Patents by Inventor Takahiro Kurokawa

Takahiro Kurokawa 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: 8358569
    Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.
    Type: Grant
    Filed: May 2, 2011
    Date of Patent: January 22, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Fujita, Takeshi Maeda, Manabu Shiozawa, Takahiro Kurokawa
  • Patent number: 8315147
    Abstract: In a multilayer optical recording medium having at least three recording layers, an influence of interlayer crosstalk due to unnecessary light is suppressed. Each of the recording layers includes an information recording area, and the recording layers other than the nearest recording layer and the farthest recording layer when viewed from a light incident side include a first annular area having uneven patterns formed thereon, and a second annular area having uneven patterns formed thereon, the first annular area being adjacent to an inner side of the information recording area, the second annular area being adjacent to an outer side of the information recording area.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: November 20, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Akemi Hirotsune, Shigeharu Kimura, Takahiro Kurokawa
  • Publication number: 20120282411
    Abstract: A nanofiber manufacturing system in which nanofiber is formed from a raw material liquid by electrostatic explosions in a nanofiber forming space and the formed nanofiber is collected and deposited on a main surface of a base sheet. The system includes: a first dielectric belt having dielectric property; sheet conveying devices for conveying the base sheet in the nanofiber forming space; a sheet contacting device putting a back surface of the base sheet and a first surface of the first dielectric belt into contact with each other; a dielectric belt driving device for running the first dielectric belt in a conveyance direction of the base sheet within the nanofiber forming space while the first surface is kept in contact with the back surface of the base sheet; and a voltage applying device for applying a voltage to the second surface of the first dielectric belt so that dielectric polarization occurs to the first dielectric belt.
    Type: Application
    Filed: September 22, 2011
    Publication date: November 8, 2012
    Inventors: Takahiro Kurokawa, Hiroto Sumida, Hiroyuki Tsuji, Kazunori Ishikawa
  • Publication number: 20120250480
    Abstract: Provided is a recording adjustment method capable of controlling an edge position of a mark with high accuracy. Based on the acquired read-out signal waveform, a starting position of a last pulse is adjusted such that a so-called L-SEAT shift value for an end edge of the mark becomes minimum.
    Type: Application
    Filed: March 2, 2010
    Publication date: October 4, 2012
    Inventors: Takahiro Kurokawa, Hiroyuki Minemura
  • Publication number: 20120243392
    Abstract: The present invention achieves tracking servo using a recording signal on a grooveless optical disc. Trial writing signals are written by using multiple recording conditions, and a recommended recording condition having favorable qualities of a reproduction signal and a tracking error signal is determined based on the trial writing signals. Then, recording is performed by using the recommended recording condition. In addition, by using a recording condition determined based on an optimum power control performed prior to the recording, signals are recorded adjacent to each other in at least two tracks. Signals are recorded by using the determined recording condition under which a tracking error signal quality obtained from the recording signal matches a desired value of a tracking error signal quality of the medium.
    Type: Application
    Filed: December 22, 2011
    Publication date: September 27, 2012
    Inventors: Soichiro ETO, Takahiro Kurokawa
  • Publication number: 20120242010
    Abstract: A deposit of nanofibers which has an even thickness and even quality is produced. A nanofiber manufacturing apparatus according to the present invention includes: an effusing body (115) which has an effusing hole (118) through which a solution (300) is effused; a charging electrode (128); a charging power supply (122) which applies a given voltage between the effusing body (115) and the charging electrode (128); a drawing electrode (121) which draws nanofibers (301) produced in space, the drawing electrode (121) having, on a surface, a planar deposition region (A) onto which the drawn nanofibers (301) are deposited; a drawing power supply (123) which applies a given potential to the drawing electrode (121); and an insulating layer (101) which suppresses variation in resistance values of the nanofibers deposited in the deposition region (A) and is placed throughout the deposition region (A).
    Type: Application
    Filed: December 6, 2010
    Publication date: September 27, 2012
    Inventors: Kazunori Ishikawa, Hiroto Sumida, Takahiro Kurokawa
  • Patent number: 8264932
    Abstract: An optical disc device and an adjusting method for a recording condition for use with the optical disc device that records data into an optical disc medium by using codes whose shortest run length is 2T and reproduces the recorded data by using an adaptive equalizing procedure and a PRML procedure, wherein the recording condition is so adjusted that a reproduced signal with desired quality can be obtained, by using, as the adaptive equalizing procedure, a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an renewed by a LMS method, located symmetrically with each other along the time axis.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: September 11, 2012
    Assignee: Hitachi Consumer Electronics Co., Ltd.
    Inventors: Hiroyuki Minemura, Takahiro Kurokawa
  • Publication number: 20120201113
    Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.
