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).

  • WRITE ONCE INFORMATION RECORDING MEDIUM AND DISK APPARATUS
    Publication number: 20080002562
    Abstract: According to one embodiment, in a multilayered write once information recording medium, the light reflectance of a recording mark formed in a first recording film by irradiation with a short-wavelength laser beam is higher than a light reflectance before irradiation with the short-wavelength laser beam, the light reflectance of a recording mark formed in a second recording film by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam, and the light reflectance of a recording mark formed in a third recording film, which is arbitrarily formed, by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 3, 2008
    Inventors: Seiji Morita, Koji Takazawa, Kazuyo Umezawa, Naoki Morishita, Naomasa Nakamura
  • INFORMATION RECORDING MEDIUM AND DISC APPARATUS
    Publication number: 20080002563
    Abstract: According to one embodiment, an information recording medium has two or more recording layers, the track pitch falls within the range from 250 to 500 nm, and the half maximum full-width of the groove of the substrate falls within the range from 47.5% to 72.5%.
    Type: Application
    Filed: June 27, 2007
    Publication date: January 3, 2008
    Inventors: Ryosuke YAMAMOTO, Masaaki MATSUMARU, Kazuyo UMEZAWA, Koji TAKAZAWA, Seiji MORITA, Naomasa NAKAMURA, Hideo ANDO
  • Single-sided, multilayered optical disc, BCA recording apparatus, BCA recording method, and optical disc apparatus
    Publication number: 20070298207
    Abstract: According to one embodiment, a single-sided, multilayered optical disc which performs recording and playback when irradiated with a laser beam having a predetermined wavelength, and has at least two recording layers that are independent of each other with respect to the light incident surface, a reflecting layer farthest from the light incident surface contains an Ag alloy, and has a light absorbance of 20% (inclusive) to 50% (inclusive) to a laser beam and/or a thermal conductivity of 50 (inclusive) to 250 (inclusive) W/m·K.
    Type: Application
    Filed: June 19, 2007
    Publication date: December 27, 2007
    Inventors: Keiichiro Yusu, Naomasa Nakamura, Nobuhisa Yoshida, Koji Takazawa, Seiji Morita, Hideo Ando
  • Write-once type multilayer optical disc, recording method, reproducing method, and recording device
    Publication number: 20070286980
    Abstract: Manufacturing of a higher quality write-once type multilayer optical disc is facilitated. The optical disc includes a plurality of recording layers in which recording or reproduction is carried out by a blue or blue-violet laser beam of a wavelength of about 405 nm. Each of the recording layers includes a recording layer which uses an organic dye. The plurality of recording layers includes a layer in which a groove pattern around a recording mark is deformed when information is recorded, and a layer in which the groove pattern around the recording mark is not deformed when information is recorded.
    Type: Application
    Filed: June 6, 2007
    Publication date: December 13, 2007
    Inventors: Yasuaki Ootera, Kazuyo Umezawa, Koji Takazawa, Naoki Morishita, Hideo Ando, Seiji Morita, Naomasa Nakamura
  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20070280092
    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: May 30, 2007
    Publication date: December 6, 2007
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • OPTICAL DISC, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20070281123
    Abstract: According to one embodiment, a re-recordable write-once optical disc by which recording/reproducing can be properly done with a short-wavelength blue laser is provided. The disc has recording layers on which marks are recorded by the laser power of a modulated short wavelength, with a space formed between the recorded marks. The recording layer of the disc uses an organic dye material by which no physical modification or no physical change substantially occurs in an area of the recorded marks.
