Patents by Inventor Toshinori Watanabe
Toshinori Watanabe 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).
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Patent number: 6122151Abstract: A spin-valve magnetoresistive element includes a hard bias layer formed on a pinned magnetic layer with a non-magnetic layer therebetween, and thus the magnetic field from the hard bias layer is efficiently applied into a free magnetic layer. Also, the pinned magnetic layer is not influenced by the hard bias layer because of the interposition of the non-magnetic layer. Accordingly, the pinned magnetic layer and the free magnetic layer are properly put into single magnetic domain states, and thus, Barkhausen noise is reduced and satisfactory micro-track-asymmetry can be obtained.Type: GrantFiled: August 18, 1999Date of Patent: September 19, 2000Assignee: Alps Electric Co., Ltd.Inventors: Masamichi Saito, Toshinori Watanabe
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Patent number: 6112402Abstract: A magnetoresistive sensor fabricated by creating first antiferromagnetic layers on the upper surfaces of a lower-gap layer the antiferromagnetic layer having first and second exposed portions separated by a track width formed by the upper surface of the lower-gap layer. Then, a free magnetic layer, a nonmagnetic electrically conductive layer, a pinned magnetic layer and a second antiferromagnetic layer are stacked on the first antiferromagnetic layers and a portion on the track width one after another. Since the free magnetic layer is created after the first antiferromagnetic layer, the free magnetic layer and the first antiferromagnetic layer are adhered to each other with a high degree of reliability. When the direction of magnetization in the free magnetic layer is changed by an external magnetic field, the electrical resistance of the magnetoresistive sensor also changes. The change in electrical resistance is, in turn, used for detecting the external magnetic field.Type: GrantFiled: August 22, 1997Date of Patent: September 5, 2000Assignee: Alps Electric Co., Ltd.Inventors: Masamichi Saito, Toshinori Watanabe, Kiyoshi Sato, Toshihiro Kuriyama
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Patent number: 6042897Abstract: The present invention provides a combination read/write thin film magnetic head wherein the width of a gap layer is the same as the track width Tw, and a shielding magnetic layer of a soft magnetic material is formed on both sides of the gap layer so that blots of a record magnetic field out of the track width Tw can be absorbed by the shielding magnetic layer, and write fringing can be prevented. Particularly, when the saturation magnetic flux density and thickness of the shielding magnetic layer are appropriately adjusted, it is possible to suppress write fringing, and at the same time maintain reproduced output at a high level.Type: GrantFiled: December 14, 1998Date of Patent: March 28, 2000Assignee: Alps Electric Co., Ltd.Inventors: Toshinori Watanabe, Kiyoshi Sato
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Patent number: 6018443Abstract: Hard films consisting of a permanent magnet material are formed on both the sides of shield layers to orient the magnetization of the shield layers in an easy axis of magnetization (X direction), thereby putting the shield layers into a single domain state. Therefore, anisotropic dispersion does not occur in the shield layers, the hysteresis of a thin film magnetic head is eliminated as a whole, a coercive force becomes very small, and the magnetic reversibilities of the shield layers in a direction perpendicular to the drawing paper surface becomes preferable. For this reason, the reliability of a reproduced output signal from a magnetoresistance element layer is improved.Type: GrantFiled: April 30, 1998Date of Patent: January 25, 2000Assignee: Alps Electric Co., Ltd.Inventors: Toshinori Watanabe, Masamichi Saito
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Patent number: 5992004Abstract: A longitudinal bias layer and an electrode layer are formed on a non-magnetic material layer. The longitudinal bias layer and the electrode layer are partially removed by an etching technique so that a narrow gap defining the track width Tw is formed in the longitudinal bias layer and the electrode layer. Furthermore, a three-layer film consisting of, from bottom to top, a magnetoresistance effect layer, a non-magnetic layer, and a transverse bias layer, or otherwise a spin valve film consisting of a free magnetic layer, a non-magnetic layer, a fixed magnetic layer and a bias layer is formed on the above structure. The three-layer film or the spin valve film is then partially removed by an etching technique so that the three-layer film or the spin valve film remains only in the above-described narrow gap formed in the longitudinal bias layer and the electrode layer.Type: GrantFiled: April 4, 1997Date of Patent: November 30, 1999Assignee: Alps Electric Co., Ltd.Inventors: Kiyoshi Sato, Yoshihiko Kakihara, Masamichi Saito, Toshihiro Kuriyama, Toshinori Watanabe
