Patents by Inventor Norio Takato
Norio Takato 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: 7499613Abstract: A Y branch circuit according to the present invention includes; a under clad; a circuit core, formed on the under clad and having a main core and two branch cores, connected to the main core, and an over clad that embeds the circuit core. The main core and the two branch cores are connected across an interval. The two branch cores have a width-to-height ratio of 50% to 150% and have a gap, at the main core end, that is narrower at the over clad side than at the under clad side.Type: GrantFiled: June 5, 2006Date of Patent: March 3, 2009Assignee: NTT Electronics CorporationInventors: Yasuhiro Hida, Toshimi Kominato, Yasuyuki Inoue, Norio Takato, Yasumori Ohmura
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Publication number: 20060278960Abstract: A Y branch circuit according to the present invention includes; a under clad; a circuit core, formed on the under clad and having a main core and two branch cores, connected to the main core, and an over clad that embeds the circuit core. The main core and the two branch cores are connected across an interval. The two branch cores have a width-to-height ratio of 50% to 150% and have a gap, at the main core end, that is narrower at the over clad side than at the under clad side.Type: ApplicationFiled: June 5, 2006Publication date: December 14, 2006Applicants: Nippon Telegraph and Telephone Corporation, NTT Electronics CorporationInventors: Yasuhiro Hida, Toshimi Kominato, Yasuyuki Inoue, Norio Takato, Yasumori Ohmura
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Patent number: 7086789Abstract: An optical element module is equipped with a casing, an optical element provided inside the casing, a pipe which communicates the inside of the casing to the outside, and a primary coated optical fiber which is inserted through the pipe and connected to the optical element.Type: GrantFiled: August 26, 2003Date of Patent: August 8, 2006Assignee: NTT Electronics CorporationInventors: Nobuo Tomita, Fumiaki Hanawa, Norio Takato, Satoru Konno, Yuichi Kikuchi, Jyunko Katoh, Yoshitaka Enomoto, Akira Miyashita, Hisashi Izumita
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Publication number: 20040202434Abstract: An optical element module is equipped with a casing, an optical element provided inside the casing, a pipe which communicates the inside of the casing to the outside, and a primary coated optical fiber which is inserted through the pipe and connected to the optical element.Type: ApplicationFiled: August 26, 2003Publication date: October 14, 2004Inventors: Nobuo Tomita, Fumiaki Hanawa, Norio Takato, Satoru Konno, Yuichi Kikuchi, Jyunko Katoh, Yoshitaka Enomoto, Akira Miyashita, Hisashi Izumita
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Patent number: 5546483Abstract: An integrated optical waveguide circuit includes a substrate; an optical wavelength multiplexer and an optical power splitter formed on a same surface of the substrate. The optical wavelength multiplexer is composed of a first slab optical waveguide, a second slab optical waveguide, a single or a plurality of input optical waveguides connected to the first slab optical waveguide at one end of the first slab optical waveguide, a plurality of arrayed optical waveguides arranged in parallel and having different lengths and connected to the first slab optical waveguide and the second slab optical waveguide, and a plurality of output optical waveguides arranged in parallel and connected to the second slab optical waveguide. The optical power splitter is composed of the second slab optical waveguide, one or more input optical waveguides, and the plurality of output optical waveguides arranged in parallel and connected to the second slab optical waveguide.Type: GrantFiled: August 1, 1994Date of Patent: August 13, 1996Assignee: Nippon Telegraph and Telephone CorporationInventors: Yasuyuki Inoue, Masao Kawachi, Katsunari Okamoto, Norio Takato, Fumihiko Yamamoto, Hiroyuki Suda, Shinichi Furukawa, Akira Morinaka
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Patent number: 5044715Abstract: A guided-wave optical branching component is composed of a Mach-Zehnder interferometer having two or more directional couplers. A slight difference .DELTA.L in the optical-path length is provided in two or more optical waveguides connecting the two or more directional couplers. The difference of the optical-path length is less than the shortest wavelength in the operational wavelength region of the guided-wave optical branching component, and the coupling ratio of each of the two directional couplers monotonically increases with wavelength in the operational wavelength region. By using the optical branching components thus constructed (i.e., Mach-Zehnder interferometer type 3-dB optical coupler) in conjunction with a phase shifter, a Mach-Zehnder interferometer type optical switch can be achieved.Type: GrantFiled: February 5, 1990Date of Patent: September 3, 1991Assignee: Nippon Telegraph and Telephone CorporationInventors: Masao Kawachi, Kaname Jinguji, Norio Takato, Akihiro Takagi
