Patents by Inventor Masaaki Ikawa

Masaaki Ikawa 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).

  • Patent number: 12135542
    Abstract: To provide more test data during the manufacture of non-volatile memories and other integrated circuits, machine learning is used to generate virtual test values. Virtual test results are interpolated for one set of tests for devices on which the test is not performed based on correlations with other sets of tests. In one example, machine learning determines a correlation study between bad block values determined at die sort and photo-limited yield (PLY) values determined inline during processing. The correlation can be applied to interpolate virtual inline PLY data for all of the memory dies, allowing for more rapid feedback on the processing parameters for manufacturing the memory dies and making the manufacturing process more efficient and accurate. In another set of embodiments, the machine learning is used to extrapolate limited metrology (e.g., critical dimension) test data to all of the memory die through interpolated virtual metrology data values.
    Type: Grant
    Filed: November 2, 2022
    Date of Patent: November 5, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Tsuyoshi Sendoda, Yusuke Ikawa, Nagarjuna Asam, Kei Samura, Masaaki Higashitani
  • Patent number: 12105137
    Abstract: To provide more test data during the manufacture of non-volatile memories and other integrated circuits, machine learning is used to generate virtual test values. Virtual test results are interpolated for one set of tests for devices on which the test is not performed based on correlations with other sets of tests. In one example, machine learning determines a correlation study between bad block values determined at die sort and photo-limited yield (PLY) values determined inline during processing. The correlation can be applied to interpolate virtual inline PLY data for all of the memory dies, allowing for more rapid feedback on the processing parameters for manufacturing the memory dies and making the manufacturing process more efficient and accurate. In another set of embodiments, the machine learning is used to extrapolate limited metrology (e.g., critical dimension) test data to all of the memory die through interpolated virtual metrology data values.
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: October 1, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yusuke Ikawa, Tsuyoshi Sendoda, Kei Samura, Masaaki Higashitani
  • Publication number: 20180316234
    Abstract: A rotor includes a rotor core and one or more magnets. The rotor core includes magnet supporters radially formed around a rotating shaft. The magnet includes a supported part supported by the magnet supporter and a projection projecting from the magnet supporter in an axial direction of the rotating shaft, The rotor core and the supported parts arranged annularly form a first generation part that generates a cogging torque of a first waveform, and the projections arranged annularly form a second generation part that generates a second cogging torque that differs in phase from the cogging torque of the first waveform.
    Type: Application
    Filed: November 18, 2015
    Publication date: November 1, 2018
    Inventors: Masaaki Ikawa, Wataru SAKURAI
  • Patent number: 6803685
    Abstract: The present invention provides a mechanical encoder device for use in a miniature motor, which encoder can provide, for each revolution of the motor, a plurality of pulses whose duty ratio does not change with time. A rotary contact portion 12 is provided on a rotor shaft 1, and a pair of rotation-detecting brushes 14 in sliding contact with the rotary contact portion 12 are provided on a brush holder 29 of an end cap 6. A plurality of rotary contact pieces 13 are arranged on the outer circumferential surface of the rotary contact portion 12 such that slits are formed therebetween. The paired rotation-detecting brushes 14 are each formed of a resilient metal and each assume the shape of a cantilever plate or wire spring whose side surface portion is subjected to sliding contact.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: October 12, 2004
    Assignee: Mabuchi Motor Co., Ltd.
    Inventors: Masaaki Ikawa, Hisashi Ogino, Wataru Sakurai
  • Publication number: 20040113499
    Abstract: The present invention provides a mechanical encoder device for use in a miniature motor, which encoder can provide, for each revolution of the motor, a plurality of pulses whose duty ratio does not change with time. A rotary contact portion 12 is provided on a rotor shaft 1, and a pair of rotation-detecting brushes 14 in sliding contact with the rotary contact portion 12 are provided on a brush holder 29 of an end cap 6. A plurality of rotary contact pieces 13 are arranged on the outer circumferential surface of the rotary contact portion 12 such that slits are formed therebetween. The paired rotation-detecting brushes 14 are each formed of a resilient metal and each assume the shape of a cantilever plate or wire spring whose side surface portion is subjected to sliding contact.
    Type: Application
    Filed: September 17, 2003
    Publication date: June 17, 2004
    Inventors: Masaaki Ikawa, Hisashi Ogino, Wataru Sakurai
  • Patent number: 4734607
    Abstract: A miniature motor having a plurality of commutator segments with commutator terminals which are connected to rotor windings. The commutator terminals are disposed on an insulating cylinder which is fixedly fitted to a motor rotating shaft, and a spark-quenching resistor connects each of the commutator segments. This resistor is a disc-shaped electrically conductive rubber ring which is fitted to the insulating cylinder so that the end face of the disc-shaped ring comes in contact with the commutator segment and commutator terminals and is brought into intimate contact with the commutator terminals by heating.
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: March 29, 1988
    Assignee: Mabuchi Motor Co., Ltd.
    Inventors: Masaaki Ikawa, Kazuichi Mabuchi