Patents by Inventor Yutaka Soda
Yutaka Soda 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: 6246545Abstract: To provide a head slider capable of enhancing the electromagnetic transductional characteristic of a magnetic head and a magnetic disk unit provided with the head slider, the head slider provided with a rail on each side and floated over a magnetic disk by air flow, the head slider for reading or recording information from/in the magnetic disk mounted on the rail on one side of the head slider, and the rails formed asymmetrically so that the floated quantity of the rail on the side on which the head slider is mounted is lower than the floated quantity of the rail on the side on which the head slider is not mounted.Type: GrantFiled: February 19, 1998Date of Patent: June 12, 2001Assignee: Sony CorporationInventors: Hiroaki Ono, Norio Saito, Yutaka Soda
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Patent number: 6130810Abstract: A magnetic reluctance effect magnetic head in which a forward side electrode is stacked on at least the surface of a magnetic reluctance effect element facing a magnetic recording medium, and in which an upper magnetic pole is stacked on the forward side electrode for facing the magnetic reluctance effect element. A connecting length L1 between the magnetic reluctance effect element and the forward side electrode is shorter than a facing length L2 over which the upper magnetic pole and the magnetic reluctance effect element face each other via a magnetic gap G. The upper magnetic pole and the magnetic reluctance effect element have an area in which the upper magnetic pole and the magnetic reluctance effect element face each other over a distance g2 larger than a magnetic gap length g1 of the magnetic gap G. The upper magnetic pole may be formed to be progressively spaced apart from the magnetic reluctance effect element by being angled 30.degree.Type: GrantFiled: April 22, 1994Date of Patent: October 10, 2000Assignee: Sony CorporationInventors: Takuji Shibata, Norio Saito, Yutaka Soda
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Patent number: 5872691Abstract: A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current.Type: GrantFiled: December 9, 1997Date of Patent: February 16, 1999Assignee: Sony CorporationInventors: Munekatsu Fukuyama, Yasuo Sasaki, Yutaka Soda, Koji Fukumoto, Tetsuo Sekiya
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Patent number: 5825594Abstract: A magneto-resistance effect-type magnetic head according to the present invention can generate a high reproduction output by increasing a quantity of magnetic flux passing across an effective magneto-sensitive zone of a magneto-resistance effect element, while maintaining its inherent functions as a means for preventing unnecessary magnetic flux from entering the MR element or as a recording pole. The magneto-resistance effect-type magnetic head for reproducing signals from a magnetic recording medium, includes a magneto-resistance effect element, upper and lower magnetic layers between which the magneto-resistance effect element is interposed, and a low-permeability magnetic layer provided on at least one of surfaces of the upper and lower magnetic layers which surfaces are opposed to the magneto-resistance effect element, the low-permeability magnetic layer having a magnetic permeability not more than half of a magnetic permeability of the upper or lower magnetic layer.Type: GrantFiled: November 6, 1996Date of Patent: October 20, 1998Assignee: Sony CorporationInventors: Koji Fukumoto, Yutaka Soda, Norio Saito, Takuji Shibata
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Patent number: 5822159Abstract: A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current.Type: GrantFiled: April 4, 1997Date of Patent: October 13, 1998Assignee: Sony CorporationInventors: Munekatsu Fukuyama, Yasuo Sasaki, Yutaka Soda, Koji Fukumoto, Tetsuo Sekiya
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Patent number: 5786965Abstract: A magneto-resistance effect magnetic head in which the MR effects of the two MR thin films of a MR device are balanced for suppressing Barkhausen noise and assuring a stabilized output. Between a lower-layer magnetic shield core and an upper layer magnetic shield core is arranged an MR device, made up of two MR thin films such that a distance d.sub.1 between the lower-layer magnetic shield core and the MR thin film is smaller than a distance d.sub.2 between the upper-layer magnetic shield core and the MR thin film. A film thickness t.sub.1 of the MR thin film towards the lower-layer magnetic shield core is set so as to be thinner than a film thickness t.sub.2 of the MR thin film towards the upper-layer magnetic shield core. Preferably, the relation 0.5<t.sub.1 /t.sub.2 holds. Also, a resistivity .rho..sub.1 of the MR thin film closer to the lower layer magnetic shield core may be larger than a resistivity .rho..sub.2 of the MR thin film. Preferably, the relation .rho..sub.1 /.rho..sub.2 >3 holds.Type: GrantFiled: March 31, 1997Date of Patent: July 28, 1998Assignee: Sony CorporationInventors: Norio Saito, Kenichi Baba, Yutaka Soda
