Patents by Inventor Ryoichi Kawasaki

Ryoichi Kawasaki 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: 11980417
    Abstract: In an ophthalmology system, an right-eye imaged image is displayed on a display section for presentation to an observer through an optical unit and a reflection member. A left-eye imaged image is also displayed on a display section for presentation to an observer through an optical unit and a reflection member. A separation between the left and right imaged images is made wider than a spacing between the left and right optical units. This enables image presentation with the optical axes for the observer viewing the images intersecting in front so as to cause a convergence angle to arise.
    Type: Grant
    Filed: November 13, 2020
    Date of Patent: May 14, 2024
    Assignee: NIKON CORPORATION
    Inventors: Tomohiro Kawasaki, Ryoichi Sataka, Masahiro Mizuta
  • Patent number: 8427921
    Abstract: In the present invention, to improve CD read/write characteristics having poor image height characteristics, a third light emitting source emitting a third laser beam for CD is disposed on an optical axis of an objective lens. Thereby, the third laser beam emitted from the third light emitting source travels along the optical axis of the objective lens, thus generating no coma aberration in the third laser beam. Furthermore, in the present invention, a second light emitting source emitting a second laser beam for DVD and a first light emitting source emitting a first laser beam for BD are disposed across the third light emitting source. Thereby the phase propagation directions of coma aberrations in the first and second laser beams coincide with each other. Adjustment of the coma aberration in one of the laser beams enables the coma aberration in the other laser beam to be adjusted.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: April 23, 2013
    Assignees: SANYO Electric Co., Ltd., SANYO Optec Design Co., Ltd.
    Inventors: Ryoichi Kawasaki, Tohru Hotta
  • Patent number: 8427924
    Abstract: An optical-pickup apparatus includes: a three-wavelength-laser diode including first-, second-, and third-laser elements to emit first-, second-, and third laser beams having first, second, and third wavelengths, respectively, the three laser elements housed in the same case; an objective lens to focus the three laser beams onto first- to third-optical-disc-signal-recording layers, respectively; a first photodetector to be irradiated with first-return light reflected from the first-optical-disc-signal-recording layer, a second photodetector to be irradiated with second- and third-return lights respectively reflected from the second- and third-optical-disc-signal-recording layers; a polarizing-beam splitter to reflect the three laser beams toward the lens, and allow the three return lights having passed through the lens to pass therethrough; a semitransparent mirror on which the three return lights having passed through the polarizing-beam splitter are incident, and which guide the first-return light toward th
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: April 23, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8429681
    Abstract: An optical member driving apparatus comprising: a holding member configured to have an optical member mounted thereon; a driving unit assembly configured to be capable of driving the holding member; a connecting member configured to connect the holding member and the driving unit assembly; and a jointing member configured to joint the connecting member and either or both of the holding member and the driving unit assembly.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: April 23, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Mitsuhiro Hashimoto, Ryoichi Kawasaki
  • Patent number: 8385180
    Abstract: An optical pickup apparatus comprising: a laser diode; an objective lens made of a synthetic resin configured to focus laser light emitted from the laser diode to a signal recording layer of an optical disc; and a collimating lens having a diffraction grating and arranged in an optical path between the laser diode and the objective lens, the collimating lens being so moved in an optical axis direction of the laser light as to correct spherical aberration occurring in response to a change in temperature when performing a recording operation for the optical disc, and the collimating lens correcting by the diffraction grating chromatic aberration occurring when switching from the recording operation to a reproducing operation for the optical disc.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: February 26, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8369193
    Abstract: An optical-pickup apparatus includes: a first-objective lens; a second-objective lens; a lens holder including a first-lens barrel having the first-objective lens mounted on an end face thereof and a second-lens barrel having the second-objective lens mounted on an end face thereof; an actuator unit having the lens holder mounted thereon; and a housing having the actuator unit mounted thereon, the first and second objective lenses each being mounted on the lens holder such that a direction, in which wavefront of coma aberration on each lens face is most advanced in phase, is aligned with a radial direction of an information-recording medium, the actuator unit being mounted on the housing such that an optical axis of the first-objective lens is inclined in the radial direction at an inclination angle of the axis toward a recording surface of the medium required to cancel coma aberration of the first-objective lens to the surface.
