Patents by Inventor Yuji Ishii

Yuji Ishii 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: 20090244674
    Abstract: A mirror driving circuit applies a voltage to drive a mirror and switches an optical path of light output from a channel of an input port to a channel of an output port. The mirror driving circuit includes an offset-voltage applying unit that applies an offset voltage to the mirror, an applied-voltage determining unit that determines an applied voltage to be applied to the mirror based on a relation between the channel of the input port and the channel of the output port forming a path of the light, and a voltage applying unit that applies to the mirror a remaining voltage obtained by subtracting the offset voltage from the applied voltage.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 1, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Yuji Ishii, Takashi Shimizu
  • Publication number: 20090190882
    Abstract: An optical device includes an I/O port group and a movable mirror reflecting light input through an input port of the I/O group, aligning the light reflected with an output port of the I/O port group, and changing the angle of the light reflected according to a driving voltage supplied thereto. The optical device further includes a control unit that adjusts the driving voltage within a range lower than the voltage at which the degree of alignment of the light with respect to the output port is maximized and controls attenuation of the light reflected by the moveable mirror.
    Type: Application
    Filed: September 30, 2008
    Publication date: July 30, 2009
    Applicant: Fujitsu Limited
    Inventors: Hiroyuki Furukawa, Yuji Ishii, Kazuyuki Mori
  • Patent number: 7558448
    Abstract: An optical switching system includes a connection information memory portion (21) that stores connection information between input ports and output ports, a control characteristic memory portion (23) that stores control characteristic data of micro mirrors with respect to each of a plurality of temperatures, a temperature sensor (25) that senses a temperature in the optical switching system, and a computing portion (22) that refers to the control characteristic data stored in the control characteristic memory portion so as to calculate a controlled variable for the angle control of the micro mirrors based on the connection information stored in the connection information memory portion and the temperature sensed by the temperature sensor.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: July 7, 2009
    Assignee: Fujitsu Limited
    Inventors: Yuji Ishii, Shinji Yamashita
  • Patent number: 7486850
    Abstract: An optical switch system has a plurality of micro mirrors arranged in a plane, and an angle of each of the micro mirrors can be controlled for reflecting an optical signal entered from one or more input ports so that the reflected optical signal enters a selected output port of one or more output ports. The optical switch system includes a storage portion for storing connection information between the input port and the output port, a correction quantity obtaining portion for obtaining a correction quantity for a cross talk generated between neighboring micro mirrors among the plurality of micro mirrors, a computing portion for determining a controlling quantity of the micro mirror in accordance with the connection information and the correction quantity, and a drive output portion for driving the micro mirror in accordance with the controlling quantity.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: February 3, 2009
    Assignee: Fujitsu Limited
    Inventors: Yuji Ishii, Kenji Rikimaru, Shinji Yamashita
  • Patent number: 7485937
    Abstract: A tunnel junction device capable of controlling its spin retention is provided. The tunnel junction device includes a La0.6Sr0.4MnO3-? electrode (12), a La0.6Sr0.4Mn1-yRuyO3-? electrode (14), both as ferromagnetic (including ferrimagnetic) metal materials, and a LaAlO3-? (electrically insulating layer) (13) arranged between the two electrodes (12) and (14).
