Patents by Inventor Tsuyoshi Onitsuka
Tsuyoshi Onitsuka 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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Publication number: 20180122417Abstract: A magnetic recording medium includes a substrate and a stacked film on the substrate and including a magnetic recording layer. An elastic modulus Esub of the substrate satisfies Equation (1) below, where h is a film thickness of the stacked film and Efilm is an Young's modulus of the stacked film: Esub?(200*Efilm)/(6*h)??(1).Type: ApplicationFiled: February 28, 2017Publication date: May 3, 2018Inventors: Akira WATANABE, Tomoki UMETSU, Tsuyoshi ONITSUKA, Hiroyuki HYODO
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Publication number: 20170062001Abstract: According to one embodiment, a method of evaluating a scratch mark includes, for a magnetic recording medium including a magnetic recording layer containing magnetic particles and a metal oxide grain boundary provided between the magnetic particles, detecting and evaluating a scratch mark based on information about the reflection intensity of light in a predetermined wavelength range. The predetermined wavelength range includes at least a second wavelength range from 600 nm to 700 nm and a first wavelength range from 300 nm to 500 nm.Type: ApplicationFiled: December 23, 2015Publication date: March 2, 2017Inventors: Akira Watanabe, Tsuyoshi Onitsuka, Hiroyuki Hyodo
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Publication number: 20160158790Abstract: A tool for dip-coating a disc-shaped substrate having a through hole therein includes a support member having a portion made of a porous material, that is to be inserted into the through hole and support the disc-shaped substrate during the dip-coating. Further, a method for dip-coating a disc-shaped substrate having a through hole therein, includes supporting the substrate on a portion of a tool, the portion being made of a porous material, submerging the substrate and the tool into a dip coating liquid, and taking the substrate and the tool out of the dip coating liquid.Type: ApplicationFiled: June 15, 2015Publication date: June 9, 2016Inventors: Akira WATANABE, Tsuyoshi ONITSUKA
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Publication number: 20160027461Abstract: A method for forming a particle layer includes covering surfaces of particles with a first polymer, covering a surface of a substrate with a second polymer having a same skeletal structure as the first polymer, and applying a liquid in which the particles covered with the first polymer are dispersed, onto the surface of the substrate covered with the second polymer.Type: ApplicationFiled: November 20, 2014Publication date: January 28, 2016Inventors: Akira WATANABE, Kaori KIMURA, Tsuyoshi ONITSUKA
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Patent number: 8995089Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.Type: GrantFiled: July 17, 2013Date of Patent: March 31, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
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Patent number: 8858809Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.Type: GrantFiled: September 7, 2012Date of Patent: October 14, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
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Publication number: 20140248513Abstract: According to one embodiment, there is provided a method for producing a magnetic recording medium which includes forming a mask layer on a magnetic recording layer, applying metal fine particles on the mask layer, covering the metal fine particles with an overcoat layer, irradiating with energy beams through the overcoat layer so as to deactivate a protective coating of the metal fine particles, transferring a metal fine particle pattern from the mask layer to the magnetic recording layer, and removing the mask layer from the magnetic recording layer.Type: ApplicationFiled: July 12, 2013Publication date: September 4, 2014Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Akihiko Takeo
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Publication number: 20140247519Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.Type: ApplicationFiled: July 17, 2013Publication date: September 4, 2014Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
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Publication number: 20140147701Abstract: A magnetic recording medium is manufactured by forming a magnetic recording layer on a substrate, forming a protective layer on the magnetic recording layer, executing a sputtering process using a target containing a first ingredient and a second ingredient to form on the protective layer a grain-state mask layer that includes grains formed of the first ingredient and grain boundaries between the grains formed of the second ingredient, etching the grain boundaries so that a projection pattern of the grains is formed, and transferring the projection pattern of the grains to the magnetic recording layer.Type: ApplicationFiled: April 23, 2013Publication date: May 29, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Takeshi IWASAKI, Kazutaka TAKIZAWA, Akira WATANABE, Kaori KIMURA, Tsuyoshi ONITSUKA
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Patent number: 8652338Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.Type: GrantFiled: November 15, 2012Date of Patent: February 18, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
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Publication number: 20130248485Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.Type: ApplicationFiled: September 7, 2012Publication date: September 26, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
