Patents by Inventor Tadashi Fukuzawa

Tadashi Fukuzawa 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: 7903911
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: March 8, 2011
    Assignee: International Business Machines Corporation
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Publication number: 20090148099
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Application
    Filed: December 18, 2008
    Publication date: June 11, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: KAZUO SEKIYA, TADASHI FUKUZAWA
  • Patent number: 7489840
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: February 10, 2009
    Assignee: International Business Machines Corporation
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Patent number: 7421858
    Abstract: Provided is an optical transmission substrate including: a first substrate; an optical waveguide which has clad covering a core and a periphery of the core and extends on an upper surface of the first substrate; a second substrate provided parallel to the first substrate so that a lower surface thereof contacts an upper surface of the optical waveguide; a reflection surface which is provided on a cross section of the core at an end of the optical waveguide and reflects light, which travels through the core of the optical waveguide, toward the second substrate; and a light guide which is provided in the second substrate and guides the light, which is reflected toward the second substrate, toward an upper surface of the second substrate from a position closer to the core than an upper surface of the clad.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: September 9, 2008
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Masaki Hasegawa
  • Patent number: 7373044
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: May 13, 2008
    Assignee: International Business Machines Corporation
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Publication number: 20070137254
    Abstract: Provided is an optical transmission substrate including: a first substrate; an optical waveguide which has clad covering a core and a periphery of the core and extends on an upper surface of the first substrate; a second substrate provided parallel to the first substrate so that a lower surface thereof contacts an upper surface of the optical waveguide; a reflection surface which is provided on a cross section of the core at an end of the optical waveguide and reflects light, which travels through the core of the optical waveguide, toward the second substrate; and a light guide which is provided in the second substrate and guides the light, which is reflected toward the second substrate, toward an upper surface of the second substrate from a position closer to the core than an upper surface of the clad.
    Type: Application
    Filed: February 27, 2007
    Publication date: June 21, 2007
    Inventors: Tadashi Fukuzawa, Masaki Hasegawa
  • Patent number: 7212713
    Abstract: Provided is an optical transmission substrate including: a first substrate; an optical waveguide which has clad covering a core and a periphery of the core and extends on an upper surface of the first substrate; a second substrate provided parallel to the first substrate so that a lower surface thereof contacts an upper surface of the optical waveguide; a reflection surface which is provided on a cross section of the core at an end of the optical waveguide and reflects light, which travels through the core of the optical waveguide, toward the second substrate; and a light guide which is provided in the second substrate and guides the light, which is reflected toward the second substrate, toward an upper surface of the second substrate from a position closer to the core than an upper surface of the clad.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: May 1, 2007
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Masaki Hasegawa
  • Publication number: 20060002713
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Application
    Filed: June 13, 2005
    Publication date: January 5, 2006
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Publication number: 20050284180
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Application
    Filed: June 13, 2005
    Publication date: December 29, 2005
    Applicant: International Business Machines Corporation
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Patent number: 6947671
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: September 20, 2005
    Assignee: International Business Machines Corp
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Publication number: 20050117833
    Abstract: Provided is an optical transmission substrate including: a first substrate; an optical waveguide which has clad covering a core and a periphery of the core and extends on an upper surface of the first substrate; a second substrate provided parallel to the first substrate so that a lower surface thereof contacts an upper surface of the optical waveguide; a reflection surface which is provided on a cross section of the core at an end of the optical waveguide and reflects light, which travels through the core of the optical waveguide, toward the second substrate; and a light guide which is provided in the second substrate and guides the light, which is reflected toward the second substrate, toward an upper surface of the second substrate from a position closer to the core than an upper surface of the clad.
    Type: Application
    Filed: October 29, 2004
    Publication date: June 2, 2005
    Applicant: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Masaki Hasegawa
  • Publication number: 20040258354
    Abstract: An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.
    Type: Application
    Filed: April 16, 2004
    Publication date: December 23, 2004
    Applicant: International Business Machines Corporation
    Inventors: Kazuo Sekiya, Tadashi Fukuzawa
  • Patent number: 6295106
    Abstract: Novel liquid crystal display (LCD) structures for full-color liquid crystal displays using photoluminescent (PL) fibers. The new architectures simplify the LCD fabrication process by replacing complicated, time consuming photolithography steps for color filter fabrication to a low-cost, high-throughput fiber spinning technology. The new LCD architecture implementing the approach has a higher power efficiency than conventional LCDs. Three structures of LCD devices utilizing photoluminescent (PL) fiber arrays includes: a first structure having PL fiber arrays situated behind the LC shutter (relative to viewers); a second structure having PL fiber arrays situated on top of the LC shutter; and a third structure where the PL fiber arrays are located outside the LC cell. In one of these structures, the fibers not only photoluminesce, but also polarize incident light thus reducing LCD fabrication cost.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: September 25, 2001
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Sayuri Kohara, Victor Yee Way Lee, Robert D. Miller, John Campbell Scott, Sally A. Swanson
  • Patent number: 6249328
    Abstract: A white cold-cathode fluorescent lamp, which is used as an illumination backlight for liquid crystal, is replaced by cold-cathode fluorescent lamps that emit red, green and blue lights, respectively. Since a liquid crystal picture is illuminated by the fluorescent lights in a time-sequential manner, a multi-color display can be provided without spatially dividing liquid crystal pixels using a color filter; and as it is not necessary for one pixel to be divided into three color cells, the size of a pixel can be reduced. Furthermore, in the liquid crystal display device, a phosphor having a short emission life is employed to coat the interior of the cold-cathode fluorescent lamp and enable the cold-cathode fluorescent lamp to be turned on and off rapidly, so that degradation of display colors due to slow fluorescence decay can be prevented and moving pictures can be displayed.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: June 19, 2001
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Shigeo Shionoya
  • Patent number: 5638207
    Abstract: An optical system is provided in which flare is prevented and, when the light reflected from a reflection component is modulated by a photoelastic phenomenon, the effect of the modulation on the measurement of the intensity of the reflected light can be eliminated, and, further, a flying height tester for a magnetic head is provided using such optical system. A multilambda plate is provided in the flare-prevention optical system for allowing the light reaching a reflection component and the light reflected from the reflection component to pass, and for allowing the phase difference between the ordinary ray and the extraordinary ray to vary by 2.pi. or more depending on the wavelength of light. Since the light passed through the multilambda plate only varies in the peak position and the peak height varies little even if the light has experienced modulation, no error occurs in the spectrum intensity of the light. A depolarizer may be substituted for the multilambda plate.