    Type: Application
    Filed: April 17, 2012
    Publication date: August 9, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Shinji FUJITA, Takeshi MAEDA, Manabu SHIOZAWA, Takahiro KUROKAWA
  • Patent number: 8186987
    Abstract: Provided is a nano-fiber manufacturing apparatus which manufactures nano-fibers by an electrostatic explosion, and has a low possibility of explosion even when a flammable solvent is used. The nano-fiber manufacturing apparatus (101) having an ejection unit (110) which ejects solution (200) that is raw material liquid for nano-fibers (200) to a manufacturing space in which the nano-fibers (200) are manufactured by an electrostatic explosion of the solution (200), and a charging unit which charges the solution (200). The nano-fiber manufacturing apparatus (101) includes a gas supply source (103) which supplies safety gas to change an atmosphere of the manufacturing space, in which the solution (200) is ejected, into a low oxygen atmosphere, and a partition (102) which maintains the manufacturing space at a lower oxygen atmosphere than an atmosphere of an outside space of the partition (102).
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Hiroto Sumida, Takahiro Kurokawa, Kazunori Ishikawa, Mitsuhiro Takahashi, Mikio Takezawa, Yoshiaki Tominaga
  • Publication number: 20120098150
    Abstract: In a nanofiber manufacturing apparatus (1) which produces nanofibers by electrically stretching a solution in space, a hollow supporting unit (32) which is rotated around an axial line AL by a motor (41) supports a cartridge (33) which supplies a solution (20) stored therein, a pressurizing member (38) is pressurized by air introduced through a rotary joint (43) so that the solution (20) flows into an interior space (34a) of an effusing body (34) which is rotated together with the supporting body (32), and the solution (20) is radially effused from effusing holes (34c) by the pressure of the air and centrifugal force due to the rotation of the effusing body (34).
    Type: Application
    Filed: June 21, 2010
    Publication date: April 26, 2012
    Inventors: Takahiro Kurokawa, Hiroto Sumida, Masahide Yokoyama, Kazunori Ishikawa
  • Patent number: 8163227
    Abstract: A nanofiber spinning method and device for producing a high strength and uniform yarn made of nanofibers. The device includes: a nanofiber producing unit (2) which produces nanofibers (11) by extruding polymer solution, prepared by dissolving polymeric substances in a solvent, through small holes (7) and charging the polymer solution, and by allowing the polymer solution to be stretched by an electrostatic explosion, and which allows the nanofibers to travel in a single direction; a collecting electrode unit (3) to which an electric potential different from that of the charged polymer solution is applied, and which attracts the produced nanofibers (11) while simultaneously rotating and twisting the nanofibers, and gathers them for forming a yarn (20) made of the nanofibers (11); and a collecting unit (5) which collects the yarn (20) passed through the center of the collecting electrode unit (3).
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: April 24, 2012
    Assignee: Panasonic Corporation
    Inventors: Hiroto Sumida, Takahiro Kurokawa, Kazunori Ishikawa, Mitsuhiro Takahashi, Mikio Takezawa, Yoshiaki Tominaga
  • Publication number: 20120091606
    Abstract: A method for manufacturing a fine polymer including: generating superheated steam by a superheated steam generating unit (101); adjusting the pressure of the generated superheated steam by a pressure adjusting unit (102); receiving a polymer by a reception unit (103); heating the received polymer to a predetermined temperature by a heating unit (104); discharging the heated polymer through a first discharge port (111); and discharging the superheated steam through a second discharge port (121) at the same time as the time when the heated polymer is discharged. Here, the second discharge port (121) surrounds the first discharge port (111), and the first discharge port (111) and the second discharge port (121) face the same direction.
    Type: Application
    Filed: December 27, 2011
    Publication date: April 19, 2012
    Inventors: Mitsuhiro TAKAHASHI, Mikio Takezawa, Yoshiaki Tominaga, Takahiro Kurokawa, Hiroto Sumida, Kazunori Ishikawa
  • Patent number: 8154973
    Abstract: A highly efficient and reliable reproduced signal evaluation method and an optical disc drive using that method in which assuming that the number of 2T's appearing successively in a predetermined evaluation bitstream is i, the evaluation bitstream is divided into a main bitstream (5+2i) long and sub bitstreams at the ends of the main bitstream. The check process to determine whether a predetermined evaluation bitstream is included in the binarized bitstreams is replaced with a main bitstream agreement check. This can prevent an increase in the circuit size. At the same time, by separately summing up for each main bitstream the calculated results of Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bitstream, the size of an evaluation summing circuit can be reduced.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: April 10, 2012
    Assignee: Hitachi Consumer Electronics Co., Ltd.
    Inventors: Hiroyuki Minemura, Soichiro Eto, Takahiro Kurokawa, Shuichi Kusaba
  • Patent number: 8130610
    Abstract: To compensate for edge shifts varying largely in accordance with preceding mark lengths. Provided are a method and a recorder in which a duration of a cooling pulse in each recording pulse string to form a mark having a length of nT is determined on the basis of an edge shift amount of a front edge of a mark whose preceding mark has a length of nT, where n is an integer and T is a channel bit length.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: March 6, 2012
    Assignee: Hitachi Consumer Electronics Co., Ltd.
