Patents by Inventor Koichiro Nishikawa

Koichiro Nishikawa 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: 7791986
    Abstract: There is provided an optical information recording/reproducing apparatus including a unit for detecting the focus error signal from the reflected light flux from a recording layer of an optical recording medium, and a unit for focusing the light flux on the recording layer of the optical disk on the basis of the focus error signal. In the case of detecting the focus error signal, the light flux of the effective numeric aperture NAeff<1 due to an objective lens and the SIL within a pupil is obtained by a splitting device as the focus error signal, whereby it is possible to suppress the reflected light from the bottom surface of the SIL from being mixed into the focus error signal as a noise.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: September 7, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Koyama, Koichiro Nishikawa, Shinnosuke Torii, Chihiro Nagura, Haruhiko Horiguchi
  • Patent number: 7706227
    Abstract: An optical information recording/reproduction apparatus includes a correction device that corrects aberration, due to a change in thicknesses of a transparent substrate and spherical aberration generated by inserting an optical attenuation device into an optical path or retreating the optical attenuation device from the optical path, by changing intervals between a plurality of lenses. The correction device is disposed between an objective lens and a light source. The correction device also functions as a collimator lens. The optical attenuation device is provided in an optical path of diverging light flux from the light source to the correction device, for attenuating an optical output from the light source. A discrimination circuit discriminates (i) a kind of the optical recording medium and (ii) an insertion of the optical attenuation device into the optical path or a retreating of the optical attenuation device from the optical path, and produces a discrimination result.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: April 27, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Koichiro Nishikawa
  • Patent number: 7680013
    Abstract: Provided is a spatial light modulator SLM and a photodetector element CMOS sensor are placed on the same chip, and the alignment thereof and a relay lens system are eliminated, whereby an optical system is reduced in cost and made compact. Specifically, provided is an optical information recording and reproducing apparatus for recording information by allowing information light and reference light to interfere with each other and reproducing the information using the reference light including: a light source; a spatial light modulator for generating at least an information light with respect to a light beam from the light source; an objective lens for irradiating a recording medium with the light beam from the spatial light modulator; and a photodetector element for receiving a reproduction light from the recording medium, in which the spatial light modulator and the photodetector element are formed on the same semiconductor substrate.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: March 16, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Koyama, Osamu Nagatsuka, Shinnosuki Torii, Koichiro Nishikawa
  • Patent number: 7417938
    Abstract: Provided is an optical pickup apparatus which has a function for correcting spherical aberration caused by a thickness error of a transparent substrate and which is sufficiently compact, wherein a collimator lens used in the apparatus is composed of two lens groups, an interval between the two lens groups is changeable, and therefore spherical aberration caused by the thickness error of the transparent substrate is corrected.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: August 26, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventor: Koichiro Nishikawa
  • Patent number: 7400567
    Abstract: The recording medium 12 is radiated with light beam from the second light source to obtain servo signal from the reflected light. At least one of the relay lenses 8 in the relay optical system is moved perpendicularly to the optical axis according to the servo signal to follow-up moving direction of the recording medium. The light beam from the second laser light source merges with an optical system from the first laser light source to the recording medium 12 between at least one of the relay lenses 8 and the spatial light modulator 3.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: July 15, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichiro Nishikawa, Takashi Fukuhara
  • Publication number: 20070217300
    Abstract: There is provided an optical information recording/reproducing apparatus including a unit for detecting the focus error signal from the reflected light flux from a recording layer of an optical recording medium, and a unit for focusing the light flux on the recording layer of the optical disk on the basis of the focus error signal. In the case of detecting the focus error signal, the light flux of the effective numeric aperture NAeff<1 due to an objective lens and the SIL within a pupil is obtained by a splitting device as the focus error signal, whereby it is possible to suppress the reflected light from the bottom surface of the SIL from being mixed into the focus error signal as a noise.
    Type: Application
    Filed: March 14, 2007
    Publication date: September 20, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Osamu Koyama, Koichiro Nishikawa, Shinnosuke Torii, Chihiro Nagura, Haruhiko Horiguchi
  • Publication number: 20070183279
    Abstract: An apparatus for optically reproducing and recording information includes a light source, an objective lens, a light detecting element, and a processor. The objective lens focuses light beams emitted from the light source on an optical recording medium having tracks disposed at a track pitch. The wavelength of the light beams is greater than the track pitch of the medium. The light detecting element receives light beams reflected from the medium. The light detecting element includes a first region that receives substantially only light beams generated by interference between zeroth-order diffracted beams and first-order diffracted beams among the light beams reflected from the tracks of the medium and a second region that receives substantially only the zeroth-order diffracted beams. The processor generates focusing error signals using astigmatic focusing error detection on the basis of an output from the second region of the light detecting element.
