Patents by Inventor Kenichi Akita

Kenichi Akita 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: 20120261916
    Abstract: A power-generation motor control system is a control system that controls a power-generation motor provided with an armature and a magnetic-field winding, and is characterized in that when the power-generation motor is operated as a motor, before a power source energizes the armature, a preliminary excitation current, with the value of which the induction voltage across the armature does not exceed the voltage of the power source, is applied to the magnetic-field winding in accordance with the rotation speed of the power-generation motor so that preliminary excitation of the power-generation motor is performed.
    Type: Application
    Filed: October 17, 2011
    Publication date: October 18, 2012
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Mitsunori TABATA, Masato MORI, Kenji NAKAJIMA, Kenichi AKITA
  • Publication number: 20120262130
    Abstract: A power converter control apparatus includes a power converter part having a bridge circuit formed of a switching element and a field circuit controlling conduction of a field winding in an AC generator, and a control apparatus part having a field current detector, a temperature detector detecting a temperature of a generator part, the power converter part, or the control apparatus part, a field current instruction computation portion computing a field current instruction value of the generator, a temperature rise suppression portion computing a generated current suppression value on the basis of an output of the temperature detector and computing a field current suppression value on the basis of the computed generated current suppression value, a field current instruction selection portion selecting the field current instruction value or the field current suppression value whichever is the smaller, and a field current control portion controlling a field current.
    Type: Application
    Filed: October 11, 2011
    Publication date: October 18, 2012
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenji NAKAJIMA, Masato MORI, Kenichi AKITA, Mitsunori TABATA
  • Patent number: 8284527
    Abstract: A magnetic head, according to one embodiment, includes a sensor film, a sensor cap film provided above the sensor film, a pair of shields including an upper magnetic shield and a lower magnetic shield which serve as electrodes that pass current in a film thickness direction of the sensor film, a track insulating film contacting both sides of the sensor film in the track width direction, a graded domain control film arranged on both sides in the track width direction of the sensor film adjacent the track insulating film, and an element height direction insulating film positioned on an opposite side of the sensor film relative to an air-bearing surface, wherein an edge position of the element height direction insulating film adjacent the sensor film on the air-bearing surface side is substantially the same as an edge position of the sensor cap film in the element height direction.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: October 9, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobuo Yoshida, Masato Shiimoto, Kenichi Akita, Kan Yasui
  • Patent number: 8270123
    Abstract: In one embodiment, a vertical-current-type reproducing magnetic head includes a sensor film, an upper shield paired with a lower shield that together flow a current into the sensor film in a thickness direction of the sensor film, and magnetic-domain control magnetic films provided above both sides of the sensor film in a track width direction of the sensor film. The shield is formed via a nonmagnetic adhesion layer including a discontinuous region near the sensor film, and the sensor film contacts the upper shield. In another embodiment, a method includes forming a resist layer, etching a sensor film while using the resist layer as a mask, forming first insulating films, domain-control magnetic films, and nonmagnetic adhesion layers in a stacked manner, lifting-off the resist layer, and forming an upper shield that together with a lower shield flow current into the sensor film in a thickness direction of the sensor film.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: September 18, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenichi Akita, Nobuo Yoshida, Katsuro Watanabe
  • Publication number: 20120112709
    Abstract: A field winding type rotary electric machine includes a motor generator; a field current detection unit; a field current control unit which controls a field current; a field current limiting determination section which calculates a field current integration value and determines whether or not the field current integration value reaches a predetermined field current integration threshold value; and a field current limiting command section which, when it is determined that the field current integration value reaches the predetermined field current integration threshold value, outputs a command which sets the field current to be lower than or equal to a predetermined field current limiting value to the field current control unit during a predetermined limiting time, and outputs a command which changes the predetermined limiting time depending on the field current. Accordingly, a temperature rise of the machine is suppressed and limiting of the field current can be released as needed.
