Patents by Inventor Kaoru Okamoto

Kaoru Okamoto 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: 7858806
    Abstract: Conventional I-form crystals of 5-hydroxy-1-methylhydantoin contain, remaining therein in a considerable amount, the organic solvent used in a purification step. In contrast, in II-form crystals, the amount of the organic solvent remaining therein is smaller than the detection limit. Namely, the II-form crystals contain substantially no residual organic solvent. The novel II-form crystals of 5-hydroxy-1-methylhydantoin obtained through recrystallization from water not only contain substantially no residual organic solvent, but also have a high bulk density and are hence advantageous for pharmaceutical preparation. They further have properties advantageous for production, such as low adhesion. The crystals are significantly useful as a material for medicines required to have high safety, such as drugs for renal insufficiency.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: December 28, 2010
    Assignee: Nippon Zoki Pharmaceutical Co., Ltd.
    Inventors: Kaoru Okamoto, Naoharu Nishimura, Akira Ishii
  • Patent number: 7855093
    Abstract: A method of manufacturing semiconductor laser device capable of reducing ?L, with manufacturing restrictions satisfied, is provided. In a distributed-feedback or distributed-reflective semiconductor laser device, immediately before burying regrowth of a diffraction grating, halogen-based gas is introduced to a reactor, and etching is performed on the diffraction grating so that each side wall has at least two or more crystal faces and a ratio of length of an upper side in a waveguide direction to a bottom side parallel to a (100) surface is 0 to 0.3. And, a reactive product formed on side surfaces of the diffraction grating and in trench portions between stripes of the diffraction grating at an increase of temperature for regrowth is removed. Therefore, the diffraction grating with reduced height and a sine wave shape is obtained, thereby ?L of the device is reduced. Thus, an oscillation threshold and optical output efficiency can be improved.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: December 21, 2010
    Assignee: Opnext Japan, Inc.
    Inventors: Kaoru Okamoto, Ryu Washino, Kazuhiro Komatsu, Yasushi Sakuma
  • Patent number: 7848200
    Abstract: A method of reproducing multilevel information using a light spot. The multilevel information is recorded by defining virtual cells at regular intervals on tracks of an optical information recording medium and varying sizes of information pits in the cells. The method includes the steps of obtaining cell boundary values, each of the cell boundary values being obtained by performing sampling when the center of the light spot reaches a boundary between adjacent cells, calculating cell boundary value metrics on the basis of the cell boundary values and prestored reference values for the cell boundary values, calculating path metrics on the basis of the cell boundary value metrics, selecting a path metric having a minimum value of the path metrics, and reproducing the multilevel information on the basis of the path metric having the minimum value of the path metrics.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: December 7, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kaoru Okamoto, Jun Sumioka, Masakuni Yamamoto
  • Patent number: 7808874
    Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.
    Type: Grant
    Filed: March 8, 2010
    Date of Patent: October 5, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Patent number: 7808873
    Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.
    Type: Grant
    Filed: March 8, 2010
    Date of Patent: October 5, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Patent number: 7804754
    Abstract: In three consecutive cells consisting of a preceding cell, a center cell, and a subsequent cell, a possible change rate of the amplitude of a reproduced signal for the center cell with respect to the sum of the multiple values of the preceding and subsequent cells is obtained in advance. Then, for reproduction, the sum of the multiple values of the adjacent preceding and subsequent cells is obtained with respect to each cell. The amplitude of the reproduced signal obtained at the center cell is corrected to be closer to a reference value on the basis of the obtained change rate and sum.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: September 28, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakuni Yamamoto, Jun Sumioka, Kaoru Okamoto
  • Patent number: 7778133
    Abstract: An optical information recording/reproducing apparatus is adapted to record and/or reproduce multilevel information on/or from an optical information recording medium. The multilevel information is recorded in the form of pits in cells virtually formed at regular intervals on a track. The respective levels are represented by varying the length or the area of information pits such that a reproduced signal has a different amplitude level depending on the length or the area of information pits. A reproduced signal correction circuit corrects a reproduced signal obtained by performing sampling at the center of each cell. An error power calculation circuit calculates error power on the basis of the difference between the corrected reproduced signal and an ideal value of each level of the cell. A decoder performs decoding on the basis of the calculated error power values.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: August 17, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kaoru Okamoto, Jun Sumioka, Masakuni Yamamoto
  • Publication number: 20100165826
    Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.
    Type: Application
    Filed: March 8, 2010
    Publication date: July 1, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Publication number: 20100157781
    Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.
