Patents by Inventor Tatsuhiro Kobayashi

Tatsuhiro Kobayashi 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).

  • Patent number: 7142492
    Abstract: A method for determining the recording power of a laser beam so that jitter from a reproduced signal obtained by reproducing data recorded in a data rewritable type optical recording medium can be controlled within an acceptable tolerance even when cross erasing of data occurs. The power of a laser beam is measured for each level of the recording power of the laser beam. Critical parameters are calculated for each level of the recording power of the laser beam. The critical parameters are projected onto a data rewritable type optical recording medium for recording data therein. Direct overwriting required for saturating an influence of cross erasing of data is performed x times in one embodiment to determine a critical parameter. A data recording apparatus storing a critical parameter used for determining the power of a laser beam is associated with ID data for identifying the kind of optical recording medium.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: November 28, 2006
    Assignee: TDK Corporation
    Inventors: Tatsuhiro Kobayashi, Tatsuya Kato, Hiroyasu Inoue
  • Patent number: 7142491
    Abstract: A method for determining the recording power of a laser beam so that jitter from a reproduced signal obtained by reproducing data recorded in a data rewritable type optical recording medium can be controlled within a tolerance even when cross erasing of data occurs, the reproduced signal having the highest obtainable level. The power of a laser beam is measured for each level of the recording power of the laser beam. Critical parameters are also calculated for each level of the recording power of the laser beam. The critical parameters are projected onto a data rewritable type optical recording medium for recording data therein. A data recording apparatus storing a critical parameter used for determining the power of a laser beam is associated with ID data for identifying the kind of optical recording medium. A data recording apparatus storing an optimum recording power used for determining the power of a laser beam is also associated with ID data for identifying the kind of optical recording medium.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: November 28, 2006
    Assignee: TDK Corporation
    Inventors: Tatsuya Kato, Tatsuhiro Kobayashi, Hiroyasu Inoue
  • Patent number: 7132148
    Abstract: An optical recording disc is constituted by laminating a substrate, a reflective layer, a third dielectric layer, a light absorption layer, a second dielectric layer, a metal recording layer, a first dielectric layer and a light transmission layer in this order, and is constituted so that when a laser beam is irradiated onto the optical recording disc from the side of the light transmission layer, the metal recording layer is deformed and/or is changed in quality to form a state-changed region in the metal recording layer and the second dielectric layer and the light absorption layer are deformed and/or are changed in quality to form state-changed regions in the second dielectric layer and the light absorption layer, whereby a recording mark is formed in the metal recording layer, the second dielectric layer and the light absorption layer.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: November 7, 2006
    Assignee: TDK Corporation
    Inventors: Narutoshi Fukuzawa, Tatsuhiro Kobayashi, Takashi Kikukawa
  • Publication number: 20060245339
    Abstract: An optical recording medium 10 of the present invention has a support substrate 11 and a light-transmitting layer 12, and further has a first dielectric layer 31, a noble metal nitride layer 23, a second dielectric layer 32, a light absorption layer 22, a third dielectric layer 33, and a reflection layer 21, all of which are interposed between the light-transmitting layer 12 and the support substrate 11. In the optical recording medium of the present invention, a laser beam 40 is irradiated on the substrate from the light entrance face 12a, to thus locally decompose the noble metal nitride layer 23, so that record marks can be formed by means of resultant bubble pits. In this case, a gas filling the bubble pits, which are to form the record marks, is a chemically-stable nitrogen gas (N2). The risk of this gas oxidizing or corroding other layers is very remote, and high storage reliability can be achieved.
    Type: Application
    Filed: July 22, 2004
    Publication date: November 2, 2006
    Applicant: TDK Corporation
    Inventors: Narutoshi Fukuzawa, Takashi Kikukawa, Tatsuhiro Kobayashi
  • Publication number: 20060245338
    Abstract: It is an object of the present invention to provide an optical recording disc which can record data constituted by a recording mark train including recording marks and blank regions neighboring recording marks therein and reproduce the data therefrom even in the case where the lengths of a recording mark and a blank region between neighboring recording marks are shorter than the resolution limit, thereby markedly increasing the storage capacity thereof and can improve the C/N ratio of the reproduced signal.
