US 12,174,045 B2
Position detection unit, lens module, and imaging apparatus
Yongfu Cai, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Jan. 13, 2021, as Appl. No. 17/148,036.
Claims priority of application No. 2020-023517 (JP), filed on Feb. 14, 2020.
Prior Publication US 2021/0255001 A1, Aug. 19, 2021
Int. Cl. G01D 5/16 (2006.01); G01D 5/14 (2006.01); G02B 7/04 (2021.01); H02K 11/215 (2016.01); H02K 33/18 (2006.01)
CPC G01D 5/16 (2013.01) [G01D 5/145 (2013.01); G02B 7/04 (2013.01); H02K 11/215 (2016.01); H02K 33/18 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A position detection unit comprising:
a magnetic sensor;
a first magnetic field generator that includes a first magnet and generates a first magnetic field, the first magnet including a first magnetic material and having a first shape; and
a second magnetic field generator that includes a second magnet, generates a second magnetic field, and is movable along a first direction with respect to the first magnetic field generator and the magnetic sensor, the second magnet including a second magnetic material and having a second shape,
wherein the magnetic sensor is configured to generate a detection signal that corresponds to a direction of a magnetic field of interest, and configured to detect a positional change of the second magnetic field generator, the magnetic field of interest being a composite of the first magnetic field along a first plane and the second magnetic field along the first plane, and
wherein the first magnet has a first temperature coefficient of residual magnetic flux density, and the second magnet has a second temperature coefficient of residual magnetic flux density, the second temperature coefficient of residual magnetic flux density being smaller in absolute value than the first temperature coefficient of residual magnetic flux density.