    Type: Application
    Filed: January 16, 2007
    Publication date: August 9, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Koichiro NISHIKAWA
  • Publication number: 20070120042
    Abstract: A collinear system optical information recording-reproduction apparatus is provided which gives sufficiently high interference modulation degree even with inexpensive semiconductor laser as the recording-reproduction light source. Specifically in this apparatus, recording is conducted by introducing a light flux from a light source to a spatial light modulator having an information pattern area and a reference pattern area, introducing the produced information light and reference light to object lens to record the information to a recording medium by the object lens by holography; and reproduction is conducted by projecting the reference light only from the spatial light modulator to the recording medium, and introducing the light reflected by the recording medium to a light-receiving element. In this apparatus the average information light intensity and the average reference light intensity introduced into the object lens are made equal.
    Type: Application
    Filed: November 15, 2006
    Publication date: May 31, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Koichiro NISHIKAWA
  • Publication number: 20070121437
    Abstract: The recording medium 12 is radiated with light beam from the second light source to obtain servo signal from the reflected light. At least one of the relay lenses 8 in the relay optical system is moved perpendicularly to the optical axis according to the servo signal to follow-up moving direction of the recording medium. The light beam from the second laser light source merges with an optical system from the first laser light source to the recording medium 12 between at least one of the relay lenses 8 and the spatial light modulator 3.
    Type: Application
    Filed: November 17, 2006
    Publication date: May 31, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Koichiro NISHIKAWA
  • Publication number: 20070121468
    Abstract: Provided is a spatial light modulator SLM and a photodetector element CMOS sensor are placed on the same chip, and the alignment thereof and a relay lens system are eliminated, whereby an optical system is reduced in cost and made compact. Specifically, provided is an optical information recording and reproducing apparatus for recording information by allowing information light and reference light to interfere with each other and reproducing the information using the reference light including: a light source; a spatial light modulator for generating at least an information light with respect to a light beam from the light source; an objective lens for irradiating a recording medium with the light beam from the spatial light modulator; and a photodetector element for receiving a reproduction light from the recording medium, in which the spatial light modulator and the photodetector element are formed on the same semiconductor substrate.
    Type: Application
    Filed: November 22, 2006
    Publication date: May 31, 2007
    Applicant: Canon Kabushiki Kaisha
    Inventors: Osamu Koyama, Osamu Nagatsuka, Shinnosuke Torii, Koichiro Nishikawa
  • Patent number: 7167436
    Abstract: The present invention provides an optical recording medium capable of detecting groove start signals and groove end signals with an inexpensive detection circuit and allowing quick, stable clock detection and tracking pull-in, which optical recording medium is constructed in such a way that the depth DG of the grooves satisfies DG/(?/N)<0.16, where ? is a wavelength of a light beam and N is an index of refraction of a substrate, and that the distance Ls between the groove edge and the pit closest thereto satisfies Ls>1.2 FWHM, where FWHM is a full width at half maximum of the light beam in the track direction.
    Type: Grant
    Filed: May 14, 2003
    Date of Patent: January 23, 2007
    Assignees: Canon Kabushiki Kaisha, Matsushita Electric Industrial Co., Ltd.
    Inventors: Osamu Koyama, Koichiro Nishikawa, Eiji Ueda, Yasumori Hino
  • Publication number: 20060171275
    Abstract: An optical information recording/reproduction apparatus capable of eliminating a waste of learning time for spherical aberration learning and rationalizing the spherical aberration-correcting operation is provided. Specifically, the optical information recording/reproduction apparatus includes: a discrimination circuit for discriminating the kind of an optical disk, that is, whether a recording layer is a single-layer, or whether double-layers or an optical disk is a disk corresponding to red-laser or a disk corresponding to blue-laser; a correction device for correcting the aberration due to a change in thicknesses of the transparent substrate of an optical disk by changing intervals between a plurality of lenses; a learning circuit for searching a correction amount while changing intervals between the plurality of lenses; and a circuit for changing initial positions of intervals between the plurality of lenses at start of learning in accordance with a discrimination result by the discrimination circuit.
