Patents by Inventor Kazuo Nakata
Kazuo Nakata 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: 6149321Abstract: A drawing plate for a film end drawing device is provided which is inserted through a film entrance of a patrone into the patrone. The drawing plate is used in drawing one end portion of a film wound in the patrone from the film entrance. The drawing plate is provided, on its surface to be overlaid with the film, with a friction material having a large coefficient of friction such that the one end portion of the film in the patrone can be drawn out from the film entrance by means of frictional resistance of the friction material.Type: GrantFiled: October 2, 1998Date of Patent: November 21, 2000Assignee: Noritsu Koki Co., Ltd.Inventors: Masanori Nishibata, Nobuyuki Wada, Hideto Yoshizuka, Keiji Ueno, Kazuo Nakata, Masayasu Nakaoka, Takumi Shigeno
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Patent number: 5585032Abstract: Ferromagnetic fine powder for magnetic recording, characterized by comprising platelet like ferrite crystal particles which have such a metallic element composition that the Ba/Fe molar ratio is 1/50 to 1/8 and that the total amount of Ni and Zn is less than 0.5 mole and not less than 0.07 mole per mole of Fe, a crystal phase of magnetoplumbite phase, spinel phase or composite phase thereof and a saturation magnetization of 60 emu/g or more; and a process for producing said ferromagnetic fine powder for magnetic record.Type: GrantFiled: May 9, 1995Date of Patent: December 17, 1996Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kazuo Nakata, Masaharu Hirai, Nobusuke Takumi, Saburo Kato
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Patent number: 5246609Abstract: A process for producing ferromagnetic fine particles for magnetic recording which comprises preparing a starting material solution containing Ba, Fe and Me (Me representing at least one element selected from the group consisting of Co, Ti, Ni, Mn, Zr, Zn, Ge, Nb and V, the amount of which is 0.2 mol or less per mol of Fe) selected such that the molar ratio of Ba/(Fe+Me) is (1+m)/12 (m being a number of 0.1 to 2), mixing this starting material solution with an alkaline solution to form a coprecipitate-containing alkaline suspension, collecting and using the coprecipitate as precursor, or subjecting the coprecipitate-containing alkaline suspension to a heat treatment at a temperature below 250.degree. C. to form a precursor, and calcining such precursor at 650.degree.-950.degree. C. to produce the hexagonal platelet Ba-ferrite particles. The process is further characterized in that a boron compound is contained in the precursor in an amount of (0.01 to 1) mmol (calculated as B.sub.2 O.sub.Type: GrantFiled: August 20, 1992Date of Patent: September 21, 1993Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kazuo Nakata, Masaharu Hirai, Nobusuke Takumi, Saburo Kato
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Patent number: 5204779Abstract: A zoom lens consisting of a front lens portion having a plurality of lens units which are separated from each other by spaces which vary for zooming, and a rear lens portion comprising an image forming relay lens group for introducing rays of light emitted from the front lens portion to an image surface. The rear lens portion consists of a front relay group that is widely spaced ahead of a rear relay group. The rear relay group comprises a first movable lens group having a positive refractive power that moves along the optical axis for macro photography, and a second movable lens group having a positive refractive power that independently moves along the optical axis to adjust tracking.Type: GrantFiled: January 30, 1991Date of Patent: April 20, 1993Assignee: Canon Kabushiki KaishaInventors: Kazuo Nakata, Shigeru Oshima
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Patent number: 4953952Abstract: A color liquid crystal display panel with improvements in brightness of display, viewing angle and workability which comprises a liquid crystal layer which is provided with two light-polarizing plates on opposite side as substrates. One of the light-polarizing plates is made, in the following order, from the light-polarizing layer, a color filter layer formed on the outside surface of a protective film layer, the protective film layer of non-rotary polarization polymer and a transparent conductive film layer formed on the inside surface of the protective film layer. The other light-polarizing plate is made in the following order, from the light-polarizing layer and a transparent conductive film layer.Type: GrantFiled: July 7, 1988Date of Patent: September 4, 1990Assignee: Sumitomo Chemical Company, Ltd.Inventors: Takuzo Okumura, Toyokazu Okada, Hitoshi Kikui, Kazuo Nakata
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Patent number: 4720862Abstract: A method and apparatus for speech signal detection and classification in which a partial auto-correlation and residual power analyzation circuit extracts a normalized first-order partial auto-correlation coefficient and K.sub.1 a normalized zero-order residual power E.sub.N from an input signal, and a sound source analyzation circuit extracts a normalized residual correlation .phi. from the input signal, and in which on the basis of these extracted parameters, speech signals are detected, and, when so detected, the detected speech signals are classified into a voiced sound V, an unvoiced sound U and silence S. The classification of the respective voiced sound, unvoiced sound and silence is determined on the basis of preset threshold values that are mutually considered and which correspond to values of these extracted K.sub.1, E.sub.N and .phi. parameters for establishing boundary values for classifying the input signals into a voiced sound, an unvoiced sound or silence.Type: GrantFiled: January 28, 1983Date of Patent: January 19, 1988Assignee: Hitachi, Ltd.Inventors: Kazuo Nakata, Takanori Miyamoto
