Magneto-optic Media Disc Patents (Class 428/848.9)
  • Patent number: 9339868
    Abstract: In a method of processing a substrate in accordance with an embodiment, a trench may be formed in the substrate, a stamp device may be disposed at least in the trench; at least one part of the trench that is free from the stamp device may be at least partially filled with trench filling material; and the stamp device may be removed from the trench.
    Type: Grant
    Filed: April 8, 2014
    Date of Patent: May 17, 2016
    Assignee: Infineon Technologies AG
    Inventors: Joerg Ortner, Michael Sorger
  • Patent number: 8349476
    Abstract: To provide a process to improve acid resistance of a glass substrate for an information recording medium. A process for producing the glass substrate for an information recording medium, includes processing a glass formed into a plate by a float process, a down-draw method or a press method, wherein, in cooling the glass at the last step the glass has a temperature of at least its strain point, the time during which the glass temperature is at least its strain point and at most a temperature where the glass viscosity is 1010dPa·s is at least 13 minutes.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: January 8, 2013
    Assignee: Asahi Glass Company, Limited
    Inventors: Jun Endo, Tetsuya Nakashima
  • Patent number: 8241769
    Abstract: A glass substrate for a magnetic disk, wherein, in regions with respect to two places arbitrarily selected on a surface of the glass substrate on its central portion side relative to its outer peripheral end, a surface shape with a shape wavelength in a band of 60 to 500 ?m is extracted from surface shapes in each of the regions and, assuming that a root mean square roughness Rq of the surface shape is given as a microwaviness Rq, the difference between the microwavinesses Rq of the regions is 0.02 nm or less or the difference between standard deviations of the microwavinesses Rq of the regions is 0.04 nm or less.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: August 14, 2012
    Assignee: Hoya Corporation
    Inventors: Kouji Kitsunai, Takashi Maeda
  • Patent number: 8185968
    Abstract: A magnetic head inspection method is provided with the step that an area smaller than a half of a scanning and measurement area of a magnetic probe in a cantilever unit of the MFM is set as a scanning and measurement area on a surface of a recording portion of the magnetic head that is scanned by the AFM, so as to greatly reduce the inspection time (tact time) of the AFM.
    Type: Grant
    Filed: February 10, 2011
    Date of Patent: May 22, 2012
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Tsuneo Nakagomi, Norimitsu Matsusita
  • Patent number: 8153284
    Abstract: A method for manufacturing a glass substrate which has a uniform and minute pattern of stripes formed on the surface thereof by ultraprecision polishing, and which allows the recording capacity of a magnetic disk to be increased, includes an inspecting step before the glass substrate is subjected to ultraprecision polishing, whether the Young's modulus Es in topmost part as determined by the nanoindentation method and the Young's modulus Eg as determined by ultrasonic resonance fulfill the inequality 0.8 Eg<Es<1.2 Eg; or the hardness Hs in topmost part as determined by the nanoindentation method and the Vickers hardness Hv fulfill the inequality 0.8 Hv<Hs<1.2 Hv.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: April 10, 2012
    Assignee: Konica Minolta Opto, Inc.
    Inventor: Hideki Kawai
  • Patent number: 8092280
    Abstract: The present invention relates to a method for producing a glass substrate for a magnetic disk, the method including a step of polishing a main surface of a circular glass plate while supplying a polishing slurry containing a polishing material, in which polishing is performed, after a polishing surface is subjected to dressing treatment, by using a polishing pad having: a first resin foam layer which forms the polishing surface, includes a resin foam having pores with a pore diameter of more than 20 ?m and has a thickness of 400 ?m or less; and a second resin foam layer which is provided between a platen for fixing the polishing pad and the first resin foam layer, includes a resin foam having pores with a pore diameter of 20 ?m or less and has a thickness of 50 to 250 ?m, and in which a total thickness of the first resin foam layer and the second resin foam layer is 550 ?m or less, and a international rubber hardness degree of the polishing pad measured by the M method according to JIS K6253 is 40 IRHD or mor
    Type: Grant
    Filed: December 1, 2009
    Date of Patent: January 10, 2012
    Assignee: Asahi Glass Company, Limited
    Inventors: Mizuho Ishida, Norihito Shida, Katsuhiro Matsumoto, Kazuo Mannami
  • Patent number: 7857680
    Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeO2 crystal powder, the CeO2 crystal powder being obtained in such a manner that a melt containing CeO2 is quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeO2 crystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeO2 crystal powder from the CeO2 crystals-precipitated amorphous material.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: December 28, 2010
    Assignee: Asahi Glass Company, Limited
    Inventors: Katsuaki Miyatani, Osamu Miyahara, Yuzuru Tanabe, Hiroshi Usui, Yoshihisa Beppu, Kazuo Sunahara, Mitsuru Horie, Satoshi Kashiwabara, Tomohiro Sakai, Yoshinori Kon, Iori Yoshida
  • Patent number: 7179551
    Abstract: A storage media comprises: a substrate comprising a plastic resin portion, wherein to plastic resin portion comprises poly(arylene ether) and a styrene material selected from the group consisting of polystyrene, styrenic copolymer(s), and reaction products and combinations comprising at least one of the foregoing styrene material(s), and a data layer on the substrate. The data layer can be at least partly read from, written to, or a combination thereof by an energy field. Additionally, when the energy field contacts the storage media, the energy field is incident upon the data layer before it could be incident upon the substrate.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: February 20, 2007
    Assignee: General Electric Company
    Inventors: Thomas Paul Feist, Kevin Hsingtao Dai, Glen David Merfeld
  • Patent number: RE42824
    Abstract: A magneto-optical device including a substrate which is transparent to light in a visible spectrum region and, a plurality of ferromagnetic layers arranged thereon, each ferromagnetic layer preferably having a width ranging from in an inclusive range of 5 to through 100 nanometers and a thickness ranging from in an inclusive range of 0.1 to through 5 microns. The, wherein said ferromagnetic layers are parallel to each other and separated by a distance ranging from in an inclusive range of 0.2 to through 2 microns. The ferromagnetic layers are arranged preferably on the side walls of grooves formed parallel to each other in the transparent substrate.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: October 11, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Tadao Katsuragawa