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Patent number: 5972420Abstract: A magnetoresistive sensor fabricated by creating first antiferromagnetic layers on the upper surfaces of a lower-gap layer, the antiferromagnetic layer having first and second exposed portions separated by a track width formed by the upper surface of the lower-gap layer. Then, a free magnetic layer, a nonmagnetic electrically conductive layer, a pinned magnetic layer and a second antiferromagnetic layer are stacked on the first antiferromagnetic layers and a portion on the track width one after another. Since the free magnetic layer is created after the first antiferromagnetic layer, the free magnetic layer and the first antiferromagnetic layer are adhered to each other with a high degree of reliability. When the direction of magnetization in the free magnetic layer is changed by an external magnetic field, the electrical resistance of the magnetoresistive sensor also changes. The change in electrical resistance is, in turn, used for detecting the external magnetic field.Type: GrantFiled: August 22, 1997Date of Patent: October 26, 1999Assignee: Alps Electric Co., LtdInventors: Masamichi Saito, Toshinori Watanabe, Kiyoshi Sato, Toshihiro Kuriyama
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Patent number: 5961876Abstract: An organopolysiloxane composition for viscous fluid couplings permits little torque variation even when used at a high temperature for an extended period of time. The organopolysiloxane composition comprises an organopolysiloxane liquid with a viscosity of 100 to 1,000,000 sq. mm/s and a platinum compound in an amount such that the amount of platinum metal relative to the liquid is 0.1 to 1,000 ppm. The organopolysiloxane liquid is typically a trimethylsiloxy-endblocked polydimethylsiloxane.Type: GrantFiled: March 31, 1998Date of Patent: October 5, 1999Assignee: Dow Corning Toray Silicone Co., Ltd.Inventors: Shoji Akamatsu, Mari Tateishi, Toshinori Watanabe
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Patent number: 5959813Abstract: The present invention provides a combination read/write thin film magnetic head wherein the width of a gap layer is the same as the track width Tw, and a shielding magnetic layer of a soft magnetic material is formed on both sides of the gap layer so that blots of a record magnetic field out of the track width Tw can be absorbed by the shielding magnetic layer, and write fringing can be prevented. Particularly, when the saturation magnetic flux density and thickness of the shielding magnetic layer are appropriately adjusted, it is possible to suppress write fringing, and at the same time maintain reproduced output at a high level.Type: GrantFiled: November 17, 1997Date of Patent: September 28, 1999Assignee: Alps Electric Co., Ltd.Inventors: Toshinori Watanabe, Kiyoshi Sato
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Patent number: 5923503Abstract: A longitudinal bias layer and an electrode layer are formed on a non-magnetic material layer. The longitudinal bias layer and the electrode layer are partially removed by an etching technique so that a narrow gap defining the track width Tw is formed in the longitudinal bias layer and the electrode layer. Furthermore, a three-layer film consisting of, from bottom to top, a magnetoresistance effect layer, a non-magnetic layer, and a transverse bias layer, or otherwise a spin valve film consisting of a free magnetic layer, a non-magnetic layer, a fixed magnetic layer and a bias layer is formed on the above structure. The three-layer film or the spin valve film is then partially removed by an etching technique so that the three-layer film or the spin valve film remains only in the above-described narrow gap formed in the longitudinal bias layer and the electrode layer.Type: GrantFiled: March 14, 1996Date of Patent: July 13, 1999Assignee: Alps Electric Co., Ltd.Inventors: Kiyoshi Sato, Yoshihiko Kakihara, Masamichi Saito, Toshihiro Kuriyama, Toshinori Watanabe
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Patent number: 5869963Abstract: PtMn films are used as antiferromagnetic layers of a dual spin-valve type magnetoresistive sensor. An exchange anisotropic magnetic field is achieved regardless of whether the PtMn film is formed over or under the pinned magnetic layer. Also, an effective exchange anisotropic magnetic field is produced even with heat treatment at a relatively low temperature. Alternatively, a PtMn film is used as an antiferromagnetic layer of a spin-valve film laminate. The use of a PtMn film enables a sufficient exchange anisotropic magnetic field to be produced even with a relatively low heat treatment temperature and a relatively small film thickness. Therefore, the number of total layers of the spin-valve film laminate can be increased to increase a magnetoresistance ratio, and a total thickness of the spin-valve film laminate can be made relatively small.Type: GrantFiled: September 3, 1997Date of Patent: February 9, 1999Assignee: Alps Electric Co., Ltd.Inventors: Masamichi Saito, Toshinori Watanabe
