Patents by Inventor Toshiaki TACHIBANA

Toshiaki TACHIBANA 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).

  • Patent number: 8999535
    Abstract: [Problem] An object is to provide a perpendicular magnetic recording medium in which a narrower track width is achieved by enhancing an exchange coupling magnetic field Hex of a soft magnetic layer so that a higher recording density can be achieved. [Solution] A perpendicular magnetic recording medium according to the present invention is configured to include a magnetic recording layer 122 that records a signal, and a soft magnetic layer 114 provided below the magnetic recording layer, on a base 110 on a main surface of which textures are formed, wherein the textures includes first textures 110a that is linear rails in a certain direction, and second textures 110b that are trails intersecting at a predetermined angle with the first textures; and the angle of intersection between the first textures and the second textures is 10° or less.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: April 7, 2015
    Assignee: WD Media (Singapore) PTE, Ltd
    Inventor: Toshiaki Tachibana
  • Patent number: 8883249
    Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: November 11, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Toshiaki Tachibana, Takahiro Onoue, Keiichi Kajita
  • Patent number: 8871368
    Abstract: A perpendicular magnetic recording medium with SNR improved by reducing noise due to an auxiliary recording layer so that a higher recording density can be achieved. The perpendicular magnetic recording medium 100 includes a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: October 28, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Takahiro Onoue, Teiichiro Umezawa, Toshiaki Tachibana, Masafumi Ishiyama
  • Patent number: 8859118
    Abstract: An object is to provide a perpendicular magnetic recording medium including a ground layer that prevents corrosion, while achieving a primary object of promoting finer magnetic particles of a magnetic recording layer and isolation of these magnetic particles. The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, at least on a base 110: a magnetic recording layer 122 on which a signal is recorded; a ground layer 118 provided below the magnetic recording layer; a non-magnetic layer 116 for controlling crystal orientation of the ground layer; and a soft magnetic layer 114 provided below the non-magnetic layer. The ground layer 118 is configured to have three layers including, in an order from bottom, a first ground layer 118a and a second ground layer 118b that contain ruthenium, and a third ground layer 118c that contains a metal.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: October 14, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Toshiaki Tachibana, Takahiro Onoue
  • Publication number: 20120140359
    Abstract: [Summary] [Problem] An object is to provide a perpendicular magnetic recording medium in which a narrower track width is achieved by enhancing an exchange coupling magnetic field Hex of a soft magnetic layer so that a higher recording density can be achieved. [Solution] A perpendicular magnetic recording medium according to the present invention is configured to include a magnetic recording layer 122 that records a signal, and a soft magnetic layer 114 provided below the magnetic recording layer, on a base 110 on a main surface of which textures are formed, wherein the textures includes first textures 110a that is linear rails in a certain direction, and second textures 110b that are trails intersecting at a predetermined angle with the first textures; and the angle of intersection between the first textures and the second textures is 10° or less.
    Type: Application
    Filed: May 31, 2011
    Publication date: June 7, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventor: TOSHIAKI TACHIBANA
  • Publication number: 20110212346
    Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is improved by reducing noise thought to be due to an auxiliary recording layer so that a higher recording density can be achieved, and a method of manufacturing the same. In order to achieve the above object, a representative configuration of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.
    Type: Application
    Filed: September 16, 2009
    Publication date: September 1, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Takahiro Onoue, Teiichiro Umezawa, Toshiaki Tachibana, Masafumi Ishiyama
  • Publication number: 20110206947
    Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.
    Type: Application
    Filed: December 28, 2010
    Publication date: August 25, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Toshiaki TACHIBANA, Takahiro Onoue, Keiichi Kajita
  • Publication number: 20110171495
    Abstract: An object is to provide a perpendicular magnetic recording medium including a ground layer that prevents corrosion, while achieving a primary object of promoting finer magnetic particles of a magnetic recording layer and isolation of these magnetic particles. The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, at least on a base 110: a magnetic recording layer 122 on which a signal is recorded; a ground layer 118 provided below the magnetic recording layer; a non-magnetic layer 116 for controlling crystal orientation of the ground layer; and a soft magnetic layer 114 provided below the non-magnetic layer. The ground layer 118 is configured to have three layers including, in an order from bottom, a first ground layer 118a and a second ground layer 118b that contain ruthenium, and a third ground layer 118c that contains a metal.
    Type: Application
    Filed: January 10, 2011
    Publication date: July 14, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Toshiaki TACHIBANA, Takahiro ONOUE