Patents by Inventor Takeshi Hojo

Takeshi Hojo 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: 20040085906
    Abstract: The purpose of the present invention is supplying a packet tracing system which can trace a route of a packet using existing network components. Packet printing devices 1a, 1b, and 1c generate packet identifying information for each packet which transmits through the communication line and write the packet identifying information to a storage part. An IDS 3 detects suspicious packets in a network under surveillance. A management system which receives a suspicious packet in a network generates a hash value for the suspicious packet and sends a request for examination which contains the hash value to the packet printing devices 1a, 1b and 1c. The packet printing devices 1a, 1b and 1c examine an internal storage part and send a result of examination to the management system 2. The management system 2 obtains a transmission route of the suspicious packet to be traced and by the result of examination and information of network construction.
    Type: Application
    Filed: August 25, 2003
    Publication date: May 6, 2004
    Inventors: Hisamichi Ohtani, Takeshi Hojo, Keiichi Iwata, Glen Mansfield Keeni
  • Patent number: 6131297
    Abstract: To provide a gyro compass for the use of a high speed ship, in a gyro compass of the type having north-seeking means which is applied to support a gyro sphere or gyro case immersed in a liquid in a tank, a substantially first-order lag filter is provided in an azimuth follow-up loop or a damping loop, the substantially first-order lag filter having a time constant T.sub.F which is approximately equal to a ratio C/k.sub.T of the viscosity torque coefficient C to the twisting torque coefficient k.sub.T of the torque produced between the tank and the gyro case. A speed error correcting means has a substantially first-order lag filter having a time constant which is approximately equal to that of the north-seeking means, and is applied to correct the output of azimuth indicator by a speed error correcting angle through the substantially first-order lag filter.
    Type: Grant
    Filed: January 9, 1999
    Date of Patent: October 17, 2000
    Assignee: Tokimec, Inc.
    Inventors: Kanshi Yamamoto, Shin-ichi Kawada, Takeshi Hojo, Michio Fukano
  • Patent number: 6019056
    Abstract: An anti-rolling apparatus according to the present invention includes rail members which are formed in straight form and disposed perpendicular to a rolling axis of an object whose rolling is to be reduced, a movable weight capable of reciprocating along the rail members, and two springs for generating a stability force for the movable weight, wherein the two springs are elongated or contracted alternately when the movable weight is reciprocated.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: February 1, 2000
    Assignee: Tokimec Inc.
    Inventors: Toru Maeda, Takeshi Hojo, Michio Fukano, Naoki Sakuraoka, Isao Masuzawa
  • Patent number: 5920983
    Abstract: An electrostatic supporting type acceleration detecting gyro apparatus is formed as an active type so as to be able to positively cancel a displacement of a gyro rotor. Control DC voltages for generating electrostatic supporting forces and displacement detection AC voltages for detecting a displacement of gyro rotor are applied to electrostatic supporting electrodes, and mechanism control circuits detect displacement indicating voltage signals (P.sub.1A) through (P.sub.4B). A displacement of the gyro rotor and the control DC voltages applied to the electrostatic supporting electrodes are computed based on the displacement detection voltages (P.sub.1A) through (P.sub.4B) outputted from the mechanism control circuits.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: July 13, 1999
    Assignee: Tokimec Inc.
    Inventors: Takao Murakoshi, Takeshi Hojo, Takafumi Nakaishi, Shigeru Nakamura
  • Patent number: 5821420
    Abstract: This invention relates to a vibration-type gyro apparatus for measuring an angular velocity using the Coriolis force exerted on a tuning fork. The tuning fork has two vibrational members symmetric about a Z axis. The two vibrational members vibrate along Z axis and are displaced along a Y axis by the Coriolis force. Each of the two vibrational members includes a cantilevered tabular member arranged along an XZ plane and has a shape symmetric about the center axis thereof. Electrode sections are formed on the two sides of the vibrational members, and electrodes are formed in the internal space of a casing at positions corresponding to the electrode sections. The electrodes are arranged by being deviated outward or inward of the center axis of the vibration members with respect to the electrode sections. Each of the electrodes is supplied with a displacement detection AC voltage and a control voltage from a detection and drive circuit.
    Type: Grant
    Filed: January 14, 1997
    Date of Patent: October 13, 1998
    Assignee: Tokimec, Inc.
