Patents by Inventor Tetsuya Yagi
Tetsuya Yagi 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: 7715886Abstract: The present invention aims to provide a reception apparatus that receives and demodulates a signal transmitted by using time-division multiplexing, with reduced power consumption. In detail, a receiving unit including a tuner operates to receive a signal only during a time period for which a desired signal is transmitted. The received signal is converted into digital data, and the digital data is stored into a memory. With the use of the digital data stored in the memory, a PLL performs all of the necessary operations from synchronization establishment to demodulation.Type: GrantFiled: May 11, 2005Date of Patent: May 11, 2010Assignee: Panasonic CorporationInventors: Ippei Kanno, Ryosuke Mori, Daisuke Hayashi, Kouji Setoh, Tetsuya Yagi, Noritaka Iguchi
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Publication number: 20100027724Abstract: Quick resumption of reproduction of received data is achieved with low cost. A receiver for receiving an OFDM signal has a demodulation unit and a transmission mode control unit. The demodulation unit performs, on a received signal, demodulation and detection of establishment of synchronization in accordance with a transmission mode that is a combination of an FFT mode and a guard interval, and outputs a synchronization establishment signal indicating an obtained result of the detection of establishment of synchronization. The transmission mode control unit holds an FFT mode and a guard interval adopted when the synchronization establishment signal indicates establishment of synchronization, and outputs a combination of the held FFT mode and the held guard interval as the transmission mode to be used in the demodulation unit.Type: ApplicationFiled: March 28, 2008Publication date: February 4, 2010Inventors: Takaya Hayashi, Tetsuya Yagi
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Patent number: 7653162Abstract: An average power indicating channel characteristics is outputted from a reference value calculation unit as a reference value. An interference level corresponding to the degree of influence by frequency selective interference is outputted from an interference detection unit. A reliability determination unit determines a carrier that has been subjected to interference on the basis of the reference value and the interference level, to decide a reliability level. An error correction unit performs error correction of a demodulation signal on the basis of the reliability level.Type: GrantFiled: August 18, 2008Date of Patent: January 26, 2010Assignee: Panasonic CorporationInventors: Takaya Hayashi, Kenichiro Hayashi, Tetsuya Yagi
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Patent number: 7627010Abstract: A semiconductor laser has a reflectance of the front facet coating film or the rear facet coating film dramatically that decreases at wavelengths greater than a predetermined wavelength. This characteristic causes the loss of the semiconductor laser to dramatically increase at wavelengths greater than the predetermined wavelength. As a result, the oscillation wavelength of the semiconductor laser at high temperatures is clamped to around the predetermined wavelength.Type: GrantFiled: September 13, 2007Date of Patent: December 1, 2009Assignee: Mitsubishi Electric CorporationInventor: Tetsuya Yagi
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Publication number: 20090213888Abstract: A semiconductor laser device includes a semiconductor laser, a dangling bond terminating film a cleaved surface of the semiconductor laser and composed of a lithium film or a beryllium film, and a coating film on the dangling bond terminating film.Type: ApplicationFiled: January 9, 2009Publication date: August 27, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventor: Tetsuya Yagi
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Patent number: 7505536Abstract: An energy dispersal circuit, which generates a PRBS (Pseudo Random Binary Sequence) and executes an XOR (exclusive-OR) operation with respect to a data signal and the PRBS based on a bit, includes a register value calculator for calculating a register value of a shift register based on inputted data and a packet number. The register value calculator has a bit divider for dividing the packet number from LSB to MSB, packet shift operators for bit-shifting an initial value of the shift register from 20 bits to 2N?1 bits, and selectors for selecting inputs and outputs thereof.Type: GrantFiled: December 15, 2004Date of Patent: March 17, 2009Assignee: Panasonic CorporationInventors: Tetsuya Yagi, Tomohiro Kimura
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Publication number: 20090052564Abstract: An average power indicating channel characteristics is outputted from a reference value calculation unit as a reference value. An interference level corresponding to the degree of influence by frequency selective interference is outputted from an interference detection unit. A reliability determination unit determines a carrier that has been subjected to interference on the basis of the reference value and the interference level, to decide a reliability level. An error correction unit performs error correction of a demodulation signal on the basis of the reliability level.Type: ApplicationFiled: August 18, 2008Publication date: February 26, 2009Inventors: Takaya Hayashi, Kenichiro Hayashi, Tetsuya Yagi
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Patent number: 7466645Abstract: Disclosed is an OFDM signal receiving apparatus for diversity reception, with a plurality of antennas, of an OFDM signal containing Y sub-carriers, where 2X?1<Y<2X and X>1. The OFDM signal receiving apparatus includes a plurality of receiving systems, and a diversity processing unit connected to the receiving systems and fed with sequences of data on sub-carriers demodulated by the respective receiving systems. At least one of the receiving systems includes an FFT circuit for Fast Fourier transforming, in parallel, only a sequence of data on 2Z sub-carriers contained in the OFDM signal received with a corresponding antenna, where X>Z. The diversity processing unit performs a diversity process on sequences of data on sub-carriers, out of all the Y sub-carries, redundantly demodulated.Type: GrantFiled: December 14, 2005Date of Patent: December 16, 2008Assignee: Panasonic CorporationInventors: Ryosuke Mori, Koji Setoh, Daisuke Hayashi, Tetsuya Yagi, Noritaka Iguchi, Akira Kisoda, Sadashi Kageyama
