Patents by Inventor Kazuyo Umezawa

Kazuyo Umezawa 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).

  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20110075548
    Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the first light reflecting layer is smaller than the thickness of the second light reflecting layer.
    Type: Application
    Filed: December 6, 2010
    Publication date: March 31, 2011
    Inventors: Koji TAKAZAWA, Seiji MORITA, Kazuyo UMEZAWA, Naoki MORISHITA, Yasuaki OOTERA, Hideo ANDO, Naomasa NAKAMURA
  • Storage medium, reproducing method, and recording method
    Patent number: 7914969
    Abstract: According to one embodiment, a write-once type information storage medium comprises a recording layer which is formed by mixing a plurality of organic dye based recording materials whose molecular weights are different from each other, and wherein a mixture ratio of organic dye based recording materials whose molecular weight is small is larger than a mixture ratio of organic dye based recording materials whose molecular weight is large.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: March 29, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideo Ando, Seiji Morita, Koji Takazawa, Yasuaki Ootera, Naoki Morishita, Kazuyo Umezawa
  • Write-once information recording medium and disk apparatus
    Patent number: 7885173
    Abstract: According to one embodiment, a write-once information recording medium includes a transparent resin substrate having concentric or spiral grooves and lands, and a recording film formed on the grooves and lands of the transparent resin substrate, wherein the recording film includes an organic dye layer containing a metal complex monomer and a metal complex polymer, a recording mark is formed in the organic dye layer by emission of a short-wavelength laser beam, and a light reflectance of the recording mark formed by emission of the short-wavelength laser beam is higher than that before emission of the short-wavelength laser beam, and the grooves wobble within a predetermined amplitude range.
    Type: Grant
    Filed: January 29, 2009
    Date of Patent: February 8, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Seiji Morita, Koji Takazawa, Kazuyo Umezawa, Naoki Morishita, Naomasa Nakamura
  • Multi-layer optical disc, information recording method and information reproducing method
    Patent number: 7869339
    Abstract: According to one embodiment, single-sided dual-layer recordable disc 100 may be used. Information recording is performed by forming mark and space portions on data area DA using modulated laser power. Pp denotes the maximum laser power or peak power for forming the mark portion, and Pb denotes the bias power for forming the space portion. Power ratio Pb/Pp is calculated for each of recording layers L0 and L1. Information is recorded on any of the recording layers L0 and L1 based on the result of calculation. Here, the calculated power ratio Pb/Pp changes among the recording layers L0 and L1, thereby optimizing the recording condition for a multi-layer recordable optical disc within relatively short time.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: January 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuyo Umezawa, Seiji Morita, Koji Takazawa, Hideo Ando, Yasuaki Ootera, Naomasa Nakamura, Naoki Morishita
  • Optical recording medium, information recording method, and information reproducing method
    Patent number: 7864654
    Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the first light reflecting layer is smaller than the thickness of the second light reflecting layer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: January 4, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • STORAGE MEDIUM, REPRODUCING METHOD, AND RECORDING METHOD
    Publication number: 20100329099
    Abstract: According to an embodiment, a storage medium includes a transparent resin substrate having a concentric or spiral groove and a recording film formed on the groove on the transparent resin substrate, a recording mark being formed by irradiation of a laser beam, wherein a reproduction durability count in a case where reproduction is continuously carried out by a laser beam is 1,000,000 or more.
    Type: Application
    Filed: August 31, 2010
    Publication date: December 30, 2010
    Inventors: SEIJI MORITA, Koji Takazawa, Kazuyo Umezawa, Hideo Ando, Yasuaki Ootera, Naoki Morishita, Naomasa Nakamura
  • STORAGE MEDIUM, REPRODUCING METHOD, AND RECORDING METHOD
    Publication number: 20100309772
    Abstract: According to one embodiment, a write-once type information storage medium comprises an organic dye based recording material having sensitivity at a wavelength of 405 nm and at a recording wavelength in the range of 600 nm to 700 nm, wherein, when absorbance of a maximum absorption wavelength in the vicinity of 405 nm is defined as 1, the absorbance is 5% or more at any wavelength in the range of 600 nm to 700 nm.
