Patents by Inventor Kazuo Sakai

Kazuo Sakai 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).

  • Patent number: 5428342
    Abstract: A system for analyzing the operating conditions of electrical apparatus in order for the aged to check the change and abnormal state of life and for the external institute to check the safety of the houses or homes and so on. The data of standard power spectra of particular consumption current for each apparatus are stored in the memory of the system. The electrical signal detected from the wiring conductor is converted into a digital signal by the preprocessor and undergoes fast Fourier transform at the processor so as to be converted into an extracted power spectrum. If the extracted power spectrum includes a particular one of the standard power spectra as a result of comparing this spectrum with the standard power spectra, the operating conditions of that apparatus are stored in the memory with lapse of time.
    Type: Grant
    Filed: April 22, 1992
    Date of Patent: June 27, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Hideo Enoki, Masataka Kawauchi, Hiroshi Ohki, Ichiro Nakamura, Kazuo Sakai
  • Patent number: 5423284
    Abstract: A method which permits the growth of high-quality crystals of n-type II-VI compound semiconductors containing sulfur, by suppressing the reaction of a group III or VII element as a dopant with a group II material at low temperature. A raw material gas containing an organometallic material of the group III or organic material of the group VII is premixed with a raw material gas containing organic sulfur material, then the premixture is mixed with a raw material gas containing an organometallic material of the group II, and the mixture is used to grow a crystal of an n-type II-VI compound semiconductor on a semiconductor substrate by a metal organic vapor phase epitaxial growth method.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: June 13, 1995
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Kohsuke Nishimura, Kazuo Sakai, Yasuyuki Nagao
  • Patent number: 5352051
    Abstract: This invention relates to a writing instrument wherein a temporary ink storage member made of a synthetic resin injection molded article is sandwiched between a pen tip and an ink tank. In the present invention, a flange portion for fitting to a predetermined apparatus, which is positioned around an outer peripheral portion of the temporary ink storage member, is formed integrally with a shaft made of a synthetic resin injection molded article. In embodiments of the invention, the temporary ink storage member is made flexible, the shaft is made of a material which is softer than that of the tip holder, and the tip holder is used as a writing thickness display member. The temporary ink storage member can be used as an ink color display member and a cap is used as an application display member. In other embodiment, the cap can be fitted selectively in accordance with types of writing instruments.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: October 4, 1994
    Assignee: Pentel Kabushiki Kaisha
    Inventors: Takashi Tamura, Masamitsu Nagahama, Koichi Enuma, Yoshihiro Wada, Masayuki Kawasaki, Kazuo Sakai, Kazunori Suzuki
  • Patent number: 5315422
    Abstract: An optical logic element is disclosed which performs an XOR operation through utilization of the high-speed property of light. On each branched waveguide of a Mach-Zehnder interference type optical waveguide there is provided a phase modulating element whose refractive index undergoes a change when it is irradiated by light. The interference type optical waveguide is adapted to provide different optical output levels when the refractive index changes of the phase modulating elements are both zero or a predetermined value and when they differ from each other. Thus, the optical logic element is capable of performing the XOR or XNOR operation at an ultrahigh speed.
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: May 24, 1994
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Katsuyuki Utaka, Yasuyuki Nagao, Yuichi Matsushima, Kazuo Sakai
  • Patent number: 5220472
    Abstract: A surface of an upper rotary drum of a video tape recorder is machines such that it has a surface roughness in a range from 1 .mu.m to 2 .mu.m so as to enable a releasing of air on the upper rotary drum surface uniformly whereby a thickness of an air film between a magnetic tape and a head is uniformly reduced without affecting the tape running. The surface may be grooved concurrently with the roughened surface. A window is formed in rotary drum for receiving at least one magnetic head.
