Patents by Inventor Kazuo Watabe

Kazuo Watabe 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 pickup unit and information recording/reproduction apparatus
    Patent number: 7668064
    Abstract: According to one embodiment, an optical pickup unit which can record, reproduction and erase information in/from an information recording medium has tracks with different pitches, the dividing means has at least a part of a dividing boundary line placing between an end of a 1st order diffraction light with the largest diffraction angle and an end of a 1st order diffraction light with the smallest diffraction angle of the reflected laser beam.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: February 23, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Nobuaki Kaji, Sumitaka Maruyama, Akihito Ogawa, Kazuo Watabe
  • OPTICAL DISC AND OPTICAL DISC DEVICE
    Publication number: 20090207721
    Abstract: An optical disc has a read-only system lead-in area and a recordable data area. Disc boundary information representing a boundary in a radial direction of an area on which capability of recording at a predetermined recording speed is guaranteed is recorded on the system lead-in area while being related to each tuple speed. An optical disc device, upon user's instruction of tuple-speed recording, compares the boundary information related to the instructed tuple speed with a present recording position, performs recording at the instructed tuple speed if the present recording position is on the outside of the boundary, and performs recording at a tuple speed lower than the instructed tuple speed if the present recording position is on the inside of the boundary.
    Type: Application
    Filed: February 13, 2009
    Publication date: August 20, 2009
    Applicants: SANYO Electric Co., Ltd., Toshiba Corporation, NEC Corporation
    Inventors: Morio Nakatani, Masato Fuma, Kazuo Watabe, Yutaka Kashihara, Akihito Ogawa, Yutaka Yamanaka, Tatsunori Ide, Shuichi Ohkubo
  • INFORMATION RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION RECORDING AND REPRODUCING APPARATUS
    Publication number: 20090196142
    Abstract: According to one embodiment, in an information recording medium for which a phase change material is used and in which information is recorded on, reproduced from, and erased from a recording layer by light irradiation, a recrystallization width WR at a periphery of an amorphous recording mark formed on the recording layer by light irradiation, and a recording mark width WA and a track pitch TP satisfy 1.0<WR/WA<1.1 and 2/3<WA/TP<4/3.
    Type: Application
    Filed: January 29, 2009
    Publication date: August 6, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Keiichiro YUSU, Masahiro SAITO, Kazuto KURODA, Takashi USUI, Kazuo WATABE, Chosaku NODA, Nobuaki KAJI, Tsukasa NAKAI
  • MASTER RECORDING APPARATUS AND MASTER RECORDING METHOD
    Publication number: 20090196148
    Abstract: According to one embodiment, the invention provides a master recording apparatus and method which can form a pit having a symmetrical pit shape with excellent reproducibility. An embodiment of the invention is a master recording apparatus where a resist film on a master for an optical disk is irradiated with irradiation light from a semiconductor laser to record information on the resist film, where the resist film is formed as an inorganic resist film, and means for outputting the irradiation light from the semiconductor laser as a short pulse laser with a pulse width between 200 ps and 1 ns is provided.
    Type: Application
    Filed: January 29, 2009
    Publication date: August 6, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Keiichiro YUSU, Masahiro SAITO, Kazuto KURODA, Takashi USUI, Kazuo WATABE, Chosaku NODA, Nobuaki KAJI, Masaaki MATSUMARU, Ryosuke YAMAMOTO
  • INFORMATION RECORDING APPARATUS AND CONTROL METHOD THEREOF
    Publication number: 20090196138
    Abstract: According to one embodiment, in one embodiment of the invention, a laser drive circuit is provided with a first current source, a second drive current source, and a third current source. The control section selectively obtains a plurality of laser light use mode of controlling the from first to third current sources to use pulse laser light accompanying relaxation oscillation, and a complex laser light use mode of using laser light where laser pulses are combined, whose starting end has an abrupt impulse change portion caused by relaxation oscillation and whose intermediate section is a flat portion with a fixed intensity.
