Patents by Inventor Seiji Fujiwara
Seiji Fujiwara 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: 6972621Abstract: A power amplifier capable of compensating for distortion by pre-distortion and achieving a large distortion suppressing effect even if IM3L components and IM3U components occurring at the power amplifier have a large level difference. A power amplifying circuit 117 amplifies an original signal. An envelope detector 119 generates an envelope signal having components identical to envelope components included in the original signal. Based on the original signal a distortion signal generating circuit 112 generates a distortion signal for canceling distortion components occurring while the original signal is amplified by the power amplifying circuit 117. In a power combiner 116, the envelope signal is injected to the original signal, thereby eliminating the asymmetric characteristic of the distortion components. In the power amplifying circuit 117, the distortion signal is injected to the original signal, thereby suppressing the distortion components.Type: GrantFiled: October 15, 2004Date of Patent: December 6, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
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Patent number: 6960957Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.Type: GrantFiled: March 25, 2003Date of Patent: November 1, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
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Patent number: 6960958Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.Type: GrantFiled: January 5, 2004Date of Patent: November 1, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
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Publication number: 20050237113Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.Type: ApplicationFiled: April 7, 2005Publication date: October 27, 2005Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
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Publication number: 20050193771Abstract: When separated phases are formed in a glass by a nucleation and growth mechanism, a phase separation region only in a small desired area is difficult to form by a conventional method, in which the entire glass is heated. Thus, an optical waveguide structure, or a photonic crystal, which requires an orderly arrangement of high-refractive-index regions, cannot be manufactured. The present invention provides a method for forming a phase separation region by converging a laser pulse in a glass containing a metastable immiscible phase to separate only an area at a focal point of the laser or in the vicinity of the focal point into phases. The focal point of the laser is moved continuously or intermittently relative to the glass to form a linear phase separation region or a dotted phase separation region in two or three dimensions in the glass. The pulse width of the laser is preferably between 10 femtoseconds and 10 picoseconds.Type: ApplicationFiled: April 18, 2003Publication date: September 8, 2005Inventors: Kiyotaka Miura, Seiji Fujiwara, Kazuyuki Hirao
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Feedforward amplifier, communication apparatus, feedforward amplification method, program and medium
Patent number: 6940346Abstract: The conventional feedforward amplifier is unable to suppress distortion components efficiently. The present invention provides a feedforward amplifier wherein the vector adjustor is adjusted so that (1) suppression is performed on only the distortion component generated within a predetermined frequency range out of the range of frequencies to be suppressed in which distortion components to be suppressed occur or (2) the suppression of the distortion component generated within the predetermined frequency range is greater than the suppression of the distortion component generated within the frequency range other than the predetermined frequency range out of the range of frequencies to be suppressed, and the pre-distortion circuit is adjusted so that at least the distortion component generated within the frequency range other than the predetermined frequency range is suppressed.Type: GrantFiled: November 30, 2001Date of Patent: September 6, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masayuki Miyaji, Kaoru Ishida, Toshimitsu Matsuyoshi, Hisashi Adachi, Seiji Fujiwara -
Patent number: 6933780Abstract: A predistortion circuit has an input terminal for inputting a predetermined signal; a nonlinear device directly or indirectly connected to the input terminal; a bias supply circuit for applying a voltage to the nonlinear device; specific-frequency suppressing means connected to one side or both sides of the nonlinear device directly without another intervening device and of suppressing all or part of such frequencies that are from a frequency corresponding to DC to a frequency corresponding to an occupied band width of an input signal inputted to the input terminal and/or suppressing at least one higher harmonic frequency of a carrier wave of the input signal; and an output terminal for outputting a signal.Type: GrantFiled: January 31, 2001Date of Patent: August 23, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Seiji Fujiwara, Toru Matsuura, Kaoru Ishida, Makoto Sakakura
