Patents Assigned to TDK Electronic Company
  • Patent number: 4014707
    Abstract: A dielectric ceramic composition comprises as principle constituents, 86 - 99.6 mole % of barium titanate, 0.2 - 10 mole % of niobium pentaoxide and 0.2 - 4 mole % of cerium oxide.
    Type: Grant
    Filed: July 8, 1975
    Date of Patent: March 29, 1977
    Assignee: TDK Electronics Company, Limited
    Inventors: Hitoshi Tanaka, Hitoshi Masumura, Shinobu Fujiwara
  • Patent number: 4010310
    Abstract: An improved magnetic powder characterized by high coercive force and high magnetic flux density which is formed by admixing a cobalt compound with a magnetic iron oxide, and adding to said admixture a complex forming agent which complexes with the cobalt compound to promote adsorption of cobalt onto the surface of the magnetic iron oxide.
    Type: Grant
    Filed: July 21, 1975
    Date of Patent: March 1, 1977
    Assignee: TDK Electronics Company, Limited
    Inventors: Yuichi Kubota, Shinji Umeki, Yasumichi Tokuoka
  • Patent number: 4008432
    Abstract: Apparatus for detecting an external magnetic field comprises a magnetic sensor which produces para-magnetic oscillations and includes an elongated member of an electrically conductive material and a thin magnetic film disposed thereabout. Alternative embodiments of the invention are presented in each of which the detection of an external magnetic field by the sensor results in a change in the oscillating state. In a first embodiment, the sensor is maintained normally in an oscillating state of a given domain and thus a given phase; when the sensor is subjected to an external magnetic field of appropriate intensity and polarity, the magnetization of the sensor shifts from the first domain to the second domain and accordingly there is produced a change or reversal in phase of the oscillatory output derived from the sensor. In that change of phase, the sensor output passes through a zero voltage value which is detected for providing an indication of the sensing of the external magnetic field.
    Type: Grant
    Filed: December 26, 1973
    Date of Patent: February 15, 1977
    Assignee: TDK Electronics Company, Limited
    Inventors: Takao Sugisaki, Tatsushiro Ochiai, Kyoichi Nishikawa, Minoru Higurashi
  • Patent number: 4006408
    Abstract: A magnetic substance detecting device is disclosed as being capable of parametric oscillation, and including a magnetic sensor formed of an elongated wire with a magnetic thin film plated on the wire, the film being of uniaxial magnetic anisotropy and having a magnetic hard axis in its axial direction and a magnetic easy axis in its circumferential direction. The magnetic substance to be detected is coupled with a magnetic or electrical circuit associated with the magnetic oscillation domain of the magnetic wire of the magnetic sensor to convert the state of the oscillation output of its detecting coil, thus detecting the magnetic substance.
    Type: Grant
    Filed: February 7, 1973
    Date of Patent: February 1, 1977
    Assignee: TDK Electronics Company, Limited
    Inventors: Takao Sugisaki, Tatsushiro Ochiai, Kyoichi Nishikawa, Minoru Higurashi
  • Patent number: 4003840
    Abstract: Microwave absorber comprising a mixture of ferrite powder having particle size of less than 1.65 mm and an organic high molecular weight compound.
    Type: Grant
    Filed: May 12, 1975
    Date of Patent: January 18, 1977
    Assignee: TDK Electronics Company, Limited
    Inventors: Ken Ishino, Takashi Watanabe, Yasuo Hashimoto
  • Patent number: 4000516
    Abstract: Magnetic tape apparatus includes a master tape loop box magazine for temporarily storing a magnetic tape in a zig-zag condition, a transferring device disposed within the magazine for moving the tape to a tape outlet of the magazine, a detector for detecting the apparent density of the magnetic tape at the magazine outlet, and a travelling device which is operated only when the apparent density of the magnetic tape detected by the detector is below or less than a predetermined value. The apparatus is applicable to both endless and reel-to-reel type tape apparatus.