    Type: Application
    Filed: March 28, 2011
    Publication date: May 10, 2012
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenichi AKITA, Masato MORI, Kenji NAKAJIMA, Mitsunori TABATA
  • Publication number: 20110255320
    Abstract: In an electric power converter for a vehicle which is connected to an alternating-current generator for a vehicle and performs synchronous rectification, switching mistakes are reduced and efficiency is improved by setting an optimal control allowance time in generating a switching timing signal from a diode ON signal. A control allowance according to the operating state of a generator can be determined by obtaining a control allowance time as a sum of a control delay time which is constant irrespective of the operating state of the generator, and an allowance time which varies depending on the operating state of the generator. Thereby, optimal switching timing is obtained and the reduction of switching mistakes and an improvement in efficiency are performed.
    Type: Application
    Filed: October 20, 2010
    Publication date: October 20, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Mitsunori TABATA, Masato MORI, Kenji NAKAJIMA, Kenichi AKITA
  • Publication number: 20110193504
    Abstract: Generation voltage control or generation torque control is performed as suitable control based on an external command or a load of a generator motor, to thereby prevent a rapid change of a generation torque or excessive power generation. A power converter control apparatus includes: a power conversion unit including a bridge circuit for controlling energization of an armature winding and a field circuit for controlling energization of a field winding; and a control device including B-terminal voltage detection means, field current detection means, generation voltage control means, generation torque control means, and control selection means. The control selection means selects the one of the generation voltage control means and the generation torque control means based on one of a command from an outside and a load of the generator motor.
    Type: Application
    Filed: June 16, 2010
    Publication date: August 11, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenji Nakajima, Masato Mori, Kenichi Akita, Mitsunori Tabata
  • Publication number: 20110134564
    Abstract: A magnetic head, according to one embodiment, includes a sensor film, a sensor cap film provided above the sensor film, a pair of shields including an upper magnetic shield and a lower magnetic shield which serve as electrodes that pass current in a film thickness direction of the sensor film, a track insulating film contacting both sides of the sensor film in the track width direction, a graded domain control film arranged on both sides in the track width direction of the sensor film adjacent the track insulating film, and an element height direction insulating film positioned on an opposite side of the sensor film relative to an air-bearing surface, wherein an edge position of the element height direction insulating film adjacent the sensor film on the air-bearing surface side is substantially the same as an edge position of the sensor cap film in the element height direction.
    Type: Application
    Filed: November 30, 2010
    Publication date: June 9, 2011
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobuo Yoshida, Masato Shiimoto, Kenichi Akita, Kan Yasui
  • Patent number: 7893868
    Abstract: A radar device is mounted on a vehicle, for detecting an object, and includes: a transmitting unit for transmitting an electromagnetic wave as a transmitter signal; a receiving unit for receiving a reflected signal that is reflected from the object as a receiver signal; a signal processing unit for measuring a distance and a relative velocity between the vehicle and the object on the basis of a beat signal that is obtained by the transmitter signal and the receiver signal; and an interference detecting unit for detecting the interference signal from another radar device or a communication device on the basis of a signal intensity of the frequency range that is not used for measuring the distance to the object and the relative velocity of the object.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: February 22, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Akita, Kado Nakagawa
  • Publication number: 20100301816
    Abstract: Provided is a field winding type generator-motor capable of minimizing cost increase and structure modification while preventing a failure due to a temperature rise, without mounting a temperature sensor. The field winding type generator-motor according to the present invention includes: a dynamo-electric machine that has a field winding; a field current detecting section for detecting field current; a field current restriction deciding section for deciding whether or not the decision value has reached a predetermined decision threshold value by calculating a decision value based on the field current detected by the field current detecting section; and a field current controller for controlling the field current flowing in the field winding so that the field current is restricted to a predetermined permissible value in a case where the field current restriction deciding section decides that the decision value has reached the predetermined decision threshold value.