    Type: Application
    Filed: July 28, 2010
    Publication date: December 9, 2010
    Inventors: Hideo ANDO, Seiji Morita, Koji Takazawa, Yasuaki Ootera, Naoki Morishita, Kazuyo Umezawa
  • STORAGE MEDIUM, REPRODUCING METHOD, AND RECORDING METHOD
    Publication number: 20100302926
    Abstract: According to one embodiment, a write-once type information storage medium comprises an organic dye based recording material having sensitivity at a wavelength of 405 nm and at a recording wavelength in the range of 600 nm to 700 nm, wherein, when absorbance of a maximum absorption wavelength in the vicinity of 405 nm is defined as 1, the absorbance is 5% or more at any wavelength in the range of 600 nm to 700 nm.
    Type: Application
    Filed: August 13, 2010
    Publication date: December 2, 2010
    Inventors: Hideo ANDO, Seiji Morita, Koji Takazawa, Yasuaki Ootera, Naoki Morishita, Kazuyo Umezawa
  • STORAGE MEDIUM, REPRODUCING METHOD, AND RECORDING METHOD
    Publication number: 20100290327
    Abstract: According to one embodiment, a write-once type information storage medium comprises an organic dye based recording material having sensitivity at a wavelength of 405 nm and at a recording wavelength in the range of 600 nm to 700 nm, wherein, when absorbance of a maximum absorption wavelength in the vicinity of 405 nm is defined as 1, the absorbance is 5% or more at any wavelength in the range of 600 nm to 700 nm.
    Type: Application
    Filed: July 28, 2010
    Publication date: November 18, 2010
    Inventors: Hideo ANDO, Seiji Morita, Koji Takazawa, Yasuaki Ootera, Naoki Morishita, Kazuyo Umezawa
  • INFORMATION RECORDING MEDIUM AND DISK APPARATUS USING THE MEDIUM
    Publication number: 20100246366
    Abstract: According to one embodiment, an information recording medium has a plurality of recording layers, and records and reproduces information by using a semiconductor layer of 450 nm or less. When reproducing information, letting x be the frequency of repetitive recording of a shortest mark length and shortest space length of the information, the ratio of the value of a highest level to the value of a level at x/190 of a sum signal detected within the frequency range of x/3240 to x/190 is lower than 32 dB, or the ratio of the average value of the amplitudes of signals of repetitive recording of the shortest mark length and shortest space length to the value of the highest level within the frequency range of x/3240 to x/190 is higher than 10 dB.
    Type: Application
    Filed: June 7, 2010
    Publication date: September 30, 2010
    Inventors: Kazuyo UMEZAWA, Seiji Morita, Koji Takazawa, Naomasa Nakamura, Naoki Morishita, Shinichi Katsuda
  • MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD
    Publication number: 20100237041
    Abstract: According to one embodiment, a cured first ultraviolet-curing resin material layer having a first three-dimensional pattern is formed on a first principal surface of a magnetic recording medium having a central hole. A cured second ultraviolet-curing resin material layer having a second three-dimensional pattern is formed on a second principal surface opposite to the first principal surface of the magnetic recording.
    Type: Application
    Filed: March 16, 2010
    Publication date: September 23, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Seiji Morita, Shinobu Sugimura, Kazuyo Umezawa, Masatoshi Sakurai
  • RESIN STAMPER FOR PATTERN TRANSFER AND MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD USING THE SAME
    Publication number: 20100233514
    Abstract: According to one embodiment, pattern transfer is performed using a combination of an ultraviolet-curable resin having a surface tension of 31 to 39 mN/m and a stamper having a critical surface tension of 31 mN/m or less.