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: February 3, 2009
    Assignees: National Institute of Advanced Industrial Science and Technology, Japan Science and Technology Agency
    Inventors: Yoshinori Tokura, Masashi Kawasaki, Hiroshi Akoh, Hiroyuki Yamada, Yuji Ishii, Hiroshi Sato, Yoshio Kaneko
  • Patent number: 7467171
    Abstract: In a digital filter device which filters a plurality of signals by a single digital filter, an input data memory stores the input data strings generated by computing processors, and a digital filter reads the input data strings in a predetermined sequence to be filtered and generates output data strings. An output data memory stores the output data strings, and a data processor reads the output data strings in a predetermined sequence to be processed. Furthermore, a filter memory and coefficient memories respectively store data-under-calculation and a filter coefficient in a delay circuit included in the digital filter.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: December 16, 2008
    Assignee: Fujitsu Limited
    Inventors: Yuji Ishii, Kenji Rikimaru, Kazuyuki Mori, Yuji Tochio
  • Patent number: 7466915
    Abstract: A mirror controller of an optical switch comprises a signal generator (10, 82, 83) for passing the optical signal on the same light path as the one for optical communication using the optical switch, and an image analyzer (15, 16, 81) detecting the optical signal as the light scattered by at least one of tilt mirrors (111, 123) and an output collimator array (14). The image analyzer detects the position of the light beam image as a control position (121, 141, 85) based on the scattered light, and controls the tilt mirrors in such a manner that the detected control position coincides with the predetermined desired target position (122, 142, 84, 86) on at least one of the tilt mirrors and the output collimator array. The mirror controller can realize the connection test of the optical signal between input and output with high accuracy and reliability.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: December 16, 2008
    Assignee: Fujitsu Limited
    Inventors: Yuji Ishii, Kazuyuki Mori, Tamotsu Akashi, Yoshio Sakai
  • Patent number: 7466967
    Abstract: A communication system that can improve communication quality by accurately re-creating reproduction timing at the receiving end even at the time of receiving VBR data or in the case of the occurrence of a packet loss. A send rate recognition section recognizes a send rate from a time stamp. A memory stores data. A dummy data addition section adds dummy data for correcting the difference between a read rate set for reading out data from the memory and the send rate to the data written to the memory. A read clock generation section generates a read clock which is equal to the read rate. A dummy data removal section removes the dummy data from the data read out from the memory on the basis of the read clock.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: December 16, 2008
    Assignee: Fujitsu Limited
    Inventors: Naoyuki Takeshita, Toshikazu Senuki, Tetsuya Yasui, Shinichirou Miyajima, Yuji Ishii, Katsuhiro Eguchi, Masahiro Abe, Jun Endoh
  • Publication number: 20080285915
    Abstract: An optical transmission system (1) alters quantity of incident light by reflecting an optical signal by a micro mirror (11) to enter an optical fiber (13) and by controlling an angle of the micro mirror (11), so that attenuation of the optical signal is controlled. An optical filter (14) is disposed between the micro mirror (11) and the optical fiber (13), for correcting a relationship between a control angle or control voltage of the micro mirror (11) and attenuation of the optical signal to be close to a linear relationship.
    Type: Application
    Filed: August 9, 2007
    Publication date: November 20, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Kenji Rikimaru, Yuji Ishii, Kazuyuki Mori
  • Publication number: 20080212157
    Abstract: An optical switching system includes a connection information memory portion (21) that stores connection information between input ports and output ports, a control characteristic memory portion (23) that stores control characteristic data of micro mirrors with respect to each of a plurality of temperatures, a temperature sensor (25) that senses a temperature in the optical switching system, and a computing portion (22) that refers to the control characteristic data stored in the control characteristic memory portion so as to calculate a controlled variable for the angle control of the micro mirrors based on the connection information stored in the connection information memory portion and the temperature sensed by the temperature sensor.
    Type: Application
    Filed: November 30, 2007
    Publication date: September 4, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Yuji Ishii, Shinji Yamashita
  • Patent number: 7398019
    Abstract: An object of the invention is to provide a control apparatus and a control method having a simple constitution, which can stably perform switching of optical path in an optical signal exchanger, while suppressing an influence on a control due to the mechanical resonance of tilt mirrors. To this end, the control apparatus of the optical signal exchanger is constituted such that in an optical signal exchanger of three-dimensional type using one set of MEMS mirror arrays, each having a plurality of tilt mirrors arranged on a plane, each tilt mirror having a reflecting surface an angle of which is controllable, when the angle of the MEMS mirror on the optical path is feedback controlled by detecting power of an optical signal output from a specific position, a resonance component removing section that removes a resonance frequency component included in a control signal is shared corresponding to a pair of driving electrodes arranged in a coaxial direction of the MEMS mirror.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: July 8, 2008
    Assignee: Fujitsu Limited
    Inventors: Yuji Tochio, Kazuyuki Mori, Tetsuji Yamabana, Ichiro Watanabe, Yuji Ishii
  • Patent number: 7280507
    Abstract: If a radio LAN apparatus moves from a communication range of a first access point to a communication range of a second access point, and if communication link between the radio LAN apparatus and the first access point is broken, a memory control section stops transmitting data to the first access point. At this time, data to be transmitted to the first access point are not deleted from memory. After the radio LAN apparatus enters the communication range of the second access point, the memory control section resumes transmission of the data stored in the memory. Thereafter, the next data are transmitted. Thus, the data is transmitted in proper sequence.
