Patents Assigned to TDK Electronic Company
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Patent number: 4014707Abstract: 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: GrantFiled: July 8, 1975Date of Patent: March 29, 1977Assignee: TDK Electronics Company, LimitedInventors: Hitoshi Tanaka, Hitoshi Masumura, Shinobu Fujiwara
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Patent number: 4010310Abstract: 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: GrantFiled: July 21, 1975Date of Patent: March 1, 1977Assignee: TDK Electronics Company, LimitedInventors: Yuichi Kubota, Shinji Umeki, Yasumichi Tokuoka
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Patent number: 4008432Abstract: 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: GrantFiled: December 26, 1973Date of Patent: February 15, 1977Assignee: TDK Electronics Company, LimitedInventors: Takao Sugisaki, Tatsushiro Ochiai, Kyoichi Nishikawa, Minoru Higurashi
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Patent number: 4006408Abstract: 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: GrantFiled: February 7, 1973Date of Patent: February 1, 1977Assignee: TDK Electronics Company, LimitedInventors: Takao Sugisaki, Tatsushiro Ochiai, Kyoichi Nishikawa, Minoru Higurashi
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Patent number: 4003840Abstract: 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: GrantFiled: May 12, 1975Date of Patent: January 18, 1977Assignee: TDK Electronics Company, LimitedInventors: Ken Ishino, Takashi Watanabe, Yasuo Hashimoto
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Patent number: 4000516Abstract: 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: GrantFiled: January 30, 1975Date of Patent: December 28, 1976Assignee: TDK Electronics Company, LimitedInventors: Kazuo Watanabe, Tetsuya Fuchikuchi
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Patent number: 3997479Abstract: 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: GrantFiled: July 30, 1974Date of Patent: December 14, 1976Assignee: TDK Electronics Company, LimitedInventors: Nobuei Shimojo, Ichihito Minesaki
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Patent number: 3997457Abstract: 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: GrantFiled: March 2, 1976Date of Patent: December 14, 1976Assignee: TDK Electronics Company, LimitedInventors: Koji Takahashi, Norishige Yamaguchi, Makoto Hori, Yoshiaki Sugimura
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Patent number: 3995300Abstract: 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: GrantFiled: August 14, 1974Date of Patent: November 30, 1976Assignee: TDK Electronics Company, LimitedInventors: Hitoshi Masumura, Shinobu Fujiwara, Hitoshi Tanaka
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Patent number: 3990733Abstract: 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: GrantFiled: October 30, 1975Date of Patent: November 9, 1976Assignee: TDK Electronics Company, LimitedInventors: Haruo Shiba, Kimio Tanaka
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Patent number: 3988816Abstract: 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: GrantFiled: October 23, 1975Date of Patent: November 2, 1976Assignee: TDK Electronics Company, LimitedInventor: Takeo Tada
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Patent number: 3989042Abstract: 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: GrantFiled: May 29, 1975Date of Patent: November 2, 1976Assignee: TDK Electronics Company, LimitedInventors: Sadao Mitsui, Minoru Takahashi
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Patent number: 3977985Abstract: 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: GrantFiled: December 13, 1974Date of Patent: August 31, 1976Assignee: TDK Electronics Company, LimitedInventors: Shinji Umeki, Fujio Shibata, Kazuo Takada
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Patent number: 3958068Abstract: 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: GrantFiled: May 30, 1972Date of Patent: May 18, 1976Assignee: TDK Electronics Company, LimitedInventors: Shinji Umeki, Fujio Shibata
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Patent number: 3953656Abstract: 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: GrantFiled: February 28, 1974Date of Patent: April 27, 1976Assignee: TDK Electronic CompanyInventors: Yasumichi Tokuoka, Shinji Umeki, Yuichi Kubota
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Patent number: 3951873Abstract: 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: GrantFiled: August 2, 1974Date of Patent: April 20, 1976Assignee: TDK Electronics Company, LimitedInventors: Nobuaki Kikuchi, Tsunehiko Yoshioka, Kiyoshi Furukawa, Shinobu Fujiwara