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).

  • Publication number: 20030234688
    Abstract: 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: Application
    Filed: May 28, 2003
    Publication date: December 25, 2003
    Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
  • Patent number: 6645893
    Abstract: A glass includes (a) a matrix containing a compound of at least one nonmetallic element; and (b) a particle selectively formed in the matrix. This particle is made of the at least one nonmetallic element. A process for producing such glass includes (a) providing a blank glass containing a compound of at least one nonmetallic element; (b) condensing a pulsed laser beam to a focal point in the blank glass such that a particle is selectively formed in the blank glass at a position corresponding to the focal point, the particle being made of the at least one nonmetallic element dissociated from the compound; and (c) moving the focal point in the blank glass to produce a pattern of the particle. The glass is suitable for optical functional elements.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: November 11, 2003
    Assignee: Central Glass Company, Limited
    Inventors: Kiyotaka Miura, Seiji Fujiwara, Takuya Teshima, Natsuya Nishimura, Yoshinori Kubota
  • Publication number: 20030175562
    Abstract: Conventional hydrogen purification apparatuses cannot be used satisfactorily for applications in which much time is required for startup of the apparatus, and the apparatus is repeatedly started and stopped at frequent intervals because of complicated handling.
    Type: Application
    Filed: March 17, 2003
    Publication date: September 18, 2003
    Inventors: Kiyoshi Taguchi, Kunihiro Ukai, Seiji Fujiwara, Takeshi Tomizawa, Hidenobu Wakita
  • Publication number: 20030169110
    Abstract: 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: Application
    Filed: March 25, 2003
    Publication date: September 11, 2003
    Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
  • Publication number: 20030129100
    Abstract: 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.
    Type: Application
    Filed: August 26, 2002
    Publication date: July 10, 2003
    Inventors: Kunihiro Ukai, Kiyoshi Taguchi, Takeshi Tomizawa, Seiji Fujiwara
  • Patent number: 6590449
    Abstract: 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: Grant
    Filed: May 29, 2001
    Date of Patent: July 8, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
  • Publication number: 20030117217
    Abstract: 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: Application
    Filed: December 20, 2002
    Publication date: June 26, 2003
    Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
  • Publication number: 20030108456
    Abstract: Since carbon monoxide is generated as subcomponent in a water vapor reforming reaction, in many cases, a shifter for conducting a shift reaction on water and carbon monoxide is used in combination. Generally, in the case of a stable operation, a concentration of carbon monoxide hardly increases. However, when using conditions of a catalyst are changed due to external factors in the shifter, a concentration of carbon monoxide increases.
    Type: Application
    Filed: October 1, 2002
    Publication date: June 12, 2003
    Inventors: Kunihiro Ukai, Kiyoshi Taguchi, Takeshi Tomizawa, Yutaka Yoshida, Seiji Fujiwara
  • Publication number: 20030079232
    Abstract: At transmission of a digital modulated wave between a digital set top box and a digital TV, favorable transmission with little picture quality deterioration and noise is realized without employing a coaxial cable.
    Type: Application
    Filed: June 12, 2002
    Publication date: April 24, 2003
    Inventors: Hideki Kirino, Kunio Ninomiya, Seiji Fujiwara
  • Patent number: 6545542
    Abstract: A power amplifier that reduces intermodulation distortion generated by the amplifier while reducing the number of parts is provided. A power amplifier comprises a first balun, to which a combined signal combining two signals of different frequencies is inputted, and which outputs, based on the combined signal, the first and the second signal whose phase are opposite; a first amplifier that outputs the first amplified signal containing the differential frequency component comprising the difference of the frequencies of two signals from the first signal; a second amplifier that outputs the second amplified signal containing the component comprising the difference of the frequencies of two signals from the second signal; and a second balun that outputs the combined signal of the first and the second amplified signals. The component contained in the first and the second amplified signal are inputted via the second and the first amplifier, respectively, to reduce the component.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: April 8, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Masayuki Miyaji, Seiji Fujiwara
  • Patent number: 6507253
    Abstract: A delay circuit in which amplitude characteristic and delay time characteristic of the output signals do not have any ripple relative to the length of the transmission line is provided. The delay circuit includes a circuit that makes a part of signals distributed into two parts by the power divider (103) to be identical in amplitude and inverse in phase relative to the component of signals outputted from the terminal-a directly to the terminal-c of the circulator (104). By composing with the power combiner (107) both signals are offset each other at the output terminal. As a result, only the signals that are inputted from the input terminal (101) and transmitted through the circulator (104) and the open-ended transmission line (105) are outputted to the output terminal (102).
