Patents Assigned to TDK Electronics
  • Magnetic recording medium
    Patent number: 4420531
    Abstract: A magnetic recording medium is composed of a base and a magnetic coating which comprises a binder and a magnetic powder dispersed therein. The magnetic powder, in turn, contains a nonmagnetic powder having an average particle size of not more than 2 .mu.m and a hardness of at least 6 on Mohs scale, in an amount of 1-20% on the basis of the weight of the magnetic powder, and the binder contains a resin such as polyester resin having a group expressed by the formula --SO.sub.3 M where M is monovalent metal such as Na.
    Type: Grant
    Filed: September 17, 1981
    Date of Patent: December 13, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Fuminori Tokuda
  • Magnetic recording medium having cobalt adsorbed iron oxide layer
    Patent number: 4420537
    Abstract: A magnetic recording medium comprises a substrate coated with a magnetic composition comprising a cobalt adsorbed iron oxide powder with a phosphoric ester type anionic surfactant at a ratio of 2 wt. % or more and a binder at a ratio of said iron oxide powder to said binder of 4 or more.A magnetic recording medium has a coercive force Hc of 950 to 1200 Oe and a residual magnetic flux .phi..sub.r of 0.35 to 0.6 maxwell.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: December 13, 1983
    Assignee: TDK Electronics Co. Ltd.
    Inventors: Masashi Hayama, Hiroto Saguchi, Kenji Hirabayashi
  • Magnetic recording medium
    Patent number: 4420408
    Abstract: A magnetic recording medium comprises a combination of two or more kinds of fine abrasive powders having different true specific gravities in a magnetic layer containing a magnetic powder.
    Type: Grant
    Filed: May 20, 1981
    Date of Patent: December 13, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Norifumi Kajimoto, Kinji Sasaki
  • Magnetic tape cassette
    Patent number: 4420128
    Abstract: A magnetic tape cassette comprising a magnetic tape and two reels for winding said magnetic tape in the casing assembly has a through hole for determining the clamping position formed in the position corresponding to one of reel driving ribs for one reel and another through hole formed in the position between the adjacent ribs for the other reel.
    Type: Grant
    Filed: November 20, 1981
    Date of Patent: December 13, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Masatoshi Okamura, Haruo Shiba
  • Magnetic recording medium and production thereof
    Patent number: 4419406
    Abstract: A magnetic recording medium having a magnetic layer on one surface of a substrate and a back layer on the other surface, which is characterized by that the back layer is that formed by dispering a filler such as carbon black, graphite, SiO.sub.2, TiO.sub.2, Al.sub.2 O.sub.3,Cr.sub.2 O.sub.3, SiC, CeO.sub.2, CaCO.sub.3, zinc oxide, geothite, .alpha.Fe.sub.2 O.sub.3, talc, kaolin, CaSO.sub.4, boron nitride, Teflon powder, graphite fluoride, molybdenum disulfide, zirconia etc. In a binder containing a radiation sensitive curable resin such as acryl-modified vinyl chloride - vinyl acetate - vinyl alcohol copolymer, acryl-modified polyurethane elastomer, acryl-modified polyester resin, etc. and curing it prior to rolling. The obtained back layer is very tough and can reduce the number of dropouts.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: December 6, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Yukihiro Isobe, Kazushi Tanaka, Masaharu Nishimatsu, Osamu Shinoura, Yuichi Kubota
  • Magnetic recording medium
    Patent number: 4418126
    Abstract: A magnetic recording medium comprises a thin metallic magnetic layer on a non-magnetic substrate wherein said thin metallic magnetic layer is made of cobalt, nickel and chromium.
    Type: Grant
    Filed: July 15, 1981
    Date of Patent: November 29, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Toshiaki Izumi, Yasuta Taketomi, Takayoshi Kobuke
  • Amorphous magnetic alloy material
    Patent number: 4416709
    Abstract: The present invention relates to an amorphous magnetic alloy material suited for use as a core material of a magnetic head.When the magnetic head is subjected to a slide contact with a magnetic tape over a long period of time, a film of oxide and the like is formed on the surface of an amorphous magnetic alloy material due to chemically corrosive media frequently contained in the magnetic coating layer of the magnetic tape or due to carbon dioxide, water and the like contained in the air.The amorphous magnetic alloy material of the present invention is highly corrosion resistant due to the combination of chromium and platinum family element(s), and, the inconveniences in a magnetic head, due to chemical wear, can be prevented even where the magnetic head is operated or stored in a considerably severe condition.
    Type: Grant
    Filed: September 10, 1981
    Date of Patent: November 22, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Kazuo Ohya, Hiroki Fujishima, Norio Ishijima, Hiroyoshi Itoga, Yasuhiko Kominami
  • Magnetic recording medium
    Patent number: 4416947
    Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid ester composed of a higher fatty having a melting point of 44.degree. C. or more and a monohydric alcohol containing 3 to 8 carbon atoms into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty acid ester is selected from butyl myristate, butyl palmitate, propyl stearate, butyl stearate and the like.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: November 22, 1983
    Assignee: TDK Electronics Co. Ltd.
    Inventors: Kuniichi Yoda, Takehisa Ohkawa
  • Magnetic recording medium
    Patent number: 4416948
    Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid glycerine ester composed of a higher fatty acid having a melting point of 44.degree. C. or more and glycerine into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty glycerine ester is selected from monoglyceride of myristic acid, monoglyceride of palmitic acid, monoglyceride of stearic acid, monoglyceride of oleic acid and the like.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: November 22, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Takehisa Ohkawa, Kuniichi Yoda
  • Magnetic recording medium
    Patent number: 4416943
    Abstract: A magnetic recording medium comprises cobalt as a main component and at least one of zinc, rhodium and iridium as an additional component of an alloy of a magnetic layer.