    Type: Grant
    Filed: February 27, 1991
    Date of Patent: June 15, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Tomomi Okamoto, Hiroaki Ono, Shinji Ozaki, Kazuo Sakai
  • Patent number: 5217313
    Abstract: This invention relates to a writing instrument wherein a temporary ink storage member made of a synthetic resin injection molded article is sandwiched between a pen tip and an ink tank. In the present invention, a flange portion for fitting to a predetermined apparatus, which is positioned around an outer peripheral portion of the temporary ink storage member, is formed integrally with a shaft made of a synthetic resin injection molded article. In embodiments of the invention, the temporary ink storage member is made flexible, the shaft is made of a material which is softer than that of the tip holder, and the tip holder is used as a writing thickness display member. The temporary ink storage member can be used as an ink color display member and a cap is used as an application display member. In other embodiment, the cap can be fitted selectively in accordance with types of writing instruments.
    Type: Grant
    Filed: April 30, 1991
    Date of Patent: June 8, 1993
    Assignee: Pentel Kabushiki Kaisha
    Inventors: Takashi Tamura, Masamitsu Nagahama, Koichi Enuma, Yoshihiro Wada, Masayuki Kawasaki, Kazuo Sakai, Kazunori Suzuki
  • Patent number: 5214622
    Abstract: An information display apparatus which accumulates arbitrary information inputted to a television receiver from the outside, superimposes the information in a memory on an ordinary video signal and displays the superimposed image on a television display in accordance with a calender timer built in the television receiver. A remote control unit is provided for inputting information to the information display apparatus from the outside. Memories are disposed in the information display apparatus and the remote control unit for accumulating arbitrary information. A calender timer is provided for serving as a reference for displaying information are also disclosed. Arbitrary information inputted from the outside can be displayed on a television display at a previously appointed date.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: May 25, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Yasuhiro Nemoto, Kazuo Sakai, Masataka Kawauchi, Hideki Tanaka, Kihachiro Tanaka, Hiroshi Ohki, Ichiro Nakamura, Hideo Enoki
  • Patent number: 5208151
    Abstract: Highly purified derivatives of maltooligosaccharides can be produced at a high yield by reacting, in a mixture of a hydrophilic organic solvent and water, a mixture of maltooligosaccharides or a substance capable of being converted into the maltooligosaccharides upon reaction with an amylase, and an o-glucosyl derivative, with the amylase.The resulting derivatives of maltooligosaccharides are useful as a substrate for the determination of .alpha.-amylase activity in a humor, physiologically active substances, natural dieteic sweetenings, coloring agents and the like.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: May 4, 1993
    Assignees: Nihon Shokuhin Kako Co., Ltd., Yaizu Suisan Kagaku Kogyo Co., Ltd.
    Inventors: Taichi Usui, Teruo Nakakuki, Kazuo Sakai
  • Patent number: 5193939
    Abstract: A marine structure has a surface corrosion resistant covering material of titanium-clad steel plates that are continuously arranged in vertical and horizontal directions. Long sides of the titanium-clad steel plates at the top and bottom steps of the corrosion resistant covering material are horizontally arranged to minimize the number of joints between adjacent titanium-clad steel plates, and a space exposed at an end of each joint at the top and bottom steps of the corrosion resistant covering material is closed with a sealing cover.
    Type: Grant
    Filed: November 13, 1991
    Date of Patent: March 16, 1993
    Assignees: Nippon Steel Corporation, Trans-Tokyo Bay Highway Corporation
    Inventors: Taiji Nagatani, Seiichi Soeda, Kazuo Sakai, Yasuo Takahashi
  • Patent number: 5190385
    Abstract: A device for regenerating with ink an ink ribbon which is set in an ink ribbon cassette and has consumed ink contained therein is disclosed. The device includes a housing having an upper surface for mounting the cassette thereon; a guide pin disposed on the upper surface for slidably guiding the ribbon drawn out of the cassette; a guide roller inserted into and movable along an elongated slot formed in the upper surface for guiding the ribbon under tension in cooperation with the guide pin; a rotatable ink pad disposed on the upper surface to contact with the ribbon being guided by the guide pin and the guide roller for transfer ink on the ribbon; and driving means for moving the ribbon in the cassette. In operation, the cassette is removably held on the upper surface, and the guide roller is releasably locked at its play position with a solenoid to thereby make the ribbon contacted with the ink pad.
