# US 12,007,236 B2 · Angle sensor system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,236 B2 - Document ID: US12007236B2 - Status: Granted - Kind: B2 - Application number: 17/745,311 - Filed: 2022-05-16 - Published: 2022-08-25 - Granted: 2024-06-11 - Earliest claimed: 2018-09-19 - Assignees: TDK Corporation - Applicants: TDK Corporation - Inventors: Yongfu Cai; Hiraku Hirabayashi - Web page: https://patentgrep.com/patent/US12007236B2 ## CPC - G01B 7/30: for measuring angles or tapers; for testing the alignment of axes - G01R 33/072: {Constructional adaptation of the sensor to specific applications} - G01B 7/003: {for measuring position, not involving coordinate determination (coordinate measuring G01B7/004)} - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - G01R 33/07: Hall effect devices - G01R 33/09: Magnetoresistive devices - G01R 33/091: {Constructional adaptation of the sensor to specific applications} - G01R 33/0011: {comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor} - G01R 33/0023: {Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration (G01R33/0017 takes precedence)} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract A magnetic field generator generates a detection-target magnetic field related to an angle to be detected. An angle sensor includes a first and a second magnetic sensor and a processor. The first magnetic sensor detects, at a first detection position, a first applied magnetic field including the detection-target magnetic field, and generates first detection information having a correspondence with the angle to be detected. The second magnetic sensor detects, at a second detection position, a second applied magnetic field including the detection-target magnetic field, and generates second detection information having a correspondence with the angle to be detected. The processor generates an angle detection value by performing arithmetic processing using the first and second detection information. The ratio of a strength of the detection-target magnetic field at the second detection position to a strength of the detection-target magnetic field at the first detection position is 1.65 or more. ## Claims ### Claim 1 An angle sensor system comprising: a magnetic field generator that is configured to (i) generate a detection-target magnetic field that is a magnetic field to be detected and is related to an angle to be detected and (ii) rotate around a rotation axis; and an angle sensor that is configured to detect the detection-target magnetic field and generate an angle detection value having a correspondence with the angle to be detected, wherein the angle sensor includes: a first magnetic sensor that is configured to detect, at a first detection position, a first applied magnetic field including the detection-target magnetic field, and generate first detection information having a correspondence with the angle to be detected; and a second magnetic sensor that is configured to detect, at a second detection position, a second applied magnetic field including the detection-target magnetic field, and generate second detection information having a correspondence with the angle to be detected, the first and second detection positions are in a reference plane, the magnetic field generator is spaced from the reference plane in a direction parallel to the rotation axis, the magnetic field generator includes a magnetic structure formed of a magnetic material, the magnetic structure having a magnetization in a direction perpendicular to the rotation axis and rotating around the rotation axis, the first detection position and the second detection position are located on a same side of the magnetic structure in the direction parallel to the rotation axis, and at different distances from the rotation axis, the magnetic structure includes a first portion and a second portion coupled to each other, the second portion being between the first portion and the first and second detection positions in the direction parallel to the rotation axis, the second portion includes a cavity through which the rotation axis passes, whereas the first portion does not include any cavity through which the rotation axis passes, a strength of the detection-target magnetic field at the first detection position is a first strength and a strength of the detection-target magnetic field at the second detection position is a second strength, and the first magnetic sensor and the second magnetic sensor are positioned and configured such that a ratio of the second strength to the first strength is 1.65 or more. ### Claim 2 (depends on 1) The angle sensor system according to claim 1, wherein the magnetic field generator is configured to rotate such that, at each of the first and second detection positions, a direction of the detection-target magnetic field rotates with the angle to be detected. ### Claim 3 (depends on 1) The angle sensor system according to claim 1, wherein the ratio of the second strength to the first strength is 4 or less. ### Claim 4 (depends on 1) The angle sensor system according to claim 1, wherein the first portion is a circular plate, and the second portion has an outer periphery and an inner periphery each of which has a circular shape in any cross section of the second portion perpendicular to the rotation axis. ### Claim 5 (depends on 1) The angle sensor system according to claim 1, wherein the magnetic structure is formed in its entirety of a hard magnetic material. ### Claim 6 (depends on 1) The angle sensor system according to claim 1, wherein the first portion includes a soft magnetic material portion formed of a soft magnetic material and a hard magnetic material portion formed of a hard magnetic material, the hard magnetic material portion includes an accommodation portion through which the rotation axis passes, and the soft magnetic material portion is accommodated in the accommodation portion. ### Claim 7 (depends on 1) The angle sensor system according to claim 1, wherein as viewed in the direction parallel to the rotation axis, the first detection position is located to overlap the cavity of the second portion and the second detection position is located to overlap the second portion