Patents by Inventor Kimio Tatsuno
Kimio Tatsuno 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: 7292519Abstract: An integrated optical head records and reproduces information to and from optical discs of different types, including CD and DVD, with use of a single information recording/reproducing apparatus. The optical head has a plurality of semiconductor lasers of different wavelengths integrated by index alignment onto a substrate formed with an optoelectric integrated circuit, photodetection patterns, and a reflecting mirror.Type: GrantFiled: January 4, 2005Date of Patent: November 6, 2007Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Masahide Tokuda, Hirohisa Sano, Toshiaki Tanaka, Takeshi Shimano, Shigeru Nakamura, Takeshi Maeda, Akira Arimoto
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Patent number: 7165898Abstract: An optical module for an optical device and an optical fiber is constituted by a pre-molded plastic package. In forming the plastic package, the main flowing direction of the molding resin is substantially parallel with the optical axis of the optical fiber. The optical module is formed by molding the resin by injection using pressure and then solidifying the resin. When the plastic package is formed by comprehensive molding, the flowing direction of the resin is parallel with the optical axis direction of the optical fiber to be installed in the optical module. As a result, for comprehensive molding, the molding pressure applied to the optical fiber is reduced. By using the resin case that is formed, the resulting package exhibits high rigidity and low thermal expansion properties in connection with the flowing direction of the resin, thus reducing the external stress and thermal stress applied to the optical fiber.Type: GrantFiled: February 27, 2004Date of Patent: January 23, 2007Assignee: Hitachi, Ltd.Inventors: Takeshil Kato, Koji Yoshida, Toshinori Hirataka, Toshiaki Ishii, Kazuyuki Fukuda, Tadaaki Ishikawa, Toshimasa Miura, Tsutomu Kono, Kimio Tatsuno
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Patent number: 7164865Abstract: An object of disclosed technology is to control lasing wavelengths so that a wavelength shift does not occurs. Another object is to permit wavelengths of a light source for wavelength division multiplexing optical-fiber communication system to be variable in response to an ITU-TS grid. A means for achieving the objects is as follows: locating an etalon in a light path of diode laser light, which is a parallel plane wave changed by a collimator lens; generating a wavelength error signal from a difference between both of divided pieces of light from transmitted light or reflected light; and locking a wavelength of a diode laser device according to the wavelength error signal.Type: GrantFiled: March 15, 2001Date of Patent: January 16, 2007Assignee: Opnext Japan, Inc.Inventors: Kimio Tatsuno, Tatemi Ido, Yasunori Iwafuji, Hideyuki Kuwano, Naohiko Baba
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Patent number: 6983000Abstract: A laser diode module includes a laser diode device, a first photo detector part for receiving, first divided light that is a first portion of light when at least one of light emissions of the laser diode device is divided into two portions of light each traveling a different optical path, a second photo detector part for receiving second divided light that is a second portion of light thus divided via at least a wavelength selective member, and a controller which controls the lasing wavelength of the laser diode device on the basis of outputs of the first and second photo detector parts. A beam splitter provided between the laser diode and the wavelength selective member divides light emitted from the laser diode into the first and second divided light and a quarter-wave plate is provided in an optical path between the beam splitter and the wavelength selective member.Type: GrantFiled: July 15, 2003Date of Patent: January 3, 2006Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
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Patent number: 6965552Abstract: A method of mounting an optical device having a step on the surface opposing to a mounting substrate favorably by face-down bonding which enables a decrease in the number of components or integrate additional components on one identical substrate and, accordingly, is useful for reducing the size and the thickness of an optical head using a light source, the method includes the step of making the volume of a solder pattern to the area ratio of each electrode different for every wiring electrode portions upon mounting the electrodes on the substrate for mounting the optical device, in which the optical device having the step can be mounted favorably to the substrate by the control for the height of solder upon melting.Type: GrantFiled: February 27, 2002Date of Patent: November 15, 2005Assignees: Hitachi, Ltd., Nichia CorporationInventors: Masahide Tokuda, Kimio Tatsuno, Hirohisa Sano, Takeshi Shimano, Shigeharu Kimura
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Patent number: 6937628Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.Type: GrantFiled: March 5, 2002Date of Patent: August 30, 2005Assignee: Opnext Japan, Inc.Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Atsuhiro Yamamoto, Teruhisa Azumaguchi, Hiroaki Furuichi
