Patents by Inventor Takehiro Ohkawa
Takehiro Ohkawa 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).
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Patent number: 7212124Abstract: Provided is a portable information device having an RFID, the device being a device in which no effect is produced on original communication of the portable information device for which an EMC measure is taken, the device having good productivity, and the device keeping communication distance without damaging portability. A place where an antenna is set is located on the side of a battery cover of a battery receiving section to make the communication distance of an incorporated RFID long. A circuit configuration wherein a condenser for resonance is connected to both ends of the antenna coil and an IC is connected to an intermediate tap of the antenna coil is made so as to make it unnecessary that the resonance frequency of the RFID is individually adjusted and make the production of the RFID easy.Type: GrantFiled: June 26, 2003Date of Patent: May 1, 2007Assignee: Hitachi, Ltd.Inventors: Takehiro Ohkawa, Hiroshi Yoshigi
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Patent number: 6972662Abstract: An RFID which provides a wide working voltage range and general versatility at low cost, without the need for changing its internal circuit design due to external factors. In the RFID, there is provided an arrangement that a low impedance state is given when its internal data communication circuit is in a reset state.Type: GrantFiled: August 15, 2000Date of Patent: December 6, 2005Assignee: Renesas Technology Corp.Inventors: Takehiro Ohkawa, Miki Yuyama, Hiroshi Yoshigi, Tadashi Oonishi, Kazuki Watanabe
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Publication number: 20050122211Abstract: In an RFID (contactless identification) having a resonant circuit, the resonant frequency is directly affected by variations in the input capacitance of an IC chip due to certain manufacturing factors, causing a direct influence on a power reception efficiency and a communication distance. Thus, an RFID is provided for eliminating a step of correcting such variations, reducing the manufacturing cost, and efficiently receiving the power. An IC chip is connected to an intermediate tap of an antenna coil in series through a capacitor. Alternatively, the capacitor is replaced with two capacitors, through one of which the IC chip is connected to the intermediate tap of the antenna coil.Type: ApplicationFiled: February 9, 2004Publication date: June 9, 2005Inventors: Hiroshi Yoshigi, Takehiro Ohkawa
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Publication number: 20040233043Abstract: A communication system is provided which enhances communication stability, using chips on which function blocks are formed including sensor, chip ID, and radio transmission/reception functions. The sensor detects biological and chemical materials and physical and stoichiometric quantities such as temperature, pressure, and pH and the sensed results are transmitted to a reader by a radio frequency (RF) function. The chip with the sensor functions at a resonance frequency which is detected by the reader initially during a frequency sweep. No dedicated power source is essential to operate the chips, but instead the chips are triggered into transmitting by the radio frequency signals transmitted from the reader. The frequency and output of transmission from the reader to the chips are variable. Stable communication can be performed without being affected by variation in the chips characteristics depending on manufacturing quality.Type: ApplicationFiled: November 13, 2003Publication date: November 25, 2004Applicant: Hitachi, Ltd.Inventors: Yoshiaki Yazawa, Masao Kamahori, Ken Takei, Takehiro Ohkawa, Hiroshi Yoshigi
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Publication number: 20040140896Abstract: Provided is a portable information device having an RFID, the device being a device in which no effect is produced on original communication of the portable information device for which an EMC measure is taken, the device having good productivity, and the device keeping communication distance without damaging portability. A place where an antenna is set is located on the side of a battery cover of a battery receiving section to make the communication distance of an incorporated RFID long. A circuit configuration wherein a condenser for resonance is connected to both ends of the antenna coil and an IC is connected to an intermediate tap of the antenna coil is made so as to make it unnecessary that the resonance frequency of the RFID is individually adjusted and make the production of the RFID easy.Type: ApplicationFiled: June 26, 2003Publication date: July 22, 2004Inventors: Takehiro Ohkawa, Hiroshi Yoshigi
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Patent number: 6373708Abstract: The pattern line width of a coil is partially widened in a predetermined dimension and wiring patterns of a coil on the surface side and a coil on the rear side are arranged so as not to be in overlapped positions. Consequently, a direct current resistance of the coil can be reduced and an adverse influence by a self resonance of the coil on a communication can be reduced.Type: GrantFiled: August 13, 1999Date of Patent: April 16, 2002Assignees: Hitachi, Ltd., Hitachi Chemical Co., Ltd.Inventors: Kimiaki Ando, Takehiro Ohkawa, Kazuo Kaneko
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Patent number: 6121623Abstract: A parallel radiation detector includes a plurality of radiation detecting elements, a plurality of preamplifiers for converting signals from the radiation detecting elements into voltage signals, a signal processing device for processing the voltage signals, a main control device for controlling the signal processing device to analyze the voltage signals, a display device for displaying analyzed results from the signal processing device, a storage device for storing signals, a plurality of a reset circuits corresponding to the plurality of preamplifiers, each reset circuit for generating a reset signal for returning the corresponding one of the preamplifiers to an initial state thereof when the voltage signal from the corresponding one of the preamplifiers reaches a predetermined voltage, and an inhibitor circuit for generating an inhibit signal for inhibiting the signal processing device from receiving and processing the voltage signals from the preamplifiers temporarily, based on the reset signal.Type: GrantFiled: October 2, 1998Date of Patent: September 19, 2000Assignee: Hitachi, Ltd.Inventors: Isao Ochiai, Kimio Kanda, Takehiro Ohkawa
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Patent number: 5999409Abstract: The pattern line width of a coil is partially widened in a predetermined dimension and wiring patterns of a coil on the surface side and a coil on the rear side are arranged so as not to be in overlapped positions. Consequently, a direct current resistance of the coil can be reduced and an adverse influence by a self resonance of the coil on a communication can be reduced.Type: GrantFiled: January 21, 1998Date of Patent: December 7, 1999Assignees: Hitachi, Ltd., Hitachi Chemical Co., Ltd.Inventors: Kimiaki Ando, Takehiro Ohkawa, Kazuo Kaneko
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Patent number: 5594680Abstract: A contactless parallel data transfer device which is miniature, highly densed, and highly reliable having a coil block consisting of a first coil group installed in a portable memory and a coil block consisting of a second coil group installed in a data server for transferring access data in parallel between the portable memory (memory card, etc.) and the data server by contactless coupling, wherein the opposite coils of the first and second coil blocks are held close and opposite to each other on a contactless basis, and a parallel pulse group which is transferred in parallel between the both coil blocks is divided at least into a first parallel pulse group consisting of the first number of bits and a second parallel pulse group consisting of the second number of bits, and the parallel transfer timings of the both parallel pulse groups are different from each other, and an induced signal to the neighboring coils of each opposite coil pair of the first and second coil blocks is negated in the opposite phase.Type: GrantFiled: March 28, 1995Date of Patent: January 14, 1997Assignees: Hitachi, Ltd., Hitachi Maxell, Ltd.Inventors: Masatoshi Ohtake, Takeshi Tottori, Kazunari Nakagawa, Nobuo Hamamoto, Takehiro Ohkawa, Yutaka Kinebuti