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Patent number: 5788990Abstract: There is disclosed a water-repellent powder which is prepared by (A) coating the surface of a deliquescent powder with a curable silicone-based formation agent; and (B) curing said formation agent to provide a silicone-based cured film on said powder. Preferably, the deliquescent powder is selected from the group consisting of ammonium acetate, potassium acetate and sodium acetate.Type: GrantFiled: December 19, 1995Date of Patent: August 4, 1998Assignee: Dow Corning Toray Silicone Co., Ltd.Inventors: Shoji Akamatsu, Toshinori Watanabe
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Patent number: 5784225Abstract: The present invention provides a magnetoresistive head wherein: a magnetoresistive film is created in a read-track region at the center of the magnetoresistive head; an antiferromagnetic film and a ferromagnetic film experiencing an exchange coupling magnetic field due to direct contact with the antiferromagnetic film are created on each end of the magnetoresistive film outside the read-track region in such a way that the ferromagnetic film is located beside the magnetoresistive film; a nonmagnetic intermediate film is created between the magnetoresistive film and the ferromagnetic film for preventing ferromagnetic coupling from being developed on a contact boundary surface between the magnetoresistive film and the ferromagnetic film and for making crystal orientations of the antiferromagnetic film and the ferromagnetic film uniform; and bias magnetization is applied to the magnetoresistive film by exchange coupling between the antiferromagnetic film and the ferromagnetic film.Type: GrantFiled: February 10, 1997Date of Patent: July 21, 1998Assignee: ALPS Electric Co., Ltd.Inventors: Masamichi Saito, Toshinori Watanabe, Toshihiro Kuriyama
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Patent number: 5768067Abstract: A magnetoresistive head including a magnetoresistive film formed in a read-track region, and antiferromagnetic and ferromagnetic films are formed on each end of the magnetoresistive film outside of the read-track region such that bias magnetization is applied to the magnetoresistive film by exchange coupling between the antiferromagnetic film and the ferromagnetic film. A nonmagnetic intermediate film is formed between the ferromagnetic film and the magnetoresistive film for preventing ferromagnetic coupling on a contact boundary surface between the ferromagnetic film and the magnetoresistive film. In accordance with another aspect, a magnetoresistive head includes an antiferromagnetic layer formed from an X--Mn alloy, where X is an element selected from the group consisting of Pt, Rh, Ru, Tr, and Pd. An interdiffusion layer is formed between the antiferromagnetic film and a ferromagnetic layer or a pinned magnetic layer by heat treatment.Type: GrantFiled: September 18, 1996Date of Patent: June 16, 1998Assignee: Alps Electric Co., Ltd.Inventors: Masamichi Saito, Toshinori Watanabe, Toshihiro Kuriyama
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Patent number: 5708067Abstract: There is disclosed a heat resistant organopolysiloxane composition comprising:(A) 100 parts by weight of an organopolysiloxane having a viscosity of 100 to 1,000,000 centistokes at 25.degree. C.;(B) 0.001 to 10 parts by weight of a reaction product of an alkali metal silanolate compound with cerium chloride or a cerium carboxylate; and(C) a diorganopolysiloxane having silicon-bonded hydrogen groups only at its molecular chain terminals, component (C) being present in a quantity sufficient to provide 1 to 10,000 parts per million of silicon-bonded hydrogen based on the total weight of said composition.Type: GrantFiled: December 26, 1996Date of Patent: January 13, 1998Assignee: Dow Corning Toray Silicone Co., Ltd.Inventors: Shoji Akamatsu, Haruhiko Furukawa, Toshinori Watanabe
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Patent number: 5694275Abstract: In a magnetoresistive magnetic head having a laminate composed of a magnetoresistive (MR) layer showing the magnetoresistive effect, a SHUNT layer as a non-magnetic layer and a soft adjacent layer (SAL) for applying a transverse bias magnetic field to the MR layer, the MR layer and the SAL are made of the same Ni.sub.81 Fe.sub.19 magnetic film. Since the SAL is magnetically saturated in the same direction as the direction of leakage flux of a recording medium (y direction), permeability thereof in the y direction decreases, and the MR effect function therein can be restricted. Although the MR layer and the SAL have the same specific resistance .rho., a sufficient detection current can be made to flow through the MR layer and a high-precision magnetic detection output can be obtained by making the MR layer thicker than the SAL.Type: GrantFiled: July 28, 1995Date of Patent: December 2, 1997Assignee: Alps Electric Co., Ltd.Inventors: Toshinori Watanabe, Toshihiro Kuriyama