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Patent number: 5689225Abstract: A method for driving a magneto-resistive effect element in which a bias magnetic field is applied by a bias conductor fed with a bias current to a magneto-resistive effect element whose resistivity is changed with an impressed magnetic field, wherein the improvement comprises supplying to said bias conductor a pulsed initial current having a pulse crest value higher than the bias current value prior to supplying said bias current. The MR head can be operated with MR characteristics with stable output and with highly sensitive MR characteristics.Type: GrantFiled: February 27, 1996Date of Patent: November 18, 1997Assignee: Sony CorporationInventors: Yutaka Soda, Munekatsu Fukuyama, Jin Sato, Kiyoshi Ota
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Patent number: 5661620Abstract: A magneto-resistance effect magnetic head in which the MR effects of the two MR thin films of a MR device are balanced for suppressing Barkhausen noise and assuring a stabilized output. Between a lower-layer magnetic shield core and an upper layer magnetic shield core is arranged an MR device, made up of two MR thin films such that a distance d.sub.1 between the lower-layer magnetic shield core and the MR thin film is smaller than a distance d.sub.2 between the upper-layer magnetic shield core and the MR thin film. A film thickness t.sub.1 of the MR thin film towards the lower-layer magnetic shield core is set so as to be thinner than a film thickness t.sub.2 of the MR thin film towards the upper-layer magnetic shield core. Preferably, the relation 0.5<t.sub.1 /t.sub.2 holds. Also, a resistivity .rho..sub.1 of the MR thin film closer to the lower layer magnetic shield core may be larger than a resistivity .rho..sub.2 of the MR thin film. Preferably, the relation .rho..sub.1 /.rho..sub.2 >3 holds.Type: GrantFiled: June 7, 1995Date of Patent: August 26, 1997Assignee: Sony CorporationInventors: Norio Saito, Kenichi Baba, Yutaka Soda
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Patent number: 5535077Abstract: A magnetoresistive effect magnetic head having a film comprising laminated first and second magnetoresistive elements with an electrically conductive intermediate film therebetween, and a pair of shield members positioned on both sides of the laminated film. Even if a magnetic gap of the head is reduced in length, the magnetic equilibrium of the first and second magneto-resistive elements may be stabilized by allowing over 10% of the current through the film to go through the intermediate film, thereby enabling a high playback output to be produced when reproducing signals on a magnetic medium.Type: GrantFiled: December 15, 1994Date of Patent: July 9, 1996Assignee: Sony CorporationInventors: Norio Saito, Yutaka Soda
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Patent number: 5313342Abstract: An analog/digital compatible reproducing system is disclosed, particularly a stationary head system using a digital recorded magnetic tape having a plurality of n, digital data recorded tracks. An analog recorded magnetic tape has a first analog recorded track and a second analog recorded track between which a guardband of a certain width is provided. Signals are reproduced from the digital recorded magnetic tape by driving n reproducing magnetic head elements respectively corresponding to the n digital data recorded tracks. The analog recorded magnetic tape is reproduced by driving a plurality of m reproducing magnetic head elements of said n reproducing, magnetic head elements, corresponding to the first and second recorded tracks so that common outputs can be produced from the m reproducing magnetic head elements. There is also disclosed a tape cassette used in such system.Type: GrantFiled: November 20, 1992Date of Patent: May 17, 1994Assignee: Sony CorporationInventors: Yutaka Soda, Keisuke Fujiwara, Hiroaki Yada, Satoru Seko, Munekatsu Fukuyama, Tetsuo Sekiya