    Type: Grant
    Filed: February 19, 2004
    Date of Patent: October 9, 2007
    Assignee: Fujitsu Limited
    Inventors: Shinichirou Miyajima, Kazuhiro Ichiyanagi, Akiko Kusumoto, Yuji Nagano, Katsuhiro Eguchi, Naoyuki Takeshita, Yuji Ishii, Kazuyuki Inomoto
  • Publication number: 20070230864
    Abstract: An optical switch system has a plurality of micro mirrors arranged in a plane, and an angle of each of the micro mirrors can be controlled for reflecting an optical signal entered from one or more input ports so that the reflected optical signal enters a selected output port of one or more output ports. The optical switch system includes a storage portion for storing connection information between the input port and the output port, a correction quantity obtaining portion for obtaining a correction quantity for a cross talk generated between neighboring micro mirrors among the plurality of micro mirrors, a computing portion for determining a controlling quantity of the micro mirror in accordance with the connection information and the correction quantity, and a drive output portion for driving the micro mirror in accordance with the controlling quantity.
    Type: Application
    Filed: July 28, 2006
    Publication date: October 4, 2007
    Inventors: Yuji Ishii, Kenji Rikimaru, Shinji Yamashita
  • Publication number: 20070219320
    Abstract: A process for producing a rubber composition containing a nonconjugated polyene copolymer (A), a softener (B) and a diene rubber (C), comprising: a step of mixing a copolymer composition (I), said copolymer composition (I) comprising 100 parts by weight of a nonconjugated polyene copolymer (A), said nonconjugated polyene copolymer (A) being a random copolymer containing 96 to 70 mol % of the structural units derived from ?-olefin (A1) and 4 to 30 mol % of the structural units derived from nonconjugated polyene (A2) and having a glass transition temperature (Tg) of ?25 to 20° C., and 1 to 100 parts by weight of the softener (B); the diene rubber (C); and optionally further the softener (B). A tire tread using the rubber composition and a tire having the tire tread.
    Type: Application
    Filed: April 28, 2005
    Publication date: September 20, 2007
    Applicants: Mitsui Chemicals, Inc., Yokohama Rubber Company, Limited, The
    Inventors: Kotaro Ichino, Masao Kunizane, Yuji Ishii, Kunihide Hiraoka, Masaaki Kawasaki, Hidetatsu Murakami, Keiji Okada
  • Publication number: 20070212572
    Abstract: A tunnel junction device capable of controlling its spin retention is provided. The tunnel junction device includes a La0.6Sr0.4MnO3-? electrode (12), a La0.6Sr0.4Mn1-yRuyO3-? electrode (14), both as ferromagnetic (including ferrimagnetic) metal materials, and a LaAlO3-? (electrically insulating layer) (13) arranged between the two electrodes (12) and (14).
    Type: Application
    Filed: February 25, 2005
    Publication date: September 13, 2007
    Applicants: National Inst of Adv Industrial Science, Japn Science and Technology Agency
    Inventors: Yoshinori Tokura, Masashi Kawasaki, Hiroshi Akoh, Hiroyuki Yamada, Yuji Ishii, Hiroshi Sato, Yoshio Kaneko
  • Publication number: 20070085445
    Abstract: A stabilization apparatus according to the present invention comprises a stopper which is in contact under pressure with one side face of a movable body capable of swinging around a torsion bar, this one side face being vertical to an axial direction of the movable body, to damp the movable body. The stopper is displaced between a first position at which the stopper is in contact under pressure with the side face of the movable body, and a second position apart from the side face, according to a drive voltage applied to a stopper electrode. The drive voltage for the stopper electrode is controlled by a control section at the appropriate timing according to a drive condition of the movable body. As a result, the resonance operation can be reliably suppressed even when an angle of the movable mirror is changed at a high speed, and thus, it becomes possible to stabilize the movable mirror to be in a desired state in a short time.