    Type: Grant
    Filed: January 30, 1975
    Date of Patent: December 28, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Kazuo Watanabe, Tetsuya Fuchikuchi
  • Patent number: 3997479
    Abstract: A method of manufacturing barium titanate semiconducting ceramics having a positive temperature coefficient characteristic of resistivity in which a composite, expressed by a general formula (Ba.sub.1.sub.-x.sub.-y Pb.sub.x R.sub.y) TiO.sub.3 (where 0<x.ltoreq.0.8, y is the remainder and R represents a rare earth element) is mixed with either tantalum or niobium or both in the amount of 0.05 to 0.5 atomic % and fired in the air or in an atmosphere containing oxygen, the total amount of the rare earth in the composite combined with the total amount of tantalum or niobium or both added thereto being in the range of 0.1 to 0.55 atomic %. The addition of tantalum and/or niobium in this manufacturing method prevents the evaporation of lead from the composite and eliminates the need to employ a lead oxide gas atmosphere while providing semiconducting ceramics having stable and excellent ceramic and electrical characteristics.
    Type: Grant
    Filed: July 30, 1974
    Date of Patent: December 14, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Nobuei Shimojo, Ichihito Minesaki
  • Patent number: 3997457
    Abstract: A ceramic dielectric compositon is provided which consists essentially of a sintered metal oxide mixture expressed by the formula:[(Ba.sub.1.sub.-u Me.sub.u)O].sub.x.[(Ta.sub.1.sub.-v Nb.sub.v).sub.2 O.sub.5 ].sub.y.[Bi.sub.2 O.sub.3 ].sub.zwhere Me is at least one divalent metal selected from lead and strontium, and x, y, z, u and v are numbers falling within the following ranges0.05 .ltoreq. x .ltoreq. 0.80,0.05 .ltoreq. y .ltoreq. 0.30,0.10 .ltoreq. z .ltoreq. 0.80,0 .ltoreq. u .ltoreq. 1.00,0 .ltoreq. v .ltoreq. 1.00 andx + y + z = 1.0.This composition may contain specified metal oxide additives. The ceramic dielectric composition is sintered at a relatively low temperature and exhibits a dielectric constant varying linearly depending upon temperature variations over a wide use range, a reduced dielectric loss, enhanced resistivity and breakdown voltage, and therefore, is particularly suitable for "temperature-compensating" capacitors of a compact type with large capacity.
    Type: Grant
    Filed: March 2, 1976
    Date of Patent: December 14, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Koji Takahashi, Norishige Yamaguchi, Makoto Hori, Yoshiaki Sugimura
  • Patent number: 3995300
    Abstract: An improved reduction-reoxidation type semiconducting ceramic capacitor and the method for producing the same are disclosed. The main components of the substrate of the capacitor are CaTiO.sub.3, SrTiO.sub.3 and Bi.sub.2 O.sub.3.xTiO.sub.2. Said substrate also contains at least one member selected from the group consisting of manganese, cobalt, nickel, chromium, vanadium, niobium, tantalum, lanthanum and cerium ions in total amounts of 0.025 to 0.4% by weight. The capacitor according to the present invention excels, in the temperature independency of the capacitance and tan .delta., etc.
    Type: Grant
    Filed: August 14, 1974
    Date of Patent: November 30, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Hitoshi Masumura, Shinobu Fujiwara, Hitoshi Tanaka
  • Patent number: 3990733
    Abstract: A hub for winding a magnetic tape thereon comprises a clamp for retaining one end of a magnetic tape. The novel tape clamp comprises a substantially rigid upper web, a resilient lower web and a pair of legs depending from the ends of the upper web and connected to the ends of the lower web. The lower web supplements the resilient force of the legs. As the upper web is not subjected to a stress, the magnetic tape is wound properly on the upper web.