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Patent number: 5260836Abstract: Apparatus is provided for reproducing either M channels of digital audio signals recorded in longitudinal tracks on a record medium or an analog audio signal recorded in one or two stereo tracks. M heads are used to reproduce the M channels of digital audio signals and N of those heads (N.ltoreq.M) are used to reproduce the analog audio signal. The reproduced digital or analog audio signals are multiplexed and digitized. When digital audio signals are reproduced, the digitized multiplexed signals are digitally processed and then converted to analog form. When analog audio signals are reproduced, the digitized multiplexed signals are summed such that signals reproduced by the N heads are combined to form a digital representation of the recorded analog audio signal. The summed signals then are converted to analog form to recover the original analog audio signal.Type: GrantFiled: November 28, 1990Date of Patent: November 9, 1993Assignee: Sony CorporationInventors: Horoaki Yada, Yutaka Soda, Keisuke Fujiwara, Satoru Seko, Munekatsu Fukuyama, Tetsuo Sekiya
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Patent number: 5065390Abstract: A magneto-optical playback head which comprises a first optical waveguide facing to a light source at one end thereof and facing to a magneto-optical recording medium at other end thereof for guiding an incident light beam to the magneto-optical recording medium, a second optical waveguide for guiding a light beam reflected from the magneto-optical recording medium to a photodetector provided at one end thereof, a polarizer provided for the first optical waveguide, and an analyzer provided for the second optical waveguide, the polarizer and the analyzer being formed by providing first and second conductive layers on the first and second optical waveguides, with first and second insulating buffer layers interposed therebetween, respectively.Type: GrantFiled: April 20, 1989Date of Patent: November 12, 1991Assignee: Sony CorporationInventors: Teiichi Miyauchi, Yutaka Soda, Tetsuo Sekiya
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Patent number: 4875128Abstract: A disc cartridge including a shell, a disc within the shell, a disc restraint for selectively restraining the drive may be inserted to move the restraint is provided with a cover attached to the restraint for engaging the release pin, moving the restraint in response to movement of the release pin and closing the opening to prevent the entrance of contaminants into the shell.Type: GrantFiled: July 11, 1988Date of Patent: October 17, 1989Assignees: Minnesota Mining and Manufacturing Company, Sony CorporationInventors: Vurnen Leonard, Arthur K. Kato, Kiyoshi Ohmori, Keisuke Fujiwara, Yutaka Soda
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Patent number: 4757410Abstract: A multi-channel magnetoresistance effect type magnetic head has a short wavelength region magnetic head element and a relatively longer wavelength region magnetic head element. The two head elements are provided on a magnetic substrate with each having a magnetic circuit containing a magnetic gap facing a surface adjacent to and across from a magnetic recording medium. Each magnetic circuit has a discontinuity portion with a bridging magnetoresistance effect sensing element to magnetically connect the discontinuity portion. The longer wavelength magnetic head discontinuity portion is spaced at a greater distance from the adjacent surface than is the discontinuity portion of the shorter wavelength magnetic head element.Type: GrantFiled: October 30, 1985Date of Patent: July 12, 1988Assignee: Sony CorporationInventors: Satoru Seko, Yutaka Soda, Hiroyuki Uchida, Tetsuo Sekiya
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Patent number: 4734644Abstract: A yoke type magnetic transducer head utilizing a magnetoresistance effect in which a magnetoresistance effect sensing portion is provided so as to magnetically couple a cut-away portion in a magnetic circuit including an operation gap and a magnetic yoke having in its one portion the cut-away portion and in which a first bias magnetic field is applied to the magnetoresistance effect sensing portion by a first magnetic flux that is generated when a current is flowed through the magnetoresistance effect sensing portion, or when a current is flowed through both the magnetoresistance effect sensing portion and a bias conductor, which includes a hard magnetic layer for generating a second magnetic flux by which a second bias magnetic field is applied to the magnetoresistance effect sensing portion and for passing through the magnetic yoke a magnetic flux which cancels at least a part of the first magnetic flux which passes through the magnetic yoke.Type: GrantFiled: March 19, 1986Date of Patent: March 29, 1988Assignee: Sony CorporationInventors: Shigeyoshi Imakoshi, Hideo Suyama, Yutaka Soda, Munekatsu Fukuyama