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Patent number: 4653098Abstract: A plurality of pitch period candidates are selected from a peak of correlation of a speech waveform in a current frame from which a pitch period is to be extracted, and a speech pitch is selected from the candidates by referring to a guide index which is precalculated based on pitch periods extracted in past frames. The guide index is an average of the pitch periods in the past frames.Type: GrantFiled: January 31, 1983Date of Patent: March 24, 1987Assignee: Hitachi, Ltd.Inventors: Kazuo Nakata, Takanori Miyamoto
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Patent number: 4589015Abstract: A television camera is provided with a color resolving optical system for color resolution and for forming a plurality of optical paths, the color resolving optical system having at least one dichroic film, a plurality of image pick-up tubes disposed on the optical paths for receiving the image of an object to be photographed, and an illuminating device emitting a plurality of illuminating lights of a predetermined wavelength range and provided with an adjuster for adjusting the quantity of light of at least one of said illuminating lights. The wavelength band width of said illuminating lights is narrower than the wavelength band width color-resolved by the color resolving optical system and/or the positions at which said illuminating lights are emitted differ from one another, whereby color shading of the image pick-up tubes is eliminated.Type: GrantFiled: May 31, 1983Date of Patent: May 13, 1986Assignee: Canon Kabushiki KaishaInventors: Kazuo Nakata, Jun Hosoya, Shigeru Ohshima, Takeshi Sekiguchi
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Patent number: 4560544Abstract: A process for preparing acicular .alpha.-FeOOH by partially neutralizing and then oxidizing a ferrous salt solution in the presence of phosphoric acid or a salt thereof to form seed crystals of .alpha.-FeOOH and optionally further oxidizing said solution while neutralizing said solution with an alkali to grow said seed crystals, wherein pyrophosphoric acid or a salt thereof is used as said phosphoric acid and the seed crystals of .alpha.-FeOOH are formed at a temperature of 50.degree. to 100.degree. C. The .alpha.-FeOOH obtained according to the process of this invention is composed of fine particles and appreciably improved in acicularity and particle size distribution. Also, a magnetic recording medium made from the magnetic iron oxides derived therefrom in a usual way have a low noise characteristic and, are excellent in coercivity and other magnetic properties.Type: GrantFiled: December 10, 1984Date of Patent: December 24, 1985Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kazuo Nakata, Tsuneo Ishikawa, Taro Amamoto, Toshihiko Kawamura
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Patent number: 4539261Abstract: A process for producing a magnetic powder which comprises coating the particle surfaces of a magnetic iron oxide with a cobalt compound or a cobalt compound and a ferrous compound and further coating with a compound of at least one metal selected from the group consisting of manganese, vanadium and zinc. There is obtained a magnetic powder having high coercivity and excellent dispersibility in organic binders. This magnetic powder is useful as a material for recording media such as magnetic tapes.Type: GrantFiled: April 5, 1983Date of Patent: September 3, 1985Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kazuo Nakata, Masatsuyo Maruo, Kiyoshi Asano
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Patent number: 4501774Abstract: A process is provided for coating the particle surfaces of a phosphor-containing magnetic iron oxide powder with a cobalt compound after subjecting said powder to an activation treatment with an aqueous alkaline and/or acidic medium. The cobalt-containing magnetic iron oxide powder obtained according to this process has excellent coercivity and thermal stability, and the magnetic tape produced by using said powder has not only high coercivity but also excellent squareness, orientability and remanent induction.Type: GrantFiled: September 29, 1982Date of Patent: February 26, 1985Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kokichi Miyazawa, Kazuo Nakata, Tsuneo Ishikawa, Ichiro Honma, Masaharu Hirai, Makoto Ogasawara, Toshihiko Kawamura
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Patent number: 4491958Abstract: In a speech synthesizer designed so that natural speech is chopped at constant intervals of time and characteristic parameters of the speech are extracted from the chopped speech and used for synthesis of speech, the number of bits of a characteristic parameter per analytical frame is not changed, but the interval of time of one analytical frame is changed to change the amount of information per unit time, while the time interval of one synthesis frame of the synthesizer is changed with the time interval of one analytical frame so that the time interval of one frame upon analysis and the time interval of one frame upon synthesis are made equal, whereby a single speech synthesizer can handle speech parameters of different amounts of information.Type: GrantFiled: October 22, 1981Date of Patent: January 1, 1985Assignees: Nippon Telegraph & Telephone Public Corporation, Hitachi, Ltd.Inventors: Kazuhiro Umemura, Tohru Sampei, Kazuo Nakata, Hirokazu Sato, Murakami Kenya, Kiyoshi Intoh