    Type: Application
    Filed: January 9, 2009
    Publication date: August 6, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Nobuaki Kaji, Kazuo Watabe, Takashi Usui, Keiichiro Yusu, Chosaku Noda, Kazuto Kuroda, Masahiro Saito
  • DRIVE CONTROL APPARATUS AND DRIVE CONTROL METHOD OF SEMICONDUCTOR LASER
    Publication number: 20090141760
    Abstract: According to one embodiment, a drive control apparatus of a semiconductor laser includes a driving circuit which drives the semiconductor laser by applying pulses transiting from bias current to peak current to the semiconductor laser as laser driving current that causes relaxation oscillation of emission light intensity of the semiconductor laser, and a control circuit which controls the bias current such that the bias current has a predetermined ratio limiting fluctuation of a leading peak value of the relaxation oscillation occurring for each application of pulses relative to threshold current of the semiconductor laser. The control circuit changes the bias current to maintain the predetermined ratio relative to fluctuation of the threshold current.
    Type: Application
    Filed: October 29, 2008
    Publication date: June 4, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masahiro Saito, Takashi Usui, Kazuo Watabe, Keiichiro Yusu, Chosaku Noda, Nobuaki Kaji, Kazuto Kuroda
  • LASER DRIVE DEVICE AND INFORMATION RECORDING/REPRODUCING APPARATUS USING THE DEVICE
    Publication number: 20090109809
    Abstract: According to one embodiment, a laser drive circuit includes a photodetector which receives part of laser light emitted from a laser element to a recording medium independently of reflection laser light reflected by the recording medium, and outputs an output corresponding to the strength thereof, an integration circuit which integrates the output from the photodetector for a predetermined time, and a setting circuit which sets the intensity of a laser drive current supplied to the laser element on the basis of the output from the integration circuit.
    Type: Application
    Filed: October 24, 2008
    Publication date: April 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuto Kuroda, Kazuo Watabe, Keiichiro Yusu, Chosaku Noda, Nobuaki Kaji, Takashi Usui, Masahiro Saito
  • OPTICAL HEAD DEVICE AND INFORMATION
    Publication number: 20090109808
    Abstract: According to one embodiment, a laser drive circuit which supplies a drive current to a laser element which outputs light at a predetermined wavelength, and a laser control circuit which supplies a predetermined timing pulse for generation of relaxation oscillation in a laser drive current supplied to the laser drive circuit, the laser control circuit supplying a laser drive current higher than a threshold value which is supplied from the laser drive circuit to the laser element to enable laser light to be output from the laser element, the laser control circuit setting the laser drive current to a level lower than the threshold value on the basis of the timing pulse.
    Type: Application
    Filed: September 11, 2008
    Publication date: April 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Nobuaki Kaji, Kazuo Watabe, Takashi Usui, Keiichiro Yasu, Chosaku Noda, Kazuto Kuroda, Masahiro Saito
  • OPTICAL DISC APPARATUS AND OPTICAL DISC PROCESSING METHOD
    Publication number: 20090109816
    Abstract: According to one embodiment, a calibration section controls an LD driving section so as to carry out test writing on a recording layer of an optical disc using a light pulse having relaxation oscillation, irradiates the test-written area with a reproduction laser beam so as to detect reflected light, and determine write strategy based on the detected result. A recording process is executed on the optical disc by using the light pulse having relaxation oscillation based on the write strategy determined by the calibration section.
    Type: Application
    Filed: October 22, 2008
    Publication date: April 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takashi Usui, Kazuo Watabe, Keiichiro Yusu, Chosaku Noda, Kazuto Kuroda, Nobuaki Kaji, Masahiro Saito
  • OPTICAL DISC DEVICE AND OPTICAL DISC PROCESSING METHOD
    Publication number: 20090109815
    Abstract: According to one embodiment, an optical disc device includes a light source portion which applies laser light to an optical disc, a drive portion which supplies a drive current to the light source portion so as to cause the light source portion to apply laser light of light pulses having relaxation oscillation, and a controller which controls the drive portion to supply a drive current so as to cause the light source portion to emit laser light of (n?1)×N (N is an integral number) light pulses having relaxation oscillation with respect to a mark with recording mark length nT (n: integral number, T: channel clock) to be recorded on the optical disc.