    Inventors: Akihiro Cho, Takeshi Hojo, Shigeru Nakamura, Kazuteru Sato
  • Patent number: 5781985
    Abstract: An acceleration detection gyro apparatus is of the electrostatic supporting type. This gyro apparatus call be made inexpensive, long in life, excellent in durability and can be applied to a wide variety of fields. A gyro rotor (20) is supported relative to a gyro case (21) by an electrostatic supporting force in a non-contact fashion and rotated about the spin axis along the Z axis by a rotor driving system. The gyro rotor (20) is disk-shaped and constructed by forming metal thin film electrodes on both surfaces of a plate member made of preferably an insulating material. The gyro apparatus includes a slave control system for slaving a displacement of the gyro rotor (20) relative to the gyro case (21) in the Z-axis direction (spin axis direction) and a central position control system for slaving a displacement of the gyro rotor (20) in the X-axis and Y-axon directions.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: July 21, 1998
    Assignee: Tokimec Inc.
    Inventors: Takafumi Nakaishi, Takeshi Hojo, Takao Murakoshi, Isao Masuzawa, Shigeru Nakamura, Kazuaki Tani
  • Patent number: 5781296
    Abstract: A fiber optic gyro can overcome the defects encountered with conventional fiber optic gyros of phase-modulation method, closed-loop system with serrodyne modulation and digital modulation. A reference phase difference .DELTA..beta. and a ramp phase difference .sigma. are generated in an interference light intensity signal I by use of a triangular waveform, i.e., delta serrodyne waveform signal. The reference phase difference .DELTA..beta. is changed to constant values .DELTA..beta..sub.A and .DELTA..beta..sub.B whose absolute values are the same and whose signs are different at every times T.sub.A and T.sub.B. A phase x of the interference light intensity signal I becomes equal to x=.DELTA..theta.+.sigma.+.DELTA..beta.. The ramp phase difference .sigma. is controlled so as to satisfy .DELTA..theta.+.sigma.=0. Accordingly, at the stable point of the control loop, a Sagnac phase difference .DELTA..theta. is equal to the ramp phase difference .sigma..
    Type: Grant
    Filed: July 23, 1996
    Date of Patent: July 14, 1998
    Assignee: Tokimec Inc.
    Inventors: Kanshi Yamamoto, Shinichi Kawada, Takeshi Hojo, Yoshiyuki Okada, Isao Masuzawa
  • Patent number: 5719335
    Abstract: An acceleration detection gyro apparatus is of the electrostatic supporting type. This gyro apparatus can be made inexpensive, long in life, excellent in durability and can be applied to a wide variety of fields. A gyro rotor (20) is supported relative to a gyro case (21) by an electrostatic supporting force in a non-contact fashion and rotated about the spin axis along the Z axis by a rotor driving system. The gyro rotor (20) is disk-shaped and constructed by forming metal thin film electrodes on both surfaces of a plate member made of preferably an insulating material. The gyro apparatus includes a slave control system for slaving a displacement of the gyro rotor (20) relative to the gyro case (21) in the Z-axis direction (spin axis direction) and a central position control system for slaving a displacement of the gyro rotor (20) in the X-axis and Y-axis directions.
    Type: Grant
    Filed: April 16, 1996
    Date of Patent: February 17, 1998
    Assignee: Tokimec Inc.
    Inventors: Takafumi Nakaishi, Takeshi Hojo, Takao Murakoshi, Isao Masuzawa, Shigeru Nakamura, Kazuaki Tani
  • Patent number: 5698783
    Abstract: An electrostatic supporting type acceleration detecting gyro apparatus is formed as an active type so as to be able to positively cancel a displacement of a gyro rotor. Control DC voltages for generating electrostatic supporting forces and displacement detection AC voltages for detecting a displacement of gyro rotor are applied to electrostatic supporting electrodes, and mechanism control circuits detect displacement indicating voltage signals (P.sub.1A) through (P.sub.4B). A displacement of the gyro rotor and the control DC voltages applied to the electrostatic supporting electrodes are computed based on the displacement detection voltages (P.sub.1A) through (P.sub.4B) outputted from the mechanism control circuits.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: December 16, 1997
    Assignee: Tokimec Inc.
    Inventors: Takao Murakoshi, Takeshi Hojo, Takafumi Nakaishi, Shigeru Nakamura
  • Patent number: 5517204
    Abstract: An antenna having a central axis is supported on a supporting member which in turn is supported on an azimuth gimbal. The antenna and the supporting member are rotatable around an elevation axis perpendicular to the central axis gimbal is supported on a base and is rotatable around an azimuth axis perpendicular to the elevation axis. A first gyro having an input axis parallel to the elevation axis is secured to the supporting member, and a second gyro having an input axis perpendicular to both the central axis and the elevation angle axis is secured to the supporting member. An accelerometer is provided for outputting a signal representative of an inclination angle of the central axis relative to a horizontal plane. An azimuth transmitter is provided for outputting a signal representative of a rotation angle of the azimuth gimbal around the azimuth axis.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: May 14, 1996
    Assignee: Tokimec Inc.
