Patents by Inventor Sunao Yonekawa
Sunao Yonekawa 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: 7859794Abstract: Embodiments of the present invention help to prevent, in a magnetic head slider adapted to be able to control flying height of a head element, the occurrence of excessive frictional force, even in case of contact with a magnetic disk, and suppress vibration of the slider. According to one embodiment, an air bearing surface of a magnetic head slider includes a deep groove, a shallow-trench rail about 100 nm higher than the deep groove, a rear end shoulder, two leading end pads about 1 ?m higher than the deep groove, a trailing end pad about 970-995 nm higher than the deep groove, and an element pad about 5-30 nm higher than the trailing end pad and flush with the leading end pads. A head element includes a magnetic head element and a heater. The element pad has an area of 50-500 ?m2, and the magnetic head element is disposed near a central section of the element pad.Type: GrantFiled: September 27, 2007Date of Patent: December 28, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroshi Tani, Sunao Yonekawa
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Patent number: 7733599Abstract: Embodiments of the invention provide a magnetic disk unit in which there has been adopted a structure fixing a base and a top plate and preventing a deformation by a bimetal effect. In one embodiment, the magnetic disk unit includes a magnetic disk; a head drive mechanism in which is mounted a head accessing the magnetic disk; a base accommodating the magnetic disk and the head drive mechanism, and possessing a flat part, in which a threaded hole has been formed, in a circumference of an opening edge; and a top cover which is formed by a material whose thermal expansion coefficient differs from that of the base, in which there is provided an escape hole, for a screw, position-aligned to the threaded hole of the flat part, and which is attached to the base by the screw penetrating through the threaded hole and the escape hole for the screw.Type: GrantFiled: August 3, 2006Date of Patent: June 8, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Shigenaga, Sunao Yonekawa, Masao Iwakura, Masami Miyatake
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Patent number: 7701669Abstract: When the flying height of a magnetic head slider lowers, there arises the problem that the magnetic head slider assumes a forwardly falling attitude and a front edge portion of a leading end of the magnetic head slider comes into contact with a magnetic disk surface, causing damage to the disk surface. To address the problem, one aspect of the invention is directed to a magnetic head slider which includes an air bearing surface, a leading end and a trailing end. Three flying pads are formed on the air bearing surface and a step bearing surface is formed around the first and second flying pads near the leading end and a negative pressure groove for producing a negative pressure is formed in such a manner that the leading side is surrounded by the step bearing surface. The third flying pad is formed near the trailing end and is provided with a magnetic head. A step bearing is formed on the leading side of the third flying pad.Type: GrantFiled: August 8, 2006Date of Patent: April 20, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kouichi Watanabe, Sunao Yonekawa
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Publication number: 20080080094Abstract: Embodiments of the present invention help to prevent, in a magnetic head slider adapted to be able to control flying height of a head element, the occurrence of excessive frictional force, even in case of contact with a magnetic disk, and suppress vibration of the slider. According to one embodiment, an air bearing surface of a magnetic head slider includes a deep groove, a shallow-trench rail about 100 nm higher than the deep groove, a rear end shoulder, two leading end pads about 1 ?m higher than the deep groove, a trailing end pad about 970-995 nm higher than the deep groove, and an element pad about 5-30 nm higher than the trailing end pad and flush with the leading end pads. A head element includes a magnetic head element and a heater. The element pad has an area of 50-500 ?m2, and the magnetic head element is disposed near a central section of the element pad.Type: ApplicationFiled: September 27, 2007Publication date: April 3, 2008Applicant: Hitachi Global Storage Technologies Netherlands B. V.Inventors: Hiroshi Tani, Sunao Yonekawa