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Publication number: 20050138863Abstract: It was difficult to acquire a good CO cleanup efficiency in a hydrogen refining apparatus, for instance, when the start-up and stop operations are frequently repeated. A hydrogen refining apparatus, including a shifter having a shifting catalyst body containing noble metals and metal oxides, and a reforming section for supplying hydrogen gas containing carbon monoxide to the shifter, (1) the temperature of an upstream side of the shifting catalyst body relative to the hydrogen gas flow being substantially between 300° C. and 500° C. and (2) the temperature of a downstream side of the shifting catalyst body relative to the hydrogen gas flow being substantially at 300° C. or less.Type: ApplicationFiled: November 3, 2004Publication date: June 30, 2005Inventors: Kunihiro Ukai, Kiyoshi Taguchi, Takeshi Tomizawa, Seiji Fujiwara
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Patent number: 6902794Abstract: A coated paper used for printing and manufacturing method thereof. The coated paper comprises a coated layer mainly compose of a pigment and an adhesive on a base paper or paper web. The coated paper also comprises the thermal shrinkage force (R) which satisfies following formula when measured pursuant to the measuring method described in the specification; 0?R?45 gf A sample coated paper is moisture-adjusted in accordance with JIS-P-8111. Then, it will be cut into specific dimension along with orthogonally to the cross direction. Next, the paper will be put through Thermo Mechanical Analyzer to obtain R that is measured by predetermined technique. The coated paper will be obtained easily by using a base paper coated with PVA having a saponification degree of not less than 85 mol % in an amount of 0.5-5 g/m2 per side surface after the coating material was dried and dried.Type: GrantFiled: June 28, 2002Date of Patent: June 7, 2005Assignee: Oji Paper Co., Ltd.Inventors: Tetsuya Hirabayashi, Seiji Fujiwara, Terunobu Fukui
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Publication number: 20050046477Abstract: A power amplifier capable of compensating for distortion by pre-distortion and achieving a large distortion suppressing effect even if IM3L components and IM3U components occurring at the power amplifier have a large level difference. A power amplifying circuit 117 amplifies an original signal. An envelope detector 119 generates an envelope signal having components identical to envelope components included in the original signal. Based on the original signal a distortion signal generating circuit 112 generates a distortion signal for canceling distortion components occurring while the original signal is amplified by the power amplifying circuit 117. In a power combiner 116, the envelope signal is injected to the original signal, thereby eliminating the asymmetric characteristic of the distortion components. In the power amplifying circuit 117, the distortion signal is injected to the original signal, thereby suppressing the distortion components.Type: ApplicationFiled: October 15, 2004Publication date: March 3, 2005Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
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Publication number: 20050035818Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.Type: ApplicationFiled: September 22, 2004Publication date: February 17, 2005Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
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Publication number: 20050000825Abstract: In the IS process, the reaction between sulfur and water is performed on the positive electrode side of a cation exchange membrane and the iodine-involving reaction is on the negative electrode side, so that the subsequent separating operation is eliminated to reduce the amounts of recycling iodine and water.Type: ApplicationFiled: February 23, 2004Publication date: January 6, 2005Applicant: Japan Atomic Energy Research InstituteInventors: Mikihiro Nomura, Kaoru Onuki, Seiji Fujiwara, Hiroyuki Okuda
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Patent number: 6833758Abstract: A power amplifier capable of compensating for distortion by pre-distortion and achieving a large distortion suppressing effect even if IM3L components and IM3U components occurring at the power amplifier have a large level difference. A power amplifying circuit 117 amplifies an original signal. An envelope detector 119 generates an envelope signal having components identical to envelope components included in the original signal. Based on the original signal a distortion signal generating circuit 112 generates a distortion signal for canceling distortion components occurring while the original signal is amplified by the power amplifying circuit 117. In a power combiner 116, the envelope signal is injected to the original signal, thereby eliminating the asymmetric characteristic of the distortion components. In the power amplifying circuit 117, the distortion signal is injected to the original signal, thereby suppressing the distortion components.Type: GrantFiled: May 28, 2003Date of Patent: December 21, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
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Publication number: 20040135631Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.Type: ApplicationFiled: January 5, 2004Publication date: July 15, 2004Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
