Patents by Inventor Seigo Igaki

Seigo Igaki 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: 20070127147
    Abstract: In a contact detecting apparatus that detects contact of a head with a recording medium, a signal writing unit writes onto the recording medium, a signal that includes at least one predetermined frequency component; and a contact detecting unit detects the contact of the head with the recording medium based on an amplitude of the predetermined frequency component, by reading the signal written on the recording medium while changing a spacing between the head and the recording medium.
    Type: Application
    Filed: March 23, 2006
    Publication date: June 7, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Toru Yokohata, Takeshi Iwase, Takahisa Ueno, Seigo Igaki, Takahiro Imamura
  • Publication number: 20070127148
    Abstract: In a contact detecting apparatus that detects contact of a head with a recording medium, a signal writing unit writes onto the recording medium, a signal that includes at least one predetermined frequency component; and a contact detecting unit detects the contact of the head with the recording medium based on an amplitude of the predetermined frequency component, by reading the signal written on the recording medium while changing a spacing between the head and the recording medium.
    Type: Application
    Filed: September 20, 2006
    Publication date: June 7, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Toru Yokohata, Takeshi Iwase, Takahisa Ueno, Seigo Igaki, Takahiro Imamura, Tohru Fujimaki
  • Patent number: 7079340
    Abstract: After a measurement apparatus records a magnetization state of a reference pattern on at least one specific track of a recording medium, it generates a leakage magnetic field of a demagnetization pattern and demagnetizes the magnetization state of the reference pattern using the leakage magnetic field. Then, the measurement apparatus calculates a difference between the read output of a reference pattern before demagnetization and the read output of a reference pattern after demagnetization on the specific track and obtains a leakage magnetic field of a recording head from the obtained difference.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: July 18, 2006
    Assignee: Fujitsu Limited
    Inventors: Seigo Igaki, Takahisa Ueno, Tohru Horie, Iwao Okamoto
  • Publication number: 20050243454
    Abstract: After a measurement apparatus records a magnetization state of a reference pattern on at least one specific track of a recording medium, it generates a leakage magnetic field of a demagnetization pattern and demagnetizes the magnetization state of the reference pattern using the leakage magnetic field. Then, the measurement apparatus calculates a difference between the read output of a reference pattern before demagnetization and the read output of a reference pattern after demagnetization on the specific track and obtains a leakage magnetic field of a recording head from the obtained difference.
    Type: Application
    Filed: November 17, 2004
    Publication date: November 3, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Seigo Igaki, Takahisa Ueno, Tohru Horie, Iwao Okamoto
  • Patent number: 5993982
    Abstract: A method of evaluating a durability of a magnetic disk includes the steps of (a) obtaining conditions under which a sliding contact state of a first head with respect to a surface of a first magnetic disk stabilizes, and (b) causing a second head to make sliding contact with a surface of a second magnetic disk under the conditions and evaluating a durability of the second magnetic disk.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: November 30, 1999
    Assignee: Fujitsu Limited
    Inventors: Yoshimichi Asanai, Minoru Takahashi, Seigo Igaki, Masaki Kameyama
  • Patent number: 5859357
    Abstract: An apparatus for measuring a maximum static friction force is disclosed, in which the displacement of the relative positions of first and second objects due to the operation of a driving unit is suppressed for measuring an accurate static friction force characteristic.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: January 12, 1999
    Assignee: Fujitsu Limited
    Inventors: Masaki Kameyama, Seigo Igaki
  • Patent number: 5109428
    Abstract: An apparatus used in fingerprint identification for extracting minutia data from fingerprint image data. An optical sensor unit optically produces a sequence of fingerprint image data during a single operation of pressing a fingerpad onto an inspection plate in a direction substantially transverse to the plate and with increasing pressure over a time interval. A data storing unit stores the produced fingerprint image data in the form of a sequence of fingerprint image data obtained during the single operation of pressing the fingerpad onto the inspection plate. The stored fingerprint image data is utilizable for identification of the fingerprint.
    Type: Grant
    Filed: December 6, 1989
    Date of Patent: April 28, 1992
    Inventors: Seigo Igaki, Takashi Shinzaki, Fumio Yamagishi, Hiroyuki Ikeda, Hironori Yahagi
  • Patent number: 5088817
    Abstract: An apparatus for detecting and identifying a biological object. A transparent plate has a first surface onto which a light beam is projected and a second surface onto which a biological object to be detected and identified is placed. The light beam projected toward the first plate surface is transmitted through the plate and toward the object on the second surface, from which the light beam is reflected and retransmitted through the plate toward and through the first surface thereof and received and detected by an optical detector. The detection of a biological object is confirmed by comparing the change of the wavelength characteristics of the reflected and detected light beam in a predetermined time sequence according to the object being first placed upon and then pressed upon the second surface of the transparent plate with respective, known such characteristics thereof.