    Type: Application
    Filed: November 16, 2009
    Publication date: December 2, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenichi AKITA, Kenji Nakajima, Masato Mori
  • Publication number: 20100289329
    Abstract: A vehicle power converter including a plurality of switching elements having diodes connected thereto in parallel and constituting a multi-phase bridge circuit and a controller for conducting the switching element corresponding to each diode in synchronization with a conduction state of the diode concerned to perform synchronous rectification and is connected between a power generator-motor driven from the external to generate multi-phase AC power and DC equipment, further includes a load state detecting unit for detecting a load state of the power generator-motor when the multi-phase AC power occurs, wherein a shift from diode rectification to synchronous rectification or a shift from the synchronous rectification to the diode rectification is carried out in accordance with an output of the load state detecting unit.
    Type: Application
    Filed: November 2, 2009
    Publication date: November 18, 2010
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenji NAKAJIMA, Kenichi Akita, Masato Mori, Mistsunori Tabata, Katsuya Tsujimoto
  • Publication number: 20100123977
    Abstract: In one embodiment, a vertical-current-type reproducing magnetic head includes a sensor film, an upper shield paired with a lower shield that together flow a current into the sensor film in a thickness direction of the sensor film, and magnetic-domain control magnetic films provided above both sides of the sensor film in a track width direction of the sensor film. The shield is formed via a nonmagnetic adhesion layer including a discontinuous region near the sensor film, and the sensor film contacts the upper shield. In another embodiment, a method includes forming a resist layer, etching a sensor film while using the resist layer as a mask, forming first insulating films, domain-control magnetic films, and nonmagnetic adhesion layers in a stacked manner, lifting-off the resist layer, and forming an upper shield that together with a lower shield flow current into the sensor film in a thickness direction of the sensor film.
    Type: Application
    Filed: November 9, 2009
    Publication date: May 20, 2010
    Inventors: Kenichi Akita, Nobuo Yoshida, Katsuro Watanabe
  • Publication number: 20100087974
    Abstract: Provided is a vehicle behavior controller capable of stabilizing a behavior of a vehicle with a high response when an unstable state of the vehicle is judged. The vehicle behavior controller includes: a running state detecting unit for detecting a running state of the vehicle; an unstable state judging unit for judging the unstable state of the vehicle based on the running state; a motor generator connected to an engine of the vehicle, the motor generator operating as a power generator for using an output of a prime mover to generate power and an electric motor for assisting the output of the prime mover; and a control unit for controlling an operation of the motor generator based on r.p.m. of the motor generator, in which the control unit controls the operation of the motor generator to generate braking torque when the unstable state is judged.
    Type: Application
    Filed: April 24, 2009
    Publication date: April 8, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenji NAKAJIMA, Masato MORI, Kenichi AKITA
  • Publication number: 20090289831
    Abstract: A radar device is mounted on a vehicle, for detecting an object, and includes: a transmitting unit for transmitting an electromagnetic wave as a transmitter signal; a receiving unit for receiving a reflected signal that is reflected from the object as a receiver signal; a signal processing unit for measuring a distance and a relative velocity between the vehicle and the object on the basis of a beat signal that is obtained by the transmitter signal and the receiver signal; and an interference detecting unit for detecting the interference signal from another radar device or a communication device on the basis of a signal intensity of the frequency range that is not used for measuring the distance to the object and the relative velocity of the object.
    Type: Application
    Filed: July 30, 2009
    Publication date: November 26, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenichi AKITA, Kado NAKAGAWA
  • Publication number: 20090050955
    Abstract: A charge storage layer interposed between a memory gate electrode and a semiconductor substrate is formed shorter than a gate length of the memory gate electrode or a length of insulating films so as to make the overlapping amount of the charge storage layer and a source region to be less than 40 nm. Therefore, in the write state, since the movement in the transverse direction of the electrons and the holes locally existing in the charge storage layer decreases, the variation of the threshold voltage when holding a high temperature can be reduced. In addition, the effective channel length is made to be 30 nm or less so as to reduce an apparent amount of holes so that coupling of the electrons with the holes in the charge storage layer decreases; therefore, the variation of the threshold voltage when holding at room temperature can be reduced.
