Patents by Inventor Takara Yamamoto
Takara Yamamoto 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: 7031582Abstract: Disclosed are an optical fiber cable comprising an optical fiber and at least one covering layer formed on the outer periphery of the optical fiber, at least one layer of the covering layer being made of a material comprising a resin component containing a polyamide polymer, wherein a flexural modulus E upon displacement of 1 mm is within a range from 2 to 15 (N/mm) and the optical fiber cable passes a flame resistance test in accordance with DIN 72551-5, and an optical fiber cable with a plug using the optical fiber. Therefore, they have excellent flame resistance and good handling properties.Type: GrantFiled: December 25, 2000Date of Patent: April 18, 2006Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo, Yoshimi Kamimura, Jun Okumura
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Patent number: 6842575Abstract: The optical fiber cord of the present invention is characterized in having a primary covering layer formed from a polyamide resin that incorporates at least one of an organic acid or an organic acid anhydride on the outer periphery of the optical fiber. In addition, the optical fiber cord with a plug of the present invention has a plug on at least one end of the optical fiber cord of the present invention having a secondary covering layer on the outer periphery, wherein at the end part of the optical fiber cord that has the plug, the primary covering layer is exposed, and the plug is fastened to the exposed primary covering layer. By using the structure described above, an optical fiber cord and an optical fiber cord with a plug that has superior humidity resistance and heat resistance, and in addition can be laid easily in narrow sites because of superior flexibility and is inexpensive.Type: GrantFiled: November 29, 2000Date of Patent: January 11, 2005Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Katsuhiko Shimada, Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo
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Patent number: 6584256Abstract: The present invention discloses an optical fiber cable of diameter D1 (mm) in which an adhesive layer having a thickness of 0.5 to 200 &mgr;m, a primary coating layer and a secondary coating layer are sequentially formed around the outside of an optical fiber in which the outermost layer is composed of vinylidene fluoride polymer; wherein, in the case the diameter of the optical fiber is represented with Da (mm), the thickness of the adhesive layer is represented with d (mm), and Da+2d is represented with D2, then D1/D2=1.2 to 3.5, and an optical fiber cable with plug that uses this optical fiber. Thus, the resulting optical fiber cable has superior flame resistance, is resistant to peeling of the optical fiber and coating layers, and is resistant to the occurrence of pistoning phenomenon. The optical fiber may also be composed of a core, a sheath formed around the core, and a protective layer formed around the sheath.Type: GrantFiled: June 3, 2002Date of Patent: June 24, 2003Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Katsuhiko Shimada, Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo, Jun Okumura
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Publication number: 20030072546Abstract: The present invention discloses an optical fiber cable of diameter D1 (mm) in which an adhesive layer having a thickness of 0.5 to 200 &mgr;m, a primary coating layer and a secondary coating layer are sequentially formed around the outside of an optical fiber in which the outermost layer is composed of vinylidene fluoride polymer; wherein, in the case the diameter of the optical fiber is represented with Da (mm), the thickness of the adhesive layer is represented with d (mm), and Da+2d is represented with D2, then D1/D2=1.2 to 3.5, and an optical fiber cable with plug that uses this optical fiber. Thus, the resulting optical fiber cable has superior flame resistance, is resistant to peeling of the optical fiber and coating layers, and is resistant to the occurrence of pistoning phenomenon. The optical fiber may also be composed of a core, a sheath formed around the core, and a protective layer formed around the sheath.Type: ApplicationFiled: June 3, 2002Publication date: April 17, 2003Applicant: Mitsubishi Rayon Co., Ltd.Inventors: Katsuhiko Shimada, Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo, Jun Okumura
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Publication number: 20030044136Abstract: Disclosed are an optical fiber cable comprising an optical fiber and at least one covering layer formed on the outer periphery of the optical fiber, at least one layer of the covering layer being made of a material comprising a resin component containing a polyamide polymer, wherein a flexural modulus E upon displacement of 1 mm is within a range from 2 to 15 (N/mm) and the optical fiber cable passes a flame resistance test in accordance with DIN 72551-5, and an optical fiber cable with a plug using the optical fiber. Therefore, they have excellent flame resistance and good handling properties.Type: ApplicationFiled: June 21, 2002Publication date: March 6, 2003Inventors: Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo, Yoshimi Kamimura, Jun Okumura
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Publication number: 20030007762Abstract: The optical fiber cord of the present invention is characterized in having a primary covering layer formed from a polyamide resin that incorporates at least one of an organic acid or an organic acid anhydride on the outer periphery of the optical fiber. In addition, the optical fiber cord with a plug of the present invention has a plug on at least one end of the optical fiber cord of the present invention having a secondary covering layer on the outer periphery, wherein at the end part of the optical fiber cord that has the plug, the primary covering layer is exposed, and the plug is fastened to the exposed primary covering layer. By using the structure described above, an optical fiber cord and an optical fiber cord with a plug that has superior humidity resistance and heat resistance, and in addition can be laid easily in narrow sites because of superior flexibility and is inexpensive.Type: ApplicationFiled: May 24, 2002Publication date: January 9, 2003Inventors: Katsuhiko Shimada, Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo
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Patent number: 6453104Abstract: An optical fiber cable having a diameter of D1 (mm) and comprising an adhesion layer 0.5 to 200 &mgr; in thickness, a primary coating layer, and a secondary coating layer, all sequentially formed on the outer circumference of an optical fiber constituted on the outermost layer thereof by vinylidene fluoride polymer, wherein D1/D2=1.2 to 3.5 (the diameter of the optical fiber is Da (mm), the thickness of the adhesion layer d (mm), and Da+2d=D2); and an optical fiber cable with a plug using this optical fiber. Accordingly, these optical fiber cables are excellent in flame resistance, difficult in separating an optical fiber thereof from coating layers, and not likely to cause a pistoning phenomenon. An optical fiber may consist of a core, a sheath formed on the periphery of the core and a protection layer formed on the periphery of the sheath.Type: GrantFiled: August 28, 2001Date of Patent: September 17, 2002Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Katsuhiko Shimada, Kazuki Nakamura, Takeshi Kitayama, Takara Yamamoto, Hiroe Kubo, Jun Okumura
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Patent number: 5136683Abstract: The flame-retardant cable of this invention is a single-core or multiple-core cable comprising a plastic optical fiber and at least one covering material covering this plastic optical fiber, and this flame-retardant cable is characterized in that at least one covering material is a highly flame-retardant resin, for example, a highly flame-retardant resin having an oxygen index (OI) of at least 32, preferably from 40 to 45, such as chlorinated polyethylene. This flame-retardant cable has an excellent flame retardancy with no lowering of the performances of the optical fiber. Moreover, the cable has an excellent flame resistance.Type: GrantFiled: September 10, 1990Date of Patent: August 4, 1992Assignee: Mitsubishi Rayon Company, Ltd.Inventors: Kazunori Aoki, Takara Yamamoto, Eiji Maeda