Patents by Inventor Masaaki Shida

Masaaki Shida 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: 6675007
    Abstract: A charging system for use in a network composed of wireless terminals with a repeater function. As each terminal with a repeater function receives a communication session start request from a user terminal, it searches for a destination user terminal; when it finds the destination user terminal, it transfers the signal sent from the requesting user terminal to the destination user terminal without the mediation of base stations. The information about the amount of data thus transferred or communication time for transferring data is sent to the charging system which is under the control of the communications service provider concerned.
    Type: Grant
    Filed: February 4, 2002
    Date of Patent: January 6, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Masaaki Shida, Tomoaki Ishifuji, Nobukazu Doi, Kazuko Hamaguchi
  • Publication number: 20030189483
    Abstract: A contactless IC card having an antenna, a transmit/receive circuit for recovering data (clock) and electric power from a carrier signal received by the antenna, a logic circuit operated with the electric power supplied thereto from the transmit/receive circuit, and a memory. The transmit/receive circuit has a rectifier circuit for outputting data (clock) and rectifier circuits for electric power in such a manner that the carrier signal is inputted to each of the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. With this configuration, high frequency matching can be optimized separately for the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. It is also possible to separately optimize adjustments to a voltage of recovered data (clock) and a recovered supply voltage.
    Type: Application
    Filed: April 1, 2003
    Publication date: October 9, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takeshi Saitoh, Masaaki Shida, Tomoaki Ishifuji
  • Patent number: 6570490
    Abstract: A contactless IC card having an antenna, a transmit/receive circuit for recovering data (clock) and electric power from a carrier signal received by the antenna, a logic circuit operated with the electric power supplied thereto from the transmit/receive circuit, and a memory. The transmit/receive circuit has a rectifier circuit for outputting data (clock) and rectifier circuits for electric power in such a manner that the carrier signal is inputted to each of the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. With this configuration, high frequency matching can be optimized separately for the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. It is also possible to separately optimize adjustments to a voltage of recovered data (clock) and a recovered supply voltage.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: May 27, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Saitoh, Masaaki Shida, Tomoaki Ishifuji
  • Publication number: 20030054795
    Abstract: A charging system for use in a network composed of wireless terminals with a repeater function. As each terminal with a repeater function receives a communication session start request from a user terminal, it searches for a destination user terminal; when it finds the destination user terminal, it transfers the signal sent from the requesting user terminal to the destination user terminal without the mediation of base stations. The information about the amount of data thus transferred or communication time for transferring data is sent to the charging system which is under the control of the communications service provider concerned.
    Type: Application
    Filed: February 4, 2002
    Publication date: March 20, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Masaaki Shida, Tomoaki Ishifuji, Nobukazu Doi, Kazuko Hamaguchi
  • Publication number: 20030054796
    Abstract: A charging system for use in a network composed of wireless terminals with a repeater function. As each terminal with a repeater function receives a communication session start request from a user terminal, it searches for a destination user terminal; when it finds the destination user terminal, it transfers the signal sent from the requesting user terminal to the destination user terminal without the mediation of base stations. The information about the amount of data thus transferred or communication time for transferring data is sent to the charging system which is under the control of the communications service provider concerned.
    Type: Application
    Filed: May 30, 2002
    Publication date: March 20, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Masaaki Shida, Tomoaki Ishifuji, Nobukazu Doi, Kazuko Hamaguchi
  • Publication number: 20030043937
    Abstract: The present invention provides a demodulating semiconductor integrated circuit device used in a wireless communication system of an FM-modulation scheme, wherein a circuit for canceling a frequency offset is made up of a digital circuit, so that a high-accuracy received data decision can be performed. The semiconductor integrated circuit device includes an AD converter for converting a received analog signal to a digital signal, a demodulator for demodulating the converted data, an offset cancel circuit for recognizing a predetermined pattern from the demodulated data to detect a frequency offset and generating a data decision or determination level, and a data determination circuit for making a decision as to “1” and “0” of the data demodulated by the demodulator, based on the determination level generated by the offset cancel circuit. The offset cancel circuit is made up of a digital circuit.
