Patents by Inventor Hideo Takeshita
Hideo Takeshita 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).
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Patent number: 7233717Abstract: A reflective optical switch comprises an input/output port portion; a polarization separator/combiner for separating lights in the same optical path and combining lights in different optical paths; a Faraday rotation angle changer; a polarization rotator for changing the relationship in polarizing direction between lights in different optical paths; a birefringence element for optical path control for controlling optical path shift in response to polarizing direction; and a polarization rotating reflector for rotating polarizing direction 90 degrees on forward and return paths. The input/output port portion, the polarization separator/combiner, the Faraday rotation angle changer, the polarization rotator, the birefringence element for optical path control, and the polarization rotating reflector are arranged along the optical path, and the Faraday rotation angle changer includes a Faraday element and an electromagnet for controlling 90-degree change in polarizing direction of transmitted light thereof.Type: GrantFiled: September 10, 2004Date of Patent: June 19, 2007Assignee: FDK CorporationInventors: Hiroaki Ono, Shohei Abe, Hideo Takeshita, Hiroki Tatara, Kazuhide Kubo
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Publication number: 20050058391Abstract: A reflective optical switch comprises an input/output port portion; a polarization separator/combiner for separating lights in the same optical path and combining lights in different optical paths; a Faraday rotation angle changer; a polarization rotator for changing the relationship in polarizing direction between lights in different optical paths; a birefringence element for optical path control for controlling optical path shift in response to polarizing direction; and a polarization rotating reflector for rotating polarizing direction 90 degrees on forward and return paths. The input/output port portion, the polarization separator/combiner, the Faraday rotation angle changer, the polarization rotator, the birefringence element for optical path control, and the polarization rotating reflector are arranged along the optical path, and the Faraday rotation angle changer includes a Faraday element and an electromagnet for controlling 90-degree change in polarizing direction of transmitted light thereof.Type: ApplicationFiled: September 10, 2004Publication date: March 17, 2005Inventors: Hiroaki Ono, Shohei Abe, Hideo Takeshita, Hiroki Tatara, Kazuhide Kubo
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Patent number: 6798566Abstract: A variable optical gain equalizer in accordance with one embodiment of the present invention comprises a variable branching ratio beam splitter having a variable polarization rotator, the variable branching ratio beam splitter branching an input light beam into two light beams at an arbitrary power ratio, through control of the rotation angle of the polarization direction by the variable polarization rotator; an optical filter presenting different filter characteristics to the two branched output light beams; and a polarization coupler for polarization coupling the two light beams that have passed through the optical filter, wherein the rotation angle of the polarization direction is controlled by the variable polarization rotator so as to vary the spectra of the output light beams.Type: GrantFiled: June 13, 2002Date of Patent: September 28, 2004Assignee: FDK CorporationInventors: Shohei Abe, Hidenori Nakada, Mototsugu Goto, Ikuo Maeda, Hideo Takeshita, Hiroaki Ono, Shusuke Wada
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Patent number: 6667827Abstract: A beam shutter is provided which comprises a plane-parallel birefringent element for separation arranged to separate input light beams having orthogonal polarization directions on the same optical path; a plane-parallel birefringent element for synthesis arranged to synthesize light beams having orthogonal polarization directions on different optical paths, for output; the birefringent element for separation and the birefringent element for synthesis being disposed in a spaced apart relationship; and polarization rotating means having a variable Faraday rotator, the polarization rotating means interposed between the birefringent element for separation and the birefringent element for synthesis, for magneto-optically controlling the polarization directions; wherein transmission and interruption of output light beams are controlled by switching the polarization directions by means of the variable Faraday rotator.Type: GrantFiled: July 23, 2002Date of Patent: December 23, 2003Assignee: FDK CorporationInventors: Hiroaki Ono, Shohei Abe, Hideo Takeshita, Shusuke Wada