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Patent number: 4978188Abstract: An integrated optical device includes a substrate; a single-mode optical waveguide having a cladding layer disposed on the substrate and a core portion embedded in the cladding layer for transmitting light therethrough; and a stress applying film disposed on a desired portion of the cladding layer for adjusting stress-induced birefringence of the single-mode optical waveguide by irreversibly changing the stress exerted on the core portion by a trimming technique. The integrated optical device can be manufactured by the steps of forming a cladding layer on a substrate; forming a single-mode optical waveguide having a core portion embedded in the cladding layer for transmitting light therethrough; and forming, on the cladding layer, a stress applying film for exerting a stress on the single-mode optical waveguide to irreversibly change the stress by trimming the film.Type: GrantFiled: October 13, 1989Date of Patent: December 18, 1990Assignee: Nippon Telegraph and Telephone CorporationInventors: Masao Kawachi, Norio Takato, Kaname Jinguji, Akio Sugita, Shin Sumida
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Patent number: 4900112Abstract: An integrated optical device includes a substrate; a single-mode optical waveguide having a cladding layer disposed on the substrate and a core portion embedded in the cladding layer for transmitting light therethrough; and a stress applying film disposed on a desired portion of the cladding layer for adjusting stress-induced birefringence of the single-mode optical waveguide by irreversibly changing the stress exerted on the core portion by a trimming technique. The integrated optical device can be manufactured by the steps of forming a cladding layer on a substrate; forming a single-mode optical waveguide having a core portion embedded in the cladding layer for transmitting light therethrough; and forming, on the cladding layer, a stress applying film for exerting a stress on the single-mode optical waveguide to irreversibly change the stress by trimming the film.Type: GrantFiled: June 24, 1988Date of Patent: February 13, 1990Assignee: Nippon Telegraph and Telephone CorporationInventors: Masao Kawachi, Norio Takato, Kaname Jinguji, Akio Sugita, Shin Sumida
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Patent number: 4781424Abstract: In a single mode optical waveguide having a substrate, a cladding layer formed on the substrate, a core portion embedded in the cladding layer, and an elongated member for applying a stress to the core portion or a stress relief groove for relieving a stress from the core portion in the cladding layer along the core portion. The position, shape and material of the elongated member or the groove are determined in such a way that stress-induced birefringence produced in the core portion in accordance with a difference in thermal expansion coefficient between the substrate and the single mode optical waveguide is a desired value.Type: GrantFiled: May 13, 1987Date of Patent: November 1, 1988Assignee: Nippon Telegraph and Telephone CorporationInventors: Masao Kawachi, Kaname Jinguji, Norio Takato, Mitsuho Yasu, Katsunari Okamoto
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Patent number: 4320292Abstract: A coordinate input apparatus. A pair of optical guide channel arrays each including a required number of parallel optical guide channels (11, 12) which contain optical scatterer (22) are superposed to form an input board (100) with the optical guide channels of the two arrays intersected at right angles. Light is detected which is scattered by the optical scatterer (22) in the optical guide channels (11, 12) corresponding to irradiation of one point on the input board by a light pen (10) and reaches end surfaces (11a, 12a) of the optical guide channels. The detected signals are processed to form a binary signal train representative of the coordinate of the light pen (10).Type: GrantFiled: August 22, 1979Date of Patent: March 16, 1982Assignee: Nippon Telegraph and Telephone Public CorporationInventors: Shigeru Oikawa, Yuzo Katayama, Norio Takato, Takashi Kurokawa
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Patent number: 4240849Abstract: A polymer optical circuit with optical lead-fibers which comprise a plurality of optical fibers, each one end portion thereof being embedded in a transparent polymer film formed on a substrate, and polymer optical waveguides formed in the film between the embedded ends of the optical fibers so that the terminal ends of the optical waveguides are connected with the embedded ends of the optical fibers; the substrate, polymer film, polymer optical waveguide and optical fibers being formed as an integrated unit. A process for fabricating this polymer optical circuit is also disclosed.Type: GrantFiled: June 16, 1978Date of Patent: December 23, 1980Assignee: Nippon Telegraph and Telephone Public CorporationInventors: Takashi Kurokawa, Norio Takato, Shigeru Oikawa, Yuzo Katayama