    Type: Application
    Filed: March 8, 2010
    Publication date: June 24, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Patent number: 7738338
    Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings. The multivalued information is recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot. The multivalued information is reproduced by detecting the level of a multistage reproduced signal from the information pit. The method includes sampling a reproduced signal in the multivalued information recorded in one cell with an M-value (M<N), which is arranged at each of the plurality of cells recorded with an N-value (N?3) on the track, and detecting a cell center value.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: June 15, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Patent number: 7706243
    Abstract: An optical information reproducing method capable of determining multi-level information with high precision, and an apparatus for the method. Specifically, a cell having a reduced multi-level is provided in a portion of a data region to perform the level correction or automatic gain control. For example, a cell recorded with an M-value for each group including a plurality of cells, each of which is recorded with an N-value (N>3, M<N), is provided. A reproduction signal level of a cell recorded with the N-value, which follows the cell recorded with the M-value, is corrected based on a difference between a cell center value of a reproduction signal sampled when a center of a light spot is moved to a center of the cell recorded with the M-value and a reference value obtained from learning information.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: April 27, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Sumioka, Masakuni Yamamoto, Kaoru Okamoto
  • Patent number: 7687295
    Abstract: In an optical semiconductor device that emits or receives light substantially perpendicularly to or in parallel to an active surface formed on a semiconductor substrate, the optical semiconductor device, an electrode that is formed on the active surface side and connected to the active surface is stepped or tapered at an end of the electrode. The electrode of the optical semiconductor device is formed of three layers including an adhesive layer, a diffusion prevention layer, and an Au layer, and the stepped configuration or the taped configuration is formed by a difference of the thickness of the Au layer or the thickness of the adhesive layer/diffusion prevention layer/Au layer.
    Type: Grant
    Filed: January 31, 2008
    Date of Patent: March 30, 2010
    Assignee: Opnext Japan, Inc.
    Inventors: Ryu Washino, Susumu Sorimachi, Daisuke Nakai, Kaoru Okamoto, Shigenori Hayakawa
  • Patent number: 7687874
    Abstract: In a mesa type PIN-PD formed using a heavily doped semiconductor material, a high frequency response is degraded as slow carriers occur in a heavily doped layer when light incident into a light receiving section transmits through an absorbing layer and reaches the heavily doped layer on a side near the substrate. In a p-i-n multilayer structure, a portion corresponding to a light receiving section of a heavily doped layer on a side near a substrate is previously made thinner than the periphery of the light receiving section by an etching or selective growth technique, over which an absorbing layer and another heavily doped layer are grown to form the light receiving section of mesa structure. This makes it possible to form a good ohmic contact and to realize a PIN-PD with excellent high frequency response characteristics.
    Type: Grant
    Filed: February 5, 2007
    Date of Patent: March 30, 2010
    Assignee: Opnext Japan, Inc.
    Inventors: Kazuhiro Komatsu, Yasushi Sakuma, Daisuke Nakai, Kaoru Okamoto, Ryu Washino
  • Publication number: 20100073265
    Abstract: An active-matrix display includes a data line, at least one select line, a control unit supplying a voltage signal and a current signal to the data line, and a pixel circuit receiving the voltage signal and the current signal from the data line to drive a light emitting element, the control unit including a voltage or first current source supplying a voltage or current pulse to the data line in order to make the voltage holding unit hold the voltage signal for making the light emitting element emit light having predetermined brightness in a first selection period in which the first switch is closed, a second current source supplying the current signal for making the light emitting element emit light having the predetermined brightness to the data line in a second selection period in which the first switch and the second switch are closed, a detection circuit detecting potential held in the voltage holding unit in the second selection period, and a correction unit correcting the voltage signal based on a relat
    Type: Application
    Filed: May 21, 2008
    Publication date: March 25, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tadahiko Hirai, Jun Sumioka, Kaoru Okamoto
  • Publication number: 20100022043
    Abstract: A method of manufacturing semiconductor laser device capable of reducing ?L, with manufacturing restrictions satisfied, is provided. In a distributed-feedback or distributed-reflective semiconductor laser device, immediately before burying regrowth of a diffraction grating, halogen-based gas is introduced to a reactor, and etching is performed on the diffraction grating so that each side wall has at least two or more crystal faces and a ratio of length of an upper side in a waveguide direction to a bottom side parallel to a (100) surface is 0 to 0.3. And, a reactive product formed on side surfaces of the diffraction grating and in trench portions between stripes of the diffraction grating at an increase of temperature for regrowth is removed. Therefore, the diffraction grating with reduced height and a sine wave shape is obtained, thereby ?L of the device is reduced. Thus, an oscillation threshold and optical output efficiency can be improved.