    Type: Application
    Filed: June 30, 2004
    Publication date: November 2, 2006
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20060188683
    Abstract: It is an object of the present invention to provide an optical recording disc which can record data constituted by a recording mark train including recording marks and blank regions neighboring recording marks therein and reproduce the data therefrom even in the case where the lengths of a recording mark and a blank region between neighboring recording marks are shorter than the resolution limit and whose storage capacity can be markedly increased.
    Type: Application
    Filed: June 30, 2004
    Publication date: August 24, 2006
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20060165945
    Abstract: An optical recording medium includes a laminated body in which at least a dielectric layer 6 is interposed between a recording layer 7 and a light absorbing layer 5, the optical recording medium being constructed so that data recorded by a recording mark train including recording marks whose lengths are less than the resolution limit are reproduced. The optical recording medium has reflectance of 20 to 80% and a laser beam is irradiated at a power density of 5.6×108 to 1.2×1010 W/m2 to reproduce the recorded data.
    Type: Application
    Filed: January 24, 2006
    Publication date: July 27, 2006
    Applicant: TDK Corporation
    Inventors: Tatsuhiro Kobayashi, Takashi Kikukawa, Narutoshi Fukuzawa
  • Publication number: 20060158983
    Abstract: A super resolution optical reproducing system, which can recognize a recording mark less than a resolution limit, removes the effect of a high-frequency noise component of a high power signal obtained by irradiating a laser beam with high read power. The same recording region of an optical recording medium is irradiated according to an irradiation spot by a laser beam with an ordinary read power and an irradiation spot by a laser beam with high read power to obtain a ordinary power signal and a high power signal. The ordinary power signal and the high power signal are normalized to an average level by high pass filters and low pass filters of a high power signal processing circuit and a ordinary power signal processing circuit. Then, a subtracter subtracts the ordinary power signal from the high power signal to obtain a substrated signal.
    Type: Application
    Filed: January 12, 2006
    Publication date: July 20, 2006
    Applicant: TDK CORPORATION
    Inventors: Narutoshi Fukuzawa, Takashi Kikukawa, Tatsuhiro Kobayashi, Toshiki Aoi
  • Publication number: 20060161942
    Abstract: An optical recording device 10 of the present invention has a support substrate 11; an optical transmitting layer 12; and a first dielectric layer 31, a noble metal oxide layer 23, a second dielectric layer 32, a light absorption layer 22, a third dielectric layer 33, and a reflection layer 21, all of which are interposed, in this sequence from the optical transmitting layer, between the optical transmitting layer and the support substrate. The thickness of the support substrate 11 ranges from 0.6 mm to 2.0 mm; the thickness of the optical transmitting layer ranges from 10 ?m to 200 ?m; the thickness of the noble metal oxide layer ranges from 2 nm to 50 nm; the thickness of the second dielectric layer ranges from 5 nm to 100 nm; the thickness of the light absorption layer 22 ranges from 5 nm to 100 nm; and the thickness of the third dielectric layer 33 ranges from 10 nm to 140 nm.
    Type: Application
    Filed: June 29, 2004
    Publication date: July 20, 2006
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20060153051
    Abstract: An optical recording medium 10 having a substrate 11, an optically transparent layer 12, and a first dielectric layer 31, a noble metal oxide layer 23, a second dielectric layer 32, a light absorbing layer 22, a third dielectric layer 33 and a reflecting layer 21 which are disposed between the optically transparent layer 12 and the substrate 11, records and reproduces data into and from the optical recording medium 10 by irradiating the optical recording medium 10 with a laser beam 40 from the optically transparent layer 12 side. ?/NA is set to be not longer than 640 nm when ? designates a wavelength of the laser beam 40 and NA designates a numerical aperture of an objective lens, and setting is done as Pw×0.1?Pr?Pw×0.5 when Pw and Pr designate recording power and reproducing power of the laser beam 40 respectively, while a recording mark train including recording marks each having a length not larger than ?/4 NA is recorded and data are reproduced from the recording mark train.
