Patents by Inventor Shoji Fujisawa

Shoji Fujisawa 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: 6917126
    Abstract: A sliding means with built-in moving-magnet linear motor is provided, realizing high-speed operation and much response ability of a table to a stationary bed, and also accurate position control of the table to the bed. With the sliding means of this invention, armature windings carry a three-phase current while a driving circuit is transferred to the external driver to make the bed slim in construction. Thus, the sliding means is reduced in overall height. A field magnet of rare earth permanent magnet is effective in raising flux density, thereby providing high propulsion for the table. An encoder to monitor a position of the table is an optical encoder having an optical linear scale, which contributes to improvement in accurate monitoring. The construction in which the armature windings connected to cords, lines, and so on are placed on the stator side has no fear of causing dust and dirt, thus realizing clean environment.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: July 12, 2005
    Assignee: Nippon Thompson Co., Ltd.
    Inventors: Takaaki Tsuboi, Shoji Fujisawa, Masaki Ohno
  • Patent number: 6734583
    Abstract: A slider unit having built in a moving-coil linear motor ensuring high propulsion, is kept slim in overall height. A moving-coil assembly is made slim, with high stiffness, and is composed of an iron core of platy-configuration, and at least one set of three-phase armature coils wound around the iron core in the form of flat rectangular configuration in a plane intersecting the sliding direction. Comparatively more coil sides of the armature coils contribute to high propulsion. Like poles on either field magnet are placed in opposition to each other across the air gap, whereby the magnetic attraction is cancelled to reduce the load on the linear motion guide unit.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: May 11, 2004
    Assignee: Nippon Thompson Co., Ltd.
    Inventors: Shoji Fujisawa, Tsutomu Togashi
  • Patent number: 6573623
    Abstract: A sliding means with built-in moving-magnet linear is disclosed, which makes it possible to sense accurately a table position with a magnetic sensor element. To this end, a magnetic flux pattern is rectified outside any one N-pole of forward and aft end poles of a field magnet. Position of the table is monitored with a magnetic sensor element arranged on the bed in opposition to the field magnet. Arranged outside the end pole of the field magnet is an auxiliary magnet unlike in polarity and made as small as possible in effect on propulsion exerted on the table. The auxiliary magnet is to rectify the magnetic flux pattern outside the end pole of the field magnet to the same distribution pattern as found at a boundary between the adjacent poles opposite in polarity in the field magnet, thus making it possible to identify the accurate positions of the forward and aft end pole of the field magnet.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: June 3, 2003
    Assignee: Nippon Thompson Co., Ltd.
    Inventors: Takaaki Tsuboi, Shoji Fujisawa, Masaki Ohno
  • Publication number: 20020021050
    Abstract: A slider unit having built in a moving-coil linear motor ensuring much high propulsion, with even kept slim in the overall height to the extent comparative to the slider units ever used. A moving-coil assembly is made slim in construction, with even high in stiffness. The moving-coil assembly is composed of an iron core of platy-configuration, and at least one set of three-phase armature coils wound around the iron core in the form of flat rectangular configuration in a plane intersecting the sliding direction. As there are more coil sides of the armature coils contributing to the propulsion, compared with a pole width in the moving direction of the field magnets, the high propulsion may be realized. Moreover, since like poles on either field magnet are placed in opposition to each other across the air gap, the magnetic attraction is cancelled to reduce the load on the linear motion guide unit, so that the table is allowed withstanding much load capacity.
    Type: Application
    Filed: August 20, 2001
    Publication date: February 21, 2002
    Inventors: Shoji Fujisawa, Tsutomu Togashi
  • Patent number: 6348746
    Abstract: Disclosed a slider unit having built-in a moving-coil linear motor made compact in construction by the provision of an improved magnet yoke for supporting field magnets, which is made in a slim construction, nevertheless very high in stiffness. The magnet yoke is comprised of a pair of confronting webs and a connecting web to connect integrally the confronting webs to each other. The magnet yoke of such integral construction helps ensure the overall high stiffness despite the webs being made thin. Thus, the magnet yoke may be made considerably slim, compared with the prior magnet yoke in which the confronting webs and connecting web are produced individually. A moving-coil assembly is installed to a table movable in a sliding manner through linear motion guide units with respect to a stationary bed.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: February 19, 2002
    Assignee: Nippon Thompson Co., Ltd.
    Inventors: Shoji Fujisawa, Eiji Ida
  • Publication number: 20010054851
    Abstract: A sliding means with built-in moving-magnet linear is disclosed, which makes it possible to sense accurately a table position with a magnetic sensor element. To this end, a magnetic flux pattern is rectified outside any one N-pole of forward and aft end poles of a field magnet. Position of the table is monitored with a magnetic sensor element arranged on the bed in opposition to the field magnet. Arranged outside the end pole of the field magnet is an auxiliary magnet unlike in polarity and made as small as possible in effect on propulsion exerted on the table. The auxiliary magnet is to rectify the magnetic flux pattern outside the end pole of the field magnet to the same distribution pattern as found at a boundary between the adjacent poles opposite in polarity in the field magnet, thus making it possible to identify the accurate positions of the forward and aft end pole of the field magnet.
    Type: Application
    Filed: June 22, 2001
    Publication date: December 27, 2001
    Applicant: NIPPON THOMPSON CO., LTD
    Inventors: Takaaki Tsuboi, Shoji Fujisawa, Masaki Ohno
  • Publication number: 20010048249
    Abstract: A sliding means with built-in moving-magnet linear motor is provided, realizing high-speed operation and much response ability of a table to a stationary bed, and also accurate position control of the table to the bed. With the sliding means of this invention, armature windings carry a three-phase current while a driving circuit is transferred to the external driver to make the bed slim in construction. Thus, the sliding means is reduced in overall height. A field magnet of rare earth permanent magnet is effective in raising flux density, thereby providing high propulsion for the table. An encoder to monitor a position of the table is an optical encoder having an optical linear scale, which contributes to improvement in accurate monitoring. The construction in which the armature windings connected to cords, lines, and so on are placed on the stator side has no fear of causing dust and dirt, thus realizing clean environment.
    Type: Application
    Filed: June 4, 2001
    Publication date: December 6, 2001
    Inventors: Takaaki Tsuboi, Shoji Fujisawa, Masaki Ohno
  • Patent number: 5825104
    Abstract: The present invention discloses a compact and inexpensive linear motor table. The above effects of the present invention are achieved by allowing at least one of either the bed or table to also serve as the yoke, or the magnetic circuit portion, of a linear electromagnetic actuator in addition to its inherent function.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: October 20, 1998
    Assignee: Nippon Thompson Co., Ltd.
    Inventors: Takuo Kondo, Shoji Fujisawa, Norimitsu Kitade
  • Patent number: 5036319
    Abstract: An magnetic encoder includes a multipolar magnetic body having a row of alternate North and South poles of equal widths, and a magnetoresistive element diposed in confrontation to the multipolar magnetic body. The magnetoresistive element includes at least one A phase magnetoresistive element member and at least one B phase magnetoresisitve element disposed in juxtaposition over ##EQU1## where n is an integer greater than or equal to 1, and .lambda. is a width of each individual pole of the multiplar magnetic body. Each of the A phase magnetoresistive element members and the B phase magnetoresistive element member has a group of series connected linear conductors arranged side-by-side into a comb-like shape.
    Type: Grant
    Filed: December 26, 1990
    Date of Patent: July 30, 1991
    Assignee: Shicoh Engineering Co., Ltd.
    Inventors: Manabu Shiraki, Osami Miyao, Shoji Fujisawa, Shunji Kawashima