Magnet arrangement for position sensor device and corresponding position sensor device

Patent metadata

Field	Value
Publication number	US-2016148731-A1
Application number	US-201514935636-A
Country	US
Kind code	A1
Filing date	Nov 9, 2015
Priority date	Nov 24, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A magnet arrangement having at least one magnetic element providing a modulated magnetization in a first direction and an essentially constant magnetization in a second direction different from the first direction.

First claim

1 . A magnet arrangement, comprising:
at least one magnetic element providing a modulated magnetization in a first direction and an essentially constant magnetization in a second direction different from the first direction.

2 . The magnet arrangement of claim 1 , wherein the second direction is essentially perpendicular to the first direction.

3 . The magnet arrangement of claim 1 , wherein the at least one magnetic element comprises at least two magnetic stripes with different magnetizations.

4 . The magnet arrangement of claim 1 , wherein the first and second directions are straight directions.

5 . The magnet arrangement of claim 4 , wherein the at least one magnetic element comprises a plurality of first magnetic stripes having a first magnetization and second magnetic stripes having a second magnetization different from the first magnetization, the first and second stripes extending in the first direction and being provided adjacent to each other in an alternating manner, alternating between first and second stripes in the second direction.

6 . The magnet arrangement of claim 5 , wherein a magnetization direction of the first stripes differs from a magnetization direction of the second stripes.

7 . The magnet arrangement of claim 5 , wherein a magnitude of the magnetization of the first stripes differs from a magnitude of the magnetization of the second stripes.

8 . The magnet arrangement of claim 5 , wherein a magnetization of one of the first stripes or second stripes is zero.

9 . The magnet arrangement of claim 5 , wherein a width of the stripes in the first direction varies monotonically in the second direction.

10 . The magnet arrangement of claim 5 , wherein a width of the stripes in the first direction decreases towards edges of the magnet arrangement in at least one of the first direction and the opposite direction of the first direction.

11 . The magnet arrangement of claim 3 , wherein the first and second stripes are arranged in a spiral shape.

12 . The magnet arrangement of claim 11 , wherein a width of the stripes decreases towards at least one of an inner end of the spiral and an outer end of the spiral.

13 . The device of claim 11 , wherein the stripes with one rotation of the spiral by 360° change their distance to a center of the spiral by approximately one period of modulation.

14 . The magnet arrangement of claim 1 , wherein the magnet arrangement is arranged at an essentially circular shape, the first direction forming an angle smaller than 15° with a circumferential direction, and the second direction forming an angle smaller than 15° with a radial direction.

15 . The magnet arrangement of claim 13 , wherein the modulation in the first direction is an approximately sinusoidal modulation.

16 . The magnet arrangement of claim 1 , wherein the at least one magnetic element is provided on a magnetically soft carrier.

17 . A position sensor device, comprising:
a magnet arrangement as defined in claim 1 , and a magnet field sensor movable relative to the magnet arrangement.

18 . The device of claim 17 , wherein a movement direction of the magnetic field sensor forms an angle smaller than 15° with the second direction.

19 . The device of claim 17 , wherein the relative movement is such that a maximum range of movement covers one period or less in the first direction of the magnet arrangement.

20 . The device of claim 17 , wherein the direction of the relative movement is one of a circumferential direction or a linear direction.

21 . The device of claim 17 , wherein the magnetic field sensor is adapted to measure a first magnetic field in the first direction and a second magnetic field in a direction perpendicular to the first and second directions.

22 . The device of claim 17 , wherein the magnetic field sensor is adapted to measure a gradient in the first direction of the magnetic field in the first direction and a gradient in the first direction of a magnetic field in a direction perpendicular to the first and second directions.

23 . The device of claim 21 , wherein the device is adapted to determine a position based on a ratio of the measured magnetic fields or the measured gradients.

Assignees

• Infineon Technologies Ag

Inventors

• Ausserlechner Udo

Classifications

• G01D5/12

  using electric or magnetic means (G01D5/06 takes precedence) · CPC title

• H01F7/021 Primary

  Construction of PM (H01F7/0278 takes precedence; PM compositions H01F1/032) · CPC title

• G01D5/2451

  Incremental encoders (G01D5/2454 takes precedence) · CPC title

• G01R33/022 Primary

  Measuring gradient · CPC title