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Publication number: 20050122880Abstract: An integrated optical head records and reproduces information to and from optical discs of different types, including CD and DVD, with use of a single information recording/reproducing apparatus. The optical head has a plurality of semiconductor lasers of different wavelengths integrated by index alignment onto a substrate formed with an optoelectric integrated circuit, photodetection patterns, and a reflecting mirror.Type: ApplicationFiled: January 4, 2005Publication date: June 9, 2005Inventors: Kimio Tatsuno, Masahide Tokuda, Hirohisa Sano, Toshiaki Tanaka, Takeshi Shimano, Shigeru Nakamura, Takeshi Maeda, Akira Arimoto
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Patent number: 6826211Abstract: Conventionally, in the wavelength locking optical system, the wavelength as detected is deviated from a targeted range owing to the change of the peripheral temperature resulting from the temperature characteristics of the wavelength error detection device. To solve this prior issue, it is arranged such that a portion of the wavelength error detection device, through which portion light-beams passes, contacts a material of high heat conductivity.Type: GrantFiled: September 20, 2001Date of Patent: November 30, 2004Assignees: Hitachi, Ltd., Opnext Japan, Inc.Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Hiroaki Furuichi, Atsuhiro Yamamoto, Norio Nakazato
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Publication number: 20040228373Abstract: A laser diode module includes a laser diode device, a first photo detector part for receiving, first divided light that is a first portion of light when at least one of light emissions of the laser diode device is divided into two portions of light each traveling a different optical path, a second photo detector part for receiving second divided light that is a second portion of light thus divided via at least a wavelength selective member, and a controller which controls the lasing wavelength of the laser diode device on the basis of outputs of the first and second photo detector parts. A beam splitter provided between the laser diode and the wavelength selective member divides light emitted from the laser diode into the first and second divided light and a quarter-wave plate is provided in an optical path between the beam splitter and the wavelength selective member.Type: ApplicationFiled: July 15, 2003Publication date: November 18, 2004Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
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Publication number: 20040165840Abstract: The present invention is to reduce the package cost and secure the high reliability in an optical module having an optical device and an optical fiber.Type: ApplicationFiled: February 27, 2004Publication date: August 26, 2004Applicant: Hitachi, Ltd.Inventors: Takeshi Kato, Koji Yoshida, Toshinori Hirataka, Toshiaki Ishii, Kazuyuki Fukuda, Tadaaki Ishikawa, Toshimasa Miura, Tsutomu Kono, Kimio Tatsuno
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Patent number: 6782018Abstract: This invention is provided to reduce wavefront aberrations caused by the filling of a transparent resin intended to prevent degradation of a diode laser in a hermetically sealed package. A parallel-plane plate is arranged between a diode laser and an objective lens, and a transparent resin is filled into a space formed between the diode laser and the parallel-plane plate. With this invention, degradations of the diode lasers can be prevented and the wavefront aberrations can be reduced.Type: GrantFiled: February 26, 2002Date of Patent: August 24, 2004Assignee: Hitachi, Litd.Inventors: Kimio Tatsuno, Masahide Tokuda, Shigeharu Kimura, Takeshi Shimano, Hirohisa Sano
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Patent number: 6726375Abstract: An optical module for an optical device and an optical fiber is constituted by a pre-molded plastic package. In forming the plastic package, the main flowing direction of the molding resin is substantially parallel with the optical axis of the optical fiber. The optical module is formed by molding the resin by injection using pressure and then solidifying the resin. When the plastic package is formed by comprehensive molding, the flowing direction of the resin is parallel with the optical axis direction of the optical fiber to be installed in the optical module. As a result, for comprehensive molding, the molding pressure applied to the optical fiber is reduced. By using the resin case that is formed, the resulting package exhibits high rigidity and low thermal expansion properties in connection with the flowing direction of the resin, thus reducing the external stress and thermal stress applied to the optical fiber.Type: GrantFiled: August 16, 2002Date of Patent: April 27, 2004Assignee: Hitachi, Ltd.Inventors: Takeshil Kato, Koji Yoshida, Toshinori Hirataka, Toshiaki Ishii, Kazuyuki Fukuda, Tadaaki Ishikawa, Toshimasa Miura, Tsutomu Kono, Kimio Tatsuno
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Patent number: 6721511Abstract: An optical communication equipment includes a semiconductor laser element, an image-forming element, an optical fiber and a substrate for mounting the semiconductor laser element, the image-forming element and the optical fiber. An optical output of the semiconductor laser element is adapted to be provided to the optical fiber via the image-forming element. The image-forming element is mounted in a V-groove formed in the substrate and having a substantially “V”-shaped cross-section. A shortest distance between a light spot of the semiconductor laser element and an optical axis of the image-forming element is 1 mm at most and the image-forming element substantially satisfies the sine condition.Type: GrantFiled: August 30, 1999Date of Patent: April 13, 2004Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Koji Yoshida, Kazuyuki Fukuda, Hiroshi Naka, Satoru Kikuchi