    Type: Application
    Filed: January 20, 2006
    Publication date: August 3, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Koichiro Nishikawa
  • Patent number: 6985409
    Abstract: The present invention provides a method of recording information on a magneto-optical recording medium of domain wall displacement type having a preformat area and a data area succeeding thereto, comprising the steps of generating a reproduction signal from said medium by utilizing a light beam, detecting a reference position based on said reproduction signal, determining, based on a result of the detection, a recording start timing at which a formation of a recording magnetic domain is started at a distance at least not shorter than a displacement amount of a domain wall away from a start position of said data area; and starting a recording with said determined recording start timing.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: January 10, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Koichiro Nishikawa
  • Publication number: 20050254400
    Abstract: Provided is an optical pickup apparatus which is inexpensive and has sufficient chromatic aberration correction performance, and which includes a chromatic aberration correction optical system composed of two lens groups having positive power and negative power, wherein the lens group having the positive power is constructed such that a focal distance thereof does not change or becomes shorter when a wavelength of a semiconductor laser lengthens, One of the lens groups is moved relative to the other lens group to correct chromatic aberration caused by a change in substrate thickness.
    Type: Application
    Filed: April 19, 2005
    Publication date: November 17, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventor: Koichiro Nishikawa
  • Publication number: 20050254394
    Abstract: Provided is an optical pickup apparatus which has a function for correcting spherical aberration caused by a thickness error of a transparent substrate and which is sufficiently compact, wherein a collimator lens used in the apparatus is composed of two lens groups, an interval between the two lens groups is changeable, and therefore spherical aberration caused by the thickness error of the transparent substrate is corrected.
    Type: Application
    Filed: April 25, 2005
    Publication date: November 17, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventor: Koichiro Nishikawa
  • Publication number: 20050163000
    Abstract: An optical information recording/reproducing device makes use of a differential push-pull (DPP) method. In the optical information recording/reproducing device, after amplification of a push-pull signal of first and second subbeams at a first predetermined ratio, a differential between the push-pull signal of the first and second subbeams and a push-pull signal of a main beam is determined in order to generate a tracking control signal. In addition, after amplification of the push-pull signal of the first and second subbeams at a predetermined second ratio, a summation of the push-pull signal of the first and second subbeams and the push-pull signal of the main beam is determined in order to generate an objective lens position signal. The first predetermined ratio and the second predetermined ratio are different.
    Type: Application
    Filed: December 29, 2004
    Publication date: July 28, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Koichiro Nishikawa
  • Publication number: 20040081032
    Abstract: Two-dimensionally annular or spiral lands and grooves are formed in a magneto-optical disk having a magnetic layer composed of a magnetic domain wall displacement layer, a switching layer, and a record retaining layer. The lands and the grooves are each used as a recording and reproducing area. A side wall present between the land and the groove and its vicinity are annealed so as to change the physical properties of these areas. The width of the land is larger than the width of the groove by 0.5 to 4 times the width of the side wall. Further, the ratio of the width of the land to the width of the groove is 1.05 to 1.20. Furthermore, the grooves have a period of 1.0 to 1.2 microns.
    Type: Application
    Filed: October 14, 2003
    Publication date: April 29, 2004
    Inventor: Koichiro Nishikawa
  • Patent number: PP23452
    Abstract: A new cultivar of Delosperma plant, ‘Jewel of Desert Rosequartz’, characterized by its compact and very horizontal plant habit, its relatively small leaves, its very floriferous and long blooming flowering habit, and its flowers that are light pink in color with white centers and yellow anthers.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: March 5, 2013
    Assignee: Ron Van Dijk Consultancy B.V.
    Inventor: Koichiro Nishikawa
  • Patent number: PP23453
    Abstract: A new cultivar of Delosperma plant, ‘Jewel of Desert Ruby’, characterized by its compact and very horizontal plant habit, its relatively small leaves, its very floriferous and long blooming flowering habit, and its flowers that are deep red in color with white centers and yellow anthers.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: March 5, 2013
    Assignee: Ron Van Dijk Consultancy B.V.
    Inventor: Koichiro Nishikawa
  • Patent number: PP23471
    Abstract: A new cultivar of Delosperma plant, ‘Jewel of Desert Garnet’, characterized by its compact plant habit, its very floriferous and long blooming flowering habit, its high heat tolerance, and its flowers that are red-orange with pink centers and yellow anthers.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: March 12, 2013
    Assignee: Ronvandijk Consultancy B.V.
    Inventor: Koichiro Nishikawa