Position detection device
AssigneeTDK Corporation
InventorsKeisuke Uchida, Yongfu Cai
Life of this patent
Estimating the term…
Abstract
A position detection device includes a magnet that generates a magnetic field to be detected, and a magnetic sensor. The magnetic sensor detects the magnetic field to be detected and generates a detection value corresponding to the position of the magnet. The magnetic field to be detected has a first direction that changes within a first plane, at a reference position in the first plane. The magnetic sensor includes four MR elements. Each of the MR elements includes a first magnetic layer having first magnetization that can change in direction within a second plane corresponding to the each of the MR elements. The first plane and the second plane intersect at a dihedral angle α other than 90°. A detection value depends on the direction of the first magnetization.
Claims18
A position detection device comprising:
- a magnetic field generator configured to generate a magnetic field to be detected having a first direction at a reference position within a first plane;
- and
- a magnetic sensor configured to detect the magnetic field to be detected and generate a detection value corresponding to a relative position of the magnetic field generator with respect to the magnetic sensor, the magnetic sensor including:
- at least one magnetoresistive element each including a first magnetic layer having first magnetization that can change in direction within a second plane corresponding to the at least one magnetoresistive element, the second plane being oblique to the first plane, the magnetic field to be detected received by each of the at least one magnetoresistive element includes an in-plane component parallel to the second plane, the in-plane component having a second direction that changes with a change in the first direction, the first magnetic layer being configured such that the direction of the first magnetization changes with a change in the second direction, and the detection value depending on the direction of the first magnetization,
- wherein the magnetic field generator and the magnetic sensor are configured such that as the relative position of the magnetic field generator with respect to the magnetic sensor changes, the first direction changes within a predetermined variable range in the first plane.
A position detection device comprising:
- a magnet configured to generate a magnetic field to be detected;
- and
- a magnetic sensor configured to detect the magnetic field to be detected and generate a detection value corresponding to a relative position of the magnet with respect to the magnetic sensor, the magnetic sensor including:
- a magnetoresistive element including a first magnetic layer having first magnetization that can change in direction with a direction of the magnetic field to be detected received by the magnetoresistive element within a reference plane;
- and
- a substrate that supports the magnetoresistive element, the substrate including a main surface including a flat surface, and a slope oblique to the main surface, the magnetoresistive element being located on the slope, the reference plane being parallel to the slope,
- wherein the relative position of the magnet with respect to the magnetic sensor can change so that a predetermined point in the magnet moves within a linear range of movement,
- the range of movement lies in a vertical plane perpendicular to the main surface,
- the magnet is magnetized in a direction parallel to the vertical plane, and
- the reference plane is oblique to the vertical plane.
A magnetic sensor configured to detect a magnetic field to be detected having a first direction at a reference position within a first plane, and generate a detection value corresponding to a relative position of the magnetic sensor with respect to a magnetic field generation source of the magnetic field to be detected, wherein:
- the magnetic sensor includes a magnetoresistive element;
- the magnetoresistive element includes a first magnetic layer having first magnetization that can change in direction within a second plane corresponding to the magnetoresistive element, the second plane being oblique to the first plane;
- the magnetic field to be detected received by the magnetoresistive element includes an in-plane component parallel to the second plane, the in-plane component having a second direction that changes with a change in the first direction;
- the first magnetic layer is configured such that the direction of the first magnetization changes with a change in the second direction;
- the detection value depends on the direction of the first magnetization;
- and
- the magnetic sensor is configured such that as the relative position of the magnetic sensor with respect to the magnetic field generation source changes, the first direction changes within a predetermined variable range in the first plane.
Dependencies are inferred from the claim text.