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Publication number: 20030048529Abstract: An optical circulator comprises a first birefringent element for separation and synthesis; a first polarization rotation block; a circulator function block; a second polarization rotation block; and a second birefringent element for separation and synthesis; the circulator function block includes a first birefringent element for optical path control; a second birefringent element for optical path control which shifts the optical paths depending on the polarization directions and which has twice the optical path shifting amount of the first birefringent element for optical path control; and a ¼ wave plate and a reflector allowing light beams along peripheral optical paths to bypass and acting on only light beams along central optical paths.Type: ApplicationFiled: September 11, 2002Publication date: March 13, 2003Inventors: Shusuke Wada, Shohei Abe, Hideo Takeshita, Hiroaki Ono, Yuko Ota
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Publication number: 20030021003Abstract: A beam shutter is provided which comprises a plane-parallel birefringent element for separation arranged to separate input light beams having orthogonal polarization directions on the same optical path; a plane-parallel birefringent element for synthesis arranged to synthesize light beams having orthogonal polarization directions on different optical paths, for output; the birefringent element for separation and the birefringent element for synthesis being disposed in a spaced apart relationship; and polarization rotating means having a variable Faraday rotator, the polarization rotating means interposed between the birefringent element for separation and the birefringent element for synthesis, for magneto-optically controlling the polarization directions; wherein transmission and interruption of output light beams are controlled by switching the polarization directions by means of the variable Faraday rotator.Type: ApplicationFiled: July 23, 2002Publication date: January 30, 2003Inventors: Hiroaki Ono, Shohei Abe, Hideo Takeshita, Shusuke Wada
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Publication number: 20020191274Abstract: A variable optical gain equalizer in accordance with one embodiment of the present invention comprises a variable branching ratio beam splitter having a variable polarization rotator, the variable branching ratio beam splitter branching an input light beam into two light beams at an arbitrary power ratio, through control of the rotation angle of the polarization direction by the variable polarization rotator; an optical filter presenting different filter characteristics to the two branched output light beams; and a polarization coupler for polarization coupling the two light beams that have passed through the optical filter, wherein the rotation angle of the polarization direction is controlled by the variable polarization rotator so as to vary the spectra of the output light beams.Type: ApplicationFiled: June 13, 2002Publication date: December 19, 2002Inventors: Shohei Abe, Hidenori Nakada, Mototsugu Goto, Ikuo Maeda, Hideo Takeshita, Hiroaki Ono, Shusuke Wada
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Patent number: 5803993Abstract: The present invention provides an outer ring for a high strength constant velocity joint which has an excellent torsional strength and torsional fatigue strength and can provide an improved processability, and a process for producing the same. An outer ring used for a high strength constant velocity joint having an involute serration part and a screw part, the outer ring made of a steel containing:C: 0.45 to 0.53%, Si: 0.05 to 0.25%, Mn: 0.7 to 1.0%, Al: 0.01 to 0.05%, Mo: 0.2 to 0.4%, N: 0.003 to 0.012%, the remainder being Fe and inevitable impurities, the inevitable impurities including:Cr: 0.05% or less than 0.05%, P: 0.015% or less than0.015%, S: 0.01% or less than 0.01%, and O: 0.002% orless than 0.002%,wherein an old austenite crystal grain at the involute serration end is 8 or more in JIS grain size classification; a surface hardness at the end is 720 or more in Hv; and a ratio (CD/R) is 0.35 to 0.Type: GrantFiled: October 17, 1996Date of Patent: September 8, 1998Assignee: NTN CorporationInventors: Kazuhiko Yoshida, Tatsuhiro Goto, Akira Wakita, Toshio Kawasaki, Toyofumi Hasegawa, Hideo Takeshita, Toshiki Suwa
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Patent number: 4431445Abstract: A steel for machine construction having excellent cold forgeability and machinability, the steel having a composition of below 0.6% C, below 0.35% Si, below 1.65% Mn, below 3.5% Ni, below 3.5% Cr, below 0.35% Mn, 0.010-0.10% Al and below 0.002% B, the rest being Fe and impurities with limited contents of Ca in the range of 0.0005-0.05%, S of below 0.12% and Al.sub.2 O.sub.3 inclusion of below 0.002%.Type: GrantFiled: July 9, 1981Date of Patent: February 14, 1984Assignee: Kabushiki Kaisha Kobe Seiko ShoInventors: Sadayoshi Furusawa, Hideo Takeshita, Tsuyoshi Kohoka, Jiro Koarai, Shuji Iwata