Patents by Inventor Masao Mizumaki

Masao Mizumaki 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: 9136750
    Abstract: A motor capable of performing mechanical position adjustment of a magnetic detection unit to thereby adjust a phase difference between signals output from respective two magnetosensitive pole pieces. A rotor includes a magnet having an axial end surface magnetized to have circumferentially alternately different poles. A stator has two outer magnetic pole portions opposed to an outer peripheral surface of the magnet. Two coils are energized to excite the outer magnetic pole portions. A magnetic sensor is opposed to an axial end surface of the magnet. The magnetosensitive pole pieces of the magnetic sensor detect a magnetic field change caused by rotation of the magnet. The magnetosensitive pole pieces are arranged side by side in a direction orthogonal to a diametrical direction of the magnet. The position of the magnetic sensor can be adjusted in the diametrical direction of the magnet.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: September 15, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Masao Mizumaki
  • Patent number: 8696222
    Abstract: An image-pickup apparatus includes a lead screw, a moving member, an image-pickup element, a mirror member that is capable of rotating between a first state and a second state, an urging member, and a first abutment member configured to abut against the mirror member when the mirror member is in the first state. An engagement portion parallel to a rotational axis of the mirror member is protruded from the mirror member. The engagement portion is held by both ends of the urging member when the mirror member rotates between the first state and the second state. A first end of the urging member elastically deforms so as to be apart from the engagement portion when the mirror member abuts against the first abutment member.
    Type: Grant
    Filed: May 13, 2013
    Date of Patent: April 15, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20130308935
    Abstract: An image-pickup apparatus includes a lead screw, a moving member, an image-pickup element, a mirror member that is capable of rotating between a first state and a second state, an urging member, and a first abutment member configured to abut against the mirror member when the mirror member is in the first state. An engagement portion parallel to a rotational axis of the mirror member is protruded from the mirror member. The engagement portion is held by both ends of the urging member when the mirror member rotates between the first state and the second state. A first end of the urging member elastically deforms so as to be apart from the engagement portion when the mirror member abuts against the first abutment member.
    Type: Application
    Filed: May 13, 2013
    Publication date: November 21, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Masao Mizumaki
  • Publication number: 20120200180
    Abstract: A motor capable of performing mechanical position adjustment of a magnetic detection unit to thereby adjust a phase difference between signals output from respective two magnetosensitive pole pieces. A rotor includes a magnet having an axial end surface magnetized to have circumferentially alternately different poles. A stator has two outer magnetic pole portions opposed to an outer peripheral surface of the magnet. Two coils are energized to excite the outer magnetic pole portions. A magnetic sensor is opposed to an axial end surface of the magnet. The magnetosensitive pole pieces of the magnetic sensor detect a magnetic field change caused by rotation of the magnet. The magnetosensitive pole pieces are arranged side by side in a direction orthogonal to a diametrical direction of the magnet. The position of the magnetic sensor can be adjusted in the diametrical direction of the magnet.
    Type: Application
    Filed: February 2, 2012
    Publication date: August 9, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Masao MIZUMAKI
  • Patent number: 8184354
    Abstract: A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: May 22, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Mizumaki, Hiroshi Akada
  • Patent number: 8035327
    Abstract: A motor drive unit includes a controller configured to drive a motor to a target position by using a first driving mode in which a state of energization of coils of the motor is switched in accordance with outputs from rotor position detectors and a second driving mode in which a state of energization of the coils is switched on the basis of a predetermined time interval. The controller turns on the energization of the coils during a predetermined time under an energization condition at a completion of driving to the target position when the rotor position detectors detect that the rotor position shifts from the target position after turning off the energization of the coils according to the completion of driving to the target position.
    Type: Grant
    Filed: January 27, 2009
    Date of Patent: October 11, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20110128604
    Abstract: A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.