    Inventors: Takao Murakoshi, Takeshi Hojo, Kanshi Yamamoto, Kazuteru Sato, Koichi Umeno, Yoshinori Kamiya, Kazuya Arai, Mutumi Takahashi, Yasuke Kosai
  • Patent number: 5416976
    Abstract: A gyro compass having a gyro case housing therein a gyro and supported with freedom of three axes, functions for outputting a signal corresponding to an inclined angle of the gyro spin axis relative to the horizontal plane, and a function for applying a torque around a vertical axis of the gyro case in proportion to an input signal. A controller is supplied with a signal corresponding to the inclined angle and a latitude value at which the gyro compass is located, and a constant relative to the input latitude value is determined by the controller after the gyro compass is energized. A signal, resulting from differentiating the signal corresponding to the inclined angle during a predetermined time, is added to the product of the signal corresponding to the inclined angle and the constant. This added signal functions as the input signal for the gyro, whereby a constant optimum north-seeking movement is carried out regardless of the change of the latitude value.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: May 23, 1995
    Assignee: Tokimec Inc.
    Inventors: Fuyuki Hane, Shinichi Kawada, Takeshi Hojo, Mamoru Akimoto, Kazushige Murabayashi
  • Patent number: 5272815
    Abstract: A gyro compass having a gyro case housing therein a gyro and supported with freedom of three axes, functions for outputting a signal corresponding to an inclined angle of the gyro spin axis relative to the horizontal plane and a function for applying a torque around a vertical axis of the gyro case in proportion to an input signal, and a controller supplied with the signal corresponding to the inclined angle and a latitude value at which the gyro compass is located, wherein a constant relative to the input latitude value is set by the controller after the gyro compass is energized, a signal, which results from differentiating the signal corresponding to the inclined angle during a predetermined time, is added to a signal, which results from multiplying the signal corresponding to the inclined angle with the constant and an added result is set as the input signal, whereby a constant optimum north-seeking movement is carried out regardless of the change of the latitude value to thereby reduce a settle time.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: December 28, 1993
    Assignee: Tokimec Inc.
    Inventors: Fuyuki Hane, Shinichi Kawada, Takeshi Hojo, Mamoru Akimoto, Kazushige Murabayashi
  • Patent number: 5247748
    Abstract: A gyro compass having a gyro case housing therein a gyro whose spin axis is held substantially in the horizontal plane, a supporting device for supporting the gyro case with freedom of three axes and means for applying a torque proportional to an inclined angle of the gyro spin axis relative to the horizontal plane around a vertical axis of the gyro case perpendicular to the spin axis is disclosed in which there are provided a detecting device for detecting an inclination angle of the spin axis relative to said horizontal plane, torquer for applying a torque to the gyro case about its vertical axis, and an acceleration error controlling device for receiving an output signal from the detecting means and for controlling the torquer such that the torquer produces a predetermined torque to be applied to the gyro case about its vertical axis.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: September 28, 1993
    Assignee: Tokimec Inc.
    Inventors: Takeshi Hojo, Shin-Ichi Kawada, Noboru Itakura
  • Patent number: 5200727
    Abstract: A force generating apparatus having spacings through which magnetic fluxes are traveled, a magnetic circuit including two permanent magnets supplying magnetic fluxes to the spacings and a conductor disposed in the direction perpendicular to the magnetic fluxes in the spacings is comprised of two pair of permanent magnets of the same size, and a member for disposing the two pair of permanent magnets such that magnetic axes thereof are opposed in parallel to each other, wherein a total sum of magnetic moments caused by the two pair of permanent magnets is cancelled out. Therefore, the force generating apparatus can be prevented from producing a harmful torque even if an external magnetic field acts thereon.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: April 6, 1993
    Assignee: Tokimec Inc.
    Inventors: Mitsuru Katoh, Shinichi Kawada, Michio Fukano, Takeshi Hojo
  • Patent number: 5109693
    Abstract: A pair of torquer magnets each comprising a cup-shaped yoke is provided with a disk-like permanent magnet and a pole piece. A through-hole provided through the center of the torquer magnet and a spool member made of a magnetic compensating metal is inserted into and fixed in the through-hole. The spool is shaped to have a central portion intermediate its end of a substantially smaller diameter.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: May 5, 1992
    Assignee: Tokyo Keiki Co., Ltd.