    Type: Application
    Filed: June 29, 2004
    Publication date: July 13, 2006
    Applicant: TKD Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20060126482
    Abstract: It is an object of the present invention to provide an optical recording disc which can record data constituted by a recording mark train including recording marks and blank regions neighboring recording marks therein and reproduce the data therefrom even in the case where the lengths of a recording mark and a blank region between neighboring recording marks are shorter than the resolution limit, thereby markedly increasing the storage capacity thereof and can improve the C/N ratio of the reproduced signal.
    Type: Application
    Filed: June 30, 2004
    Publication date: June 15, 2006
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20060072409
    Abstract: It is an object of the present invention to provide a method for determining the power of a laser beam which can determine the recording power of the laser beam so that jitter of a reproduced signal obtained by reproducing data recorded in a data rewritable type optical recording medium can be controlled within a tolerance even when cross erasing of data occurs and that the reproduced signal having the highest level can be obtained.
    Type: Application
    Filed: June 27, 2003
    Publication date: April 6, 2006
    Applicant: TDK Corporation
    Inventors: Tatsuya Kato, Tatsuhiro Kobayashi, Hiroyasu Inoue
  • Publication number: 20060062110
    Abstract: In a data recording and readingout system in which data is recorded and readout, or is readout on, or from an optical recording medium 1 by irradiating a laser beam having a wavelength “?” via an objective lens of a numerical aperture “NA” onto said optical recording medium, while the optical recording medium contains a layered structure formed by sandwiching a dielectric layer 6 between a recording layer 7 and an optical absorption layer 5, with respect to the optical recording medium 1 arranged in such a manner that data recorded by a recorded mark train can be readout and the recorded mark train contains a recorded mark smaller than, or equal to a limit of resolution, the laser beam is irradiated via the objective lens and a solid immersion lens having a refractive index “n” which is positioned between the optical recording medium and the objective lens, so that the data is recorded and readout, or is readout with respect to the optical recording medium by a recorded mark train which contains a recorded ma
    Type: Application
    Filed: September 2, 2005
    Publication date: March 23, 2006
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi, Toshiki Aoi, Hajime Utsunomiya
  • Publication number: 20060013089
    Abstract: It is an object of the present invention to provide a method for determining the power of a laser beam which can determine the recording power of the laser beam so that jitter of a reproduced signal obtained by reproducing data recorded in a data rewritable type optical recording medium can be controlled within a tolerance even when cross erasing of data occurs and that the reproduced signal having the highest level can be obtained.
    Type: Application
    Filed: June 27, 2003
    Publication date: January 19, 2006
    Inventors: Tatsuhiro Kobayashi, Tatsuya Kato, Hiroyasu Inoue
  • Publication number: 20050255282
    Abstract: An optical recording medium that is constituted so that a laser beam is irradiated to record and reproduce data, the optical recording medium including a laminated body that is formed by sandwiching a second dielectric layer 6 between a recording layer 7 and a light absorption layer 5, the light absorption layer 5 containing “Ge”, “Sb and Ge”, “Sb and In”, or “Sb and Ga” as a main component.
    Type: Application
    Filed: April 29, 2005
    Publication date: November 17, 2005
    Applicant: TDK Corporation
    Inventors: Narutoshi Fukuzawa, Takashi Kikukawa, Tatsuhiro Kobayashi
  • Publication number: 20050243677
    Abstract: According to the invention, a record mark is formed by: using one ON-pulse pattern and one ON-pulse pattern following it when the record mark to be formed is shorter than a specified length X (nT<X); and using two ON-pulse patterns and two ON-pulse patterns respectively following them when the record mark to be formed is longer than the specified length X (nT>X). This makes is possible to secure a heat amount per unit time sufficiently in forming a short record mark even when a targeted recording linear velocity is high. Also, an unwanted heat pocket becomes hard to arise in the record layer even when a sufficient heat amount per unit time is secured in forming a long record mark. Therefore, it becomes possible to form a record mark having a good shape even when data is recorded at a high linear velocity.