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Patent number: 4713710Abstract: The present invention is to construct a combination magnetic head apparatus in which thin film type magnetic head element portions, circuits and circuit parts accompanying therewith are mounted on first and second magnetic shield plates to thereby construct a recording head and a reproducing head and both the magnetic shield plates are bonded together at the back surfaces thereof with the result that the apparatus can be made small in size, the assembling thereof can be simplified and the accuracy thereof can be improved.Type: GrantFiled: February 25, 1986Date of Patent: December 15, 1987Assignee: Sony CorporationInventors: Yutaka Soda, Hideko Imamura, Hiroyuki Uchida, Tetsuo Sekiya
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Patent number: 4703378Abstract: A magnetoresistance effect type magnetic transducer head apparatus comprises a magnetoresistance effect sensing element, means for applying a high-frequency magnetic field to the sensing element, means for taking-out an output signal from the sensing element, a filter for taking-out the high-frequency component of the output, and another filter for rectifying the output and taking-out the low-frequency component. The magnetic head apparatus may be constructed as a digital circuit so that a multi-channel apparatus can be easily implemented.Type: GrantFiled: February 26, 1985Date of Patent: October 27, 1987Assignee: Sony CorporationInventors: Shigeyoshi Imakoshi, Hideo Suyama, Yutaka Soda, Munekatsu Fukuyama, Yasuhiro Iida
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Patent number: 4695908Abstract: A thin film type magnetic transducer head comprises a magnetic substrate, and a thin film magnetic core formed on the substrate through an effective magnetic gap at one end of the substrate to be faced to a magnetic recording medium, the magnetic substrate and the thin film magnetic core forming a magnetic circuit to reproduce signals on the magnetic medium, wherein a length between a center of the magnetic gap and an edge of the magnetic core and wave length satisfy definite relations, thereby the S/N ratio and the output are improved in the digital magnetic recording.Type: GrantFiled: August 23, 1984Date of Patent: September 22, 1987Assignee: Sony CorporationInventors: Shigeyoshi Imakoshi, Yutaka Soda, Hideo Suyama
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Patent number: 4679107Abstract: A magnetic head utilizing the magnetoresistance effect comprising a magnetoresistance effect element and a conductor for applying a bias magnetic field to the element by being supplied with a bias current. The conductor is further supplied with a decaying alternating current superimposed on the bias current in advance of the playback operation, so that the hysteresis effect of the magnetic circuit is cancelled and the invariable output characteristics of the magnetic head are obtained.Type: GrantFiled: August 23, 1984Date of Patent: July 7, 1987Assignee: Sony CorporationInventors: Shigeyoshi Imakoshi, Yutaka Soda, Hideo Suyama, Yasuhiro Iida
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Patent number: 4673999Abstract: A multi channel magnetic transducer head comprises a magnetic substrate, and a plurality of thin film type magnetic transducer head elements arranged on the magnetic substrate, each magnetic transducer head element including a coil conductor disposed on the magnetic substrate and a thin film magnetic core to constitute a magnetic circuit in co-operation with the substrate, wherein a non-magnetic gap spacer layer with a predetermined thickness is formed at track width portion below front end of the thin film magnetic core on the magnetic core, a non-magnetic layer with thickness larger than that of the gap spacer layer is formed at track spacing portion, the thin film magnetic core has width covering at least the gap spacer layer of the track width portion, thereby good magnetic recording can be performed.Type: GrantFiled: August 23, 1984Date of Patent: June 16, 1987Assignee: Sony CorporationInventors: Hideo Suyama, Shigeyoshi Imakoshi, Yutaka Soda, Takeyuki Fuse, Iwao Abe, Noboru Wakabayashi