Patents by Inventor Nobuhiro Kikuchi
Nobuhiro Kikuchi 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: 7474817Abstract: An integrated optical waveguide has a first optical waveguide, a second optical waveguide, and a groove. The second optical waveguide is coupled to the first optical waveguide and has a refractive index that is different from the first optical waveguide. The groove is disposed so as to traverse an optical path of the first optical waveguide and is separated from an interface between the first optical waveguide and the second optical waveguide by a predetermined spacing. The spacing from the interface and the width of the groove are determined such that reflection at a boundary between the first optical waveguide and the second optical waveguide is weakened. A semiconductor board may be disposed at a boundary between the first optical waveguide and the second optical waveguide.Type: GrantFiled: May 30, 2007Date of Patent: January 6, 2009Assignee: Nippon Telegraph and Telephone Corporation.Inventors: Nobuhiro Nunoya, Yasuo Shibata, Naoki Fujiwara, Nobuhiro Kikuchi, Yuichi Tomori
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Patent number: 7471864Abstract: An integrated optical waveguide has first, second, and third optical waveguiding regions. The second optical waveguiding region has a refractive index different from that of the first optical waveguiding region. The second optical waveguiding region has an interface surface with the first optical waveguiding region that is inclined with respect to the waveguide direction of the first optical waveguiding region. The third optical waveguiding region has an interface surface with the second optical waveguiding region that is disposed such that a refraction direction through the interface surface is in line with the waveguide direction.Type: GrantFiled: May 30, 2007Date of Patent: December 30, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Nobuhiro Nunoya, Yasuo Shibata, Naoki Fujiwara, Nobuhiro Kikuchi, Yuichi Tomori
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Publication number: 20070223856Abstract: An integrated optical waveguide has a first optical waveguide, a second optical waveguide, and a groove. The second optical waveguide is coupled to the first optical waveguide and has a refractive index that is different from the first optical waveguide. The groove is disposed so as to traverse an optical path of the first optical waveguide and is separated from an interface between the first optical waveguide and the second optical waveguide by a predetermined spacing. The spacing from the interface and the width of the groove are determined such that reflection at a boundary between the first optical waveguide and the second optical waveguide is weakened. A semiconductor board may be disposed at a boundary between the first optical waveguide and the second optical waveguide.Type: ApplicationFiled: May 30, 2007Publication date: September 27, 2007Applicant: Nippon Telegraph and Telephone CorporationInventors: Nobuhiro Nunoya, Yasuo Shibata, Naoki Fujiwara, Nobuhiro Kikuchi, Yuichi Tomori
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Publication number: 20070223857Abstract: An integrated optical waveguide has first, second, and third optical waveguiding regions. The second optical waveguiding region has a refractive index different from that of the first optical waveguiding region. The second optical waveguiding region has an interface surface with the first optical waveguiding region that is inclined with respect to the waveguide direction of the first optical waveguiding region. The third optical waveguiding region has an interface surface with the second optical waveguiding region that is disposed such that a refraction direction through the interface surface is in line with the waveguide direction.Type: ApplicationFiled: May 30, 2007Publication date: September 27, 2007Applicant: Nippon Telegraph and Telephone CorporationInventors: Nobuhiro Nunoya, Yasuo Shibata, Naoki Fujiwara, Nobuhiro Kikuchi, Yuichi Tomori
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Patent number: 7262905Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: GrantFiled: June 14, 2006Date of Patent: August 28, 2007Assignee: Nippon Telegraph & Telephone CorporationInventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori
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Publication number: 20070140724Abstract: An image forming apparatus includes an image forming unit; a fixing device; a main power circuit configured to supply electric power; an auxiliary power circuit configured to store and supply the electric power; a switching device configured to switch between a charge and discharge mode for the auxiliary power circuit; and a control device configured to, when the image is formed by a facsimile function, control the switching device so as to operate the auxiliary power circuit not in the discharge mode so that the electric power of the main power circuit is supplied to the fixing device, and when the image is formed on the basis of other functions, control the switching device so as to operate the auxiliary power circuit in the discharge mode so electric power of the main power circuit and that of the auxiliary power circuit are supplied to the fixing device.Type: ApplicationFiled: December 8, 2006Publication date: June 21, 2007Applicant: CANON KABUSHIKI KAISHAInventor: Nobuhiro Kikuchi
