Patents by Inventor Hiroshi Chikugawa

Hiroshi Chikugawa 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).

  • Publication number: 20050026319
    Abstract: The present invention relates to an optical pickup used for an optical recording information instrument such as CD-ROM, CD-R, MO, DVD and the like, and a semiconductor laser device assembled to be incorporated in the optical pickup, as well as to a method for manufacturing said semiconductor laser device. The present invention also relates to a semiconductor laser element comprising a plurality of semiconductor laser chips, which is incorporated in the semiconductor laser device and to a method for manufacturing said semiconductor laser element, especially to an apparatus for accurately bonding and assembling a semiconductor laser element used in manufacturing said semiconductor laser element, such as a semiconductor laser chip die-bonding machine and the like.
    Type: Application
    Filed: August 30, 2004
    Publication date: February 3, 2005
    Inventors: Hiroshi Chikugawa, Shinji Yudate
  • Publication number: 20040240872
    Abstract: Light emitting semiconductor device(s) of the present invention is/are provided with three LED elements by way of lead frame(s) on substrate(s). Reflector(s)—having parabolically curved surface(s) at inner wall(s) thereof is/are installed at periphery or peripheries of these LED elements. Radiative angle(s) of light radiating from such reflector(s) is/are controlled by alteration of height(s) of reflector(s). Such height(s) may be lowered to increase radiative angle(s) &thgr; of light therefrom after the fashion of curve(s) so as to establish broader irradiative locus or loci and/or such height(s) may be raised to decrease radiative angle(s) &thgr; of light radiating therefrom after the fashion of curve(s) so as to establish narrower irradiative locus or loci.
    Type: Application
    Filed: May 25, 2004
    Publication date: December 2, 2004
    Inventor: Hiroshi Chikugawa
  • Publication number: 20040071175
    Abstract: In a semiconductor laser device, a flange (33) of a cap (32) is provided with straight-line cut-off portions (34) that are the same in number as notches (36, 37) of a stem (35). With the cut-off portions (34) positioned so as not to overlap the notches (36, 37) of the stem (35) in position, welding between the cap (32) and the stem (35) is performed. The cut-off portions (34) of the cap (32) secure obtainment of a reference plane 38 with a large area in a place where the notches (36, 37) of the stem (35) are absent. As a result, sufficient precision in optical characteristics can be secured while suppressing an influence of unevenness of the stem (35) having a small diameter on a deviation angle &thgr; of an optical axis from a normal line to a reference plane of an optical pickup.
    Type: Application
    Filed: October 7, 2003
    Publication date: April 15, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Hiroshi Chikugawa
  • Publication number: 20030091075
    Abstract: The present invention relates to an optical pickup used for an optical recording information instrument such as CD-ROM, CD-R, MO, DVD and the like, and a semiconductor laser device assembled to be incorporated in the optical pickup, as well as to a method for manufacturing said semiconductor laser device. The present invention also relates to a semiconductor laser element comprising a plurality of semiconductor laser chips, which is incorporated in the semiconductor laser device and to a method for manufacturing said semiconductor laser element, especially to an apparatus for accurately bonding and assembling a semiconductor laser element used in manufacturing said semiconductor laser element, such as a semiconductor laser chip die-bonding machine and the like.
    Type: Application
    Filed: November 8, 2002
    Publication date: May 15, 2003
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Hideaki Tatsuta, Hiroshi Chikugawa, Takaaki Horio, Shinji Yudate
  • Patent number: 5557116
    Abstract: A semiconductor laser device includes a base, a semiconductor laser chip and a resin layer enclosing the laser chip. The base may have a monitor photodiode mounted thereon in the vicinity of the laser chip. The resin layer enclosing the laser chip or both of the laser chip and the monitor diode chip is made of a single synthetic resin having a thickness not greater than 500 .mu.m and also having a surface substantially parallel to an outwardly oriented beam emitting end face of the laser chip.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: September 17, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsushige Masui, Nobuyuki Miyauchi, Zenpei Tani, Hiroshi Chikugawa, Makoto Tsuji, Masaru Ogawa, Takehiro Shiomoto
  • Patent number: 5127015
    Abstract: A driving circuit of a semiconductor laser includes a photodiode receiving a light of the semiconductor laser, a first detecting circuit for calculating a mean value signal of outputs of the semiconductor laser in accordance with an output of the photodiode, a second detecting circuit for calculating a maximum value signal of the outputs of the semiconductor laser, a circuit receiving the mean value signal for supplying a bias current for driving the semiconductor laser, a high-frequency superimposing circuit for modulating the bias current by high-frequency waves, and a modulating degree control circuit comparing the mean value signal with the maximum value signal for making a period of time for which the minimum value of the optical output values of the semiconductor laser becomes zero, in accordance with the comparison results.
    Type: Grant
    Filed: April 17, 1991
    Date of Patent: June 30, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Chikugawa, Masaru Ogawa, Kunio Suzuki