Patents by Inventor Yongfu CAI

Yongfu CAI has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220357182
    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 ? other than 90°. A detection value depends on the direction of the first magnetization.
    Type: Application
    Filed: July 15, 2022
    Publication date: November 10, 2022
    Applicant: TDK CORPORATION
    Inventors: Keisuke UCHIDA, Yongfu CAI
  • Patent number: 11493570
    Abstract: A magnetic sensor device includes a magnetic field converter that receives an input magnetic field input along a first direction and outputs an output magnetic field along a second direction, which is orthogonal to the first direction. A magnetic field detector is provided at a position where the output magnetic field can be applied. A magnetic shield that blocks an external magnetic field along the second direction. is provided. The magnetic field converter has a shape in which the length in a third direction, which is orthogonal to both the first direction and the second direction, is longer than the length in the second direction, when viewed along the first direction. The magnetic shield is provided at a position overlapping with the magnetic field converter and the magnetic field detector, when viewed along the first direction.
    Type: Grant
    Filed: September 9, 2021
    Date of Patent: November 8, 2022
    Assignee: TDK Corporation
    Inventors: Yongfu Cai, Yuta Saito
  • Patent number: 11486734
    Abstract: A magnetic sensor system includes a magnetic field generator and a magnetic sensor. The magnetic sensor includes a plurality of MR elements. The plurality of MR elements are each configured so that a bias magnetic field in a second direction orthogonal to a first direction is applied to a free layer, and to change in resistance with a strength of a magnetic field component. A maximum strength of the magnetic field component applied to each of the MR elements is greater than or equal to 1.2 times the strength of a bias magnetic field.
    Type: Grant
    Filed: July 26, 2021
    Date of Patent: November 1, 2022
    Assignee: TDK CORPORATION
    Inventors: Yongfu Cai, Hayato Miyashita, Tsuyoshi Umehara, Yuta Saito
  • Publication number: 20220333953
    Abstract: A magnetic sensor includes first to fourth resistors, a power supply port, a ground port, a first output port, and a second output port. The first resistor and the second resistor are located in a first region and connected in series via a first connection point connected to the first output port. The third resistor and the fourth resistor are located in a second region and connected in series via a second connection point connected to the second output port, at least a part of the second region being located at a position different from the first region in a direction parallel to an X direction. The first and second resistors are located between the third and fourth resistors in a direction parallel to a Y direction.
    Type: Application
    Filed: April 5, 2022
    Publication date: October 20, 2022
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi UMEHARA, Hiraku HIRABAYASHI, Yongfu CAI
  • Patent number: 11474168
    Abstract: A magnetic sensor device having a spin-valve-type magnetoresistive effect element and capable of stably applying a bias magnetic field on the free layer of the magnetoresistive effect element includes a spin-valve-type magnetoresistive effect element, a substrate on which the magnetoresistive effect element is positioned, a power source that supplies a substantially constant electric current applied on the magnetoresistive effect element, and a magnetic field generator that is connected to the electric current path of the electric current applied on the magnetoresistive effect element in series. The magnetic field generator is provided to be capable of applying a bias magnetic field on at least a portion of the magnetoresistive effect element. The magnetic field generator is close to a portion of the magnetoresistive effect element and is positioned at a different level from the substrate.
    Type: Grant
    Filed: August 25, 2021
    Date of Patent: October 18, 2022
    Assignee: TDK Corporation
    Inventors: Naoki Ohta, Yongfu Cai
  • Patent number: 11428545
    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 ? other than 90°. A detection value depends on the direction of the first magnetization.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: August 30, 2022
    Assignee: TDK CORPORATION
    Inventors: Keisuke Uchida, Yongfu Cai
  • Publication number: 20220268564
    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.
    Type: Application
    Filed: May 16, 2022
    Publication date: August 25, 2022
    Applicant: TDK CORPORATION
    Inventors: Yongfu CAI, Hiraku HIRABAYASHI
  • Publication number: 20220208627
    Abstract: In an assembly in which a space between two elements is filled with a filler containing resin, a configuration that can limit both the size of the assembly and the cost of the fillers is provided. An assembly of stacked elements has: first element having first surface; resin layer that is arranged on first surface and that contains a plurality of fillers; and second element that is arranged on resin layer and that has second surface that is in contact with resin layer. In a section that is perpendicular to second surface, the average flattening ratio of fillers that are in contact with second surface is larger than the average flattening ratio of fillers that are not in contact with second surface. Here, the flattening ratio is a ratio of the maximum length of the filler in a direction parallel to second surface to the maximum thickness of the filler in a direction perpendicular to second surface.