    Inventors: Takeshi Hojo, Michio Fukano, Mitsuru Kato
  • Patent number: 4879918
    Abstract: A gyro compass having a gyro case incorporating a gyro of which the spin axis is substantially horizontal, a vertical ring disposed around the outer periphery of the gyro case and for rotatably supporting the gyro case around a vertical axis, a follow-up pickup for detecting an angular displacement between the gyro case and the vertical ring around the vertical axis, an accelerometer having an input axis parallel to the spin axis, a vertical torquer mounted on the vertical ring for applying a torque of magnitude proportional to an input signal to the gyro case around the vertical axis, and a control apparatus for receiving an output signal of the accelerometer and for supplying its output to the vertical torquer, in which during a predetermined time after the gyro compass is started to operate, the output signal from the accelerometer is differentiated to produce a differentiation signal which is then supplied to the vertical torquer to reduce a settling time of the north-seeking action.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: November 14, 1989
    Assignee: Tokyo Keiki Co., Ltd.
    Inventors: Takeshi Hojo, Kanshi Yamamoto, Shinichi Kawada, Kazushige Murabayashi, Mamoru Akimoto, Michio Fukano
  • Patent number: 4831544
    Abstract: An attitude and heading reference detecting apparatus having three gyros and three acceleometers mounted to a navigation vehicle in such a manner that their input axes are made coincident with principal three axial directions of the navigation object, respectively, a magnetic azimuth sensor, a signal transforming section supplied with the outputs from the three gyros, the outputs from the three accelerometers and the output from the magnetic azimuth sensor, a computing section supplied with the output from the signal transforming section and a signal output section supplied with the output from the computing section, for producing an attitude and heading reference signal and for delivering the same to the outside.
    Type: Grant
    Filed: November 17, 1987
    Date of Patent: May 16, 1989
    Assignee: Tokyo Keiki Co., Ltd.
    Inventors: Takeshi Hojo, Kanshi Yamamoto, Mikio Morohoshi, Fuyuki Hame
  • Patent number: 4792676
    Abstract: A gyro apparatus includes a support in a base table for supporting one end of a vibrating member which has a circular cross-section and which is driven by a drive apparatus mounted on the base table to vibrate it in the longitudinal or axial direction. The vibrating member may be light conducting and a light source sends light through it which is projected onto a light detector so as to detect vibrations perpendicular to the axis direction of the vibrating member.
    Type: Grant
    Filed: October 20, 1986
    Date of Patent: December 20, 1988
    Assignee: Kabushiki Kaisha Tokyo Keiki
    Inventors: Takeshi Hojo, Takafumi Nakaishi
  • Patent number: 4791727
    Abstract: In a gyro apparatus comprising a binnacle, a gyro the spin axis of which is made substantially horizontal, a supporting apparatus for supporting the gyro from the binnacle with a freedom of three axes, a north-seeking apparatus for giving a north-seeking action to the gyro, a follow-up ring following up the gyro around its vertical axis, a servo motor for rotating the follow-up ring by a deviation singal around the vertical axis of teh gyro relative to the follow-up ring and a transmiting apparatus for transmitting an azimuth angle of the spin axis relative to the binnacle to the outside, the gyro apparatus is characterized in that the transmitting apparatus is formed of a digital encoder having a reference angular position transmitting device and a first counter apparatus being made operable by an output signal of the encoder.
    Type: Grant
    Filed: October 20, 1987
    Date of Patent: December 20, 1988
    Assignee: Kabushikikaisha Tokyo Keiki
    Inventors: Takeshi Hojo, Takafumi Nakaishi, Mikio Morohoshi
  • Patent number: 4708024
    Abstract: A gyro apparatus comprising a gyro casing incorporating therein a gyro the spin axis of which is made substantially horizontal, a supporting apparatus for supporting the gyro casing with a freedom of three axes, a north-seeking apparatus for giving a north-seeking action to the gyro, a follow-up ring having a follow-up shaft which follows the gyro casing around its substantially vertical axis, a binnacle for supporting the follow-up shaft, a servo motor for rotating the follow-up shaft and a slip ring for supplying a power to the gyro and the like through the follow-up shaft, in which the follow-up ring is formed as a fork-shape and supported to the binnacle in a canti-lever fashion, the follow-up shaft is rotatably supported to the binnacle by one thin-type ball bearing having a large diameter and one bearing having a small diameter, the follow-up shaft is fixedly provided with a rotor of a pancake-type servo motor of a direct drive system, a stator of the servo motor is attached to the binnacle at the posit
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: November 24, 1987
    Assignee: Kabushikikaisha Tokyo Keiki
    Inventors: Takeshi Hojo, Takafumi Nakaishi