    Type: Application
    Filed: May 23, 2007
    Publication date: December 6, 2007
    Inventors: Kazuyo Umezawa, Seiji Morita, Koji Takazawa, Hideo Ando, Yasuaki Ootera, Naomasa Nakamura, Naoki Morishita
  • OPTICAL DISC, INFORMATION RECORDING METHOD, INFORMATION REPRODUCING METHOD, AND DISC DRIVE
    Publication number: 20070280095
    Abstract: According to one embodiment, a write-once optical disc which uses a short-wavelength laser allows BCA information recording even using a long-wavelength laser. To this end, a groove is cut in advance on a BCA part on a molded substrate of the optical disc to store a dye. In this way, the sensitivity of the dye in the BCA increases, to allow a laser having a wavelength other than the wavelength corresponding to information recording of the dye to record a barcode pattern on the BCA.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 6, 2007
    Inventors: Nobuhisa YOSHIDA, Yasuaki Ootera, Kazuyo Umezawa, Naomasa Nakamura, Koji Takazawa, Hideo Ando
  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20070280094
    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, in this optical recording medium, an intermediate layer whose thickness variation is managed to be equal to or less than a predetermined value is provided between a first recording part and a second recording part.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 6, 2007
    Inventors: Koji Takazawa, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • MULTI-LAYER OPTICAL DISC, INFORMATION RECORDING METHOD AND INFORMATION REPRODUCING METHOD
    Publication number: 20070280068
    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: May 30, 2007
    Publication date: December 6, 2007
    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: 20070280093
    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: May 31, 2007
    Publication date: December 6, 2007
    Inventors: Koji TAKAZAWA, Seiji Morita, Kazuyo Umezawa, Naoki Morishita, Yasuaki Ootera, Hideo Ando, Naomasa Nakamura
  • RECORDABLE MULTILAYER OPTICAL DISK, RECORDING METHOD, REPRODUCING METHOD, AND RECORDING APPARATUS
    Publication number: 20070275205
    Abstract: For example, a recordable single-sided two-layer optical disk which is recorded into and reproduced from with light whose wavelength is 405 nm is so configured that, if the front layer is an L0 layer and the inner layer is an L1 layer when viewed from the light entrance surface (or the light-receiving surface), the absorbance of the L1 layer in the wavelength range of 600 to 800 nm is higher than that of the L0 layer. In a part of the L1 layer whose absorbance to light in the range of 600 to 800 nm is high, an area (BCA) in which specific information on the optical disk is to be recorded is provided.
    Type: Application
    Filed: March 12, 2007
    Publication date: November 29, 2007
    Inventors: Yasuaki Ootera, Kazuyo Umezawa, Koji Takazawa, Naoki Morishita, Hideo Ando, Seiji Morita, Naomasa Nakamura
  • Phase-change optical recording medium
    Patent number: 7294382
    Abstract: A phase-change optical recording medium has a phase-change recording film to which recording and erasure can be reversibly performed by irradiation with light, and at least one dielectric film formed of a SiOC film containing Si, O and C, and having a carbon concentration within a range of between 0.1 and 30 atomic %.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: November 13, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Sumio Ashida, Keiichiro Yusu, Takayuki Tsukamoto, Noritake Oomachi, Naomasa Nakamura, Katsutaro Ichihara
  • Phase-change optical recording medium
    Patent number: 7291375
    Abstract: A phase-change optical recording medium has a phase-change recording film to which recording and erasure can be reversibly performed by irradiation with light, and at least one dielectric film formed of a SiOC film containing Si, O and C, and having a carbon concentration within a range of between 0.1 and 30 atomic %.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: November 6, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsukasa Nakai, Sumio Ashida, Keiichiro Yusu, Takayuki Tsukamoto, Noritake Oomachi, Naomasa Nakamura, Urara Ichihara, legal representative, Katsutaro Ichihara, deceased
  • OPTICAL RECORDING MEDIUM, INFORMATION RECORDING AND REPRODUCING APPARATUS, AND INFORMATION RECORDING AND REPRODUCING METHOD
    Publication number: 20070248785
    Abstract: According to one embodiment, in a phase-change optical disk which has a substrate and a stacked structure including an interference film, a phase-change recording film, an interface film, and a reflecting film and which enables the recording film to be recorded into or erased from reversibly with light, the elements constituting the recording film have a segregation or a concentration distribution in the direction of the thickness of the recording film from a region in contact with the phase-change recording film, or in the in-plane direction (or in the direction perpendicular to the thickness) of the recording film.
