The present subject matter relates to devices, systems, and methods for identifying the position of a movable component. A position sensor system is provided in which a Hall effect sensor is coupled to a fixed housing, and a plurality of magnets is coupled to a movable component that is movable to a sensing position at which the plurality of magnets is proximal to the Hall effect sensor. In this configuration, the plurality of magnets is arranged to produce an aggregate magnetic field having a flux concentration directed toward the Hall effect sensor when the plurality of magnets is in the sensing position.

The rotation angle detection device includes: a magnet; a magnetic detection element disposed on the one side in the axial direction relative to the magnet with a gap interposed between the magnetic detection element and the magnet; and a shield. The shield is disposed at a location in the axial direction between a location in the axial direction of a wire member allowing current to flow therethrough and a location in the axial direction of the magnetic detection element, is disposed radially outward of the magnet as seen in the axial direction, and has a portion that overlaps with the wire member as seen in the axial direction. The wire member is disposed at a location in the axial direction that is closer to the magnet than the magnetic detection element is, and is disposed radially outward of the magnet as seen in the axial direction.

A detecting unit outputs a first output value varying with a rotation angle of a rotary body in a first cycle and outputs a second output value varying with the rotation angle in a second cycle. The variation in the second output value is different from the variation in the first output value in a positive/negative sign. A magnitude relationship between the first output value and the second output value changes with variation in the rotation angle at rotation angles during the first cycle. A selector unit selects, from the first output value and the second output value, a value of at least a minimum value and a maximum value of the first output values corresponding to the rotation angles. A computing unit computes, on the basis of the selected value, a value related to the rotation angle.

To reduce the influence of an unintended magnetic flux of a permanent magnet on detection accuracy. An absolute encoder (2) includes a magnet provided at a tip end side of any one of a first worm gear portion (11) and a second worm gear portion (22), and an angle sensor configured to detect a rotation angle of the magnet in response to a change in magnetic flux generated from the magnet. In the magnet, a first magnetic pole portion of a first polarity and a second magnetic pole portion of a second polarity different from the first polarity are formed adjacent to each other as viewed from an axial end surface of the magnet. The first magnetic pole portion and the second magnetic pole portion are formed adjacent to each other in a radial direction with a radial center of the magnet as a boundary, and the first magnetic pole portion and the second magnetic pole portion are formed adjacent to each other in an axial direction with an axial center as a boundary. The absolute encoder (2) is provided with a magnetic interference reduction member formed of a magnetic material on a radially outer peripheral surface of the magnet.

The present invention aims at providing A magnetic sensor that is less expensive and that is highly sensitive is provided.

A magnetic sensor of the present invention has: a magnetic field detecting element; and a plurality of magnets that are arranged at intervals in a first direction, the magnets moving in the first direction relative to the magnetic field detecting element. The magnets have respective first faces that face the magnetic field detecting element. The magnets are magnetized in a second direction that crosses the first direction such that the first faces of an adjacent pair of the magnets have different polarities. The magnetic sensor further includes at least one soft magnetic body that is provided on the first face of at least one of the magnets.

Embodiments of the disclosure provide magnetic sensing systems and methods for a galvanometer scanner configured to rotate within a predetermined angular range. An exemplary magnetic sensing system includes a disc permanent magnet configured to provide a magnetic field. The magnetic sensing system further includes a Hall sensor configured to generate a voltage proportional to the strength of the magnetic field as the Hall sensor and the disc permanent magnet move relatively to each other when the galvanometer scanner rotates. One of the disc permanent magnet and the Hall sensor locates on and rotates with the galvanometer scanner and the other locates off the galvanometer scanner. The magnetic sensing system also includes at least one controller configured to determine a rotation angle of the galvanometer scanner based on the generated voltage by the Hall Sensor.

A system includes an encoder magnet, a magnetic field sensor, and a shield structure. The encoder magnet is configured to rotate about an axis of rotation and is configured to produce a measurement magnetic field. The magnetic field sensor is axially displaced away from the encoder magnet and is configured to detect the measurement magnetic field. The shield structure at least partially surrounds both of the encoder magnet and the magnetic field sensor for shielding against stray magnetic fields. The shield structure attaches to a secondary structure. The shield structure and the encoder magnet may be coupled via the secondary structure so that they are commonly rotational. Alternatively, the sensor package and the shield structure are coupled via the secondary structure so that they are nonrotational relative to the encoder magnet.

A magnetic sensor unit capable of accurately detecting a change of a magnetic field by a magnetic sensor and accurately positioning each magnet with respect to a yoke. The magnetic sensor unit comprises a yoke fixed to a rotor relatively displaced with respect to a base plate, two magnets fixed to the yoke and disposed apart from each other in a relative displacement direction of the rotor, and a magnetic sensor fixed to the base plate and detecting a change of a magnetic field formed by the two magnets. The yoke has a convex portion protruding between the two magnets. The convex portion includes abutting portions on which the two magnets abut.

The magnetic detection device includes: a first magnetic rotary body which rotates about a rotation shaft and has an outer circumferential portion which is a magnetic body; a second magnetic rotary body has an outer circumferential portion which is a magnetic body; a magnet which has a magnetization direction along the axial direction; a first magneto-resistive element provided on another side in the axial direction of the magnet; a second magneto-resistive element provided on one side in the axial direction of the magnet; a first magnetic guide provided between the magnet and the first magneto-resistive element; and a second magnetic guide provided between the magnet and the second magneto-resistive element, wherein the outer circumferential portion of the first magnetic rotary body and the outer circumferential portion of the second magnetic rotary body cause different magnetic fields between the magnet and the respective outer circumferential portions.

The technology provides for an extension member configured to direct a magnetic field from a magnet to a Hall Effect sensor to facilitate detection of magnetic field. By varying the dimensions of the extension member, which may be any arbitrary shape, the relative positions of the magnet and the Hall Effect sensor may be less constrained by the reach of the magnetic field of the magnet, thereby allowing more design possibilities. The extension member may be used in a case, where the extension member may facilitate detection of whether the case is open or closed, the extension member may further provide magnetic attraction to keep the case closed.