Magnetic field generator, magnetic sensor system and magnetic sensor

A magnetic sensor system comprising a scale and a magnetic sensor arranged in a variable relative positional relationship with each other, the magnetic sensor system being configured to detect a physical quantity associated with the relative positional relationship between the scale and the magnetic sensor, wherein

• the scale is formed of a magnetic field generator,
• the magnetic field generator includes a plurality of magnetic field generation units arranged in a predetermined pattern to generate a plurality of external magnetic fields,
• each of the plurality of magnetic field generation units includes a first ferromagnetic material section and a first antiferromagnetic material section,
• the first antiferromagnetic material section is in contact with and exchange-coupled to the first ferromagnetic material section,
• the first ferromagnetic material section has an overall magnetization, and
• the plurality of magnetic field generation units includes first and second magnetic field generation units configured so that the overall magnetization of the first ferromagnetic material section of the first magnetic field generation unit is in a different direction from the overall magnetization of the first ferromagnetic material section of the second magnetic field generation unit.

A magnetic sensor comprising:

• a plurality of magnetic detection elements for detecting a magnetic field to be detected;
• and
• a bias magnetic field generator for generating a plurality of bias magnetic fields to be applied to the plurality of magnetic detection elements, wherein
• the bias magnetic field generator is formed of a magnetic field generator,
• the magnetic field generator includes a plurality of magnetic field generation units arranged in a predetermined pattern to generate a plurality of external magnetic fields,
• each of the plurality of magnetic field generation units includes a first ferromagnetic material section and a first antiferromagnetic material section,
• the first antiferromagnetic material section is in contact with and exchange-coupled to the first ferromagnetic material section,
• the first ferromagnetic material section has an overall magnetization,
• the plurality of magnetic field generation units includes first and second magnetic field generation units configured so that the overall magnetization of the first ferromagnetic material section of the first magnetic field generation unit is in a different direction from the overall magnetization of the first ferromagnetic material section of the second magnetic field generation unit, and
• each of the plurality of bias magnetic fields results from the overall magnetization of the first ferromagnetic material section of at least one of the plurality of magnetic field generation units.