An object of the present invention is to reduce leakage magnetic flux in a magnetic sensor provided with a sensor substrate and an external magnetic member. A magnetic sensor includes: a sensor substrate having an element forming surface on which magnetic sensing elements are formed, first and second side surfaces, and a back surface; a first external magnetic member provided between the first and second magnetic sensing elements; and a second external magnetic member having first and second parts and covering the first side surface and second side surface, respectively. The first and second parts of the second external magnetic member protrude from the element forming surface. According to the present invention, since the first and second parts of the second external magnetic member protrude from the element forming surface, leakage of magnetic flux between the first and second external magnetic members is reduced.

A magnetic field detection device, containing a) a first soft magnetic body containing a1) a first plate including a first surface having a first outer edge; and a2) a first protrusion disposed directly or indirectly on the first surface of the first plate at a first arrangement position set back from the first outer edge, the first protrusion including a first tip on an opposite side to the first surface; and b) a magnetic detector provided in a vicinity of the first tip, wherein the magnetic detector has a magnetic sensing direction along the first surface, and the first protrusion is capable of bending a direction of a first magnetic flux, which comes into the first plate, along the first surface.

A magnetic field detection device, containing a) a first soft magnetic body containing a1) a first plate including a first surface having a first outer edge; and a2) a first protrusion disposed directly or indirectly on the first surface of the first plate at a first arrangement position set back from the first outer edge, the first protrusion including a first tip on an opposite side to the first surface; and b) a magnetic detector provided in a vicinity of the first tip, wherein the magnetic detector has a magnetic sensing direction along the first surface, and the first protrusion is capable of bending a direction of a first magnetic flux, which comes into the first plate, along the first surface.

A magnetic sensor includes: a sensitive layer made of a soft magnetic material with uniaxial magnetic anisotropy, the sensitive layer being configured to sense a magnetic field by a magnetic impedance effect; and a magnet layer made of a magnetized hard magnetic material and disposed to face the sensitive layer. The magnet layer is configured to apply a DC magnetic bias Hb in a direction intersecting a direction of the uniaxial magnetic anisotropy in the sensitive layer, the DC magnetic bias Hb having a greater value than an anisotropic magnetic field Hk of the sensitive layer.

A magneto-sensitive wire for a magnetic sensor with both measurement range expansion and environment resistance performance improvement, includes a Co-based alloy containing more Fe than a reference composition that is amorphous overall and exhibits zero magnetostriction. The Co-based alloy may have an Fe ratio (Fe/(Co+Fe+Ni)) of 6.1% to 9.5%. The Fe ratio is an atomic fraction of the Fe amount with respect to the total amount of a magnetic element group consisting of Co, Fe, and Ni. By heating an amorphous wire of a Co-based alloy at a temperate at least equal to a crystallization start temperature and lower than a crystallization end temperature, allows the magneto-sensitive wire to have a composite structure in which crystal grains are dispersed in the amorphous phase. The magneto-sensitive wire's anisotropy field is, for example, 5 to 70 Oe and the stress sensitivity, indicative of magnetostriction, is −30 to 30 mOe/MPa.

A magneto-sensitive wire for a magnetic sensor with both measurement range expansion and environment resistance performance improvement, includes a Co-based alloy containing more Fe than a reference composition that is amorphous overall and exhibits zero magnetostriction. The Co-based alloy may have an Fe ratio (Fe/(Co+Fe+Ni)) of 6.1% to 9.5%. The Fe ratio is an atomic fraction of the Fe amount with respect to the total amount of a magnetic element group consisting of Co, Fe, and Ni. By heating an amorphous wire of a Co-based alloy at a temperate at least equal to a crystallization start temperature and lower than a crystallization end temperature, allows the magneto-sensitive wire to have a composite structure in which crystal grains are dispersed in the amorphous phase. The magneto-sensitive wire's anisotropy field is, for example, 5 to 70 Oe and the stress sensitivity, indicative of magnetostriction, is −30 to 30 mOe/MPa.

A magnetic sensor includes: plural sensitive elements 31 each including a soft magnetic material layer 105 having a longitudinal direction and a transverse direction and a conductor layer having higher conductivity than the soft magnetic material layer 105 and extending through the soft magnetic material layer 105 in a longitudinal direction, the sensitive element 31 having uniaxial magnetic anisotropy in a direction intersecting the longitudinal direction and being configured to sense a magnetic field by a magnetic impedance effect; and a connecting portion 32 continuous with the conductor layer of the sensitive element and configured to connect transversely adjacent sensitive elements 31 in series.

A current sensing system, comprising at least one magnetic tunnel junction device placed adjacent to a current carrying conductor electrically connected to a battery of a vehicle. The magnetic tunnel junction device is configured to measure a magnetic field around the conductor. A monitoring device is operatively connected to the magnetic tunnel junction device, wherein the monitoring device is configured to receive the magnetic field measurement and determine an estimate of the current flowing through the conductor.

An information processing device and a magnetic sensor system are provided, in which accuracy of frequency measurement is less likely to deteriorate even though the frequency of output signals outputted from the magnetic sensor increases, and which have detection limits for high frequency measurement even with a minute frequency change rate. An information processing device 120 includes: an obtaining part 31 obtaining an output signal outputted by a magnetic sensor and oscillating at a frequency determined in response to strength of a magnetic field; a frequency determination part 32 utilizing interference between the output signal and a reference signal with a reference frequency, which is a frequency used as a reference, to determine the frequency of the output signal; and a magnetic field calculation part 40 calculating the strength of the magnetic field based on the determined frequency of the output signal.

A magnetic sensor 1 includes: a nonmagnetic substrate 10; a sensitive element 31 laminated on the substrate 10, the sensitive element 31 being made of a soft magnetic material, the sensitive element 31 having a longitudinal direction and a transverse direction and having uniaxial magnetic anisotropy in a direction intersecting the longitudinal direction, the sensitive element 31 being configured to sense a magnetic field by a magnetic impedance effect; and a pair of thin-film magnets 20a, 20b laminated on the substrate 10 and disposed to face each other in the longitudinal direction across the sensitive element 31, the pair of thin-film magnets 20a, 20b being configured to apply a magnetic field in the longitudinal direction of the sensitive element 31.