    Type: Application
    Filed: March 16, 2022
    Publication date: June 30, 2022
    Inventors: Yongfu CAI, Shuhei MIYAZAKI
  • Patent number: 11360286
    Abstract: A magnetic sensor includes first to fourth resistors, a power supply port, a ground port, a first output port, and a second output port. The first resistor and the second resistor are located in a first region and connected in series via a first connection point connected to the first output port. The third resistor and the fourth resistor are located in a second region and connected in series via a second connection point connected to the second output port, at least a part of the second region being located at a position different from the first region in a direction parallel to an X direction. The first and second resistors are located between the third and fourth resistors in a direction parallel to a Y direction.
    Type: Grant
    Filed: March 9, 2021
    Date of Patent: June 14, 2022
    Assignee: TDK CORPORATION
    Inventors: Yongfu Cai, Hiraku Hirabayashi, Tsuyoshi Umehara
  • Patent number: 11359908
    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.
    Type: Grant
    Filed: July 31, 2019
    Date of Patent: June 14, 2022
    Assignee: TDK CORPORATION
    Inventors: Yongfu Cai, Hiraku Hirabayashi
  • Patent number: 11340319
    Abstract: A magnetic sensor device has a multipolar magnet having a first surface and a second surface, which is opposite to the first surface, in which magnetic poles of differing polarity are arranged alternately to divide the first surface radially into n regions (where n>4), and a magnetic detection part provided to be opposite to the first surface of the multipolar magnet. The multipolar magnet is provided to be capable of relative movement in at least one direction in a plane substantially parallel to the first surface and the second surface. The magnetic detection part outputs a signal corresponding to change in the magnetic field accompanying relative movement of the multipolar magnet, and the geometric centers of the multipolar magnet and the magnetic detection part substantially match in a direction orthogonal to the first surface.
    Type: Grant
    Filed: September 23, 2019
    Date of Patent: May 24, 2022
    Assignee: TDK Corporation
    Inventor: Yongfu Cai
  • Patent number: 11322418
    Abstract: In an assembly in which a space between two elements is filled with a filler containing resin, a configuration that can limit both the size of the assembly and the cost of the fillers is provided. Assembly 10 of stacked elements has: first element 2 having first surface 21; resin layer 61 that is arranged on first surface 21 and that contains a plurality of fillers F; and second element 4 that is arranged on resin layer 61 and that has second surface 41 that is in contact with resin layer 61. In a section that is perpendicular to second surface 41, the average flattening ratio of fillers F2 that are in contact with second surface 41 is larger than the average flattening ratio of fillers F1, F3 that are not in contact with second surface 41. Here, the flattening ratio is a ratio of the maximum length of the filler in a direction parallel to second surface 41 to the maximum thickness of the filler in a direction perpendicular to second surface 41.
    Type: Grant
    Filed: November 15, 2019
    Date of Patent: May 3, 2022
    Assignee: TDK Corporation
    Inventors: Yongfu Cai, Shuhei Miyazaki
  • Publication number: 20220090940
    Abstract: A position detection unit includes a magnetic sensor and a first magnetic field generator. The first magnetic field generator is spaced from and opposed to the magnetic sensor in a first-axis direction, includes a first multipolar magnet, and generates a first magnetic field to be exerted on the magnetic sensor. The first multipolar magnet includes N and S poles adjacent to each other along a plane orthogonal to the first-axis direction. The magnetic sensor and the first magnetic field generator are relatively movable with respect to each other along a second-axis direction orthogonal to the first-axis direction. A center position of the magnetic sensor in a third-axis direction orthogonal to both of the first-axis direction and the second-axis direction is different from a position in the third-axis direction of an interface between the N and S poles adjacent to each other in the third-axis direction.
    Type: Application
    Filed: July 28, 2021
    Publication date: March 24, 2022
    Applicant: TDK CORPORATION
    Inventor: Yongfu CAI
  • Patent number: 11274942
    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 sensor includes an MR element and a substrate. The substrate includes a main surface. The magnetic field to be detected received by the MR element has a first direction that changes within a first plane. The MR element includes a magnetic layer having first magnetization that can change in direction within a second plane parallel to the main surface. The first plane and the second plane intersect at a dihedral angle ? other than 90°. A detection value depends on the direction of the first magnetization.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: March 15, 2022
    Assignee: TDK CORPORATION
    Inventors: Yongfu Cai, Hiraku Hirabayashi
  • Publication number: 20220042826
    Abstract: A magnetic sensor system includes a magnetic field generator and a magnetic sensor. The magnetic sensor includes a plurality of MR elements. The plurality of MR elements are each configured so that a bias magnetic field in a second direction orthogonal to a first direction is applied to a free layer, and to change in resistance with a strength of a magnetic field component. A maximum strength of the magnetic field component applied to each of the MR elements is greater than or equal to 1.2 times the strength of a bias magnetic field.