    Type: Application
    Filed: March 12, 2010
    Publication date: September 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo Umezawa, Seiji Morita, Shinobu Sugimura, Masatoshi Sakurai
  • ULTRAVIOLET-CURING RESIN MATERIAL FOR PATTERN TRANSFER AND MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD USING THE SAME
    Publication number: 20100230384
    Abstract: According to one embodiment, an ultraviolet-curing resin material for pattern transfer contains at least one of 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, and 1,3-adamantanedimethanol diacrylate, isobornyl acrylate, polyfunctional acrylate, and a polymerization initiator, or contains at least one of the acrylates described above, a polymerization initiator, and fluorine-based alcohol.
    Type: Application
    Filed: March 12, 2010
    Publication date: September 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Seiji Morita, Kazuyo Umezawa, Masatoshi Sakurai
  • ULTRAVIOLET-CURABLE RESIN MATERIAL FOR PATTERN TRANSFER AND MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD USING THE SAME
    Publication number: 20100230383
    Abstract: According to one embodiment, this invention uses an ultraviolet-curable resin material for pattern transfer containing 80 to 95 wt % of isobornyl acrylate, 1 to 20 wt % of trifunctional acrylate, and 0.5 to 6 wt % of a polymerization initiator.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo Umezawa, Seiji Morita, Masatoshi Sakurai
  • Optical recording medium, information recording method, and information reproducing method
    Patent number: 7778144
    Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the first light reflecting layer is smaller than the thickness of the second light reflecting layer.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: August 17, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • STAMPER AND STAMPER EVALUATION METHOD
    Publication number: 20100188952
    Abstract: According to one embodiment, this invention determines whether a maximum value Hmax and minimum value Hmin of an HF signal obtained when a data recording portion is irradiated with a laser having a wavelength of 450 nm or less and an NA of 0.6 or more meet (Hmax?Hmin)/Hmax<0.13 . . . (1), or whether a maximum value Hmax, a minimum value Hmin, and a most frequent voltage value Have of a signal level of an HF signal obtained when a data recording portion is irradiated with a laser having a wavelength of 450 nm or less and an NA of 0.6 or more meet Hmax/Have?1.05 . . . (2) and Hmin/Have?0.90 . . . (3).
    Type: Application
    Filed: October 1, 2009
    Publication date: July 29, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo UMEZAWA, Seiji MORITA, Masatoshi SAKURAI
  • STAMPER AND STAMPER EVALUATION METHOD
    Publication number: 20100188964
    Abstract: According to one embodiment, letting Vf be a maximum voltage value level within the range of a frequency 60 to 170 times the rotational speed of a stamper and Vave be the average sum signal voltage value of a data recording portion in the sum signal of a voltage signal when the data recording portion is irradiated with a laser having a wavelength of 450 nm or less and an NA of 0.6 or more, whether Vf and Vave meet Vf/Vave<7.7×10?4 . . . (1) is determined.
    Type: Application
    Filed: September 29, 2009
    Publication date: July 29, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo UMEZAWA, Seiji MORITA, Masatoshi SAKURAI
  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20100188963
    Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.
    Type: Application
    Filed: April 5, 2010
    Publication date: July 29, 2010
    Inventors: Koji TAKAZAWA, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD
    Publication number: 20100159281
    Abstract: According to one embodiment, an ultraviolet-curable resin material to be used contains a monomer represented by formula (1) presented earlier, a resin stamper is used as a stamper, and the surface of a magnetic recording layer and the three-dimensional pattern surface of the resin stamper are contacted in a vacuum.
    Type: Application
    Filed: December 21, 2009
    Publication date: June 24, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Seiji Morita, Kazuyo Umezawa, Shinobu Sugimura, Masatoshi Sakurai
  • STAMPER, STAMPER TESTING METHOD, AND STAMPER TESTING APPARATUS
    Publication number: 20100148095
    Abstract: According to one embodiment, a stamper has a data area and servo area, and has concentric or spiral grooves formed in the data area.
    Type: Application
    Filed: August 10, 2009
    Publication date: June 17, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo Umezawa, Seiji Morita, Masatoshi Sakurai