    Type: Application
    Filed: February 9, 2011
    Publication date: June 2, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masao Mizumaki, Hiroshi Akada
  • Patent number: 7907321
    Abstract: A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: March 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Mizumaki, Hiroshi Akada
  • Patent number: 7843093
    Abstract: A stepping motor as a driving device has a stator with a plate part, and first and second outer magnetic pole parts axially extending from the plate part. A rotor formed by a rotary shaft and a core, each formed of a soft magnetic material, are disposed between the outer magnetic pole parts. The rotor has one axial end rotatably supported in the plate part. A magnet is rigidly fitted on an outer periphery of the rotor and magnetized such that different poles circumferentially alternate. A top plate is rigidly secured to the respective foremost ends of the pole parts and rotatably supports the other axial end of the rotor. The pole parts are engaged in a bobbin having a cover part covering the outer peripheral surface of the magnet. First and second coils are wound around the outer magnetic pole parts via the bobbin.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: November 30, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Patent number: 7781924
    Abstract: A drive apparatus which is small in size, short in axial length, low in cost, and high in output. A stepping motor as the driving apparatus includes a first coil, a second coil, a magnet, and a rotor comprised of a core and a rotary shaft. First through fourth outer magnetic pole portions are opposed to the outer peripheral surface of the magnet with a predetermined gap between them. The first and the second coils are disposed adjacent to the magnet in an axial direction of the rotary shaft and disposed at respective ends of the rotary shaft. The first and second outer magnetic pole portions are inserted inside the first and second coils, respectively. As viewed in the circumferential direction of the magnet, the third and fourth outer magnetic pole portions are disposed close to the first and second outer magnetic pole portions, respectively.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: August 24, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20090189552
    Abstract: A motor drive unit includes a controller configured to drive a motor to a target position by using a first driving mode in which a state of energization of coils of the motor is switched in accordance with outputs from rotor position detectors and a second driving mode in which a state of energization of the coils is switched on the basis of a predetermined time interval. The controller turns on the energization of the coils during a predetermined time under an energization condition at a completion of driving to the target position when the rotor position detectors detect that the rotor position shifts from the target position after turning off the energization of the coils according to the completion of driving to the target position.
    Type: Application
    Filed: January 27, 2009
    Publication date: July 30, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Masao Mizumaki
  • Publication number: 20080192326
    Abstract: A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.
    Type: Application
    Filed: February 4, 2008
    Publication date: August 14, 2008
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masao Mizumaki, Hiroshi Akada
  • Patent number: 7352089
    Abstract: A driving apparatus includes a stepping motor having a lead screw, a rack, and a rack-retaining bar, a barrel, a barrel-retaining bar, and a connecting spring for connecting the rack to the barrel. The connecting spring includes an engaging portion that engages with a spherical output member of the rack. The stepping motor in which the lead screw and the rack are integrated with each other and the barrel are connected to each other with provides a structure that absorbs relative positioning error and backlash.
    Type: Grant
    Filed: June 19, 2006
    Date of Patent: April 1, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Patent number: 7304408
    Abstract: A driving apparatus includes a magnet that is magnetized to at least two poles in a circumferential direction and fixed to a rotor axis formed with a soft magnetic material, and first and second coils arranged in the same direction as the magnet with respect to the magnet-axis direction and arranged adjacent to an end surface of the magnet in the magnet-axis direction. The first magnetic pole portion is excited by energizing the first coil, and the second magnetic pole portion is excited to a pole opposite to the first magnetic pole portion by energizing the second coil. A yoke portion is formed with a soft magnetic material for supporting the first and second magnetic pole portions. The first magnetic pole portion includes a first coil insertion portion that is inserted to an internal diameter portion of the first coil, and a first magnet facing portion that is arranged to face a magnetized outer circumferential portion of the magnet with a predetermined gap at a predetermined angle.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: December 4, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Patent number: 7183676
    Abstract: A small-sized and low-cost stepping motor includes a stator made of a soft magnetic material integrally having first and second outer magnetic poles, a first coil wound around a first bobbin externally fitted to the first outer magnetic pole, a second coil wound around a second bobbin externally fitted to the second outer magnetic pole, and a rotor part made of a soft magnetic material having a magnet fixed around a first column part by interference fit. The rotor part is rotatably supported by a first shaft part of a cover in a hole of the rotor part. An urging member made of a nonmagnetic material is rotatably fitted into the hole of the rotor part, and a compression coil spring urging the rotor part in the axial direction together with the urging member is disposed in the hole.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: February 27, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20070018514
    Abstract: A drive apparatus which is small in size, short in axial length, low in cost, and high in output. A stepping motor as the driving apparatus includes a first coil, a second coil, a magnet, and a rotor comprised of a core and a rotary shaft. First through fourth outer magnetic pole portions are opposed to the outer peripheral surface of the magnet with a predetermined gap therebetween. The first and the second coils are disposed adjacent to the magnet axially of the rotary shaft and disposed at respective ends of the rotary shaft. The first and second outer magnetic pole portions are inserted inside the first and second coils, respectively. As viewed in the circumferential direction of the magnet, the third and fourth outer magnetic pole portions are disposed close to the first and second outer magnetic pole portions, respectively.