    Type: Application
    Filed: February 10, 2005
    Publication date: November 3, 2005
    Applicant: TDK Corporation
    Inventors: Tatsuhiro Kobayashi, Koji Mishima
  • Publication number: 20050226119
    Abstract: A reproduction apparatus is capable of reproducing information recorded on information recording media including at least a super RENS recording medium. The reproduction apparatus includes: an optical head that receives laser light that has been reflected or transmitted by the information recording medium and photoelectrically converts the laser light to an electric signal; a signal processing circuit that extracts an AC component from the electric signal and attenuates the AC component by a predetermined attenuation; an amplitude controlling circuit that controls an amplitude of an electric signal outputted from the signal processing circuit so as to become a predetermined amplitude; and a reproduction circuit that reproduces information recorded on the medium based on an electric signal outputted from the amplitude controlling circuit. An information recording medium testing apparatus includes the reproduction apparatus and a test information generating circuit that generates test information.
    Type: Application
    Filed: April 7, 2005
    Publication date: October 13, 2005
    Applicant: TDK Corporation
    Inventors: Takashi Kikukawa, Narutoshi Fukuzawa, Tatsuhiro Kobayashi
  • Publication number: 20050219994
    Abstract: An optical recording medium for recording data by irradiating a laser beam and forming a recording mark row containing at least one of recording marks and blank areas smaller than a resolution limit and reproducing the recorded data, comprising a layered body having a recording layer, a light absorbing layer, and a dielectric layer at intermediary of the recording layer and the light absorbing layer, wherein the light absorbing layer is crystalline when film formation is completed, and has a property to maintain the crystalline even when the laser beam is irradiated.
    Type: Application
    Filed: March 28, 2005
    Publication date: October 6, 2005
    Applicant: TDK CORPORATION
    Inventors: Narutoshi Fukuzawa, Takashi Kikukawa, Tatsuhiro Kobayashi
  • Publication number: 20050207308
    Abstract: When a space region shorter than the radius of a beam spot is formed, pre-heating with an assist pulse is not performed, and an off pulse pattern is fixed at a base power level. When a space region longer than the radius of the beam spot and shorter than the diameter of the beam spot is formed, an assist pulse is applied to the end of the space region to be formed. The length of the assist pulse is made greater, the longer the space region to be formed. Further, when a space region longer than the diameter of the beam spot is formed, an assist pulse is applied to the end of the space region to be formed, and the length of the assist pulse is kept constant regardless of the length of the space region to be formed.
    Type: Application
    Filed: February 4, 2005
    Publication date: September 22, 2005
    Applicant: TDK Corporation
    Inventors: Tatsuhiro Kobayashi, Koji Mishima
  • Publication number: 20050169157
    Abstract: An optical recording disc is constituted by laminating a substrate, a reflective layer, a third dielectric layer, a light absorption layer, a second dielectric layer, a metal recording layer, a first dielectric layer and a light transmission layer in this order, and is constituted so that when a laser beam is irradiated onto the optical recording disc from the side of the light transmission layer, the metal recording layer is deformed and/or is changed in quality to form a state-changed region in the metal recording layer and the second dielectric layer and the light absorption layer are deformed and/or are changed in quality to form state-changed regions in the second dielectric layer and the light absorption layer, whereby a recording mark is formed in the metal recording layer, the second dielectric layer and the light absorption layer.
    Type: Application
    Filed: October 27, 2004
    Publication date: August 4, 2005
    Applicant: TDK Corporation
    Inventors: Narutoshi Fukuzawa, Tatsuhiro Kobayashi, Takashi Kikukawa