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Patent number: 5675460Abstract: A magnetic head of the type which includes a pair of magnetic cores joined to each other through the intermediation of gap layers, with Fe-type metal magnetic thin films being arranged between the gap layers and the magnetic cores, the metal magnetic thin films being formed of a magnetic material which can be represented by the composition formula: Fe-X-M-C, with the concentration of the element X being higher in the surface portions of the metal magnetic thin films than in the other portions thereof. In the above composition formula, X represents one or two or more of the following elements: Al, Si, Cr, Mo and W, and M represents one or two or more of the following elements: Ti, V, Zr, Nb, Hf and Ta. Due to this construction, the metal magnetic thin films can contain the element X at high concentration in the surface portions thereof, which element combines with oxygen in the surface portions to generate an oxide coating, thereby providing a magnetic head excelling in corrosion resistance.Type: GrantFiled: October 10, 1995Date of Patent: October 7, 1997Assignee: Alps Electric Co., Ltd.Inventors: Toshinori Watanabe, Fumihito Koike, Masamichi Saito
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Patent number: 5661202Abstract: There is disclosed a heat-resistant agent which exhibits good solubility in various organopolysiloxanes and which confers superior heat-resistance thereto, said heat-resistant agent having the formula ##STR1## wherein R.sup.2 is independently selected from hydrocarbon or halogenated hydrocarbon groups having 1 to 10 carbon atoms, R.sup.1 is independently selected from R.sup.2 or a eugenol residue, m is an integer having an average value of 5 to 500 and n is an integer having an average value of 0 to 500, with the proviso that there is at least one eugenol residue in the molecule. Also disclosed is a composition comprising an organopolysiloxane and the above described heat-resistant agent.Type: GrantFiled: October 28, 1996Date of Patent: August 26, 1997Assignee: Dow Corning Toray Silicone Co., Ltd.Inventors: Shoji Akamatsu, Haruhiko Furukawa, Toshinori Watanabe
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Patent number: 4942536Abstract: In a case where an electronic circuit having the same function is to be realized by a different device, it is indispensable to prepare circuit diagrams conforming to devices and to utilize them for the job of circuit simulation or chip layout. When the circuit diagrams are to be automatically translated for the above purpose, translation rules become different depending upon the connective relations of an element to be translated, with other elements in the circuit or upon a function performed by the element. The present invention puts the rules into knowledge from the viewpoint of knowledge engineering and utilizes it thereby to realize the intended purpose.Type: GrantFiled: April 21, 1986Date of Patent: July 17, 1990Assignees: Hitachi, Ltd., Hitachi Microcomputer Engineering Ltd.Inventors: Toshinori Watanabe, Fumihiko Mori, Tamotsu Nishiyama, Makoto Furihata, Yasuo Kominami, Noboru Horie
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Patent number: 4890227Abstract: An autonomous resource management method for improving performance of a system in which plurality of process units compete for resources. Previously determined allocation policies are stored in memory along with system status data, control data and an evalution of the effectiveness of the allocation policy. During the operation of the system, the status is detected and an allocation policy is retrieved from memory based on the detected status. The allocation policy is then modified and sent to the scheduler. The effect of modifying the allocation policy is detected and an evaluation of the modified allocation policy is stored in memory. Inferior allocation policies are deleted from memory.Type: GrantFiled: August 25, 1987Date of Patent: December 26, 1989Assignee: Hitachi, Ltd.Inventors: Toshinori Watanabe, Koichi Haruna, Hiroshi Motoyama, Toru Nishigaki, Koji Sasaki, Teruo Yakata, Yoshitaka Watanabe
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Patent number: 4803636Abstract: In order to translate an original circuit consisting of a set of first devices into a target circuit which consists of a set of second devices different from the first devices, and which has the same functions as the original circuit, provision is made of memory means for storing translation rules in the first devices, translation rules in the second devices, and translation rules between the first devices and the second devices, and translation means which successively refers to these translation rules and translates the original circuit data into the target circuit data via steps that translate the original circuit data into a plurality of intermediate data.Type: GrantFiled: September 25, 1986Date of Patent: February 7, 1989Assignees: Hitachi Ltd., Hitachi Micro Computer Eng. Ltd.Inventors: Tamotsu Nishiyama, Toshinori Watanabe, Noboru Horie, Makoto Furihata, Yasuo Kominami, Fumihiko Mori