    Type: Grant
    Filed: March 7, 2001
    Date of Patent: January 14, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshimitsu Matsuyoshi, Toru Matsuura, Kaoru Ishida, Seiji Fujiwara
  • Publication number: 20020182382
    Abstract: 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.
    Type: Application
    Filed: June 28, 2002
    Publication date: December 5, 2002
    Inventors: Tetsuya Hirabayashi, Seiji Fujiwara, Terunobu Fukui
  • Publication number: 20020177424
    Abstract: A predistortion linearizer has
    Type: Application
    Filed: April 9, 2002
    Publication date: November 28, 2002
    Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Seiji Fujiwara
  • Patent number: 6458413
    Abstract: The method of making a coated paper having a thermal shrinkage force (R), which satisfies the following relationship 0≦R≦45 gf, includes coating a paper web on both sides with an aqueous solution of polyvinyl alcohol to form a coated paper web, drying the coated paper web to form a base paper with a polyvinyl alcohol coating having a coating weight on a dry basis of 0.5 to 5.0 g/m2 per side of the base paper and then applying a coating composition composed of an adhesive and at least one inorganic pigment to the base paper having the polyvinyl alcohol coating, followed by drying in order to form a coating layer on the base paper. The aqueous solution of the polyvinyl alcohol preferably has a viscosity of from 100 to 2000 mPa·s measured with a Brookfield viscometer at 60 rpm and 20° C. and the polyvinyl alcohol dissolved in the aqueous solution has a saponification degree of not less than 85 mol %.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: October 1, 2002
    Assignee: Oji Paper Co., Ltd.
    Inventors: Tetsuya Hirabayashi, Seiji Fujiwara, Terunobu Fukui
  • Publication number: 20020113648
    Abstract: 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: Application
    Filed: September 21, 2001
    Publication date: August 22, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayuki Miyaji, Kaoru Ishida, Toshimitsu Matsuyoshi, Seiji Fujiwara
  • Publication number: 20020067211
    Abstract: A power amplifier that reduces intermodulation distortion generated by the amplifier while reducing the number of parts is provided. A power amplifier comprises a first balun, to which a combined signal combining two signals of different frequencies is inputted, and which outputs, based on the combined signal, the first and the second signal whose phase are opposite; a first amplifier that outputs the first amplified signal containing the differential frequency component comprising the difference of the frequencies of two signals from the first signal; a second amplifier that outputs the second amplified signal containing the component comprising the difference of the frequencies of two signals from the second signal; and a second balun that outputs the combined signal of the first and the second amplified signals. The component contained in the first and the second amplified signal are inputted via the second and the first amplifier, respectively, to reduce the component.
    Type: Application
    Filed: October 22, 2001
    Publication date: June 6, 2002
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Toshimitsu Matsuyoshi, Kaoru Ishida, Masayuki Miyaji, Seiji Fujiwara
  • Publication number: 20010048346
    Abstract: 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: Application
    Filed: May 29, 2001
    Publication date: December 6, 2001
    Inventors: Toru Matsuura, Kaoru Ishida, Makoto Sakakura, Seiji Fujiwara
  • Publication number: 20010031691
    Abstract: A glass includes (a) a matrix containing a compound of at least one nonmetallic element; and (b) a particle selectively formed in the matrix. This particle is made of the at least one nonmetallic element. A process for producing such glass includes (a) providing a blank glass containing a compound of at least one nonmetallic element; (b) condensing a pulsed laser beam to a focal point in the blank glass such that a particle is selectively formed in the blank glass at a position corresponding to the focal point, the particle being made of the at least one nonmetallic element dissociated from the compound; and (c) moving the focal point in the blank glass to produce a pattern of the particle. The glass is suitable for optical functional elements.
    Type: Application
    Filed: February 21, 2001
    Publication date: October 18, 2001
    Inventors: Kiyotaka Miura, Seiji Fujiwara, Takuya Teshima, Natsuya Nishimura, Yoshinori Kubota
  • Publication number: 20010028507
    Abstract: 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: Application
    Filed: January 30, 2001
    Publication date: October 11, 2001
    Inventors: Kiyotaka Miura, Seiji Fujiwara
  • Publication number: 20010013809
    Abstract: A predistortion circuit has
    Type: Application
    Filed: January 31, 2001
    Publication date: August 16, 2001
    Inventors: Seiji Fujiwara, Toru Matsuura, Kaoru Ishida, Makoto Sakakura