    Type: Application
    Filed: July 23, 2002
    Publication date: March 6, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takao Kobayashi, Masaaki Shida, Kazuhiko Kawai
  • Patent number: 6527177
    Abstract: In a conventional method which defines an authentication key for each record, as the number of the records is increased in an access right management for records in a memory of an IC card, the number of the types of authentication keys is also increased to require a larger memory area for storing the authentication keys, thus causing lower memory efficiency. In order to solve such a problem, terminal types (ex. “0H”-“7H”) are defined for interrogators, so that only the number of authentication keys equal to the number of the terminal types are stored. Each record has the number of access permission bits equal to the number of the terminal types, and specifies terminal types, to which an access is permitted, by setting the bits ON or OFF.
    Type: Grant
    Filed: February 24, 2000
    Date of Patent: March 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Tomoaki Ishifuji, Masaaki Shida
  • Patent number: 6508400
    Abstract: In a conventional method which defines an authentication key for each record, as the number of the records is increased in an access right management for records in a memory of an IC card, the number of the types of authentication keys is also increased to require a larger memory area for storing the authentication keys, thus causing lower memory efficiency. In order to solve such a problem, terminal types (ex. “0H”-“7H”) are defined for interrogators, so that only the number of authentication keys equal to the number of the terminal types are stored. Each record has the number of access permission bits equal to the number of the terminal types, and specifies terminal types, to which an access is permitted, by setting the bits ON or OFF.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: January 21, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Tomoaki Ishifuji, Masaaki Shida
  • Patent number: 6031863
    Abstract: The wireless LAN system has an information-carrying capacity which is several times the transmission rate obtained by a single cell. The wireless LAN system properly notifies hopping information even if an error in transmission arises. Hopping control is carried out on a master base-station device 10a and slave base-station devices 10b and 10c based on a synchronizing frame generated from hopping timing of the master base-station device 10a. After completion of the hopping control, each base-station device 10 starts to send hopping information to radio terminals 2 present in the same cell. Radio terminals 2, which are in the same cell as one of the base stations 10, work under the base-station device 10.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: February 29, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hidehiko Jusa, Masaaki Shida
  • Patent number: 6014406
    Abstract: A frequency-hopped mobile communication system is disclosed, in which a mobile wireless station automatically becomes a base station in accordance with the surrounding conditions, thereby automatically reconfiguring a communication network. A control frame is generated by at least one master station, and frequencies are hopped by a plurality of slave stations in accordance with the control frame. Each slave station switches the master thereof to be tracked, in accordance with the receiving conditions of the control frame and the relation between the control frame received from the master station and the status of the slave station and decides in which mode, master station or slave station, the slave station is to operate. The cells are thus automatically reconfigured.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: January 11, 2000
    Assignees: Hitachi, Ltd., Hitachi Computer Engineering Co., Ltd.
    Inventors: Masaaki Shida, Tomoaki Ishifuji, Masato Hirai, Hidehiko Jusa, Takaharu Aoyama, Kenichiro Orita
  • Patent number: 6010075
    Abstract: An IC card (107) sends its identification code in units of one bit in response to a question from a controller (103). The controller sends back to the IC card the received one bit of the identification code. The IC card compares the received and sent bits. If both are equal, the IC card sends the next one bit to the controller and if not, refrains from sending the next one bit. Thus, even when the number of IC cards which are to be identified and the number of IC cards which send their identification codes are simultaneously large, a reduction in the identification efficiency is suppressed to within a small value.
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: January 4, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Tomoaki Ishifuji, Toshikazu Nishino, Takeshi Saitoh, Masaaki Shida
  • Patent number: 4294657
    Abstract: The apparatus for manufacturing the fiberboard is in the form of two vertically opposed endless conveyors upon each of which a fiber layer is formed. Each conveyor has a slanted running portion as a part thereof. A suction box is disposed along the inner surface of each of the slanted running portions so that a fiber layer producing section is formed in each slanted portion. A passage is formed between the conveyors to direct a slurry flow of fibers along each conveyor. The relative speeds of the slurry flow through the passage along the surface of the conveyors is adjusted to be different than the running speed of the conveyors; a supply duct for the slurry flow is disposed in the center of said passage and has an outlet near the upper ends of the fiber layer forming sections. The two layers simultaneously formed can be placed upon each other to form a single layer of fiberboard.
    Type: Grant
    Filed: August 5, 1980
    Date of Patent: October 13, 1981
    Assignee: Kabushiki Kaisha Fuji Seisakusho
    Inventors: Tsutomu Saito, Masaaki Shida