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Publication number: 20080304587Abstract: An OFDM reception device detects a time at which impulse noise occurs in a received OFDM signal, and specifies a start position candidate period that does not have intersymbol interference and is estimated to have a guard interval signal in a symbol. When setting a FFT window of an effective symbol length in a symbol duration of each symbol, if the impulse noise occurrence time is included in the symbol, the OFDM reception device determines a start position of the FFT window within a range of the start position candidate period so as to exclude the impulse noise occurrence time as much as possible.Type: ApplicationFiled: December 21, 2005Publication date: December 11, 2008Inventors: Koji Setoh, Ippei Kanno, Akira Kisoda, Daisuke Hayashi, Ryosuke Mori, Tetsuya Yagi, Noritaka Iguchi
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Publication number: 20080240198Abstract: A semiconductor laser of the present invention is constructed such that the reflectance of the front facet coating film or the rear facet coating film dramatically decreases at wavelengths greater than a predetermined wavelength. This causes the loss of the semiconductor laser to dramatically increase at wavelengths greater than the predetermined wavelength. As a result, the oscillation wavelength of the semiconductor laser at high temperatures is clamped to around the predetermined wavelength.Type: ApplicationFiled: September 13, 2007Publication date: October 2, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventor: Tetsuya Yagi
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Patent number: 7424072Abstract: An average power indicating channel characteristics is outputted from a reference value calculation unit as a reference value. An interference level corresponding to the degree of influence by frequency selective interference is outputted from an interference detection unit. A reliability determination unit determines a carrier that has been subjected to interference on the basis of the reference value and the interference level, to decide a reliability level. An error correction unit performs error correction of a demodulation signal on the basis of the reliability level.Type: GrantFiled: April 15, 2003Date of Patent: September 9, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takaya Hayashi, Kenichiro Hayashi, Tetsuya Yagi
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Patent number: 7369162Abstract: An Image sensing apparatus employing a multi-chip system and having a super-parallel circuit structure capable of performing processes such as image processing in real time. A first chip of a first of a first stage has first pixel circuits each having an optical sensor and first processing circuits and arranged in a matrix. A second chip of a second stage has second pixel circuits each having an analog memory for storing analog information from the preceding stage and second processing circuits and arranged in a matrix so as to correspond to the first pixel circuits. In each of the first and the second chip, each of the first and the second processing circuits receives an analog signal from another first and second processing circuit in the vicinity so as to perform first and second analog processing and performs circuit noise compensation by parallel calculation.Type: GrantFiled: September 3, 2002Date of Patent: May 6, 2008Assignee: Japan Science and Technology AgencyInventors: Tetsuya Yagi, Seiji Kameda
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Publication number: 20080054277Abstract: The semiconductor laser device includes an active layer, a p-type cladding layer, and a p-type cap layer. The layers are sequentially stacked so that the semiconductor laser device is provided. The p-type cap layer includes both a p-type dopant and an n-type dopant. In another aspect, the p-type cap layer includes a first layer including a first p-type dopant and a second layer including a second p-type dopant having a diffusion coefficient smaller than that of the first p-type dopant. The first layer is far from the active layer, and the second layer is close to the active layer. In further aspect, the p-type cap layer includes carbon (C) as a p-type dopant. According to these configuration, the p-type dopant can be prevented from being diffused in the active layer and the p-type cladding layer.Type: ApplicationFiled: October 25, 2007Publication date: March 6, 2008Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Masayoshi Takemi, Kenichi Ono, Yoshihiko Hanamaki, Chikara Watatani, Tetsuya Yagi, Harumi Nishiguchi, Motoko Sasaki, Shinji Abe, Yasuaki Yoshida
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Publication number: 20070281757Abstract: A receiving device performs reception in a service period of a broadcast signal and switches to a power saving mode in a non-service period. The service period is composed of a first period during which an application data table of an MPE-FEC frame is transmitted and a second period, following the first period, during which an RS data table of the MPE-FEC frame is transmitted. An error correction unit 12 performs one of error correction that uses the whole RS data table according to MPE-FEC, and erasure correction that uses a same number of parity bytes as bytes having bit errors. When the bit errors are corrected by the error correction unit 12 performing erasure correction, a power control unit 30 switches a receiving circuit to a power saving mode before the second period ends.Type: ApplicationFiled: December 2, 2005Publication date: December 6, 2007Inventors: Noritaka Iguchi, Ryosuke Mori, Tetsuya Yagi, Koji Setoh, Daisuke Hayashi, Ippei Kanno