    Type: Grant
    Filed: August 17, 1995
    Date of Patent: June 10, 1997
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Teiji Hisano, Yasuji Ozawa, Yasuyuki Takahashi, Hiroshi Watabe
  • Patent number: 5547705
    Abstract: A nonlinear optical device comprising a substrate and a film structure coated on to the substrate. The film has, in a direction normal to the substrate, an intercalation structure including a semiconductor layer and an organic layer that lave different energy gaps. The intercalation structure includes a plurality of semiconductor layers and a plurality of organic layers which comprise a quantum well system. The film structure includes an assembly of microcrystals having domain size smaller than that of the wavelength of light with which the device operates. The microcrystals have an axis aligned in a direction normal to the substrate and have randomly oriented axes in a direction parallel to the substrate. A method for producing the device comprises providing a solution of an organic material in a solvent and placing a quantity of the solution on a substrate to form the organic material film structure thereon. The film is formed by spin coating of the solution on the substrate.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: August 20, 1996
    Assignee: International Business Machine Corporation
    Inventors: Tadashi Fukuzawa, Satoru S. Kano, Kiyoshi Kumata, Victor Y. Lee, Franklin M. Schellenberg, Yutaka Takahashi
  • Patent number: 5502565
    Abstract: This invention provides a method and apparatus for accurately measuring the flying height of a magnetic head at high speed by using a white lamp and a color CCD camera. The invention entails substituting tentative refraction coefficients and extinction coefficients representative of colors in theoretical equations expressing the relationship between interference light intensity and flying height, thereby optimizing the parameters by non-linear regression. The flying height of a magnetic head is measured by using the coefficient thus determined. Also, this invention enables determination of flying height at very high speed through effecting the above optimization in consideration of constants associated with the shape of the head under consideration, and adapting the above theoretical equations.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: March 26, 1996
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Teiji Hisano, Tetsuji Morita, Koichi Ikarugi
  • Patent number: 5475488
    Abstract: A high-sensitivity apparatus having simple constitution that measures the flying height of a magnetic head. Light emitted from a white light source 25 is directed to the gap between a disk 23 and a head 21, and subjected to multiple reflection between the disk 23 and the head 21. Reflected light from an opaque object, which may be either the disk 23 or the head 21, is divided into at least three components having respective wavelength regions which are directed to different photodetectors 35, 36, and 37 for the respective wavelength regions. An estimation device 38 estimates the flying height of the head according to the least-square method from the outputs of the photodetectors using functions prepared in advance for the respective wavelength regions, and correlates the disk-head gap and the reflected light intensities detected by the respective photodetectors. Real-time calculation according to the least-square method is performed by means of a table look-up technique or a tracking servo technique.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: December 12, 1995
    Inventors: Tadashi Fukuzawa, Teiji Hisano, Kohichi Ikarugi, Tetsuji Morita, Kohki Noda
  • Patent number: 5287377
    Abstract: The present invention is the use of coupled quantum wells in the active region of a semiconductor laser to modulate the frequency and amplitude of the light output of the laser. In a particular embodiment of the present invention the coupled quantum wells are contained in a graded index of refraction semiconductor double heterostructure laser. The active region of this tunable laser consists of two quantum wells having a width of approximately 50 Angstroms or less which are separated by a barrier layer having a width of approximately 20 Angstroms or less. The quantum well material is intrinsic GaAs and the barrier layer is Al.sub.x Ga.sub.1-x As wherein x=0.23. The active region is surrounded by the double heterostructure in which one side is doped p-type and the second side is doped n-type. The resulting laser is a p-i-n type structure.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: February 15, 1994
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Ling Y. Liu, Emilio E. Mendez
  • Patent number: 5281543
    Abstract: Disclosed is a new method suitable for making highly integrated quantum wire arrays, quantum dot arrays in a single crystal compound semiconductor and FETs of less than 0.1 micron gate length. This makes it possible to construct a high-performance electronic device with high speed and low power consumption, using a combination of low-temperature-growth molecular beam epitaxy (LTG-MBE) and focused ion beam (FIB) implantation. The compound semiconductor (GaAs) epitaxial layers, which are made by LTG-MBE, are used as targets of Ga FIB implantation to make Ga wire or dot arrays. Precipitation of arsenic microcrystals, which are initially embedded in a single crystal GaAs layer and act as Schottky barriers, are typically observed in an LTG GaAs layer. A thermal annealing process, after implantation, changes the arsenic microcrystals to GaAs crystals if the arsenic microcrystals are in the region in which the Ga ions are implanted.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: January 25, 1994
    Assignee: International Business Machines Corporation
    Inventors: Tadashi Fukuzawa, Hiro Munekata