    Type: Grant
    Filed: June 22, 1991
    Date of Patent: March 2, 1993
    Assignee: Pentel Kabushiki Kaisha
    Inventors: Tetuo Taguchi, Hiroshi Wada, Keiichi Emura, Yutaka Shinohara, Yoshihiro Wada, Isao Onuki, Kazunori Suzuki, Kazuo Sakai
  • Patent number: 5132747
    Abstract: An avalanche photo diode in which the guard ring portion and the front of the pn junction of the light receiving portion are formed at the same depth from the surface of an InP layer, so that the guard ring performs its desired function.
    Type: Grant
    Filed: May 17, 1991
    Date of Patent: July 21, 1992
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Yuichi Matsushima, Kazuo Sakai, Shigeyuki Akiba
  • Patent number: 5122844
    Abstract: A quantum well structure is disclosed, which is comprised of a quantum well layer of a thickness substantially equal to the de Broglie wavelength of electrons and carrier confinement layers of an energy gap greater than that of the quantum well layer. A second material of a lattice constant different from that of a first material primarily for the quantum well layer is disposed in the quantum well layer to provide a phase shift in the period of the crystal lattice of the first material, thereby forming energy levels in the forbidden band of the quantum well layer. A semiconductor device which employs such a quantum well structure and is so constructed as to utilize its physical phenomenon which is caused by the energy levels in the forbidden band. In concrete terms, the present invention has its feature in allowing ease in the fabrication of an intermediate infrared or blue light emitting device, for instance.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: June 16, 1992
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Shigeyuki Akiba, Masashi Usami, Yuichi Matsushima, Kazuo Sakai, Katsuyuki Utaka
  • Patent number: 5115361
    Abstract: A magnetic tape loading apparatus has a rotatable cylindrical drum, tape guides, tape pulling movable members and guide members. The guide members guide the tape guide and control a posture of the tape guide by changing the position and the inclination.
    Type: Grant
    Filed: October 25, 1990
    Date of Patent: May 19, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Takao Terayama, Hajime Yokota, Kazuo Sakai, Nobuyuki Kaku
  • Patent number: 5010376
    Abstract: A light emitting semiconductor device which emits blue and/or green light has an active layer and a pair of clad layers which sandwich the active layer (3), deposited on a substrate (1). The substrate (1) is made of GaAs, InP, GaAsP or Ge. Said active layer (3) and said clad layers (2, 4) are made of II-VI group compound semiconductor which is lattice-matched with the substrate at both room temperature and growing temperature, for instance 500.degree. C. Said II-VI group compound semiconductor has the same linear thermal expansion coefficient as that of the substrate. The linear thermal expansion coefficient of the II-IV group compound semiconductor is adjusted by additive of Cd, Mg or Hg.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: April 23, 1991
    Assignee: Kokusai Denshin Denwa Co., Ltd.
    Inventors: Kohsuke Nishimura, Kazuo Sakai
  • Patent number: 4992837
    Abstract: A light emitting semiconductor device which emits blue and/or green light has an active layer and a pair of clad layers which sandwich the active layer, and which are deposited on a semiconductor substrate. The substrate is made of one of GaAs, GaP, InP, Si, Ge, ZnSe and mixed crystals of GaAsP. The active layer is made of at least one of II-VI group compound semiconductor, I-III-VI.sub.2 group compound semiconductor, and II-IV-V.sub.2 group compound semiconductor. The clad layer is made of II-transition metal-VI group compound semiconductor, which is lattice-matched to the active layer.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: February 12, 1991
    Assignee: Kokusai Denshin Denwa Co., Ltd.