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Patent number: 6678432Abstract: To resolve a problem in which in an optical output and wavelength monitor integrated type semiconductor laser module monolithically integrated in parallel with a plurality of semiconductor lasers, since light emitting positions of the respective semiconductor lasers differ, an allowable range of an optical incident position of the monitor is exceeded, the optical incident position of the monitor is confined in the allowable range by integrating backward optical waveguides for guiding backward beam of the respective semiconductor lasers to a narrow range at a backward end of a semiconductor chip along with the semiconductor lasers, whereby there can be easily realized a semiconductor laser module with a built-in optical monitor even in the case of the chip integrated with the plurality of semiconductor lasers and can be realized an inexpensive optical module having high function.Type: GrantFiled: February 20, 2001Date of Patent: January 13, 2004Assignee: Hitachi, Ltd.Inventors: Junji Shigeta, Kimio Tatsuno, Masataka Shirai
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Patent number: 6668140Abstract: In a module for optical communication comprising an optical fiber including an axial-end surface, and an optical element including an optical surface facing to the axial-end surface in such a manner that a light is transmitted between the optical surface and the axial-end surface, a synthetic resin is arranged between the optical surface and the axial-end surface so that the light is transmitted through the synthetic resin between the optical surface and the axial-end surface.Type: GrantFiled: December 6, 2001Date of Patent: December 23, 2003Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Kouji Yoshida, Takeshi Kato, Toshinori Hirataka, Norihiro Yazaki, Shoichi Takahashi, Hiroshi Naka
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Publication number: 20030147333Abstract: A method of mounting an optical device having a step on the surface opposing to a mounting substrate favorably by face-down bonding which enables a decrease in the number of components or integrate additional components on one identical substrate and, accordingly, is useful for reducing the size and the thickness of an optical head using a light source, the method typically includes the step of making the area ratio of each electrode to a solder pattern different for every wiring electrode portions upon mounting the electrodes on the substrate for mounting the optical device, in which the optical device having the step can be mounted favorably to the substrate by the control for the height of solder upon melting, and the volume of the solder is previously controlled depending on the wettability of a region of the substrate covered by the solder.Type: ApplicationFiled: February 27, 2002Publication date: August 7, 2003Inventors: Masahide Tokuda, Kimio Tatsuno, Hirohisa Sano, Takeshi Shimano, Shigeharu Kimura
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Patent number: 6597712Abstract: In a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of the laser diode, which makes a control signal unstable. A solution to this problem is to arrange polarization controlling elements between a wavelength deviation detection filter and a laser diode to stabilize the deviation signal, and to perform wavelength-locking with the stabilizer signal.Type: GrantFiled: August 23, 2001Date of Patent: July 22, 2003Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi
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Publication number: 20030128726Abstract: This invention is provided to reduce wavefront aberrations caused by the filling of a transparent resin intended to prevent degradation of a diode laser in a hermetically sealed package. A parallel-plane plate is arranged between a diode laser and an objective lens, and a transparent resin is filled into a space formed between the diode laser and the parallel-plane plate. With this invention, degradations of the diode lasers can be prevented and the wavefront aberrations can be reduced.Type: ApplicationFiled: February 26, 2002Publication date: July 10, 2003Applicant: Hitachi, Ltd.Inventors: Kimio Tatsuno, Masahide Tokuda, Shigeharu Kimura, Takeshi Shimano, Hirohisa Sano
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Publication number: 20030067948Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.Type: ApplicationFiled: March 5, 2002Publication date: April 10, 2003Inventors: Kimio Tatsuno, Katsumi Kuroguchi, Atsuhiro Yamamoto, Teruhisa Azumaguchi, Hiroaki Furuichi
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Publication number: 20030039276Abstract: The problem of the disclosed technology is that, in a wavelength locking optical system, a resonator is formed between a wavelength deviation detection device and a facet of a laser diode, which makes a control signal unstable.Type: ApplicationFiled: August 23, 2001Publication date: February 27, 2003Inventors: Kimio Tatsuno, Hiroaki Furuichi, Kazumi Kawamoto, Katsumi Kuroguchi