Power generation element, encoder, method for manufacturing magnetic member, and signal acquisition method

A power generation element comprising:

• a magnetic member that produces a large Barkhausen effect by a change in an external magnetic field;
• and
• a coil wound around the magnetic member,
• wherein
• the magnetic member has a structure in which three or more magnetic sensitive layers are stacked, and
• each of the three or more magnetic sensitive layers has a coercive force that increases in order of alignment in a stacking direction.

A power generation element comprising:

• a magnetic member that produces a large Barkhausen effect by a change in an external magnetic field;
• and
• a coil wound around the magnetic member,
• wherein
• the magnetic member includes a first magnetic sensing part extending in a winding axis direction of the coil, and a second magnetic sensing part having softer magnetism than the first magnetic sensing part and aligned with the first magnetic sensing part in a direction intersecting the winding axis direction of the coil, and
• the first magnetic sensing part has a larger cross-sectional area when cut in a direction orthogonal to the winding axis direction of the coil from both ends toward a center in the winding axis direction of the coil.

A power generation element comprising:

• a magnetic member that produces a large Barkhausen effect by a change in an external magnetic field;
• and
• a coil wound around the magnetic member,
• wherein the magnetic member includes
• a first magnetic sensing part having a wire shape or a film shape,
• a non-magnetic part that covers the first magnetic sensing part from a direction intersecting a winding axis direction of the coil and is not magnetized by the external magnetic field, and
• a second magnetic sensing part that covers the non-magnetic part from a side opposite to a side of the first magnetic sensing part in the non-magnetic part and has magnetic characteristics different from those of the first magnetic sensing part.