US 12,188,997 B2
Magnetic field detection device and magnetic field detection device array
Makoto Kameno, Tokyo (JP); Taiju Akushichi, Tokyo (JP); Takato Fukui, Tokyo (JP); Yuichiro Yamaji, Tokyo (JP); Osamu Harakawa, Tokyo (JP); and Tamon Kasajima, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Appl. No. 17/928,852
Filed by TDK Corporation, Tokyo (JP)
PCT Filed May 27, 2021, PCT No. PCT/JP2021/020251
§ 371(c)(1), (2) Date Nov. 30, 2022,
PCT Pub. No. WO2021/246289, PCT Pub. Date Dec. 9, 2021.
Claims priority of application No. 2020-096653 (JP), filed on Jun. 3, 2020.
Prior Publication US 2023/0176145 A1, Jun. 8, 2023
Int. Cl. G01R 33/025 (2006.01); G01R 33/09 (2006.01)
CPC G01R 33/025 (2013.01) [G01R 33/09 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A magnetic field detection device comprising:
a bobbin;
a cancel coil wound around the bobbin;
a cover member fixed to the bobbin and covering the cancel coil in a direction perpendicular to an axial direction of the cancel coil;
a first magnetic sensor fixed to the bobbin or cover member;
a second magnetic sensor fixed to the bobbin or cover member; and
a feedback circuit that makes a cancel current flow in the cancel coil according to an output signal of the second magnetic sensor to cancel an environmental magnetic field in a cancel space,
wherein the cover member has first and second side surfaces extending in the axial direction of the cancel coil and positioned on mutually opposite sides,
wherein the first and second side surfaces have first and second engagement portions, respectively,
wherein the first engagement portion has a shape engageable with a shape of the second engagement portion,
wherein the first magnetic sensor is disposed in the cancel space,
wherein sensor heads of the first and second magnetic sensors are different in position in the axial direction of the cancel coil,
wherein the bobbin or cover member has a first cavity opened at one side thereof in the axial direction and a second cavity opened at other side thereof in the axial direction,
wherein the first magnetic sensor is installed in the first cavity, and
wherein the second magnetic sensor is installed in the second cavity.