Displacement detecting device and continuously variable transmission device

A system, comprising:

• a magnet for forming a magnetic field;
• and
• a sensor between the magnet and a recess or projection portion on a circumferential surface of an object to be measured, wherein the object is rotatable around a rotation axis direction of the circumferential surface and displaceable along the rotation axis direction, a first end of the recess or projection portion and a second end of the recess or projection portion are in a same plane with the circumferential surface in the rotation axis direction, the first end is a first detection position of the sensor, the second end is a second detection position of the sensor, and the sensor is configured to:
• output a first signal proportional to a first magnetic flux density in the rotation axis direction at a predetermined time,
• output a second signal proportional to a second magnetic flux density in a direction perpendicular to the circumferential surface of the object at the predetermined time,
• calculate an angle based on the first magnetic flux density and the second magnetic flux density, and
• output a third signal proportional to the angle based on the first magnetic flux density and the second magnetic flux density.

A system, comprising:

• a magnet for forming a magnetic field;
• and
• a sensor between the magnet and an object having a circumferential surface, wherein the object is displaceable along a displacement direction, the object has a recess or projection portion on the circumferential surface and an interaction between the magnet and a curve in a portion of the circumferential surface of the object is configured to induce the magnetic field, and the sensor is configured to:
• output a first signal proportional to a first magnetic flux density in the displacement direction at a predetermined time,
• output a second signal proportional to a second magnetic flux density in a direction perpendicular to the circumferential surface of the object at the predetermined time,
• calculate an angle based on the first magnetic flux density and the second magnetic flux density, and
• output a third signal proportional to the angle based on the first magnetic flux density and the second magnetic flux density.