    Type: Application
    Filed: October 29, 2008
    Publication date: April 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takashi Usui, Kazuo Watabe, Keiichiro Yusu, Chosaku Noda, Kazuto Kuroda, Nobuaki Kaji, Masahiro Saito
  • OPTICAL RECORDING HEAD DEVICE, OPTICAL RECORDING APPARATUS, AND RECORDING METHOD
    Publication number: 20090103422
    Abstract: According to one embodiment, an optical recording head device includes a light source which outputs such a relaxation oscillation optical pulse that a full width at half maximum of a single pulse is 820 ps or less, a driving unit for driving the light source, an objective lens which converges emission light from the light source on a recording layer of a recording medium, and captures reflective light which is reflected by the recording layer of the recording medium, a distribution unit, placed between the light source and the objective lens, for distributing incident light, and a photodetection unit for receiving via the distribution unit the reflective light which is reflected by the recording layer of the recording medium, wherein a resonator length of the light source is 6560 ?m or less.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 23, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuo WATABE, Takashi USUI, Keiichiro YUSU, Chosaku NODA, Kazuto KURODA, Nobuaki KAJI, Masahiro SAITO
  • INFORMATION RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND INFORMATION REPRODUCING METHOD
    Publication number: 20080304401
    Abstract: According to one embodiment, an optical information recording medium includes pre-grooves with an irregular shape and lands each of which is sandwiched between the pre-grooves adjacent to each other, where the pre-grooves and lands are defined on an interface between a recording layer and a light reflection layer in a recording film, where the recording film includes a light reflectivity that enables reproduction with light of 650±5 nm, the recording layer includes a recording sensitivity with respect to light by a wavelength shorter than 650±5 nm, and a recording mark can be formed on the pre-groove by using light with a wavelength shorter than 650±5 nm.
    Type: Application
    Filed: January 4, 2008
    Publication date: December 11, 2008
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideo Ando, Hisashi Yamada, Seiji Morita, Koji Takazawa, Naomasa Nakamura, Kazuo Watabe, Nobuaki Kaji, Masahiko Mawatari, Nobuhisa Yoshida, Koichi Nagai
  • Information storage medium, recording method, reproducing method, and reproducing apparatus
    Patent number: 7426167
    Abstract: An information layer 0 comprises a system lead-in area, data lead-in area, data area, and middle area, an information layer 1 comprises a system lead-out area, data lead-out area, data area, and middle area, an end position of the data area of layer 1 is positioned outer than a start position of the data area of layer 0, the data lead-in area comprises a guard track zone wider than a test zone in the data lead-out area, the data lead-out area comprises a guard track zone wider than a test zone and a management zone in the data lead-in area, the middle area of layer 0 comprises a guard track zone wider than a test zone in the middle area of layer 1, and the middle area of layer 1 comprises a blank zone wider than a test zone in the middle area of layer 0.
    Type: Grant
    Filed: November 27, 2006
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuo Watabe, Hideo Ando, Sumitaka Maruyama, Yutaka Kashihara, Akihito Ogawa
  • OPTICAL HEAD APPARATUS, INFORMATION RECORDING/REPRODUCING APPARATUS INCLUDING THE OPTICAL HEAD APPARATUS, AND INFORMATION RECORDING/REPRODUCING METHOD
    Publication number: 20080205212
    Abstract: According to one embodiment, an optical head device provides a signal processing circuit which sets a control amount to move an objective lens so that a distance between the objective lens and a given recording layer of the an optical disc coincides with a focal position, an optical path length correction mechanism which corrects an influence of an aberration component producing an error in the focal distance, a thickness difference detection circuit which finds an amount of correction to be made by the optical path length, and an aberration correction circuit which generates a correction signal to correct the influence of the aberration component producing the error in the focal distance detected by the thickness difference detection circuit, and supplies the correction signal to the optical path length correction mechanism.
