Patents by Inventor Naomasa Nakamura

Naomasa Nakamura 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
    Patent number: 7995442
    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: Grant
    Filed: April 5, 2010
    Date of Patent: August 9, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • Signal processing system and information storage medium
    Patent number: 7949071
    Abstract: According to one embodiment, a first encoder encodes main information, a second encoder encodes sub-information, a first modulator modulates a carrier based on an output of the first encoder, a duplicating module duplicates an output of the second encoder to generate encoded sub-information units, and a second modulator amplitude-modulates an output of the first modulator based on the encoded sub-information units. The second modulator amplitude-modulates with ?/(?×(2N)1/2) being 0.4 or less, wherein a noise power of a transmission path or a storage medium is ?2, a number of the encoded sub-information units is N, signal levels after amplitude modulation, which correspond to bit 1 and bit 0 of the encoded sub-information units, are A and B, and a level difference A?B is ?.
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: May 24, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuji Nagai, Chosaku Noda, Kazuo Watabe, Akihito Ogawa, Kazuto Kuroda, Nobuhisa Yoshida, Nobumasa Naito, Naoki Morishita, Naomasa Nakamura, Hideaki Ohsawa, Hiroharu Sato, Hisashi Yamada, Toshihiko Kaneshige
  • MULTI-LAYER OPTICAL DISC, INFORMATION RECORDING METHOD AND INFORMATION REPRODUCING METHOD
    Publication number: 20110085434
    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: Application
    Filed: December 20, 2010
    Publication date: April 14, 2011
    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
    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
  • 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
  • Write-once information recording medium and coloring matter material therefor
    Patent number: 7876666
    Abstract: A write-once information recording medium comprises a transparent resin substrate having a concentrically or spirally shaped groove and a land formed thereon, and a recording firm formed on the groove and the land of the transparent resin substrate, a recording mark being formed on the medium by emission of a short wavelength laser light, the recording medium having an L to H feature in which a light reflectivity of the recording mark portion formed by the emission of the short wavelength laser light is higher than a light reflectivity obtained before the emission of the short wavelength laser light.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: January 25, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Seiji Morita, Koji Takazawa, 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
  • Phase change recording medium
    Patent number: 7858166
    Abstract: According to one embodiment, in a phase change optical disk which has a substrate and a multi-layered including an interference film, phase change recording film, interface film, and reflecting film, and in which information is reversibly recorded in or erased from the recording film by using light, an element (e.g., Ge or Te) forming the phase change recording film has segregation or a concentration distribution in the thickness direction of the recording film from a portion in contact with the phase change recording film.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: December 28, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Noritake Oomachi, Sumio Ashida, Naomasa Nakamura, Keiichiro Yusu, Yasuhiro Satoh
  • 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
  • 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
  • Phase-change optical recording medium
    Patent number: 7767285
    Abstract: A phase-change optical recording medium has a recording film that brings about reversible phase-change between a crystalline phase and an amorphous phase upon irradiation with light and an interface film formed in contact with at least one surface of the recording film and comprising hafnium (Hf), silicon (Si), oxygen (O) and carbon (C).
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: August 3, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Sumio Ashida, Keiichiro Yusu, Takayuki Tsukamoto, Noritake Oomachi, Naomasa Nakamura, Katsutaro Ichihara
  • 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
  • Optical recording medium, and information recording/playback apparatus and method using the medium
    Patent number: 7736715
    Abstract: In a single-sided, recordable/rewritable phase change optical recording medium having one or more layers, an interface layer adjacent to a phase change optical recording film contains at least Zr (zirconium), O (oxygen), and N (nitrogen), and further contains one or both of Y (yttrium) and Nb (niobium).
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: June 15, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Noritake Oomachi, Sumio Ashida, Naomasa Nakamura, Keiichiro Yusu, Yasuhiro Satoh
  • SIGNAL PROCESSING SYSTEM AND INFORMATION STORAGE MEDIUM
    Publication number: 20100135436
    Abstract: According to one embodiment, a first encoder encodes main information, a second encoder encodes sub-information, a first modulator modulates a carrier based on an output of the first encoder, a duplicating module duplicates an output of the second encoder to generate encoded sub-information units, and a second modulator amplitude-modulates an output of the first modulator based on the encoded sub-information units. The second modulator amplitude-modulates with ?/(?×(2N)1/2) being 0.4 or less, wherein a noise power of a transmission path or a storage medium is ?2, a number of the encoded sub-information units is N, signal levels after amplitude modulation, which correspond to bit 1 and bit 0 of the encoded sub-information units, are A and B, and a level difference A?B is ?.
    Type: Application
    Filed: November 25, 2009
    Publication date: June 3, 2010
    Inventors: Yuji NAGAI, Chosaku Noda, Kazuo Watabe, Akihito Ogawa, Kazuto Kuroda, Nobuhisa Yoshida, Nobumasa Naito, Naoki Morishita, Naomasa Nakamura, Hideaki Ohsawa, Hiroharu Sato, Hisashi Yamada, Toshihiko Kaneshige
  • Optical recording medium, information recording method, and information reproducing method
    Patent number: 7715304
    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: Grant
    Filed: May 31, 2007
    Date of Patent: May 11, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20100110868
    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 18, 2009
    Publication date: May 6, 2010
    Inventors: Koji TAKAZAWA, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • Phase-change optical recording media and optical recording-reproducing apparatus
    Patent number: 7643397
    Abstract: The present invention relates to an optical recording media including two or more information layers, at least one of the information layers including a writable recording film. In the optical recording media, at least one information layer has protrusions and recesses that permit tracking and at least another one information layer is substantially flat.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: January 5, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Yasuaki Ootera, Sumio Ashida, Keiichiro Yusu, Nobuhisa Yoshida, Koji Takazawa, Naomasa Nakamura
  • RECORDABLE INFORMATION RECORDING MEDIUM
    Publication number: 20090324891
    Abstract: According to one embodiment, a recordable information recording medium includes an organic dye layer contains an organic dye including a cation portion having monomethinecyanine and an anion portion having an azo metal complex, and a quencher having a formazan metal complex.
    Type: Application
    Filed: June 30, 2009
    Publication date: December 31, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Seiji Morita, Kazuyo Umezawa, Koji Takazawa, Naoki Morishita, Naomasa Nakamura