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Publication number: 20070047130Abstract: Embodiments of the invention provide a magnetic disk unit in which there has been adopted a structure fixing a base and a top plate and preventing a deformation by a bimetal effect. In one embodiment, the magnetic disk unit includes a magnetic disk; a head drive mechanism in which is mounted a head accessing the magnetic disk; a base accommodating the magnetic disk and the head drive mechanism, and possessing a flat part, in which a threaded hole has been formed, in a circumference of an opening edge; and a top cover which is formed by a material whose thermal expansion coefficient differs from that of the base, in which there is provided an escape hole, for a screw, position-aligned to the threaded hole of the flat part, and which is attached to the base by the screw penetrating through the threaded hole and the escape hole for the screw.Type: ApplicationFiled: August 3, 2006Publication date: March 1, 2007Applicant: Hitachi Global Storage TechnologiesInventors: Hiroaki Shigenaga, Sunao Yonekawa, Masao Iwakura, Masami Miyatake
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Publication number: 20070030597Abstract: When the flying height of a magnetic head slider lowers, there arises the problem that the magnetic head slider assumes a forwardly falling attitude and a front edge portion of a leading end of the magnetic head slider comes into contact with a magnetic disk surface, causing damage to the disk surface. To address the problem, one aspect of the invention is directed to a magnetic head slider which includes an air bearing surface, a leading end and a trailing end. Three flying pads are formed on the air bearing surface and a step bearing surface is formed around the first and second flying pads near the leading end and a negative pressure groove for producing a negative pressure is formed in such a manner that the leading side is surrounded by the step bearing surface. The third flying pad is formed near the trailing end and is provided with a magnetic head. A step bearing is formed on the leading side of the third flying pad.Type: ApplicationFiled: August 8, 2006Publication date: February 8, 2007Applicant: Hitachi Global Storage Techologies Netherlands B. V.Inventors: Kouichi Watanabe, Sunao Yonekawa
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Patent number: 7095587Abstract: In a slider using thermal expansion type, being adjustable on a flying height thereof, having problems to be solved, i.e., to reduce the electric power consumption, and to lesson the heat load upon a reproducing element thereof, wherein a heating device 4 is located separating from tip portions of the recording and reproducing elements 2 and 3. Also, for deforming only the vicinity of the heating device 4 and the recording and reproducing elements 2 and 3, so as to protrude from, the heating device 4 and the recording and reproducing elements 2 and 3 are surrounded by a resin film 6 of small rigidity, thereby increasing an amount of protrusion of the recording and reproducing elements 2 and 3 per a unit of electric power, but without increasing temperature of the reproducing element 3, with an aim of the structure of cutting off the force from materials of circumferences against the deformation.Type: GrantFiled: September 11, 2003Date of Patent: August 22, 2006Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Masayuki Kurita, Toshiya Shiramatsu, Hideaki Tanaka, Sunao Yonekawa, Koji Miyake, Hidekazu Kohira, Mikio Tokuyama
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Patent number: 7061726Abstract: A magnetic material having a low coefficient of thermal expansion of 11.5×10?6/K or less is used for forming at least one of a lower shield or an upper shield. A laminated film comprising a layer of the magnetic material having a low coefficient of thermal expansion of 11.5×10?6/K or less, and an 80 wt % NiFe alloy layer, is used for forming at least one of the lower shield and the upper shield. Thus, the thin film magnetic head having reduced after-record noise and reduced thermal protrusion can be obtained.Type: GrantFiled: September 18, 2003Date of Patent: June 13, 2006Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Shigekazu Ohtomo, Hiroshi Fukui, Sunao Yonekawa, Yoji Maruyama, Tadayuki Iwakura
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Patent number: 6992860Abstract: Protrusion of head elements to an air bearing surface is effectively reduced and their contact with a recording medium is thereby prevented by forming a level gap (concave) of about 3 nm in a multilayered protective film on the air bearing surface in a part matching an inductive write thin film head in a recording/reproducing separated type magnetic head and thereby offsetting protrusion of the head elements to the air bearing surface due to thermal deformation of the heads.Type: GrantFiled: February 25, 2003Date of Patent: January 31, 2006Assignee: Hitachi, Ltd.Inventors: Eiji Nakanishi, Yukihiro Isono, Shigeru Tadokoro, Sunao Yonekawa, Tetsuya Matsusaki, Masao Matsushita