    Type: Application
    Filed: July 26, 2021
    Publication date: February 10, 2022
    Applicant: TDK CORPORATION
    Inventors: Yongfu CAI, Hayato MIYASHITA, Tsuyoshi UMEHARA, Yuta SAITO
  • Publication number: 20210405133
    Abstract: A magnetic sensor device includes a magnetic field converter that receives an input magnetic field input along a first direction and outputs an output magnetic field along a second direction, which is orthogonal to the first direction. A magnetic field detector is provided at a position where the output magnetic field can be applied. A magnetic shield that blocks an external magnetic field along the second direction. is provided. The magnetic field converter has a shape in which the length in a third direction, which is orthogonal to both the first direction and the second direction, is longer than the length in the second direction, when viewed along the first direction. The magnetic shield is provided at a position overlapping with the magnetic field converter and the magnetic field detector, when viewed along the first direction.
    Type: Application
    Filed: September 9, 2021
    Publication date: December 30, 2021
    Inventors: Yongfu CAI, Yuta SAITO
  • Publication number: 20210382121
    Abstract: A magnetic sensor capable of reducing noise caused by an interference magnetic field and capable of outputting a highly accurate signal in accordance with changes in a detected magnetic field includes a magnetic detection element, a first magnetic body having a first surface and a second surface, which is opposite to the first surface, and a second magnetic body positioned approximately in the center of the first magnetic body in the short direction on the first surface of the first magnetic body. The magnetic detection element is provided to be opposite to the second magnetic body with the first magnetic body interposed in between and positioned approximately in the center of the first magnetic body in the short direction. The magnetic sensing direction of the magnetic detection element is a direction approximately parallel to the short direction of the first magnetic body and the second magnetic body, and a width W1 of the first magnetic body is larger than a width W2 of the second magnetic body.
    Type: Application
    Filed: August 23, 2021
    Publication date: December 9, 2021
    Inventor: Yongfu CAI
  • Publication number: 20210382124
    Abstract: A magnetic sensor device having a spin-valve-type magnetoresistive effect element and capable of stably applying a bias magnetic field on the free layer of the magnetoresistive effect element includes a spin-valve-type magnetoresistive effect element, a substrate on which the magnetoresistive effect element is positioned, a power source that supplies a substantially constant electric current applied on the magnetoresistive effect element, and a magnetic field generator that is connected to the electric current path of the electric current applied on the magnetoresistive effect element in series. The magnetic field generator is provided to be capable of applying a bias magnetic field on at least a portion of the magnetoresistive effect element. The magnetic field generator is close to a portion of the magnetoresistive effect element and is positioned at a different level from the substrate.
    Type: Application
    Filed: August 25, 2021
    Publication date: December 9, 2021
    Inventors: Naoki OHTA, Yongfu CAI
  • Publication number: 20210372819
    Abstract: A position detection unit includes a magnetic sensor, a first magnetic field generator, and a second magnetic field generator. The first magnetic field generator includes a first magnet and a second magnet spaced apart from each other in a first direction, and generates a first magnetic field. The second magnetic field generator generates a second magnetic field and is movable along a second direction orthogonal to the first direction with respect to the first magnetic field generator and the magnetic sensor. In the first direction, a center position of the magnetic sensor lies at a position in a region between the first magnet and the second magnet other than a midpoint position between the first magnet and the second magnet. The magnetic sensor generates a detection signal corresponding to a direction of a magnetic field to be detected, and detects a positional change of the second magnetic field generator.
    Type: Application
    Filed: April 28, 2021
    Publication date: December 2, 2021
    Applicant: TDK CORPORATION
    Inventor: Yongfu CAI
  • Patent number: 11175357
    Abstract: A magnetic sensor device includes a magnetic field converter that receives an input magnetic field input along a first direction and outputs an output magnetic field along a second direction, which is orthogonal to the first direction. A magnetic field detector is provided at a position where the output magnetic field can be applied. A magnetic shield that blocks an external magnetic field along the second direction, is provided. The magnetic field converter has a shape in which the length in a third direction, which is orthogonal to both the first direction and the second direction, is longer than the length in the second direction, when viewed along the first direction. The magnetic shield is provided at a position overlapping with the magnetic field converter and the magnetic field detector, when viewed along the first direction.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: November 16, 2021
    Assignee: TDK Corporation
    Inventors: Yongfu Cai, Yuta Saito