    Type: Application
    Filed: August 8, 2008
    Publication date: February 26, 2009
    Inventors: Kenichi AKITA, Daisuke OKADA, Keisuke KUWAHARA, Yasufumi MORIMOTO, Yasuhiro SHIMAMOTO, Kan YASUI, Tsuyoshi ARIGANE, Tetsuya ISHIMARU
  • Publication number: 20080266169
    Abstract: A radar device capable of detecting a target object by itself only in a range required by a vehicle control system by changing the detection angle depending on the distance without changing the hardware structure is provided. The radar device includes transmitting means for transmitting an electromagnetic wave as a transmission signal, receiving means for receiving the electromagnetic wave reflected from the target object as a reception signal, and signal processing means for detecting a target object existing around the vehicle from the transmission signal and the reception signal, and calculating the relative position and the relative speed between the object and the vehicle. The detection angle is changed depending on the distance for measurement, so that the target object is detected only in a region necessary in operating the vehicle control system.
    Type: Application
    Filed: August 21, 2007
    Publication date: October 30, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Kenichi AKITA
  • Publication number: 20080100493
    Abstract: A radar device is mounted on a vehicle, for detecting an object, and includes: a transmitting unit for transmitting an electromagnetic wave as a transmitter signal; a receiving unit for receiving a reflected signal that is reflected from the object as a receiver signal; a signal processing unit for measuring a distance and a relative velocity between the vehicle and the object on the basis of a beat signal that is obtained by the transmitter signal and the receiver signal; and an interference detecting unit for detecting the interference signal from another radar device or a communication device on the basis of a signal intensity of the frequency range that is not used for measuring the distance to the object and the relative velocity of the object.
    Type: Application
    Filed: February 21, 2007
    Publication date: May 1, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenichi AKITA, Kado NAKAGAWA
  • Publication number: 20070054687
    Abstract: A push-to-talk data transmission device that creates and manages groups of participating terminals dynamically. A PoC data transmission device is deployed to support push-to-talk sessions in a prescribed area. This device has a data transmitter that broadcasts a group profile repetitively in the prescribed area. The group profile is a set of parameters that prompt terminals in the prescribed area to send back their respective unique identifiers to join a push-to-talk session. A counter in the PoC data transmission device counts the number of responses returned from the terminals, and the data transmitter broadcasts a new group profile if the number of responses has reached a predetermined threshold.
    Type: Application
    Filed: February 3, 2006
    Publication date: March 8, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Kenichi Akita, Yamato Sakurai, Koujiro Seto, Ryoji Yagi, Junji Takezaki, Takao Inaguma, Takaya Nomura, Makoto Nagaki, Shinji Yamada, Masafumi Maekawa, Futoshi Nakamori
  • Publication number: 20050207429
    Abstract: A method for duplicating a home agent including an address correspondence maintaining unit for maintaining a destination address of a mobile terminal in correspondence with a home address of the mobile terminal, and a transferring unit for encapsulating an IP packet addressed to the home address of the mobile terminal and transferring the encapsulated IP packet to the destination address of the mobile terminal is disclosed. The method includes the steps of setting a home agent address, which is the same as a home agent address of an operation system home agent, to a standby system home agent, and receiving a location registration request, which is sent from the mobile terminal and addressed to the operation system home agent, with the standby system home agent.
    Type: Application
    Filed: September 22, 2004
    Publication date: September 22, 2005
    Inventors: Kenichi Akita, Yamato Sakurai, Junji Takezaki, Makoto Nagaki, Koujirou Seto, Futoshi Nakamori
  • Patent number: 6775239
    Abstract: A method of checking communication-path data in a system, in which a router connecting first and second networks operating on different protocols is connected to a switch of the second network, includes the steps of changing the router and the switch from a normal mode to a test mode, checking consistency between router communication-path data controlled by the router and switch communication-path data controlled by the switch by sending the router communication-path data to the switch during the test mode, and checking communication between the router and the switch by sending cells from the router to the switch and returning the cells from the switch to the router during the test mode.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: August 10, 2004
    Assignee: Fujitsu Limited
    Inventors: Kenichi Akita, Yuko Tangiku, Kazuhiro Ozawa