    Inventor: Takahiro Kurokawa
  • Patent number: 8121014
    Abstract: Since the conventional optical disk recording/reproducing apparatus cannot correctly measure a power of a main beam that is a part of the laser light outputted from an objective lens and is focused on a recording layer to contribute to recording/reproducing, it is difficult to accurately control a read power. A ratio of a proper read power to a threshold power of erasing is acquired beforehand. The read power is determined by measuring the threshold power of erasing and multiplying it by the ratio when learning of the read power is performed for each drive device. According to the read power learning method of this invention, it becomes possible to determine the proper read power regardless of performance variance of an optical pickup and sensitivity dispersion of a medium.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: February 21, 2012
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Takahiro Kurokawa, Hiroyuki Minemura
  • Patent number: 8110136
    Abstract: Nanofibers are formed from a polymer material by rotating a conductive rotating container having a plurality of small holes while supplying a polymer solution formed by dissolving a polymer material in a solvent into the rotating container, charging the polymer solution discharged from the small holes of the rotating container by charging means, and drawing the discharged filamentous polymer solution by centrifugal force and an electrostatic explosion resulting from evaporation of the solvent. The nanofibers from this production step are oriented and made to flow from one side toward the other side in a shaft center direction of the rotating container by a reflecting electrode and/or blowing means, or those nanofibers are deposited, to produce a polymer web. The nanofibers and the polymer web using these nanofibers can be produced uniformly by a simple configuration with good productivity.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: February 7, 2012
    Assignee: Panasonic Corporation
    Inventors: Mitsuhiro Takahashi, Mikio Takezawa, Yoshiaki Tominaga, Takahiro Kurokawa, Kazunori Ishikawa, Hiroto Sumida
  • Publication number: 20120025429
    Abstract: Provided is a nanofiber manufacturing apparatus including an effusing body (115) having an effusing hole (118) which allows the solution (300) to effuse in a given direction, a charging electrode (128) which is conductive and is disposed at a given distance from the effusing body (115), a charging power supply (122) configured to apply a given voltage between the effusing body (115) and the charging electrode (128), and a determining unit (102) configured to determine a flight path of the solution (300) and the nanofibers such that a length of the flight path C is longer than a shortest path length B which is a length of a shortest imaginary path connecting an end opening (119) of the effusing hole (118) and an accumulation part A on which the nanofibers (301) are accumulated.
    Type: Application
    Filed: October 27, 2010
    Publication date: February 2, 2012
    Inventors: Kazunori Ishikawa, Takahiro Kurokawa, Hiroto Sumida
  • Patent number: 8107339
    Abstract: A highly efficient and reliable reproduced signal evaluation method and an optical disc drive using that method in which assuming that the number of 2T's appearing successively in a predetermined evaluation bitstream is i, the evaluation bitstream is divided into a main bitstream (5+2i) long and sub bitstreams at the ends of the main bitstream. The check process to determine whether a predetermined evaluation bitstream is included in the binarized bitstreams is replaced with a main bitstream agreement check. This can prevent an increase in the circuit size. At the same time, by separately summing up for each main bitstream the calculated results of Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bitstream, the size of an evaluation summing circuit can be reduced.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: January 31, 2012
    Assignee: Hitachi Consumer Electronics Co., Ltd.
    Inventors: Hiroyuki Minemura, Soichiro Eto, Takahiro Kurokawa, Shuichi Kusaba
  • Publication number: 20120013047
    Abstract: A nanofiber manufacturing apparatus (100) which produces nanofibers (301) by electrically stretching a solution (300) in space, includes: an effusing body (115) having effusing holes (118) for effusing the solution (300) into the space, a tip part (116) in which openings (119) at ends of the effusing holes (118) are one-dimensionally arranged at given intervals, and two side wall parts (117) provided extending from both sides of the tip part (116) so that the effusing holes (118) are located between the side wall parts (117) and distance between the side wall parts (117) increases with distance from the tip part (116); a charging electrode (121) disposed at a given distance from the effusing body (115); and a charging power supply (122) which applies a given voltage between the effusing body (115) and the charging electrode (121).
    Type: Application
    Filed: August 11, 2010
    Publication date: January 19, 2012
    Inventors: Kazunori Ishikawa, Hiroto Sumida, Takahiro Kurokawa, Masanobu Miyata, Takatoshi Mitsushima
  • Patent number: 8098548
    Abstract: An interference type optical head and an optical disk apparatus which have a signal amplification effect and can be manufactured in sizes comparable to conventional optical heads. In an optical disk apparatus that performs signal amplification by making a light, which is used as a reference light without being irradiated on an optical disk and, interfere with reflected light from the optical disk, a corner cube prism that reflects the reference light is mounted on the same actuator as an objective lens. A movable portion adjusts the optical path length of the interfering light in accordance with the kind of optical disk being read and the recording layer being read. A wedge prism may be used for the movable portion, and a spherical aberration correction lens and an optical path length adjusting component may be moved integrally.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: January 17, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hideharu Mikami, Harukazu Miyamoto, Takahiro Kurokawa