    Type: Grant
    Filed: August 18, 2010
    Date of Patent: February 5, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Ryoichi Kawasaki, Tohru Hotta
  • Patent number: 8363526
    Abstract: An optical pickup apparatus, which reads signals recorded on first and second signal recording layers of an optical disc, includes: a laser diode; an objective lens to condense a laser beam to the first and second signal recording layers; and a collimating lens disposed in a light path of the laser beam between the laser diode and the objective lens and configured to correct a spherical aberration by moving in a light axis direction of the laser beam, and the objective lens includes a bifocal lens and is configured such that a second focal point does not coincide in position with the second signal recording layer when a first focal point coincides in position with the first signal recording layer, and the first focal point does not coincide in position with the first signal recording layer when the second focal point coincides in position with the second signal recording layer.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: January 29, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8363533
    Abstract: An optical pickup apparatus includes an objective lens having a numeric aperture and an incident face. An antireflection coating is formed on the incident face. A collimating lens converts laser light from a laser diode into parallel light, and causes the parallel light to be made incident on the incident face through the antireflection coating. The thickness of the antireflection coating causes a transmittance of laser light that enters the objective lens to be: set at a first predetermined transmittance value, when the numeric aperture is between zero and a first predetermined numeric aperture value; set to correlate linearly with the numeric aperture when the numeric aperture is between the first predetermined numeric aperture value and a second predetermined numeric aperture value; and set at a second predetermined transmittance value, when the numeric aperture is between the second predetermined numeric aperture value and a third predetermined numeric aperture value.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: January 29, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki, Kenji Kan, Hiroyuki Shindo
  • Patent number: 8345529
    Abstract: An optical-pickup apparatus includes: a laser diode having a first-laser element, which emits a first-laser beam, and a second-laser element, which emits a second-laser beam having a wavelength shorter than a wavelength of the first-laser beam, arranged in the same package; an objective lens to condense the first- and second-laser beams emitted from the laser diode to signal-recording layers of first- and second-optical discs, respectively, the second-optical disc being of a standard different from a standard of the first-optical disc; and a collimating lens arranged in an optical path between the laser diode and the objective lens, the collimating lens configured to change the first- and second-laser beams from divergent light to parallel light, the collimating lens being inclined with respect to optical axes of the first- and second-laser beams so that astigmatism in the first- and second-laser beams is corrected.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: January 1, 2013
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8339922
    Abstract: An optical pickup apparatus comprising: a diffraction grating configured to diffract laser light from a laser diode so that signals recorded in first and second optical discs are selectively reproduced, thicknesses of protective layers between surfaces and signal recording surfaces of the first and second optical discs being different from each other; a polarization beam splitter configured to divide laser light from the diffraction grating into first and second laser lights whose light amounts are substantially the same; a first objective lens configured to focus the first laser light onto the signal recording surface of the first optical disc; a second objective lens configured to focus the second laser light onto the signal recording surface of the second optical disc; and a photodetector configured to be applied with return lights of the first and second laser lights reflected from the signal recording surfaces of the first and second optical discs.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: December 25, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki, Tetsuhisa Hosokawa
  • Patent number: 8305868
    Abstract: An optical pickup apparatus comprising: an objective lens formed so that a first and second laser beams different in wavelength are respectively focused onto signal recording layers of a first and second optical discs; and a photodetector including a square-shaped light-receiving portion for being irradiated with return light, as a spot, of the first or second laser beam respectively reflected from the signal recording layers of the first or second optical discs, to generate a focus error signal, a length of a diagonal line of the light-receiving portion being substantially equal to a longer diameter of an elliptical spot formed in a direction of the diagonal line when the focus error signal is at a maximum level for an optical disc that is either one of the first and second optical discs, to which a laser beam shorter in wavelength out of the first and second laser beams is focused.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: November 6, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Publication number: 20120275289
    Abstract: In the present invention, to improve CD read/write characteristics having poor image height characteristics, a third light emitting source emitting a third laser beam for CD is disposed on an optical axis of an objective lens. Thereby, the third laser beam emitted from the third light emitting source travels along the optical axis of the objective lens, thus generating no coma aberration in the third laser beam. Furthermore, in the present invention, a second light emitting source emitting a second laser beam for DVD and a first light emitting source emitting a first laser beam for BD are disposed across the third light emitting source. Thereby the phase propagation directions of coma aberrations in the first and second laser beams coincide with each other. Adjustment of the coma aberration in one of the laser beams enables the coma aberration in the other laser beam to be adjusted.
    Type: Application
    Filed: July 10, 2012
    Publication date: November 1, 2012
    Applicants: SANYO ELECTRIC CO. LTD.
    Inventors: Ryoichi KAWASAKI, Tohru HOTTA
  • Patent number: 8264939
    Abstract: An optical pickup apparatus includes: a laser diode configured to emit a laser beam; and an objective lens configured to condense the laser beam into a laser spot through which a signal recorded on a signal recording layer of an optical disc is read out by the laser beam, the objective lens having formed thereon a lens surface with a second numerical aperture for acting as a lens, which is larger than a first numerical aperture for forming the laser spot.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: September 11, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Publication number: 20120201109
    Abstract: An optical-pickup apparatus includes: a diffraction grating that a laser beam enters, the diffraction grating being configured to generate a main beam that is 0th-order light and sub-beams that are +1st-order diffracted light and ?1st-order diffracted light; an objective lens to focus the main and sub-beams onto a signal-recording layer; a main-beam light-receiving portion that the main beam reflected by the signal-recording layer is applied to; and sub-beam light-receiving portions that the sub-beams reflected by the signal-recording layer are respectively applied to, each light-receiving area of the sub-beam light-receiving portions being smaller than a light-receiving area of the main-beam light-receiving portion, wherein a focusing-control operation is performed by a differential astigmatic method using the main beam applied to the main-beam light-receiving portion and the sub-beams respectively applied to the sub-beam light-receiving portions.