    Inventors: Kazuo Sakai, Yukitoshi Kushiro, Kohsuke Nishimura
  • Patent number: 4961122
    Abstract: A hydrodynamic grooved bearing device in which a shaft is inserted into a hole formed in a bearing housing and one of the shaft and bearing housing is rotated, thereby the rotated member being supported includes a plurality of grooves formed on the shaft or an inner peripheral surface of the bearing housing for generating a dynamic pressure of fluid filled between the shaft and the bearing housing. The plurality of grooves are arranged side by side with a substantially certain pitch in a direction of rotation. Each of the grooves comprises a pair of groove portions slanted relative to the direction of rotation such that a distance between the pair of groove portions becomes narrower towards the direction of rotation and a connecting groove portion connecting the narrowest distance between the slanted groove portions. The connecting groove portion is extended in a direction substantially perpendicular to the direction of rotation.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: October 2, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Sakai, Takao Terayama, Juichi Morikawa
  • Patent number: 4918496
    Abstract: An infrared emitting device for use in the 2 to 3 .mu.m region, which is low in the threshold current and operates over a wide temperature range. In accordance with the present invention, an InP substrate is employed in place of GaSb substrate and InAs substrate heretofore employed for the 2 to 3 .mu.m infrared semiconductor lasers. Moreover, as active layers or clad layers, one of more semiconductor layers are employed which differ in lattice constant from the InP substrate.
    Type: Grant
    Filed: June 30, 1988
    Date of Patent: April 17, 1990
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Yuichi Matsushima, Kazuo Sakai, Shigeyuki Akiba, Katsuyuki Utaka
  • Patent number: 4897845
    Abstract: A semiconductor optical amplifying element is disclosed which has a semiconductor multilayer structure including at least a first semiconductor layer for providing an optical gain in response to the injection of carriers thereinto, and a p-side electrode and an n-side electrode for the carrier injection. A first reflecting surface and a second reflecting surface are disposed thickwisely of the semiconductor multilayer structure and opposite to each other thereacross. The element is designed so that light incident thereon from the thickwise direction of the semiconductor multilayer structure is amplified by propagating through the element perpendicularly to the thickwise direction of the semiconductor multilayer structure while being multiple-reflected between the first reflecting surface and the second reflecting surface.
    Type: Grant
    Filed: May 10, 1989
    Date of Patent: January 30, 1990
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Katsuyuki Utaka, Yuichi Matsushima, Kazuo Sakai, Shigeyuki Akiba
  • Patent number: 4874216
    Abstract: A variable-waveguide optical branching filter is disclosed, in which a diffraction grating is formed in the cross region of two crossing waveguides, only light of a particular wavelength which is determined by the period of the diffraction grating is branched to a desired one of the waveguides, and the refractive index of the cross region is changed by control of a voltage or a current, or by way of irradiation with light, thereby changing the wavelength of light to be branched.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: October 17, 1989
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Katsuyuki Utaka, Kazuo Sakai, Yuichi Matsushima, Shigeyuki Akiba
  • Patent number: 4852108
    Abstract: A semiconductor laser is disclosed in which a light emitting region having a light emitting layer and a waveguide region having a waveguide layer which is coupled to at least one side of the light emitting layer with a high efficiency are integrated on the same substrate; the light emitting region includes an active filter section having a diffraction grating equipped with a band-pass filter function; the light emitting region and the waveguide region are electrically isolated and are each provided with an electrode; and the oscillation wavelength of the semiconductor lase is changed by changing the refractive indices of at least the waveguide region and the active filter section through voltage application or current injection to the electrodes, thereby producing a narrow-linewidth, single-wavelength oscillation output light of a wavelength which corresponds to the transmission wavelength of the active filter section determined by the preset refractive indices of the waveguide region and the active filter se
    Type: Grant
    Filed: July 7, 1988
    Date of Patent: July 25, 1989
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Katsuyuki Utaka, Kazuo Sakai, Yuichi Matsushima