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Patent number: 6728154Abstract: The invention relates to a three-dimensional optical memory medium capable of recording and reading a large quantity of information therein and therefrom, and a process for producing the same. A recording pulsed laser beam is applied to an arbitrary position in a luminescent-ion-containing solid medium as the solid medium is three-dimensionally moved relative to a converging point of the pulsed laser beam.Type: GrantFiled: January 30, 2001Date of Patent: April 27, 2004Assignee: Central Glass Company, LimitedInventors: Kiyotaka Miura, Seiji Fujiwara
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Publication number: 20040075497Abstract: The conventional feedforward amplifier is unable to suppress distortion components efficiently. The present invention provides a feedforward amplifier wherein the vector adjustor is adjusted so that (1) suppression is performed on only the distortion component generated within a predetermined frequency range out of the range of frequencies to be suppressed in which distortion components to be suppressed occur or (2) the suppression of the distortion component generated within the predetermined frequency range is greater than the suppression of the distortion component generated within the frequency range other than the predetermined frequency range out of the range of frequencies to be suppressed, and the pre-distortion circuit is adjusted so that at least the distortion component generated within the frequency range other than the predetermined frequency range is suppressed.Type: ApplicationFiled: November 6, 2003Publication date: April 22, 2004Inventors: Masayuki Miyaji, Kaoru Ishida, Toshimitsu Matsuyoshi, Hisashi Adachi, Seiji Fujiwara
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Patent number: 6720829Abstract: Provided is a distortion-compensated amplifying circuit capable of suppressing distortion without attenuating a level of carrier components, and further obtaining a larger amount of suppression of distortion, which has not been achievable by conventional distortion-compensated amplifying circuit using a pre-distortion technique. A balanced type amplifying circuit is structured such that amplifiers 115 and 116 placed in parallel are sandwiched by 90-degree hybrid circuits 114 and 117. The 90-degree hybrid circuit 114 is supplied with an original signal including carrier components and a distortion signal including distortion equal in amplitude and opposite in phase (having a phase difference of 180 degrees) to distortion that occurs when the original signal is amplified by the amplifiers 115 and 116. The 90-degree hybrid circuit 114 performs a process of differential amplification with a phase difference of 180 degrees between the original signal and the distortion signal.Type: GrantFiled: December 20, 2002Date of Patent: April 13, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
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Patent number: 6710652Abstract: A feedforward amplifier includes a first power splitter for dividing an input signal into two paths. The first path, in sequence, includes a first vector adjuster, a main amplifier, a second power splitter and a delay circuit. The second path, in sequence, includes a delay circuit, a distortion detecting power combiner, a second vector adjuster and an error amplifier. The distortion detecting power combiner combines a portion of a signal from the first path with a signal in the second path. Each vector adjuster adjusts amplitude and phase of a signal in each path. A distortion suppression power combiner synthesizes a signal in the first path with a signal in the second path. Control is included for stopping operation of the error amplifier or main amplifier based on a predetermined condition.Type: GrantFiled: September 21, 2001Date of Patent: March 23, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masayuki Miyaji, Kaoru Ishida, Toshimitsu Matsuyoshi, Seiji Fujiwara
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Publication number: 20040037757Abstract: A clarifying catalyst body in an apparatus of hydrogen purification is such that a first catalyst containing at least one kind selected from the group consisting of Pt, Pd, Ru and Rh and a second catalyst containing at least one kind selected from the group consisting of Pd, Ru, Rh and Ni are mixed or integrated, The purifying catalyst body in the apparatus of hydrogen purification consists of (1) an oxide containing at least either Al or Si, (2) at least one kind of transition metal and/or a transition metal oxide and (3) at least one kind of noble metal and/or noble metal oxide selected from the group consisting of Pt, Ru, Pd and Rh.Type: ApplicationFiled: June 30, 2003Publication date: February 26, 2004Inventors: Kiyoshi Taguchi, Kunihiro Ukai, Seiji Fujiwara, Takeshi Tomizawa, Hidenobu Wakita
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Publication number: 20040013917Abstract: Many organic raw materials contain sulfur components, and the sulfur component is a catalyst poisoning component for their catalysts to decrease steam reforming reactivity.Type: ApplicationFiled: July 10, 2003Publication date: January 22, 2004Inventors: Kunihiro Ukai, Kiyoshi Taguchi, Hidenobu Wakita, Seiji Fujiwara