excluding the cavity. ### Claim 8 (depends on 1) The angle sensor system according to claim 1, wherein the angle sensor further includes a processor that is configured to generate the angle detection value by performing arithmetic processing using the first detection information and the second detection information. ### Claim 9 An angle sensor system comprising: a magnetic field generator that is configured to (i) generate a detection-target magnetic field that is a magnetic field to be detected and is related to an angle to be detected and (ii) rotate around a rotation axis; and an angle sensor that is configured to detect the detection-target magnetic field and generate an angle detection value having a correspondence with the angle to be detected, the angle sensor including: a first magnetic sensor that is configured to detect, at a first detection position, a first applied magnetic field including the detection-target magnetic field, and generate first detection information having a correspondence with the angle to be detected; and a second magnetic sensor that is configured to detect, at a second detection position, a second applied magnetic field including the detection-target magnetic field, and generate second detection information having a correspondence with the angle to be detected, wherein the magnetic field generator includes a magnetic structure formed of a magnetic material, the magnetic structure having a magnetization in a direction perpendicular to the rotation axis and rotating around the rotation axis, the first detection position and the second detection position are located on a same side of the magnetic structure in a direction parallel to the rotation axis, and at different distances from the rotation axis, the magnetic structure includes a first portion and a second portion coupled to each other, the second portion being between the first portion and the first and second detection positions in the direction parallel to the rotation axis, the second portion includes a cavity through which the rotation axis passes, whereas the first portion does not include any cavity through which the rotation axis passes, the first portion includes a soft magnetic material portion formed of a soft magnetic material and a hard magnetic material portion formed of a hard magnetic material, the hard magnetic material portion includes an accommodation portion through which the rotation axis passes, and the soft magnetic material portion is accommodated in the accommodation portion. ### Claim 10 (depends on 9) The angle sensor system according to claim 9, wherein the angle sensor further includes a processor that is configured to generate the angle detection value by performing arithmetic processing using the first detection information and the second detection information. ### Claim 11 An angle sensor system comprising: a magnetic field generator that is configured to (i) generate a detection-target magnetic field that is a magnetic field to be detected and is related to an angle to be detected and (ii) be rotated around a rotation axis; and an angle sensor that is configured to detect the detection-target magnetic field and generate an angle detection value having a correspondence with the angle to be detected, wherein the angle sensor includes: a first magnetic sensor that is configured to detect, at a first detection position, a first applied magnetic field including the detection-target magnetic field, and generate first detection information having a correspondence with the angle to be detected; and a second magnetic sensor that is configured to detect, at a second detection position, a second applied magnetic field including the detection-target magnetic field, and generate second detection information having a correspondence with the angle to be detected, the magnetic field generator includes a magnetic structure formed of a magnetic material, the magnetic structure having a magnetization in a direction perpendicular to the rotation axis and rotating around the rotation axis, the first detection position and the second detection position are located on a same side of the magnetic structure in a direction parallel to the rotation axis, and at different distances from the rotation axis, the magnetic structure includes a first portion and a second portion coupled to each other, the second portion being located between the first portion and the first and second detection positions in the direction parallel to the rotation axis, the second portion includes a cavity through which the rotation axis passes, whereas the first portion does not include any cavity through which the rotation axis passes, the first portion is a circular plate, the second portion has an outer periphery and an inner periphery each of which has a circular shape in any cross section of the second portion perpendicular to the rotation axis, a diameter of the inner periphery decreases as the any cross section approaches the first portion, a strength of the detection-target magnetic field at the first detection position is a first strength and a strength of the detection-target magnetic field at the second detection position is a second strength, and the first magnetic sensor and the second magnetic sensor are positioned and configured such that a ratio of the second strength to the first strength is 1.65 or more. ### Claim 12 (depends on 11) The angle sensor system according to claim 11, wherein the cavity is in a shape of a hemisphere. ### Claim 13 (depends on 11) The angle sensor system according to claim 11, wherein magnetic field generator is configured to rotate such that, at each of the first and second detection positions, a direction of the detection-target magnetic field rotates with the angle to be detected. ### Claim 14 (depends on 11) The angle sensor system according to claim 11, wherein the ratio of the second strength to the first strength is 4 or less. ### Claim 15 (depends on 11) The angle sensor system according to claim 11, wherein the angle sensor further includes a processor that is configured to generate the angle detection value by performing arithmetic processing using the first detection information and the second detection information.