A magnetic field sensor includes first and second sensors for detecting first and second magnetic components according to first and second directions. Each sensor includes a flux concentrator including first and second magnetic parts, an air gap between the parts, and a magnetoresistive element in the air gap. Each magnetoresistive element includes a reference layer having a fixed magnetization direction, the fixed magnetization direction of the first and second sensors being substantially identical, and a sensitive layer having a variable magnetization direction, the variable magnetization direction of the first sensor when the first sensor is in a state of rest being substantially identical to the variable magnetization direction of the second sensor when the second sensor is in the state of rest. The air gaps of first and second sensor are oriented parallel to a direction XY which is, at ±15°, the bisector of the first and second directions.

A magnetic sensor comprises a magnetoresistive effect element including a first side surface and a second side surface facing in opposite directions along a first axis and a first end surface and a second end surface facing in opposite directions along a second axis substantially orthogonal to the first axis. The sensor has a sensitivity axis extending in a direction of the first axis, a first yoke unit provided adjacent to the first side surface of the magnetoresistive effect element, and a first bias magnetic field generation unit provided adjacent to the first end surface of the magnetoresistive effect element. The first bias magnetic field generation unit is provided to be capable of applying a bias magnetic field on the magnetoresistive effect element and the first yoke unit.

A magnetic field measurement system includes a wearable device having a plurality of wearable sensor units. Each wearable sensor unit includes a plurality of magnetometers and a magnetic field generator configured to generate a compensation magnetic field configured to actively shield the plurality magnetometers from ambient background magnetic fields. A strength of a fringe magnetic field generated by the magnetic field generator of each of the wearable sensor units is less than a predetermined value at the plurality of magnetometers of each wearable sensor unit included in the plurality of wearable sensor units.

A magnetic sensor packaging structure with a hysteresis coil comprising a substrate, a sensor chip, a spiral hysteresis coil on the substrate, and wire bonding pads. The sensor bridge arms are composed of magnetoresistive sensing elements. The sensor bridge arms are deposited on the sensor chip, and the sensor bridge arms are electrically interconnected to form a magnetoresistive sensor bridge that is located on the hysteresis coil. The magnetic field generated by the spiral hysteresis coil is collinear with a sensitive axis of the sensor bridge. The magnetoresistive sensor bridge is located on the substrate and encapsulated. By placing the spiral hysteresis coil on the substrate, it is capable of supporting larger currents with smaller resistance value. This allows the sensor hysteresis to be effectively eliminated. In addition, the packaging structure manufacturing process is simple and cost effective.

A magnetic sensor comprises a magnetoresistive effect element including a first side surface and a second side surface facing in opposite directions along a first axis and a first end surface and a second end surface facing in opposite directions along a second axis substantially orthogonal to the first axis. The sensor has a sensitivity axis extending in a direction of the first axis, a first yoke unit provided adjacent to the first side surface of the magnetoresistive effect element, and a first bias magnetic field generation unit provided adjacent to the first end surface of the magnetoresistive effect element. The first bias magnetic field generation unit is provided to be capable of applying a bias magnetic field on the magnetoresistive effect element and the first yoke unit.

A magnetic sensor for detecting magnetism generated from a conductor in which a current flows in a first direction includes a magnetic detection unit capable of detecting the magnetism, a magnetization core, and a magnetic shield. The magnetization core includes a first core section, which is substantially parallel to the first direction, and a second core section and third core section, which are each continuous from both end portions of the first core section in a second direction that is orthogonal to the first direction. The second core section and the third core section each extend from an end portion of the first core section to follow a third direction that is orthogonal to the first direction and the second direction. The magnetic detection unit has a sensitivity direction in the second direction and is positioned in a core gap sandwiched between the vicinity of the end portion of the second core section and the vicinity of the end portion of the third core section in the third direction. The magnetic shield includes a plate-shaped shield portion positioned to overlap the core gap when viewed along the third direction.

According to one embodiment of the invention, a magnetic sensor includes a first element part. The first element part includes a first magnetic element, first and s second structures, a first magnetic member, and a second magnetic member. A direction from the first magnetic layer toward the first counter magnetic layer is along a first direction. The first structure includes a first side magnetic layer. The second structure includes a second side magnetic layer. The first magnetic element is between the first structure and the second structure in a second direction crossing the first direction. The first magnetic element is separated from the first side magnetic layer and the second side magnetic layer. A direction from the first side magnetic layer toward the first magnetic member is along the first direction. A direction from the second side magnetic layer toward the second magnetic member is along the first direction.

There is provided a torque detector configured such that a magnetic shield is fixed to a holder without the need for a component for fixation of the magnetic shield, and no backlash is caused between the magnetic shield and the holder after the magnetic shield is fixed to the holder. The torque detector has engagement grooves into which a magnetic shield is to be inserted when the magnetic shield is fitted onto outer peripheral surfaces of a first holder and a second holder. The magnetic shield has end portions to be inserted into the engagement grooves, and each of the end portions is provided with engaging members that are always engaged with inner surfaces of the engagement grooves, respectively, while being inserted into the engagement grooves, to restrict movement of the end portions in the counter-insertion direction.

A sensor for sensing an external magnetic field along a sensing direction comprises a sensor bridge. The sensor bridge has a first sensor leg that includes a first magnetoresistive sense element and a second sensor leg that includes a second magnetoresistive sense element. The first and second sense elements have respective first and second pinned layers having the same reference magnetization. The first and second sense elements have respective first and second sense layers, each self-biased to have a first sense magnetization. A permanent magnet layer is proximate the second sense element. In the absence of an external magnetic field, the permanent magnet layer magnetically biases the first sense magnetization of the second sense layer produce a second sense magnetization of the second sense layer that differs from the first sense magnetization, and the first sense layer of the first sense element retains the first sense magnetization.

A three-axis digital compass comprising two X-axis magnetic sensors, two Y-axis magnetic sensors, a flux concentrator, a signal sampling unit, a signal processing unit, and a signal output unit is disclosed. The X-axis and Y-axis magnetic sensors are arranged along a periphery of the flux concentrator. An external magnetic field is distorted when passing through the flux concentrator. An Z axis component of the external magnetic field is converted into X-axis or Y-axis magnetic field components when passing through the flux concentrator, and the so converted components of the external magnetic field act on the X-axis and Y-axis magnetic sensitive sensors. An output signal of the X-axis and Y-axis magnetic sensitive sensors is sent to the signal processing unit through the signal sampling unit, and it is used to calculate the three orthogonal components of the external magnetic field. These calculated external magnetic field components are output in a digital format through the signal output unit. The three-axis digital compass has a novel structure and an elegant computation algorithm. The design is compatible with AMR, GMR, TMR or other magnetoresistive sensor technology.