Patents by Inventor Kazushi Tsuwako
Kazushi Tsuwako 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: 10916269Abstract: Disclosed here is a magnet for use in a motor. The magnet comprises a magnet body. The magnet body comprises a plurality of coated magnetic granules. Each coated magnetic granule of the plurality of coated magnetic granules comprises a magnetic granule and a metallic layer coating the magnetic granule.Type: GrantFiled: August 28, 2019Date of Patent: February 9, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Toshio Takahashi, Kazushi Tsuwako, Masamichi Sakauchi, Takako Hayakawa, Kouki Uefune
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Publication number: 20200265868Abstract: Disclosed here is a magnet comprising a magnet body. The magnet body comprises a plurality of coated magnetic granules.Type: ApplicationFiled: August 28, 2019Publication date: August 20, 2020Inventors: Toshio Takahashi, Kazushi Tsuwako, Masamichi Sakauchi, Takako Hayakawa, Kouki Uefune
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Patent number: 9293161Abstract: An iron-oxidized hard disk drive (HDD) cover has an inner surface that is substantially free of un-oxidized or pure metallic iron, fabricated by baking a stainless steel cover and thereby oxidizing the cover surface of iron. Because the cover is iron-oxidized, a costly nickel-plating process may be foregone while a “Fe smear” problem may be significantly reduced. Such an iron-oxidized cover is especially beneficial for, though not limited to, use as an inner cover in a sealed HDD.Type: GrantFiled: November 4, 2015Date of Patent: March 22, 2016Assignee: HGST Netherlands B.V.Inventors: Yuki Taniguchi, Kazushi Tsuwako, Koichi Suzuki, Masahiko Tamura
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Patent number: 9202483Abstract: An iron-oxidized hard disk drive (HDD) cover has an inner surface that is substantially free of un-oxidized or pure metallic iron, fabricated by baking a stainless steel cover and thereby oxidizing the cover surface of iron. Because the cover is iron-oxidized, a costly nickel-plating process may be foregone while a “Fe smear” problem may be significantly reduced. Such an iron-oxidized cover is especially beneficial for, though not limited to, use as an inner cover in a sealed HDD.Type: GrantFiled: January 2, 2015Date of Patent: December 1, 2015Assignee: HGST Netherlands B.V.Inventors: Yuki Taniguchi, Kazushi Tsuwako, Koichi Suzuki, Masahiko Tamura
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Patent number: 8885287Abstract: A disk drive for storing information representing data includes a base, a spindle rotatably attached to the base, and a plurality of disks having magnetizable disk surfaces attached to the spindle. The disk drive also includes a plurality of read/write transducers for writing to and reading from the plurality of magnetizable disk surfaces, and a cover attached to the base. The cover and base form a substantially sealed disk enclosure. The disk enclosure is substantially filled with a mixture of gases including an oxygen portion in the range of 0.1-3% of the mixture, and a low-density gas portion.Type: GrantFiled: January 6, 2014Date of Patent: November 11, 2014Assignee: HGST Netherlands B.V.Inventors: Minoru Koike, Masamichi Sakauchi, Koichi Suzuki, Kazushi Tsuwako
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Patent number: 8125727Abstract: A disk drive. The disk drive includes a disk configured to store data, a motor configured to rotate the disk, a head-slider and a controller. The head-slider includes a slider configured to fly in proximity to a recording surface of the disk, and an element on the slider. The controller is configured to measure a fly height between the head-slider and the disk at different common-mode voltages of the element to determine an operational common-mode voltage from a measurement result.Type: GrantFiled: September 18, 2009Date of Patent: February 28, 2012Assignee: Hitachi Global Storgae Technologies, Netherlands B.V.Inventors: Kazushi Tsuwako, Yuusuke Matsuda, Masashi Murai, Toshiya Shiramatsu
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Publication number: 20110090586Abstract: A disk drive. The disk drive includes a disk configured to store data, a motor configured to rotate the disk, a head-slider and a controller. The head-slider includes a slider configured to fly in proximity to a recording surface of the disk, and an element on the slider. The controller is configured to measure a fly height between the head-slider and the disk at different common-mode voltages of the element to determine an operational common-mode voltage from a measurement result.Type: ApplicationFiled: September 18, 2009Publication date: April 21, 2011Inventors: Kazushi Tsuwako, Yuusuke Matsuda, Masashi Murai, Toshiya Shiramatsu
