Patents Assigned to TDK Electronics
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Patent number: 4046983Abstract: A microwave heating oven has a seal located in the path formed by a gap between the oven body and the oven door for preventing microwave leakage. The seal may comprise several seals, and includes a microwave absorber as one of the seals. The microwave absorber consists of a mixture of a powder of magnetic material and an organic high molecular weight compound. The length of the microwave absorber in the direction of propagation of microwave in the path of microwave leakage is an integral multiple of about 1/2.lambda., wherein .lambda. is a wavelength of the microwave in the microwave absorber. Absorption is improved by setting the absorber in a recess in the wall or door of the oven, or by surrounding the absorber by a metal layer except on the surface thereof parallel to the direction of propagation and facing the gap.Type: GrantFiled: June 14, 1976Date of Patent: September 6, 1977Assignee: TDK Electronics Co., Ltd.Inventors: Ken Ishino, Yasuo Hashimoto, Hiroaki Abe
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Patent number: 4044386Abstract: A tape cassette characterized by a bias changeover slot located adjacent to an accidental erasure preventive slot wherein, when the accidental erasure preventive slot is kept in an inoperative state, a U-shaped snap is secured in such slot so that the base of the U-shaped snap is disposed to cover the opening of the accidental erasure preventive slot, and when the slot is to be kept in an operative state, the U-shaped snap is secured in the slot so that the base of the U-shaped snap is arranged against the wall of the slot located opposite the adjacent bias changeover slot, whereby the accidental erasure preventive slot is uncovered and the snap is secured within the cassette.Type: GrantFiled: April 22, 1976Date of Patent: August 23, 1977Assignee: TDK Electronics Co., Ltd.Inventors: Takateru Satou, Haruo Shiba
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Patent number: 4039417Abstract: A cathodic protection electrode is mounted in an iron bushing by way of a ring of alumina or forsterite, the bushing being mounted in a glass-lined metallic vessel, such as a water heater. The electrode comprises a solid solution of MFe.sub.2 O.sub.4 (wherein M is at least one metal selected from the group consisting of Mn, Ni, Co, Mg, Cu and Zn) of 0.15 to 87.1 mol%, and Fe.sub.3 O.sub.4 of 99.85 to 12.9 mol%.Type: GrantFiled: December 5, 1975Date of Patent: August 2, 1977Assignee: TDK Electronics Company, LimitedInventors: Yoshinori Sasaki, Isao Yokoyama, Motohiko Makino, Syun Awaji, Kaneo Hosoya
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Patent number: 4022716Abstract: Semiconducting ceramics are produced by firing a semiconducting composition of the barium titanate type containing vanadium oxide in the amount of 0.001 to 0.5 wt%. A change in the specific resistance over the range of the temperature at which the positive temperature coefficient characteristic of resistivity (PTCR) is exhibited can be increased by as much as 10.sup.5 times and the specific resistance value at room temperature can be controlled at a desired value. By further adding silicon dioxide to the above composition in the amount of 0.05 to 1.5 wt% the above effects can be enhanced, especially the specific resistance at ambient temperature.Type: GrantFiled: February 17, 1976Date of Patent: May 10, 1977Assignee: TDK Electronics Company, LimitedInventors: Hisayoshi Ueoka, Masatada Yodogawa
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Patent number: 4017320Abstract: A ceramic dielectric composition is provided including 30 to 94% by mol of SrTiO.sub.3, 1 to 22% by mol of Bi.sub.2 O.sub.3 and 5 to 69% by mol of TiO.sub.2, and further including 0.1 to 20% by weight of MgO with respect to the total weight of the above-mentioned three compounds SrTiO.sub.3, Bi.sub.2 O.sub.3 and TiO.sub.2, whereby the ceramic dielectric composition has a high dielectric constant and a low dielectric loss and further the variations of the dielectric constant and the dielectric loss with respect to the variation of an applied voltage, are respectively, very small.Type: GrantFiled: November 19, 1975Date of Patent: April 12, 1977Assignee: TDK Electronics Company, LimitedInventors: Shinobu Fujiwara, Hitoshi Tanaka
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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: 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: 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: 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: 3970562Abstract: An aggregation treatment apparatus for waste water which comprises a susping section for mixing particles of metal, metallic oxide or sintered metallic oxide into feed water such as sewage and drainage, and forming a slurry; an electrically aggregating section for the slurry which is installed separately from the suspending section; and a separating section which is formed integrally with the suspending section, and separating the particles from flocks in the treated water, returning the particles into the suspending section and discharging the treated water from the upper portion. The slurry is pumped from the suspending section to the electrically aggregating section. An electric field is applied to the slurry by means of an electrode tube in the electrically aggregating section, colloidal particles in the feed water is thereby aggregated to the added particles to form flocks and the treated water is then passed to the separating section.Type: GrantFiled: December 30, 1974Date of Patent: July 20, 1976Assignee: Tokyo Denki Kagaku Kogyo Kabushiki Kaisha (TDK Electronics Co., Ltd.)Inventors: Saburo Motozawa, Hiroyoshi Itoga, Hirobumi Wada, Hiromasa Marukawa
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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