    Type: Grant
    Filed: July 23, 1981
    Date of Patent: November 22, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Seitoku Saito
  • Process of making magnetic recording medium
    Patent number: 4415630
    Abstract: A magnetic recording medium comprises a substrate and a magnetic recording layer formed thereon and which is made of a magnetic coating material consisting essentially of a magnetic powder dispersed in a binder, the coating material containing a titanium coupling agent. The magnetic powder is coated with the coupling agent or is mixed with the agent and then dispersed in the binder. The binder is prepared by mixing and plasticizing a radiation-sensitive modified resin with a radiation-sensitive soft resin and subjecting the mixture to radiation cross-linking and polymerization. Process for producing the medium comprises coating the magnetic particles with the titanium coupling agent, blending the coated particles with the binder to form a magnetic coating material, and then applying the material to the substrate.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: November 15, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Yuichi Kubota, Masaharu Nishimatsu, Kazushi Tanaka
  • Magnetic recording medium
    Patent number: 4414288
    Abstract: A magnetic recording medium which comprises a substrate coated with a magnetic paint which has a magnetic powder dispersed in a binder comprising a vinyl chloride - vinyl acetate copolymer containing at least 10% of polyvinyl alcohol, a urethane resin and a polyester resin.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: November 8, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Hiroshi Kawahara, Hitoshi Azegami, Eiji Horigome
  • High density magnetic recording medium
    Patent number: 4414289
    Abstract: A magnetic recording medium comprised of a nonmagnetic base and a magnetic coating layer thereon, said magnetic coating layer comprises ferromagnetic particles dispersed in a binder vehicle, characterized in that said magnetic coating layer contains a glyceride and a sorbitan ester of fatty acid.
    Type: Grant
    Filed: March 18, 1982
    Date of Patent: November 8, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Fujio Shibata, Kenji Hirabayashi, Chihoto Mikura
  • Magnetic recording medium
    Patent number: 4411957
    Abstract: A magnetic recording medium, consisting of a base coated with a magnetic coating material, uses as a binder a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol, in which magnetic particles are dispersed. The binder may contain an isocyanate compound as a crosslinking agent for added particle durability.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: October 25, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Fukunori Tokuda, Yutaka Nakashima
  • Light recording medium
    Patent number: 4412231
    Abstract: A light recording medium which has a substrate and a recording layer provided thereon and effects recording of information by selective removal or deformation of the recording layer by laser light, which is characterized by that said recording layer contains an organic dye as a light absorber, said dye is a mixed dye obtained by mixing a plurality of dyes having different light absorbing wavelengths from each other and the recording layer has a light absorptivity of 80% or more at all the wavelengths in the range of 400-900 nm in wavelength.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: October 25, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Kenryo Namba, Akihiko Kuroiwa, Shiro Nakagawa
  • Magnetic recording medium
    Patent number: 4410590
    Abstract: A magnetic recording medium comprises a lower magnetic layer containing a magnetic powder having a coercive force of 700 Oe or higher dispersed in an organic binder which is coated on a non-magnetic substrate and an upper magnetic layer containing a magnetic powder having a coercive force higher than the coercive force of said lower magnetic la
    Type: Grant
    Filed: October 14, 1981
    Date of Patent: October 18, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Hiroshi Kawahara, Hitoshi Azegami, Eiji Horigome
  • Liquid nebulizer
    Patent number: 4410139
    Abstract: A liquid nebulizer comprising a nebulizing container for a liquid, an outlet duct, and a transducer at the bottom of the container. A partition surrounding the liquid projection produced by the transducer is included, having its upper edge above the liquid surface, so that large spray particles or drops from the outlet duct fall outside the partition.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: October 18, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Kyoichi Nishikawa, Sadao Mitsui
  • Process for preparing magnetic recording medium
    Patent number: 4410406
    Abstract: A magnetic recording medium is prepared by forming a thin magnetic layer having the formulation(Co.sub.100-x Ni.sub.x).sub.100-y P.sub.ywherein x is in a range of 0 to 35 wt. % and y is in a range of more than 0 wt. % to 6 wt. % on a non-magnetic substrate by a sputtering method.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: October 18, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Osamu Kohmoto, Takahiro Yamamoto
  • Magnetic recording medium
    Patent number: 4409300
    Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a sorbitan fatty acid ester into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such sorbitan fatty acid ester is selected from sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate and the like.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: October 11, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Takehisa Ohkawa, Kuniichi Yoda
  • Noise filter with socket attached thereto
    Patent number: 4408171
    Abstract: A noise filter with a socket attached thereto including a case made of metallic material mounting a pair of pierce type (feed through) capacitors and a power input socket having a pair of power input contacts and a grounding contact, a choke coil having a pair of coil windings wound thereabout and a capacitor interposed between said pair of coil windings mounted inside said case, said pierce type capacitors including inner piercing (feed through) terminals and outer terminals, said power input contacts and the piercing terminals of said pierce type capacitors being connected to one another via said coil windings, and said grounding contact and the outer terminals of said pierce type capacitors being electrically connected to the case.
    Type: Grant
    Filed: March 13, 1981
    Date of Patent: October 4, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Tadaharu Akino, Akira Nakamura, Hiroyuki Uemura