Patents by Inventor Ippei Sawaki

Ippei Sawaki 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).

  • Magneto-optic reading and recording head using external resonator having semiconductor laser
    Patent number: 5235588
    Abstract: A magneto-optic disc recording and reading head having an orthogonal two mode oscillation type of external resonator having a semiconductor laser, including a device for differentiating the directions of propagation of two modes of light from one another to prevent the two modes of light from being united in the laser.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: August 10, 1993
    Assignee: Fujitsu Limited
    Inventors: Kazunori Miura, Ippei Sawaki
  • Optical beam profile tranforming element
    Patent number: 5175788
    Abstract: An optical beam profile transforming element which is a monolith solid element with a low loss is provided by placing at least two parallel plastic wave guide layers in contact with each other, each of the at least two parallel plastic wave guide layers having a refractive index gradually varying in the direction of light propagation so that the at least two parallel plastic wave guide layers as a whole transform a profile of an optical beam in the direction vertical to the layers. The variation of the refractive index can be obtained by varying a concentration of a dopant in a matrix, and the variation of the concentration of a dopant in a matrix can be obtained by varying an irradiation amount of a combination of a matrix and a dopant monomer with an ultra-violet ray.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: December 29, 1992
    Assignee: Fujitsu Limited
    Inventors: Kazunori Miura, Ippei Sawaki
  • Floating type magneto-optic disk reading head system having external semiconductor laser resonator operating at orthogonal two mode oscillations
    Patent number: 4955006
    Abstract: A magneto-optic disk reading head system including an external semiconductor laser resonator. A magneto-optic disk forms a part of the external resonator. In the external resonator, orthogonal two mode oscillations are established to produce a beat signal used for reading data stored in the magneto-optic disk. The magneto-optic disk reading head system is a floating type reading head.
    Type: Grant
    Filed: January 11, 1989
    Date of Patent: September 4, 1990
    Assignee: Fujitsu Limited
    Inventors: Nobuhiro Fukushima, Ippei Sawaki
  • Non-blocking optical space switch
    Patent number: 4837855
    Abstract: An optical space switch is formed in such a manner that switch elements having two inputs and two outputs are arranged in an n.times.n matrix form and optical signals from n input highways are switched to n output highways. The switch elements are connected in such a manner that the optical signals are always passed through the same number of switch elements, from the input highways to the output highways.
    Type: Grant
    Filed: August 18, 1987
    Date of Patent: June 6, 1989
    Assignee: Fujitsu Limited
    Inventors: Kazuo Hajikano, Toshio Shimoe, Jyoei Kamoi, Ippei Sawaki, Koso Murakami
  • Bipolar voltage controlled optical switch using intersecting waveguides
    Patent number: 4730884
    Abstract: An optical switch comprising: an electrode-optic crystal substrate (1, 1'); a central waveguide (21); a pair of input waveguides (22, 23), and a pair of output waveguides (24, 25). A refractive-index-changed region (R') is provided symmetrically within some part of the central waveguide. Switching from the straight-through state to the branching state or vice versa is carried out by introducing a change in the refractive index of the index-changed region.
    Type: Grant
    Filed: July 29, 1986
    Date of Patent: March 15, 1988
    Assignee: Fujitsu Limited
    Inventors: Minoru Seino, Hirochika Nakajima, Ippei Sawaki, Hidehiro Mishiro