    Type: Application
    Filed: April 17, 2012
    Publication date: August 9, 2012
    Applicants: Sanyo Optec Design Co., Ltd., Sanyo Electric Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8223614
    Abstract: A method of manufacturing a synthetic resin lens, comprising: adjusting a degree of change in transmittance of a lens member made of synthetic resin for a blue violet laser beam with accumulated application of the blue violet laser beam, by applying to the lens member an electromagnetic wave shorter in wavelength than the blue violet laser beam.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: July 17, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki, Hiroyuki Ichikawa
  • Publication number: 20120170441
    Abstract: An optical pickup apparatus includes an objective lens having a numeric aperture and an incident face. An antireflection coating is formed on the incident face. A collimating lens converts laser light from a laser diode into parallel light, and causes the parallel light to be made incident on the incident face through the antireflection coating. The thickness of the antireflection coating causes a transmittance of laser light that enters the objective lens to be: set at a first predetermined transmittance value, when the numeric aperture is between zero and a first predetermined numeric aperture value; set to correlate linearly with the numeric aperture when the numeric aperture is between the first predetermined numeric aperture value and a second predetermined numeric aperture value; and set at a second predetermined transmittance value, when the numeric aperture is between the second predetermined numeric aperture value and a third predetermined numeric aperture value.
    Type: Application
    Filed: March 9, 2012
    Publication date: July 5, 2012
    Applicants: SANYO OPTEC DESIGN CO., LTD., SANYO ELECTRIC CO., LTD.
    Inventors: Tohru Hotta, Ryoichi Kawasaki, Kenji Kan, Hiroyuki Shindo
  • Patent number: 8213286
    Abstract: A photodetector comprising: a substrate; a photodiode fixed to the substrate, the photodiode configured to output a signal according to a light amount of a laser beam when applied with the laser beam; and a translucent resin covering the photodiode, the translucent resin being irradiated with ultraviolet light in advance for a predetermined time such that a change in transmittance of the translucent resin for the laser beam having a predetermined wavelength is set within a predetermined range.
    Type: Grant
    Filed: July 29, 2008
    Date of Patent: July 3, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8203926
    Abstract: An optical pickup apparatus comprises: a first laser diode that generates a first laser beam having a first wavelength; a second laser diode that generates a second laser beam having a second wavelength longer than the wavelength; a third laser diode that generates a third laser beam having a third wavelength longer than the first wavelength and shorter than the second wavelength; an objective lens having an inner, outer, intermediate regions on an incident surface, the first laser beam being condensed on a signal recording layer of a first optical disc by condensing actions of the inner and outer regions, the second laser beam being condensed on a signal recording layer of a second optical disc by condensing actions of the inner and intermediate regions, the third laser beam being condensed on a signal recording layer of a third optical disc by condensing actions of the inner and intermediate regions.
    Type: Grant
    Filed: November 5, 2010
    Date of Patent: June 19, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8184519
    Abstract: An optical pickup apparatus comprising: a diffraction grating that a laser beam enters, the diffraction grating being configured to generate a main beam that is 0th order light and sub-beams that are +1st order diffracted light and ?1st order diffracted light; an objective lens configured to focus the main beam and the sub-beams onto a signal recording layer; a main-beam light-receiving portion that the main beam reflected by the signal recording layer is applied to; and sub-beam light-receiving portions that the sub-beams reflected by the signal recording layer are respectively applied to, each light-receiving area of the sub-beam light-receiving portions being smaller than a light-receiving area of the main-beam light-receiving portion.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: May 22, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Ryoichi Kawasaki
  • Patent number: 8179770
    Abstract: An optical pickup apparatus comprising: a collimating lens configured to convert laser light emitted from a laser diode, from diffused light into parallel light; an objective lens; and a prism configured to guide the laser light emitted from the collimating lens to the objective lens, the prism including: a first face that the laser light emitted from the collimating lens enters; a second face that reflects the laser light entering the first face; and a third face that reflects the laser light reflected from the second face in a direction of the second face, and emits the laser light reflected again from the second face in a direction of the objective lens.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: May 15, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Optec Design Co., Ltd.
    Inventors: Tohru Hotta, Kenichirou Kawabuchi, Ryoichi Kawasaki