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Patent number: 4486467Abstract: A phosphorus-containing magnetic iron oxide powder is subjected to the activation with an aqueous alkaline medium under pressure and then coated with a cobalt compound or a cobalt compound and other metallic compound(s) to produce a cobalt-containing magnetic iron oxide powder. The magnetic iron oxide powder obtained according to this process finds its best application to the production of magnetic recording media.Type: GrantFiled: December 14, 1982Date of Patent: December 4, 1984Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kazuo Nakata, Tsuneo Ishikawa, Ichiro Honma, Arata Koyama, Masaharu Hirai, Masatoshi Amano
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Patent number: 4414245Abstract: A process which comprises coating a cobalt compound or a combination of a cobalt compound and a ferrous compound on the surface of magnetic iron oxide particles and then heating the coated particles in the presence of water vapor. The cobalt containing ferromagnetic iron oxide produced by this process is excellent in coercivity and thermal stability. Further, magnetic tape produced from this iron oxide has a high coercivity and is excellent in squareness, orientability and remanent induction.Type: GrantFiled: July 23, 1982Date of Patent: November 8, 1983Assignee: Ishihara Sangyo Kaisha, Ltd.Inventors: Kokichi Miyazawa, Kazuo Nakata, Tsuneo Ishikawa, Ichiro Honma, Arata Koyama, Masatoshi Amano
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Patent number: 4395119Abstract: Disclosed is a method for the automatic, nondestructive, measurement of the eccentricity of a core wire in a coating composition coated upon an electrode, the measurement being formed by at least two sets of optical means, each including a light source and a line sensor. One of the optical sensors is positioned to measure the diameter of a coated portion of the core wire while at least one of the remaining sensors is positioned to measure the diameter of an uncoated portion. The positions and diameters of both portions are compared to find the eccentricity of the core wire. Where three sensors are used to measure the position and thickness of the exposed wire portion, the eccentricity of a misaligned or bent rod can be determined.Type: GrantFiled: October 30, 1980Date of Patent: July 26, 1983Assignee: Kobe Steel, LimitedInventors: Kazuo Nakata, Akihiko Iochi, Isamu Kaise, Kazuo Takeuchi, Katsuhiko Nomura
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Patent number: 4349699Abstract: This PARCOR-type speech synthesizer replaces a ten-stage lattice type filter with a pipeline multiplier and feedback loop, and provides a loss circuit (for bandwidth broadening) using subtraction circuits for multiplication.Type: GrantFiled: September 30, 1980Date of Patent: September 14, 1982Assignees: Nippon Telegraph & Telephone Public Corporation, Hitachi, Ltd.Inventors: Akihiro Asada, Kazuo Nakata, Kazuhiro Umemura, Hirokazu Sato, Kenya Murakami, Kiyoshi Into
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Patent number: 4340781Abstract: Computation of the partial correlation coefficients (PARCOR K.sub.i) of a signal, using less cascaded hardware, is implemented by first deriving a sequence of auto-correlation coefficients (v.sub.j) which are then transformed into a sequence of K.sub.i using a single section digital filter plus recirculating circuitry for data iteration.Type: GrantFiled: April 30, 1980Date of Patent: July 20, 1982Assignee: Hitachi, Ltd.Inventors: Akira Ichikawa, Kazuo Nakata, Akira Nakajima, Yoshihiro Ohta, Kazuhiro Umemura
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Patent number: 4283601Abstract: Signal-to-noise is enhanced by including the upper sideband of a sampled-speech signal with the original baseband signal for further signal processing. The invention features shifting both bands to form a continuum from 0 Hz to the sampling frequency. Application in a speech recognition is shown.Type: GrantFiled: May 8, 1979Date of Patent: August 11, 1981Assignee: Hitachi, Ltd.Inventors: Akira Nakajima, Akira Ichikawa, Kazuo Nakata
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Patent number: 4211897Abstract: A multifrequency signal receiving system comprising a filter for whitening a received signal, a correlator for extracting partial autocorrelation coefficients from the output of the whitening filter, a prediction error analyzer for judging the presence or absence of the multifrequency signal by analyzing prediction analysis errors from the output of the whitening filter, and a control unit responsive to the output of the analyzer indicative of the presence of the multifrequency signal for determining the frequency included in the received signal using the partial autocorrelation coefficients thereby identifying that the received signal is the multifrequency signal.Type: GrantFiled: September 15, 1978Date of Patent: July 8, 1980Assignee: Hitachi, Ltd.Inventors: Akira Ichikawa, Kazuo Nakata, Kazuhito Hirose
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Patent number: 4088838Abstract: Improvements in a push button signal receiving device for use in a voice response system, wherein in order to permit a push button signal from a user's telephone terminal to be received even during the period when a responding voice signal is being transmitted through the system, an analyzer for the parameter analysis of the responding voice signal and an inverse filter responsive to the analyzer for flattening the spectrum of the responding voice signal which is mixed into the push button signal are provided, whereby the influence of the responding voice signal mixing into the signal to be applied to a push button signal detector is erased, and the push button signal, which may be feeble in comparison to the responding voice signal, is detected and recognized nevertheless.Type: GrantFiled: December 20, 1976Date of Patent: May 9, 1978Assignee: Hitachi, Ltd.Inventors: Kazuo Nakata, Akira Ichikawa, Akio Suehiro