring result of the current direction monitoring section.

6. The magnetic field generator according to claim 5 , wherein the operation instructing section of the judging section is configured to terminate as an abnormality when the current flowing through the inductor is not switched to the first direction current within the charge time.

7. The magnetic field generator according to claim 5 , wherein
the time judging section of the judging section is configured to judge whether a monitoring time previously set has elapsed or not, and
the operation instructing section is configured to terminate drive control of the magnetic field generation part as an abnormality without charging the magnetic field generation part in a case that the current flowing through the inductor is not switched to the first direction current even when the monitoring time has elapsed.

8. The magnetic field generator according to claim 7 , wherein
the judging section comprises a time judging section configured to judge whether a resonance time previously set has elapsed or not after the charging is stopped and judges whether a monitoring time previously set has elapsed or not after the resonance time has elapsed,
the current direction judging section is configured to acquire a number of times of inversion of the current flowing through the inductor within the resonance time based on a monitoring result of the current direction monitoring section, and
the operation instructing section is configured to drive and control the magnetic field generation part depending on the current flowing through the inductor based on a monitoring result of the current direction monitoring section within the monitoring time in a case that an acquired number of times of inversion within the resonance time is not less than a predetermined number of times.

9. The magnetic field generator according to claim 2 , wherein
the judging section comprises a time judging section configured to judge whether a resonance time previously set has elapsed or not after the charging is stopped and judge whether a monitoring time previously set has elapsed or not after the resonance time has elapsed,
the current direction judging section is configured to acquire a number of times of inversion of the current flowing through the inductor within the resonance time based on a monitoring result of the current direction monitoring section, and
the operation instructing section is configured to drive and control the magnetic field generation part depending on the current flowing through the inductor based on a monitoring result of the current direction monitoring section within the monitoring time in a case that an acquired number of times of inversion within the resonance time is not less than a predetermined number of times.

10. The magnetic field generator according to claim 9 , wherein the operation instructing section of the judging section is configured to terminate drive control of the magnetic field generation part as an abnormality in a case that the acquired number of times of inversion does not reach the predetermined number of times within the resonance time.

11. The magnetic field generator according to claim 9 , wherein
the judging section comprises a time judging section which configured to judge whether a resonance time previously set has elapsed or not after the charging is stopped, and
the operation instructing section is configured to confirm that the resonance time has elapsed and that the current flowing through the inductor is switched to the first direction current and drives and controls to charge the magnetic field generation part.

12. A control method for a magnetic field generator comprising:
previously providing a resonance part in which an inductor and a capacitor are connected with each other;
flowing an AC current between the inductor and the capacitor by charging electric charge to the capacitor and discharging the electric charge; and
when the magnetic field generation part for generating a magnetic field by a resonance is to be driven and controlled, monitoring a direction of a current flowing through the inductor of the magnetic field generation part, and controlling a timing for charging the magnetic field generation part depending on the direction of the current flowing through the inductor which is obtained by the monitoring.

13. The control method for a magnetic field generator according to claim 12 , wherein
the inductor is alternately flowed with a first direction current from one end side to the other end side and a second direction current from the other end side to the one end side, and
the magnetic field generation part is driven and controlled to be charged based

Assignees

• Nidec Sankyo Corp

Inventors

• Hoson Keiji
• Kuribayashi Ikuro
• Takeda Tomomi
• Shimizu Yohei

Classifications

• G11B5/09 Primary

  Digital recording · CPC title

• G07D9/00

  Counting coins (in combination with coin-sorting G07D3/16); Handling of coins not provided for in the other groups of this subclass · CPC title

• G06K7/08

  by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes · CPC title

• G06K7/087 Primary

  flux-sensitive, e.g. magnetic, detectors (G06K7/10336 takes precedence) · CPC title

• G11B5/00808

  magnetic cards · CPC title