Patents by Inventor Yasuhiro Iihara
Yasuhiro Iihara 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: 8593752Abstract: A HDD including write components configured to operate within an operating voltage range, charging circuitry comprising a charging capacitor. The charging capacitor includes a higher voltage when charged than the operating voltage range. The HDD also includes pulse circuitry configured to pulse power from the charging circuitry to the write components within the operating voltage range during a controlled shut down of the write components such that remaining data-sector bits are written during the controlled shut down.Type: GrantFiled: October 8, 2010Date of Patent: November 26, 2013Assignee: HGST Netherlands B.V.Inventors: Toshihisa Kiyonaga, Yasuhiro Iihara, Yoshiroh Amano, Yoshifumi Kataoka
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Publication number: 20120087032Abstract: A HDD including write components configured to operate within an operating voltage range, charging circuitry comprising a charging capacitor. The charging capacitor includes a higher voltage when charged than the operating voltage range. The HDD also includes pulse circuitry configured to pulse power from the charging circuitry to the write components within the operating voltage range during a controlled shut down of the write components such that remaining data-sector bits are written during the controlled shut down.Type: ApplicationFiled: October 8, 2010Publication date: April 12, 2012Inventors: Toshihisa KIYONAGA, Yasuhiro IIHARA, Yoshiroh AMANO, Yoshifumi KATAOKA
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Patent number: 7808739Abstract: Embodiments of the present invention help to perform appropriate servo control in response to detected vibration in a disk drive device having a vibration sensor. In an embodiment of the present invention, an HDD switches a correction servo mode to perform vibration correction in head positioning and a normal servo mode not to perform the vibration correction. The HDD performs servo positioning in either one of the serve modes and determines servo positioning accuracy in the servo mode from the measured positional error signal. The HDD obtains data indicating the servo positioning accuracy in the other servo mode from a table. The HDD compares the accuracy in the two servo modes and selects the servo mode with higher accuracy. The table contains previous measurements on servo positioning accuracy in the servo modes.Type: GrantFiled: October 28, 2008Date of Patent: October 5, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kohji Takasaki, Isao Yoneda, Nobuhiko Wasa, Yasuhiro Iihara
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Publication number: 20090135516Abstract: Embodiments of the present invention help to perform appropriate servo control in response to detected vibration in a disk drive device having a vibration sensor. In an embodiment of the present invention, an HDD switches a correction servo mode to perform vibration correction in head positioning and a normal servo mode not to perform the vibration correction. The HDD performs servo positioning in either one of the serve modes and determines servo positioning accuracy in the servo mode from the measured positional error signal. The HDD obtains data indicating the servo positioning accuracy in the other servo mode from a table. The HDD compares the accuracy in the two servo modes and selects the servo mode with higher accuracy. The table contains previous measurements on servo positioning accuracy in the servo modes.Type: ApplicationFiled: October 28, 2008Publication date: May 28, 2009Inventors: Kohji Takasaki, Isao Yoneda, Nobuhiko Wasa, Yasuhiro Iihara
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Patent number: 7417816Abstract: Embodiments of the present invention provide an inspection method for detecting a physical defect of a magnetic disk with high sensitivity without increasing the length of inspection time. In a magnetic disk drive according to one embodiment, the assembling of which has been completed, by reading inspection data written to a magnetic disk, a defect of the magnetic disk is detected in a state in which a read error occurs. Redundant bits of an ECC are added to the inspection data. If a head corresponding to a recording surface to be inspected has superior read performance, an ECC 2 is applied. If the head in question has inferior read performance, an ECC 4 is applied. Accordingly, as compared with a case where a single ECC is applied, the defect detectivity is further improved without increasing the length of inspection time.Type: GrantFiled: July 11, 2005Date of Patent: August 26, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masanori Aratani, Yasuhiro Iihara, Masaki Kudoh, Junzoh Noda, Masahiro Shimizu
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Patent number: 7333282Abstract: Embodiments of the invention avoid an off-track write when an impact is applied. A hard disk drive according to one embodiment of the present invention comprises a magnetic disk; an actuator for moving a head element section over the magnetic disk; and an HDC/MPU for prohibiting the head element section from writing onto the magnetic disk for a short period when a detected impact is found to be greater than a low reference level and not greater than a high reference level, and prohibiting the head element section from writing onto the magnetic disk for a period longer than the short period when the detected impact is found to be greater than the high reference level.Type: GrantFiled: December 22, 2005Date of Patent: February 19, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kaoru Iseri, Atsushi Tobari, Yasuhiro Iihara, Masanori Aratani
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Publication number: 20060139790Abstract: Embodiments of the invention avoid an off-track write when an impact is applied. A hard disk drive according to one embodiment of the present invention comprises a magnetic disk; an actuator for moving a head element section over the magnetic disk; and an HDC/MPU for prohibiting the head element section from writing onto the magnetic disk for a short period when a detected impact is found to be greater than a low reference level and not greater than a high reference level, and prohibiting the head element section from writing onto the magnetic disk for a period longer than the short period when the detected impact is found to be greater than the high reference level.Type: ApplicationFiled: December 22, 2005Publication date: June 29, 2006Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kaoru Iseri, Atsushi Tobari, Yasuhiro Iihara, Masanori Aratani
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Publication number: 20060012906Abstract: Embodiments of the present invention provide an inspection method for detecting a physical defect of a magnetic disk with high sensitivity without increasing the length of inspection time. In a magnetic disk drive according to one embodiment, the assembling of which has been completed, by reading inspection data written to a magnetic disk, a defect of the magnetic disk is detected in a state in which a read error occurs. Redundant bits of an ECC are added to the inspection data. If a head corresponding to a recording surface to be inspected has superior read performance, an ECC 2 is applied. If the head in question has inferior read performance, an ECC 4 is applied. Accordingly, as compared with a case where a single ECC is applied, the defect detectivity is further improved without increasing the length of inspection time.Type: ApplicationFiled: July 11, 2005Publication date: January 19, 2006Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masanori Aratani, Yasuhiro Iihara, Masaki Kudoh, Junzoh Noda, Masahiro Shimizu
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Patent number: 5918001Abstract: A disk drive has an error recovery procedure with a plurality of ERP steps. An unused capacity of an alternate area on a disk for reassigning data is determined. While executing the error recovery procedure, an execution condition for reassigning data is changed based unused capacity of the alternate area. Data is reassigned to the alternate area in response to the execution condition. This prevents the early loss of the alternate area.Type: GrantFiled: February 18, 1997Date of Patent: June 29, 1999Assignee: International Business Machines CorporationInventors: Shinji Ueno, Yasuhiro Iihara, Haruo Andoh, Takashi Nakamura