Rotation detecting device using magnetic sensor
AssigneeDenso Corporation
InventorSeiichiro Ishio
Life of this patent
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Abstract
A rotation detecting device is provided that detects the rotation of a rotating object by means of a biasing permanent magnet and multiple sensor chips. The sensor chips are disposed on front and back sides of a mounting chip along the rotation direction of the rotating object, aligned with a line perpendicular to the direction or rotation of the rotating object, so as to convert magnetic vectors of a magnetic field to a plurality of sensor signals. A selection circuit is connected to the magnetoresistance sensors and selects the one of the sensor signals whose magnitude is the largest.
Claims14
A rotation detecting device for detecting rotation of a rotating object, comprising:
- a biasing permanent magnet for providing a biasing magnetic field that extends toward the rotating object;
- a chip mount, having front and back surfaces, that extends along a rotation direction of the rotating object;
- one or more sensor chip pairs formed on the chip mount, for converting magnetic vectors of the magnetic field to a plurality of sensor signals;
- and
- output means, connected to said sensor chips, for outputting a rotation signal based on a selected signal that is selected from the plurality of sensor signals,
- wherein each of the one or more sensor chip pairs includes a first sensor chip formed on the front surface of the chip mount and a second sensor chip formed on the back surface of the chip mount, and
- wherein the sensor chip pairs are collectively aligned with a line perpendicular to the rotation direction.
A rotation detecting device for providing a rotation signal relating to rotation of a rotating object via magnetic teeth formed around the periphery thereof, said rotation detecting device comprising:
- a hollow cylindrical biasing permanent magnet magnetized to provide a biasing magnetic field toward the magnetic teeth of the rotation object;
- first and second sensor chips, disposed inside said biasing permanent magnet along the rotation direction of the rotating object, for providing first and second sensor signals, respectively;
- and
- means for selecting one of the first and second sensor signals whose magnitude is larger than the other,
- wherein the first sensor chip is disposed on a first plane, and the second sensor chip is disposed on a second plane that is separate from but parallel to the first plane, and
- wherein the first and second sensor chips are aligned with a line perpendicular to the rotation direction.
A rotation detecting device for providing a rotation signal relating to rotation of a rotating object via magnetic teeth formed around the periphery thereof, said rotation detecting device comprising:
- a hollow cylindrical biasing permanent magnet magnetized to provide a biasing magnetic field toward the magnetic teeth of the rotation object;
- a pair of sensor chips, respectively disposed inside said biasing permanent magnet on a pair of separate planes extending in parallel with each other along a rotation direction of the rotating object, each of said sensor chips including a plurality of magnetoresistance sensors formed thereon at different positions in parallel to each other so that each sensor chip provides a pair of sensor signals;
- and
- means for selecting from the sensor signals of said sensors formed at corresponding positions on the pair of sensor chips a selected pair of the sensor signals whose magnitude is larger than the other;
- and
- means for calculating a difference between the selected pair of sensor signals,
- wherein the pair of sensor chips are each aligned with a line perpendicular to the rotation direction.
A rotation detecting device for providing a rotation signal relating to rotation of a rotating object via magnetic teeth formed around the periphery thereof, said rotation detecting device comprising:
- a hollow cylindrical biasing permanent magnet magnetized to provide a biasing magnetic field extending toward the magnetic teeth of the rotation object;
- a pair of sensor chips respectively disposed inside said biasing permanent magnet on a pair of separate planes extending in parallel with each other along the rotation direction of the rotating object, for providing a plurality sensor signals;
- and
- means for selecting from the sensor signals one of the plurality of sensor signals whose magnitude is the largest.
Dependencies are inferred from the claim text.