    Type: Application
    Filed: October 2, 2009
    Publication date: January 28, 2010
    Applicant: OPNEXT JAPAN, INC.
    Inventors: Kaoru OKAMOTO, Ryu WASHINO, Kazuhiro KOMATSU, Yasushi SAKUMA
  • Publication number: 20100007656
    Abstract: Display image quality degradation caused by a burn-in phenomenon is prevented in a self-emission type display apparatus. A degradation characteristic acquisition circuit acquires degradation characteristics of a pixel region, and a boundary portion detection circuit detects a boundary of the degradation characteristics. A correction amount operation circuit arithmetically operates a correction amount based on the boundary, and a video signal correction circuit corrects a video signal. The correction amount is determined based on the boundary of the degradation characteristics such that emission luminance is gently varies in a periphery of a boundary of a pixel due to the burn-in phenomenon, and whereby the burn-in phenomenon becomes inconspicuous.
    Type: Application
    Filed: June 29, 2009
    Publication date: January 14, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kaoru Okamoto, Jun Sumioka, Tadahiko Hirai
  • Publication number: 20090270634
    Abstract: Conventional I-form crystals of 5-hydroxy-1-methylhydantoin contain, remaining therein in a considerable amount, the organic solvent used in a purification step. In contrast, in II-form crystals, the amount of the organic solvent remaining therein is smaller than the detection limit. Namely, the II-form crystals contain substantially no residual organic solvent. The novel II-form crystals of 5-hydroxy-1-methylhydantoin obtained through recrystallization from water not only contain substantially no residual organic solvent, but also have a high bulk density and are hence advantageous for pharmaceutical preparation. They further have properties advantageous for production, such as low adhesion. The crystals are significantly useful as a material for medicines required to have high safety, such as drugs for renal insufficiency.
    Type: Application
    Filed: July 7, 2009
    Publication date: October 29, 2009
    Applicant: NIPPON ZOKI PHARMACEUTICAL CO., LTD.
    Inventors: Kaoru Okamoto, Naoharu Nishimura, Akira Ishii
  • Patent number: 7593302
    Abstract: An optical information recording method includes the steps of irradiating laser light onto cells provided on a track of an optical information recording medium, recording on the optical information recording medium multilevel information including information of a level zero for which no information pit is formed, by changing, for each of the cells, widths in a track direction or sizes of information pits in the cells, and, for recording the information of a level zero, irradiating the laser light at a power that is greater than an erasing power for erasing the information pits and that does not permit formation of the information pits.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: September 22, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakuni Yamamoto, Jun Sumioka, Kaoru Okamoto
  • Patent number: 7569701
    Abstract: Conventional I-form crystals of 5-hydroxy-1-methylhydantoin contain, remaining therein in a considerable amount, the organic solvent used in a purification step. In contrast, in II-form crystals, the amount of the organic solvent remaining therein is smaller than the detection limit. Namely, the II-form crystals contain substantially no residual organic solvent. The novel II-form crystals of 5-hydroxy-1-methylhydantoin obtained through recrystallization from water not only contain substantially no residual organic solvent, but also have a high bulk density and are hence advantageous for pharmaceutical preparation. They further have properties advantageous for production, such as low adhesion. The crystals are significantly useful as a material for medicines required to have high safety, such as drugs for renal insufficiency.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: August 4, 2009
    Assignee: Nippon Zoki Pharmaceutical Co., Ltd.
    Inventors: Kaoru Okamoto, Naoharu Nishimura, Akira Ishii
  • Publication number: 20090002281
    Abstract: An active matrix organic electroluminescence(EL) display comprises plural selection and data lines mutually crossed, and a pixel circuit connected to the selection and data lines and having switching devices, a storage capacitor and an organic EL device. In a part of a period that the pixel circuit connected to the selection line is being selected, an applied first data signal is held as a voltage at the storage capacitor of the selected pixel circuit. After the selection signal applying, a first current according to the held voltage is supplied to the organic EL device, and this emits light at luminance according to the first current. In another part of the period, a second current according to an applied second data signal is supplied to the organic EL device of the selected pixel circuit, and this emits light at luminance according to the second current.
    Type: Application
    Filed: June 25, 2008
    Publication date: January 1, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kaoru Okamoto, Tadahiko Hirai, Jun Sumioka