    Type: Application
    Filed: April 17, 2007
    Publication date: October 25, 2007
    Inventors: Tsukasa Nakai, Noritake Oomachi, Sumio Ashida, Naomasa Nakamura, Keiichiro Yusu, Yasuhiro Satoh
  • OPTICAL DISK, OPTICAL DISK APPARATUS, AND OPTICAL DISK REPRODUCING METHOD
    Publication number: 20070242596
    Abstract: According to one embodiment, a multilayer optical disk includes three or more recording layers, and one of conditions (1) Rn/((Rn?1+Rn?2)/2)>0.6, and (2) Rn×(100?Rn?1)2/(Rn?2×Rn?1×Rn?1)>30 is satisfied, where Rn(%) is a reflectivity of an nth layer (n>2) when seen from a surface on which a reproducing light is incident.
    Type: Application
    Filed: March 23, 2007
    Publication date: October 18, 2007
    Inventors: Yasuaki Ootera, Nobuhisa Yoshida, Naomasa Nakamura
  • Optical disk and optical disk device
    Publication number: 20070230321
    Abstract: According to one embodiment, there is provided an optical disk including a substrate layer having a refractive index of 1.50 to 1.70 and a thickness X (?m) equal to or greater than f (n)?13 ?m, a first information layer formed on the substrate layer, an adhesive layer formed on the first information layer and having a thickness Y (?m) equal to or greater than 20 ?m, and a second information layer formed on the adhesive layer, wherein X+Y?f (n)+30 ?m and f(n)<X+Y/2 are satisfied and f (n) is given by the formula f (n)=(A1×n3)(n2+A2)/(n2?1)(n2+A3)×1000 (?m), where “n” is a refractive index of the substrate layer, A1 is 0.26200, A2 is ?0.32400, and A3 is 0.00595.
    Type: Application
    Filed: March 5, 2007
    Publication date: October 4, 2007
    Inventors: Noritake Oomachi, Tsukasa Nakai, Naomasa Nakamura, Keiichiro Yusu, Sumio Ashida
  • OPTICAL DISK, OPTICAL DISK MANUFACTURING METHOD, AND OPTICAL DISK REPRODUCING METHOD
    Publication number: 20070231528
    Abstract: According to one embodiment, there is provided an optical disk including a photopolymer layer including a recording pattern formed by concave pits, and a reflecting film formed on the photopolymer layer. The depth direction of the concave pits is opposite to the direction in which the reflecting film is formed.
    Type: Application
    Filed: March 19, 2007
    Publication date: October 4, 2007
    Inventors: Yasuaki OOTERA, Ryosuke YAMAMOTO, Nobuhisa YOSHIDA, Naomasa NAKAMURA
  • Optical disk and optical disk device
    Publication number: 20070217319
    Abstract: An optical disk including first information layer having first guide grooves consisting of first protrusive flat portion having first width and first recessed flat portion having a second width having first height difference from the first protrusive flat portion, the first information layer being formed on the transparent substrate layer, second information layer having second guide grooves consisting of second protrusive flat portion having third width formed on second recessed flat portion having fourth width having second height difference, the second information layer, wherein cycle P (?m) of the first and second guide grooves has value ranging from 0.35 ?m to 0.8 ?m and has relationship of Q1=2Z1/(P?X1?Y1), Q2=2Z2/(P?X2?Y2), 0.9<Q2/Q1<1.5, and 1<X1/Y1<4, 0.25<X2/Y2<1 is satisfied.
    Type: Application
    Filed: March 5, 2007
    Publication date: September 20, 2007
    Inventors: Noritake Oomachi, Masaaki Matsumaru, Naomasa Nakamura, Ryosuke Yamamoto, Tsukasa Nakai
  • PHASE CHANGE RECORDING MEDIUM
    Publication number: 20070178272
    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: Application
    Filed: January 31, 2007
    Publication date: August 2, 2007
    Inventors: Tsukasa NAKAI, Noritake Oomachi, Sumio Ashida, Naomasa Nakamura, Keiichiro Yusu, Yasuhiro Satoh
  • Phase-change optical recording medium
    Publication number: 20070148396
    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: Application
    Filed: February 22, 2007
    Publication date: June 28, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tsukasa Nakai, Sumio Ashida, Keiichiro Yusu, Takayuki Tsukamoto, Noritake Oomachi, Naomasa Nakamura, Katsutaro Ichihara