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Publication number: 20070254332Abstract: A method for determining whether a test bacterium is a class C beta-lactamase-producing bacterium. Spots of a class C beta-lactamase inhibitor and a beta-lactam drug are applied at an interval on the surface of a solid medium that has been coated with the test bacterium, the solid medium is cultured, and following culturing, determining whether or not the inhibitory zone formed around the beta-lactam drug has extended toward the class C beta-lactamase inhibitor. A mixture of class C beta-lactamase inhibitor and beta-lactam drug and a beta-lactam drug in spots are applied at an interval on the surface of a solid medium that has been coated with the test bacterium, the solid medium is cultured, and following culturing, observing the difference between the inhibitory zone formed around the mixture and the inhibitory zone formed around the beta-lactam drug.Type: ApplicationFiled: December 14, 2004Publication date: November 1, 2007Applicant: JAPAN HEALTH SCIENCES FOUNDATIONInventors: Tetsuya Yagi, Jun-ichi Wachino, Yoshichika Arakawa
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Publication number: 20070048587Abstract: A solid polymer fuel cell includes a membrane junction unit being provided an electrolyte membrane sandwiched by an oxidant electrode and a fuel electrode and two separators being sandwiched from both surfaces of the electrolyte membrane, the two separators being provided, in central portions of surfaces of the two separators, with gas flow channels, respectively, and a sealing portions being provided between surfaces of the two separators which are opposed to each other and between surfaces of the two separators which are opposed to the outer peripheral edge portion, respectively, in which the sealed surfaces of the two separators, which are opposed to the sealing portions, respectively, are provided with a plurality of depressions, which are independent of one another in a direction of the sealed surfaces, so that the plurality of depressions surround the gas flow channels.Type: ApplicationFiled: May 31, 2006Publication date: March 1, 2007Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Tetsuya Yagi, Tatsunori Okada
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Patent number: 7173273Abstract: A semiconductor laser device has an n-GaAs substrate. On the n-GaAs substrate, by turns, are an n-AlGaInP cladding layer, an AlGaInP/GaInP MQW active layer, a p-AlGaInP first cladding layer, a single layer p-AlxGa1-xAs etching stopping layer, a p-AlGaInP second cladding layer with a stripe protrusion, and a p-GaAs contact layer. The portion, other than the stripe-form protrusion, of the p-AlGaInP second cladding layer is covered with an insulating film. The refractive index of the p-AlxGa1-xAs-ESL is nearly equal to the refractive index of each of the lower, first upper, and second upper cladding layers.Type: GrantFiled: November 4, 2003Date of Patent: February 6, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Harumi Nishiguchi, Tetsuya Yagi, Yasuaki Yoshida
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Patent number: 7151004Abstract: In fabricating a semiconductor laser producing light with a wavelength of 770 to 810 nm, impurities are introduced into an MQW active layer near a light emitting facet of the laser to form a disordered region constituting a window layer. Pump light is applied to the window layer to generate photoluminescence whose wavelength ? dpl (nm) is measured. A blue shift amount ? bl (nm) is defined as the difference between the wavelength ? apl (nm) 0f photoluminescence generated by application of pump light to the active layer on the one hand, and the wavelength ? dpl (nm) of photoluminescence from the window layer under pump light irradiation on the other hand. The blue shift amount ? bl is referenced during the fabrication process in order to predict catastrophic optical damage levels of semiconductor lasers.Type: GrantFiled: March 2, 2004Date of Patent: December 19, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshihisa Tashiro, Zempei Kawazu, Harumi Nishiguchi, Tetsuya Yagi, Akihiro Shima
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Patent number: 7106775Abstract: A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index n1 and a thickness d1, a second dielectric film of a refractive index n2 and a thickness d2, a third dielectric film of a refractive index n3 and a thickness d3, and a fourth dielectric film of a refractive index n4 and a thickness d4, specifically, aluminum oxide Al2O3 with a refractive index n1=1.638 is used for the first dielectric film, silicon oxide SiO2 with a refractive index n2=n4=1.489 for the second and fourth dielectric films, tantalum oxide Ta2O5 with a refractive index n3=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.Type: GrantFiled: March 4, 2004Date of Patent: September 12, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiromasu Matsuoka, Yasuhiro Kunitsugu, Harumi Nishiguchi, Tetsuya Yagi, Yasuyuki Nakagawa, Junichi Horie
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Publication number: 20060164563Abstract: A tuner has a dual AGC function, and frequency-converts an input signal into an IF signal. An orthogonal detector calculates a complex signal from the IF signal. A demodulator demodulates a digital signal from the complex signals. An error corrector corrects the error of the digital signal. A signal level detector calculates a level judgment signal from the IF signal. A demodulation level detector detects a signal level of a demodulation signal on a desired band from an output signal of the demodulator. When a demodulation level judgment unit generates a judgment signal representing an influence from interference waves in adjacent channel affecting on a signal on the desired band from the demodulation signal, a control signal generator feeds back a gain control signal to the tuner in accordance with the judgment signal.Type: ApplicationFiled: June 15, 2004Publication date: July 27, 2006Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Kou Watanabe, Daisuke Hayashi, Hisaya Kato, Tetsuya Yagi