    Type: Grant
    Filed: November 17, 1989
    Date of Patent: February 18, 1992
    Inventors: Seigo Igaki, Takashi Shinzaki, Fumio Yamagishi, Ikeda: Hiroyuki
  • Patent number: 5077803
    Abstract: A biological detecting system comprising a light source; a condensing optical system for condensing a light beam from the light source and irradiating the surface of a sample to be detected with a spot of light, an imaging optical system for condensing light reflected or scattered by an irradiated portion of the sample and forming an image of the irradiated portion at a predetermined location, and a photodetector arranged at the predetermined location to detect the size of the image of the irradiated portion and output a detection signal indicating the detected size of the image.
    Type: Grant
    Filed: September 14, 1989
    Date of Patent: December 31, 1991
    Assignee: Fujitsu Limited
    Inventors: Masayuki Kato, Takashi Shinzaki, Seigo Igaki, Fumio Yamagishi, Hiroyuki Ikeda
  • Patent number: 4924085
    Abstract: An uneven surface data detection apparatus for detecting an uneven surface, such as a human finger, having projected portions and recessed portions. A transparent base having upper and lower surfaces and an upper surface defining an uneven surface contact portion is provided, and a light is incident on the uneven surface so that the light derived from the recess portions enters to the transparent base and comes out thereof. However, a part of the light derived from the projected portions is totally reflected at least one time by the lower opposite surface and focussing lens is integrally formed on the transparent base so that the totally reflected light is drawn out of transparent base and enters to an image sensor.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: May 8, 1990
    Assignee: Fujitsu Limited
    Inventors: Masayuji Kato, Seigo Igaki, Fumio Yamagishi, Hiroyuki Ikeda, Takashi Shinzaki, Shin Eguchi
  • Patent number: 4728186
    Abstract: An uneven-surface data detection apparatus, includes a transparent plate having an uneven-surface contact portion against which an uneven surface to be detected is pressed. A light source illuminates the uneven-surface contact portion through the transparent plate. An uneven-surface image drawing out optical element draws out the light reflected on the uneven-surface contact portion of the transparent plate. A detector detects the light drawn out from the transparent plate by the optical element.Light reflected by a projection-facing portion of the uneven surface contact portion to be introduced into the detector diverges from a propagation direction of light reflected by a recess-facing portion of the uneven surface contact portion. The optical element is arranged to guide the light reflected by the projection-facing portion into the detector.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: March 1, 1988
    Assignee: Fujitsu Limited
    Inventors: Shin Eguchi, Seigo Igaki, Hironori Yahagi, Fumio Yamagishi, Hiroyuki Ikeda, Takefumi Inagaki
  • Patent number: 4559452
    Abstract: An apparatus for detecting an edge of a semitransparent plane substance provided with a light source array including a plurality of light sources and a photosensor array including a plurality of photosensors. A selection circuit selects a pair of one of the light sources and one of the photosensors, respectively, and a comparator circuit compares the outputs of each of the photosensors in each pair when no detected substance exists between the light source array and the photosensor array, and the corresponding outputs when a substance exists between the light source array and the photosensor array, so that the edge portion of the substance can be detected.
    Type: Grant
    Filed: May 27, 1983
    Date of Patent: December 17, 1985
    Assignee: Fujitsu Limited
    Inventors: Seigo Igaki, Tadao Nakakuki, Takefumi Inagaki, Shuetsu Oikawa, Takashi Fujimura
  • Patent number: 4484077
    Abstract: An exposure system or apparatus and method using an electron beam for forming a pattern on a subject, which uses a figure Q which surrounds a pattern P and which is more simplified than the pattern P. Data related to the positions of the vertical and horizontal electron beam used to expose the pattern are stored in a pattern package memory based upon the surrounding figure. The data related to the positions of the electron beam, data related to the start-points of the surrounding figure, and signals based upon the scanning data are supplied to a deflection device of an electron beam device.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: November 20, 1984
    Assignee: Fujitsu Limited
    Inventors: Seigo Igaki, Yoshiro Goto, Yasuo Furukawa