Having Specified Property (e.g., Average Roughness (ra) Etc.) Patents (Class 428/845.5)
  • Patent number: 11056143
    Abstract: A magnetic recording medium is provided and includes a magnetic layer, a non-magnetic layer, a base layer and a back layer, wherein an average thickness tT of the magnetic recording medium is tT?5.3 ?m, a dimensional change amount ?w in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N??w, a thickness of the non-magnetic layer is 2.0 ?m or less, a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more, and the magnetic layer includes a magnetic powder.
    Type: Grant
    Filed: December 4, 2019
    Date of Patent: July 6, 2021
    Assignee: Sony Corporation
    Inventors: Minoru Yamaga, Noboru Sekiguchi, Tooru Sato, Takashi Aizawa
  • Patent number: 10923148
    Abstract: There is provided a magnetic recording medium which has a layer structure including a magnetic layer and a base layer, and of which an average thickness tT is tT?5.6 ?m, a dimensional change amount ?w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/N??w, a servo pattern is recorded on the magnetic layer, a standard deviation ?PES of a position error signal (PES) value obtained from a servo signal in which the servo pattern is reproduced is ?PES?25 nm, and a maximum value ?1M of a friction coefficient ?1 between a surface on a side of the magnetic layer and an LTO3 head in a case where measurement of the friction coefficient ?1 is performed 250 times is 0.04??1M?0.5.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: February 16, 2021
    Assignee: Sony Corporation
    Inventors: Taikei Enomoto, Masaru Terakawa, Minoru Yamaga
  • Patent number: 8315017
    Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. A height of protrusions with a protrusion density of 0.002 protrusion/?m2 or lower on a surface of the magnetic layer as measured by AFM is 40 nm or lower; a density of protrusions that are 15 nm or higher in height on the surface of the magnetic layer as measured by AFM ranges from 0.01 to 0.18 protrusion/?m2; and the protrusions that are 15 nm or higher in height include protrusions formed of carbon black and protrusions formed of a substance with a Mohs' hardness exceeding 7, and an average height of the protrusions formed of carbon black is greater than an average height of the protrusions formed of the substance with a Mohs' hardness exceeding 7.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: November 20, 2012
    Assignee: Fujifilm Corporation
    Inventor: Kazutoshi Katayama
  • Patent number: 7534508
    Abstract: A leader tape has, on at least one face of a support, a coating layer that contains a powder and a binder, which is characterized in that the center line average roughness (Ra) of at least one face of the leader tape is from 10 to 60 nm, the leader tape is used in a magnetic recording and reproduction device where the line recording density is at least 100 kfci, and the difference between the recording track width and the reproduction track width is from 0 to 16 ?m.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: May 19, 2009
    Assignee: FUJIFILM Corporation
    Inventor: Mikio Ohno
  • Patent number: 7494728
    Abstract: A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the magnetic layer contains the magnetic powder which comprises plate, granular or ellipsoidal magnetic particles with a particle diameter of 5 to 50 nm, and has a thickness of 0.09 ?m or less, and wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: February 24, 2009
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto
  • Patent number: 7384700
    Abstract: A leader tape comprising a support and a coating layer containing powder and a binder, wherein at least one surface of the leader tape has a center line average surface roughness (Ra) of from 10 to 60 nm, and depression hardness (DH) defined by the following equation (1) of from 60 to 140 kg/mm2 (0.588 to 1.372 GPa): DH=3.7926×10?2[Pmax/(Hmax)2](kg/mm2) ??(1) wherein Pmax is a maximum load and Hmax is a maximum displacement amount of an indenter.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: June 10, 2008
    Assignee: FUJIFILM Corporation
    Inventor: Satoru Hayakawa
  • Patent number: 7368189
    Abstract: A magnetic recording medium comprising: a magnetic layer containing ferromagnetic powder and a binder; a nonmagnetic support; and a back coat layer, in this order, wherein the nonmagnetic support contains polyester having an intrinsic viscosity of from 0.40 to 0.60 dl/g and a number average molecular weight of from 12,000 to 24,000, a surface of the magnetic layer on a side not having the nonmagnetic support has a surface roughness Ra of from 1 to 5 nm, and a surface of the back coat layer on a side not having the nonmagnetic support has a surface roughness Ra of from 6 to 20 nm.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: May 6, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Mikio Ohno, Tatsuo Ishikawa, Tomohiro Ichikawa