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Patent number: 7221500Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: GrantFiled: June 14, 2006Date of Patent: May 22, 2007Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori
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Publication number: 20070041415Abstract: The present invention is to provide a wavelength tunable DBR laser having the wider wavelength tuning characteristic, able to attain a 6 nm or more continuous wavelength shift and also higher in output power than a conventional wavelength tunable DBR laser. The DBR laser is constituted such that optical waveguides formed on a substrate, comprising an active region optical waveguide 22 having a light emitting function and passive region optical waveguides 23a and 23b provided on both ends of the active region 22, these passive region optical waveguides 23a and 23b have anterior and posterior DBR regions 24 and 29 with a wavelength tuning function, a posterior DBR region 29 is provided with a diffraction grating whose length is 95% or more in a saturated effective length value, and an anterior DBR region 24 whose length is shorter than the above length to take out the emitting light.Type: ApplicationFiled: March 23, 2005Publication date: February 22, 2007Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Naoki Fujiwara, Nobuhiro Nunoya, Nobuhiro Kikuchi, Yasuo Shibata, Hiroshi Yasaka
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Publication number: 20060268399Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: ApplicationFiled: June 14, 2006Publication date: November 30, 2006Inventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori
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Publication number: 20060232851Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: ApplicationFiled: June 14, 2006Publication date: October 19, 2006Inventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori
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Patent number: 7088501Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: GrantFiled: October 3, 2002Date of Patent: August 8, 2006Assignee: Nippon Telegraph & Telephone CorporationInventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori
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Publication number: 20060165446Abstract: In an image heating apparatus having an endless belt for heating an image T on a recording material P in a nip portion N, nip forming means for forming the nip portion N between itself and the belt, and regulating means for regulating the bias of the belt in the width direction thereof, even when in the rotation shape of the endless belt, there is a portion changing greatly in curvature, the damaging of the end portion of the endless belt resulting from the long-period use of the endless belt is prevented to thereby improve the durability of the belt. The regulating means is characterized by a flat plate-shaped rotary member provided at a predetermined distance from the belt and capable of being driven to rotate by contacting with the end surface of the belt with the bias of the belt.Type: ApplicationFiled: January 11, 2006Publication date: July 27, 2006Applicant: CANON KABUSHIKI KAISHAInventor: NOBUHIRO KIKUCHI
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Publication number: 20060050752Abstract: An optical semiconductor device and optical semiconductor integrated circuit are provided by combining, on a semiconductor substrate, materials having different refractive indices and different temperature dependence of the refractive indices. In particular, it becomes possible to control the temperature dependence of the oscillation wavelength with a propagating region having a material and/or structure whose temperature dependence of the refractive index is different from that of a gain region of the semiconductor laser. In addition, they can be configured to have a plurality of interfaces formed along the waveguide direction of the optical waveguide so that the light reflected off the first interface is weakened by the light reflected from the remaining interfaces. Also, they can be configured with the interfaces inclined to the propagating direction so that the waveguide loss due to the reflection and refraction between the optical waveguides whose refractive indices differ from each other can be reduced.Type: ApplicationFiled: March 30, 2004Publication date: March 9, 2006Inventors: Nobuhiro Nunoya, Yasuo Shibata, Naoki Fujiwara, Nobuhiro Kikuchi, Yuichi Tomori
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Publication number: 20030067678Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.Type: ApplicationFiled: October 3, 2002Publication date: April 10, 2003Inventors: Yasuo Shibata, Nobuhiro Kikuchi, Hiromi Oohashi, Yuichi Thomori