    Type: Application
    Filed: July 25, 2006
    Publication date: January 25, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Masao MIZUMAKI
  • Patent number: 7164215
    Abstract: A motor includes a rotor shaft 7 which is fixed in the inside diameter portion of a magnet 6, a first coil 2 which is arranged adjacently to the magnet in the axial direction of the rotor shaft, a first outside magnetic pole portion 1a which is excited by the first coil, is inserted on the inner periphery side of the first coil, and is arranged so as to be opposed to a predetermined angle range of the outer peripheral surface of the magnet with a predetermined gap being provided between the first outside magnetic pole portion and the outer peripheral surface of the magnet, a second coil 4 which is arranged on almost the same plane as the first coil so as to be adjacent to the magnet in the axial direction of the rotor shaft, and a second outside magnetic pole portion 1b which is excited by the second coil, is inserted on the inner periphery side of the second coil, and is arranged so as to be opposed to a predetermined angle range of the outer peripheral surface of the magnet with a predetermined gap being pr
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: January 16, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20060284496
    Abstract: A driving apparatus includes a stepping motor having a lead screw, a rack, and a rack-retaining bar, a barrel, a barrel-retaining bar, and a connecting spring for connecting the rack to the barrel. The connecting spring includes an engaging portion that engages with a spherical output member of the rack. The stepping motor in which the lead screw and the rack are integrated with each other and the barrel are connected to each other with provides a structure that absorbs relative positioning error and backlash.
    Type: Application
    Filed: June 19, 2006
    Publication date: December 21, 2006
    Applicant: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Publication number: 20060232144
    Abstract: A low-cost and high-output driving device compact in size and reduced in axial length. In a stepping motor as the driving device, a stator has a plate part, and first and second outer magnetic pole parts axially extend from the plate part. A rotor formed by a rotary shaft and a core each formed of a soft magnetic material is disposed between said first and second outer magnetic pole parts. The rotor has one axial end thereof rotatably supported in the plate part. A magnet is rigidly fitted on an outer periphery of the rotor and magnetized such that different poles circumferentially alternate. A top plate is rigidly secured to the respective foremost ends of the pole parts and rotatably support the other axial end of the rotor. The pole parts are engaged in a bobbin having a cover part covering the outer peripheral surface of the magnet. First and second coils are wound around the first and second outer magnetic pole parts via the bobbin axially between the magnet and the plate part.
    Type: Application
    Filed: April 14, 2006
    Publication date: October 19, 2006
    Applicant: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki
  • Patent number: 7122920
    Abstract: Provided are a motor and an optical apparatus each including: a rotatable rotor having a cylindrical magnet; a first coil; a first outer magnetic pole portion which is disposed at a center portion of the first coil and which is opposed to an outer circumferential surface of the magnet within a first predetermined angle range; a second outer magnetic pole portion which is adjacent to an outer circumference of the first coil and which is opposed to the outer circumferential surface of the magnet; a first inner magnetic pole portion which is adjacent to the outer circumference of the first coil and which is opposed to an inner circumferential surface of the magnet; a second coil; a third outer magnetic pole portion which is disposed at a center portion of the second coil and which is opposed to the outer circumferential surface of the magnet within a second predetermined angle range; a fourth outer magnetic pole portion which is adjacent to an outer circumference of the second coil and which is opposed to the ou
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: October 17, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masao Mizumaki