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Patent number: 6822823Abstract: A hard disk drive has an enclosure with disk construction members and is characterized by covering the enclosure with an electrically conductive sheet. The electrically conductive sheet protects the drive regardless of which direction an ESD charge is applied. The electrically conductive sheet does not permit ESD to pass through the disk construction members stored in the enclosure. Therefore, it is possible to form a structure in which a GMR head or the like in an enclosure is not damaged due to ESD even if the enclosure is handled by a general end user. Moreover, the present invention relates to an electrically conductive sheet for covering at least both principal planes of the enclosure of a hard disk drive constituted as described above. Other modes of the invention include at least both principal planes of an enclosure being covered by the electrically conductive sheet in such a way that both sheets on both principal planes are electrically connected.Type: GrantFiled: April 20, 2000Date of Patent: November 23, 2004Assignee: International Business Machines CorporationInventors: Kazushi Tsuwako, Kenichi Kuramoto, Hiroshi Matsuda, Hiroki Kitahori
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Patent number: 6618236Abstract: A magnetic head handling glove capable of preventing the buildup of static charges and electric charge leakage and capable of withstanding use in clean rooms is described. In the magnetic head handling glove 1 of the present invention, the outer surface alone or both the outer surface and inner surface of a conductive glove 2 are coated with dissipative material 3,4. This results in coating of the conductive glove with materials useable in clean rooms and may suppress possible contamination that can result when a conventional conductive glove, lacking in such coating of dissipative material, is used directly in a clean room. Besides this, the conductive glove 2 is configured to be grounded directly with wire 5. In this way, even an operator prone to the buildup of static charges can be sufficiently prevented from building up static electrical charges and electric charge leakage.Type: GrantFiled: June 29, 2000Date of Patent: September 9, 2003Assignee: International Business Machines CorporationInventors: Kazushi Tsuwako, Yasuhiro Sasao, Katsushi Yamaguchi, Hirokazu Yamamoto
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Patent number: 6259573Abstract: A preamplifier circuit to improve the ESD immunity of magnetic recording devices having magnetoresistive (MR) sensors, without degrading the sensor's high-frequency characteristics. The preamplifier circuit is coupled to an MR sensor having one terminal grounded. The preamplifier circuit includes a varistor coupled between a power supply line and a ground terminal. If a high voltage, exceeding the varistor voltage, is applied to the chassis (ground), it is discharged through the varistor between the power supply voltage line and the ground terminal, instead of through the MR head or the arm electronics module. The present invention thereby protects the MR head and the arm electronics module from ESD damage.Type: GrantFiled: February 22, 1999Date of Patent: July 10, 2001Assignee: International Business Machines CorporationInventors: Kazushi Tsuwako, Yoshiro Amano, Takao Matsui, Tsuyoshi Miura
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Patent number: 5754355Abstract: A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer head contacts the projection. The flying height of the signal transducer head is lowered, e.g., by changing the disk rotation speed from the normal rotation speed in read/write operations or by heating a suspension having a bimetal element, while the signal transducer head is positioned over the detected projection on the track. The signal transducer head strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.Type: GrantFiled: April 17, 1996Date of Patent: May 19, 1998Assignee: International Business Machines CorporationInventors: Takashi Nakamura, Isao Yoneda, Yuji Yokoe, Kazushi Tsuwako, Fujio Harako, Katsumi Suda, Michio Nakajima, Kenji Ogasawara
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Patent number: 5696643Abstract: A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer contacts the projection. The flying height of the signal transducer is lowered, e.g., by reducing the disk rotation speed from the normal rotation speed in read/write operations, while the signal transducer is positioned over the detected projection on the track. The signal transducer strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.Type: GrantFiled: April 17, 1996Date of Patent: December 9, 1997Assignee: International Business Machines CorporationInventors: Kazushi Tsuwako, Fujio Harako, Katsumi Suda, Michio Nakajima, Isao Yoneda, Kenji Ogasawara