    Type: Grant
    Filed: October 30, 1975
    Date of Patent: November 9, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Haruo Shiba, Kimio Tanaka
  • Patent number: 3988816
    Abstract: An improved roller, consisting in part of a cylindrical permanent magnet, for use in electrostatic record developing devices is disclosed. Of the plurality of magnetic poles formed on the cylindrical surface of the permanent magnet, two of the same polarity are positioned with an auxiliary magnetic pole of opposite polarity located therebetween. The magnetic field intensity of the auxiliary magnetic pole is from about 1/10 to 1/2 that of the other magnetic poles.
    Type: Grant
    Filed: October 23, 1975
    Date of Patent: November 2, 1976
    Assignee: TDK Electronics Company, Limited
    Inventor: Takeo Tada
  • Patent number: 3989042
    Abstract: In an oscillator-exciting system for a ultrasonic liquid nebulizer, a piezo-oscillator element for nebulizing the liquid is electrically connected to a self-exciting oscillating circuit as a constituent element thereof and the circuit is oscillated at that frequency at which the electric impedance of the piezo-oscillator element is inductive. A protective transistor may be connected to a current-bias resistance of the oscillating circuit, which protective transistor may be cut off by a reed switch sensing the exhaustion of the liquid being nebulized and/or by an overcurrent sensing circuit, for ceasing the oscillation in case of liquid exhaustion and/or overcurrent.
    Type: Grant
    Filed: May 29, 1975
    Date of Patent: November 2, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Sadao Mitsui, Minoru Takahashi
  • Patent number: 3977985
    Abstract: A magnetic recording medium is disclosed as comprising powdered magnetic particles upon which there is deposited a ferro-magnetic metal or alloy such as cobalt or a cobalt alloy. Each magnetic particle is a spiculate magnetite and the deposite of cobalt or a cobalt alloy is in the range of 0.5 wt.% to 30 wt.%. The particles are heat treated in either a reducing or inert atmosphere to a sufficient temperature to improve the magnetic characteristics of the particles including their coercive force, Br/.rho. and Bm/.rho.. A layer of the recording medium is disposed on a support layer of polyester to form a magnetic tape.
    Type: Grant
    Filed: December 13, 1974
    Date of Patent: August 31, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Shinji Umeki, Fujio Shibata, Kazuo Takada
  • Patent number: 3958068
    Abstract: A process is disclosed for the production of powdered magnetic material for use in magnetic recording materials. The process comprises the steps of dispersing finely divided particles of a ferromagnetic oxide into an aqueous solution, dissolving therein salts of one or more ferromagnetic metals and a water soluble reducing agent, and then heating the dispersion while stirring to form and deposit a coating of the ferromagnetic metal (or alloy) on the surface of the finely divided particles of ferromagnetic oxide.
    Type: Grant
    Filed: May 30, 1972
    Date of Patent: May 18, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Shinji Umeki, Fujio Shibata
  • Patent number: 3953656
    Abstract: The magnetic recording medium having a magnetic recording layer containing magnetic iron oxide having a cobalt content of 0.5 - 10 wt.% and a ratio of Fe.sup.2.sup.+ /Fe.sup.3.sup.+ of 0.1 - 0.35; wherein the half-value width of the differential curve of the residual magnetization curve is less than 60% of the half-value width of the differential curve of the residual magnetization curve of non-treated magnetic recording layer.
    Type: Grant
    Filed: February 28, 1974
    Date of Patent: April 27, 1976
    Assignee: TDK Electronic Company
    Inventors: Yasumichi Tokuoka, Shinji Umeki, Yuichi Kubota
  • Patent number: 3951873
    Abstract: A ceramic dielectric composition which comprises 22.5-45.2 wt. % SrO, 8.3-20.6 wt. % CaO, 29.3-80.8 wt. % TiO.sub.2, and 0.07-8.3 wt. % MgO as main components.
    Type: Grant
    Filed: August 2, 1974
    Date of Patent: April 20, 1976
    Assignee: TDK Electronics Company, Limited
    Inventors: Nobuaki Kikuchi, Tsunehiko Yoshioka, Kiyoshi Furukawa, Shinobu Fujiwara