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Publication number: 20130180948Abstract: According to one embodiment, a release layer is formed on a magnetic recording layer, a mask layer is formed on the release layer, projecting patterns are formed on the mask layer, the projecting patterns are transferred onto the mask layer, the projecting patterns are transferred onto the release layer, the projecting patterns are transferred onto the magnetic recording layer, the release layer is removed by a solvent, and a remaining mask layer is removed from the surface of the magnetic recording layer. The release layer is made of a polymeric material. The mask layer is made of at least one of a metal or a metal compound. The projecting patterns are formed by using a self-organized layer made of a block copolymer having at least two of polymer chains.Type: ApplicationFiled: July 27, 2012Publication date: July 18, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kazutaka TAKIZAWA, Akira WATANABE, Kaori KIMURA, Takeshi IWASAKI, Tsuyoshi ONITSUKA, Akihiko TAKEO
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Publication number: 20130075358Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.Type: ApplicationFiled: November 15, 2012Publication date: March 28, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kaori KIMURA, Yoshiyuki KAMATA, Satoshi SHIROTORI, Tsuyoshi ONITSUKA
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Patent number: 8338007Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.Type: GrantFiled: September 26, 2008Date of Patent: December 25, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
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Publication number: 20120087039Abstract: According to one embodiment, a magnetic recording medium includes a substrate, and a magnetic recording layer formed on the substrate. The magnetic recording layer includes recording portions having patterns regularly arranged in an longitudinal direction and containing cobalt and platinum, and non recording portions formed between the recording portions and containing boron and at least one light rare earth metal selected from the group consisting of yttrium, lanthanum, and cerium.Type: ApplicationFiled: June 20, 2011Publication date: April 12, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Takeshi Iwasaki, Kaori Kimura, Yoshiyuki Kamata, Tsuyoshi Onitsuka, Masatoshi Sakurai
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Publication number: 20100260885Abstract: According to one embodiment, an imprinting apparatus includes a first mold configured to hold a disk-shaped stamper on which patterns of recesses and protrusions are formed, a second mold configured to hold a disk-shaped substrate to which a resist is applied so that the substrate faces the stamper held by the first mold, and a suction ring which is disposed around the first mold and in which an inner groove and an outer groove are formed to correspond to an outer periphery portion of the stamper held by the first mold, the inner groove being opened to atmosphere and the outer groove being vacuum-suctioned.Type: ApplicationFiled: April 9, 2010Publication date: October 14, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Ryouichi TAKAHASHI, Satoshi SHIROTORI, Tsuyoshi ONITSUKA, Yoshiyuki KAMATA, Masatoshi SAKURAI
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Publication number: 20090161257Abstract: According to one embodiment, a magnetic recording medium includes protruded magnetic patterns formed on a substrate, and a non-magnetic material filled in recesses between the magnetic patterns and made of a multi-element amorphous alloy containing Ni or Cu, and two or more metals selected from the group consisting of Ta, Nb, Ti, Zr, Hf, Cr, Mo and Ag.Type: ApplicationFiled: March 9, 2009Publication date: June 25, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Akiko Yuzawa, Masatoshi Sakurai, Yoshiyuki Kamata, Satoshi Shirotori, Kaori Kimura, Tsuyoshi Onitsuka
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Publication number: 20090081482Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.Type: ApplicationFiled: September 26, 2008Publication date: March 26, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
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Publication number: 20080318085Abstract: A method of forming a carbon protective film is disclosed that improves electromagnetic conversion characteristics through reduction of the film thickness without any damage on a magnetic layer. Also disclosed is a magnetic recording medium that exhibits good electromagnetic conversion characteristics and corrosion resistance. The method of forming the carbon protective film uses a high frequency plasma CVD method on a disk including at least a magnetic film on a nonmagnetic substrate. A bias voltage in a range of ?200 V to zero V is applied at the beginning of discharge in a process of forming the carbon protective film, and a bias voltage in a range of ?500 V to ?200 V is applied at the end of discharge. Also disclosed is a magnetic recording medium having at least a magnetic film and a protective film on a nonmagnetic substrate, wherein the protective film is formed by the method of forming a protective film stated above according to the invention.Type: ApplicationFiled: June 11, 2008Publication date: December 25, 2008Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Tuqiang LI, Masaki MIYAZATO, Tsuyoshi ONITSUKA, Makoto ISOZAKI, Hajime KURIHARA
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Patent number: 6667116Abstract: A magnetic recording medium which includes a non-magnetic base layer having layered upon it, in sequence, a non-magnetic middle layer and a magnetic layer. The magnetic layer has ferromagnetic crystal grains surrounded by non-magnetic grain boundaries. The non-magnetic middle layer is formed of a non-magnetic oxide or nitride, and is disposed between the non-magnetic base layer and the magnetic layer. The non-magnetic oxide or nitride in the middle layer forms a fine, island-like film. At the time of film formation of the granular magnetic layer on the middle layer, this island-like film performs stationing for the ferromagnetic crystal grains and the growth nucleus for the non-magnetic grain boundary. As a result, fine dispersion of the ferromagnetic crystal grains in the granular magnetic layer is hastened, and a high coercivity is obtained even with a small Pt composition ratio. The available reduction in Pt composition ratio reduces the cost of the magnetic recording medium.Type: GrantFiled: April 27, 2000Date of Patent: December 23, 2003Assignee: Fuji Electric Co., Ltd.Inventors: Hiroyuki Uwazumi, Akira Saito, Tsuyoshi Onitsuka, Tadaaki Oikawa