  • Patent number: 7361422
    Abstract: A leader tape in which an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one side of a support, a center line average roughness (Ra) of a surface of the support is from 30 to 50 nm, and a center line average roughness (Ra) of the multi layer coated surface is larger than that (Ra) of an opposite surface of the support, and the difference is at most 4 nm.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: April 22, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Masatoshi Takahashi, Mikio Ohno
  • Patent number: 7348079
    Abstract: A magnetic recording medium is provided that has on a non-magnetic support, in order, a radiation-cured layer formed by curing a layer containing a radiation curing compound by exposure to radiation, a lower layer having a non-magnetic powder and/or a magnetic powder dispersed in a binder, and at least one magnetic layer having a ferromagnetic powder dispersed in a binder. The binder of at least the magnetic layer is a binder having a glass transition temperature of 100° C. to 200° C., and the magnetic layer has on its surface a number of micro projections having a height of 10 to 20 nm measured by atomic force microscopy (AFM) of 5 to 1,000/100 ?m2.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: March 25, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Yuichiro Murayama, Hiroshi Hashimoto
  • Patent number: 7144643
    Abstract: The invention provides a high performance magnetic recording medium used in the magnetic recording system using the MR head for the regeneration head, wherein the magnetic recording medium does not damage the MR head by direct sliding contact while having durability and self-cleaning power enough for preventing abrasion of the magnetic recording medium itself.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: December 5, 2006
    Assignee: TDK Corporation
    Inventors: Kenichi Kitamura, Hiroyuki Yamada
  • Patent number: 7029774
    Abstract: A magnetic recording medium including a substrate, a magnetic side, and a backside. The substrate defines a first surface and a second surface opposite the first surface. The magnetic side is formed over the first surface of the substrate and defines a recording surface. The backside is coated on the second surface of the substrate and is configured to decrease embossment of the recording surface. The backside defines a backside surface opposite the substrate. The backside surface having a skew less than about 0.5 and a kurtosis less than about 4.0.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: April 18, 2006
    Assignee: Imation Corp.
    Inventors: James A. Greczyna, Brian D. Brong, Stephen R. Ebner
  • Patent number: 7018730
    Abstract: Data storage tape includes a substrate having a first side and a second side opposite the first side, a recording layer disposed on the first side of the substrate, and a coating disposed on the second side of the substrate. A surface of the coating has a pattern formed therein such that the pattern communicates with at least one of a first edge and a second edge of the data storage tape.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: March 28, 2006
    Assignee: Imation Corp.
    Inventors: Steven L. Lindblom, C. Thomas Jennings, Larold L. Olson
  • Patent number: 7011900
    Abstract: A magnetic recording medium is prepared by coating a dispersion of non-magnetic powder and ferromagnetic powder in a binder and a dispersion of ferromagnetic powder in a binder to a non-magnetic substrate by a wet-on-wet coating technique to form subordinate and magnetic layers on the substrate, and subjecting the layers to magnetic field orientation. The subordinate layer has a Br of 80 to 400 gauss, and the magnetic layer has a thickness of 0.1 to 0.4 ?m. The medium has surface smoothness and good electromagnetic characteristics and lends itself to recording and reproducing signals having a minimum wavelength of 0.2 to 0.7 ?m.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: March 14, 2006
    Assignee: TDK Corporation
    Inventors: Akihiko Seki, Takayoshi Kuwajima, Naoto Yajima
  • Patent number: 7011899
    Abstract: A magnetic recording medium comprising a backcoating layer, a support, and a magnetic layer containing ferromagnetic powder, the backcoating layer having 800 to 1500 projections of 50 nm or more and less than 75 nm in height per 6400 ?m2 and 600 or less projections of 75 nm or more in height per 6400 ?m2.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: March 14, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Kazuo Kato