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Publication number: 20050024775Abstract: In a slider using thermal expansion type, being adjustable on a flying height thereof, having problems to be solved, i.e., to reduce the electric power consumption, and to lesson the heat load upon a reproducing element thereof, wherein a heating device 4 is located separating from tip portions of the recording and reproducing elements 2 and 3. Also, for deforming only the vicinity of the heating device 4 and the recording and reproducing elements 2 and 3, so as to protrude from, the heating device 4 and the recording and reproducing elements 2 and 3 are surrounded by a resin film 6 of small rigidity, thereby increasing an amount of protrusion of the recording and reproducing elements 2 and 3 per a unit of electric power, but without increasing temperature of the reproducing element 3, with an aim of the structure of cutting off the force from materials of circumferences against the deformation.Type: ApplicationFiled: September 11, 2003Publication date: February 3, 2005Inventors: Masayuki Kurita, Toshiya Shiramatsu, Hideaki Tanaka, Sunao Yonekawa, Koji Miyake, Hidekazu Kohira, Mikio Tokuyama
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Publication number: 20040223265Abstract: A magnetic material having a low coefficient of thermal expansion of 11.5×10−6/K or less is used for forming at least one of a lower shield or an upper shield. A laminated film comprising a layer of the magnetic material having a low coefficient of thermal expansion of 11.5×10−6/K or less, and an 80 wt % NiFe alloy layer, is used for forming at least one of the lower shield and the upper shield. Thus, the thin film magnetic head having reduced after-record noise and reduced thermal protrusion can be obtained.Type: ApplicationFiled: September 18, 2003Publication date: November 11, 2004Applicant: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Shigekazu Ohtomo, Hiroshi Fukui, Sunao Yonekawa, Yoji Maruyama, Tadayuki Iwakura
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Publication number: 20040037012Abstract: Protrusion of head elements to an air bearing surface is effectively reduced and their contact with a recording medium is thereby prevented by forming a level gap (concave) of about 3 nm in a multilayered protective film on the air bearing surface in a part matching an inductive write thin film head in a recording/reproducing separated type magnetic head and thereby offsetting protrusion of the head elements to the air bearing surface due to thermal deformation of the heads.Type: ApplicationFiled: February 25, 2003Publication date: February 26, 2004Inventors: Eiji Nakanishi, Yukihiro Isono, Shigeru Tadokoro, Sunao Yonekawa, Tetsuya Matsusaki, Masao Matsushita
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Patent number: 6329023Abstract: A magnetic hard disk drive comprising a magnetic disk and a magnetic head slider, characterized in that said magnetic head slider is coated with a layer having a contact angle of 50° or more when measured by using a lubricant coated on the magnetic disk, is free from start failure due to stiction caused by adhesion of the lubricant to the slider surface.Type: GrantFiled: February 16, 2001Date of Patent: December 11, 2001Assignee: Hitachi, Ltd.Inventors: Hiromitsu Tokisue, Sunao Yonekawa, Nobuyuki Ishii, Yasuyuki Horiguchi, Yoshishige Endo, Yasuhiro Yoshimura, Yutaka Ito, Osamu Narisawa, Hiroshi Yuyama, Youichi Inoue, Yukiko Ikeda
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Publication number: 20010018094Abstract: A magnetic hard disk drive comprising a magnetic disk and a magnetic head slider, characterized in that said magnetic head slider is coated with a layer having a contact angle of 50° or more when measured by using a lubricant coated on the magnetic disk, is free from start failure due to stiction caused by adhesion of the lubricant to the slider surface.Type: ApplicationFiled: February 16, 2001Publication date: August 30, 2001Inventors: Hiromitsu Tokisue, Sunao Yonekawa, Nobuyuki Ishii, Yasuyuki Horiguchi, Yoshishige Endo, Yasuhiro Yoshimura, Yutaka Ito, Osamu Narisawa, Hiroshi Yuyama, Youichi Inoue, Yukiko Ikeda
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Patent number: 6249403Abstract: A magnetic hard disk drive comprising a magnetic disk and a magnetic head slider, characterized in that said magnetic head slider is coated with a layer having a contact angle of 50° or more when measured by using a lubricant coated on the magnetic disk, is free from start failure due to stiction caused by adhesion of the lubricant to the slider surface.Type: GrantFiled: May 18, 1998Date of Patent: June 19, 2001Assignee: Hitachi, Ltd.Inventors: Hiromitsu Tokisue, Sunao Yonekawa, Nobuyuki Ishii, Yasuyuki Horiguchi, Yoshishige Endo, Yasuhiro Yoshimura, Yutaka Ito, Osamu Narisawa, Hiroshi Yuyama, Youichi Inoue, Yukiko Ikeda