    Type: Application
    Filed: February 28, 2008
    Publication date: August 28, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takehiro Hiramatsu, Hideaki Ohsawa, Kazuo Watabe, Chosaku Noda, Naoki Morishita, Akihito Ogawa, Kazuto Kuroda, Nobuaki Kaji
  • INFORMATION RECORDING APPARATUS CAPABLE OF RECORDING INFORMATION IN INFORMATION RECORDING MEDIUM, INFORMATION RECORDING METHOD, AND TARGET VALUE DETERMINING METHOD
    Publication number: 20080205216
    Abstract: According to one embodiment, an apparatus which records a signal in a recording medium in which information is written by using a first laser having a first wavelength and from which information is read by using a second laser having a second wavelength longer than that of the first laser, a signal is recorded in the recording medium by using the first laser, and a control section reproduces the signal recorded with the first laser and measures a first amount that is used to calculate a target value for optimization of recording conditions, reproduces a signal recorded with the second laser and measures a second amount for optimization of a reproduction signal, compares the first amount with the second amount, and determines the first amount under the recording conditions where the second amount becomes optimum as a target value for optimization of the recording conditions.
    Type: Application
    Filed: February 28, 2008
    Publication date: August 28, 2008
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: AKIHITO OGAWA, Hideo Ando, Hideaki Ohsawa, Kazuo Watabe, Kazuto Kuroda, Chosaku Noda, Naoki Morishita, Nobuaki Kaji, Takehiro Hiramatsu
  • Information storage medium, recording method, reproducing method, and reproducing apparatus
    Patent number: 7411888
    Abstract: An information layer 0 comprises a system lead-in area, data lead-in area, data area, and middle area, an information layer 1 comprises a system lead-out area, data lead-out area, data area, and middle area, an end position of the data area of layer 1 is positioned outer than a start position of the data area of layer 0, the data lead-in area comprises a guard track zone wider than a test zone in the data lead-out area, the data lead-out area comprises a guard track zone wider than a test zone and a management zone in the data lead-in area, the middle area of layer 0 comprises a guard track zone wider than a test zone in the middle area of layer 1, and the middle area of layer 1 comprises a blank zone wider than a test zone in the middle area of layer 0.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: August 12, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuo Watabe, Hideo Ando, Sumitaka Maruyama, Yutaka Kashihara, Akihito Ogawa
  • Information storage medium, information recording method, and information recording/reproduction apparatus
    Patent number: 7408868
    Abstract: This invention achieves high-density recording while preventing recording units from overlapping. Recording is done to form a gap between predetermined recording units. Since this gap is formed, even when a rotation driving mechanism of a medium suffers rotation nonuniformity, two neighboring recording units never overlap each other, and destruction of recording data can be prevented.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: August 5, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideo Ando, Kazuo Watabe
  • SEMICONDUCTOR LASER DRIVING DEVICE, OPTICAL HEAD, OPTICAL DISK DEVICE, AND SEMICONDUCTOR LASER DRIVING METHOD
    Publication number: 20080159349
    Abstract: A semiconductor laser driving device includes a current supply unit supplying current to a semiconductor laser; a first control unit controlling the current supply unit to supply a first current which is half or less of a lasing threshold of the semiconductor laser; and a second control unit controlling the current supply unit to supply a second current which is larger than the lasing threshold after a first time is passed from an edge of a clock signal.
    Type: Application
    Filed: December 26, 2007
    Publication date: July 3, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Nobuaki Kaji, Kazuo Watabe
  • Information storage medium, information recording method, and information recording/reproduction apparatus
    Patent number: 7382710
    Abstract: This invention achieves high-density recording while preventing recording units from overlapping. Recording is done to form a gap between predetermined recording units. Since this gap is formed, even when a rotation driving mechanism of a medium suffers rotation nonuniformity, two neighboring recording units never overlap each other, and destruction of recording data can be prevented.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: June 3, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideo Ando, Kazuo Watabe
  • Information storage medium, information recording method, and information recording/reproduction apparatus
    Patent number: 7379409
    Abstract: This invention achieves high-density recording while preventing recording units from overlapping. Recording is done to form a gap between predetermined recording units. Since this gap is formed, even when a rotation driving mechanism of a medium suffers rotation nonuniformity, two neighboring recording units never overlap each other, and destruction of recording data can be prevented.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: May 27, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideo Ando, Kazuo Watabe