    Type: Application
    Filed: January 27, 2006
    Publication date: April 19, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Kenji Rikimaru, Yuji Ishii, Kazuyuki Mori
  • Publication number: 20060088317
    Abstract: A mirror controller of an optical switch comprises a signal generator (10, 82, 83) for passing the optical signal on the same light path as the one for optical communication using the optical switch, and an image analyzer (15, 16, 81) detecting the optical signal as the light scattered by at least one of tilt mirrors (111, 123) and an output collimator array (14). The image analyzer detects the position of the light beam image as a control position (121, 141, 85) based on the scattered light, and controls the tilt mirrors in such a manner that the detected control position coincides with the predetermined desired target position (122, 142, 84, 86) on at least one of the tilt mirrors and the output collimator array. The mirror controller can realize the connection test of the optical signal between input and output with high accuracy and reliability.
    Type: Application
    Filed: January 21, 2005
    Publication date: April 27, 2006
    Applicant: FUJITSU LIMITED
    Inventors: Yuji Ishii, Kazuyuki Mori, Tamotsu Akashi, Yoshio Sakai
  • Publication number: 20060056242
    Abstract: A communication system that can improve communication quality by accurately re-creating reproduction timing at the receiving end even at the time of receiving VBR data or in the case of the occurrence of a packet loss. A send rate recognition section recognizes a send rate from a time stamp. A memory stores data. A dummy data addition section adds dummy data for correcting the difference between a read rate set for reading out data from the memory and the send rate to the data written to the memory. A read clock generation section generates a read clock which is equal to the read rate. A dummy data removal section removes the dummy data from the data read out from the memory on the basis of the read clock.
    Type: Application
    Filed: November 8, 2005
    Publication date: March 16, 2006
    Inventors: Naoyuki Takeshita, Toshikazu Senuki, Tetsuya Yasui, Shinichirou Miyajima, Yuji Ishii, Katsuhiro Eguchi, Masahiro Abe, Jun Endoh
  • Publication number: 20060053149
    Abstract: The man-months definition table 106 defines man-months for each combination of a function, data, and an infrastructure for both As_Is and To_Be of EA. The content retrieval patterns database 109 sets a development example for each combination of the function, data and the infrastructure. The EA result analysis unit 113 creates a retrieval pattern used for retrieving man-months from EA planning results of the EA planning results database 108, and the man-months calculation unit 114 searches the man-months definition table 106 to calculate development man-months. The example retrieval unit 115 creates a retrieval pattern used for retrieving content and searches the content retrieval patterns database 109 for a suitable development example.
    Type: Application
    Filed: February 4, 2005
    Publication date: March 9, 2006
    Inventors: Atsushi Iwasaki, Masaya Shozui, Yuji Ishii, Eiji Takamatsu, Takeshi Matsuoka
  • Publication number: 20050122828
    Abstract: A magnetic switching device of the present invention includes: at least one transition member; at least one electrode; and at least one free magnetic member. The transition member contains a perovskite compound that contains at least a rare earth element and an alkaline-earth metal, the electrode and the free magnetic member are arranged in parallel and in a noncontact manner on the transition member, at least one of the free magnetic members is coupled magnetically with the transition member, and the transition member undergoes at least ferromagnetism-antiferromagnetism transition by injecting or inducing electrons or holes, whereby a magnetization direction of at least one of the free magnetic members changes. This configuration is applicable to a magnetic memory that records/reads out magnetization information of the free magnetic layer and various magnetic devices that utilize a resistance change of the magnetoresistive effect portion.
    Type: Application
    Filed: September 28, 2004
    Publication date: June 9, 2005
    Applicants: Matsushita Electric Industrial Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Akihiro Odagawa, Hiroshi Sato, Toshikazu Yamada, Yuji Ishii, Isao Inoue, Hiroshi Akoh, Masashi Kawasaki, Hidenori Takagi