Patents Assigned to Nippon Telegraph & Telephone Public Corp.
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Patent number: 4554672Abstract: An improved oscillator which can adjust phase and frequency of the output signal independently from each other without time delay is disclosed. The oscillator is used for instance as a clock signal generator in a TDMA satellite communication system. The oscillator (FIG. 3) comprises a fixed oscillator (13) for providing a fixed frequency signal, a quadrature hybrid circuit (14) for providing a pair of quadrature phased signals from the output of said fixed oscillator (13), a control signal generator (17) for providing a pair of quadrature phased signals which satisfy b cos (2.pi..DELTA.f.sub.D t+.DELTA..phi..sub.D) and b sin (2.pi..DELTA.f.sub.D t+.DELTA..phi..sub.D), where b is a constant, .DELTA.f.sub.D is a desired frequency change, and .DELTA..phi..sub.Type: GrantFiled: February 21, 1984Date of Patent: November 19, 1985Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Tatsuro Masamura, Masahiro Morikura, Takayoshi Maki
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Patent number: 4537652Abstract: A process for preparing a single crystal comprising drawing up a single crystal by the Czochralski process and cooling it at a temperature not lower than 600.degree. C. at a reduced pressure or in vacuo, by which a single crystal having a dislocation density of 1.5.times.10.sup.4 cm.sup.2 or less is prepared.Type: GrantFiled: June 5, 1984Date of Patent: August 27, 1985Assignees: Sumitomo Electric Industries, Ltd., Nippon Telegraph & Telephone Public Corp.Inventors: Akihisa Kawasaki, Kohji Tada, Toshihiro Kotani, Shintaro Miyazawa
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Patent number: 4538153Abstract: An improved diversity communication system which has a single micro-strip antenna has been found. The micro-strip antenna according to the invention comprises a thin dielectric layer sandwiched by a ground conductor plane and a radiation conductor plane, a pair of feed points on the radiation conductor plane through the holes on the ground conductor plane, and said feed points being positioned so that a line between a first feed point and a center of the radiation conductor plane is substantially perpendicular to a line between a second feed point and a center of the radiation conductor plane. Each of the feed points is coupled with each branch input of a diversity receiver, and those feed points operate like separated two antennas, which have a pair of perpendicular directivities. Preferably, a radiation conductor plane is circular with a plurality of slots along the periphery of the same. The feed points of the present micro-strip antenna have little correlation between the same.Type: GrantFiled: September 3, 1982Date of Patent: August 27, 1985Assignee: Nippon Telegraph & Telephone Public Corp.Inventor: Tokio Taga
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Patent number: 4531282Abstract: In a bipolar transistor, around the border line of the surface of a base region formed on a semiconductor substrate is formed a base electrode having a constant width of less than one micron and made of polycrystalline silicon. An island shaped emitter region is formed in the base region and an emitter electrode is formed on the surface of the emitter region. The emitter electrode is electrically isolated from the base electrode by an insulating film extending between the periphery of the emitter region and the base electrode.Type: GrantFiled: January 17, 1984Date of Patent: July 30, 1985Assignee: Nippon Telegraph and Telephone Public Corp.Inventors: Tetsushi Sakai, Yoshizi Kobayasi, Hironori Yamauchi, Yoshinobu Arita
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Patent number: 4530001Abstract: The semiconductor device comprises a semiconductor substrate, a plurality of spaced active elements, for example, of a planer type formed on one surface of the substrate, and a supporting plate bonded to the opposite surface of the substrate. A groove is cut through the substrate to reach the supporting plate for isolating the active elements.Type: GrantFiled: September 15, 1981Date of Patent: July 16, 1985Assignees: Oki Electric Industry Co., Ltd., Nippon Telegraph & Telephone Public Corp.Inventors: Haruo Mori, Yasuo Ohno, Yutaka Ohta, Hiroshi Tanabe, Kotaro Kato
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Patent number: 4525027Abstract: In a single mode optical fiber comprising a core made of glass and a cladding surrounding the core and made of glass, when a difference .DELTA. between refractive indices n.sub.1 and n.sub.2 of the core and cladding is expressed by (n.sub.1 -n.sub.2)/(n.sub.1).times.100%, the refractive indices n.sub.1 and n.sub.2 are determined to satisfy a relation 1.0<.DELTA.<3.6 and a diameter of the core is determined according to this value of .DELTA..Type: GrantFiled: September 5, 1984Date of Patent: June 25, 1985Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Katsunari Okamoto, Takao Edahiro, Akio Kawana, Tetsuo Miya
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Patent number: 4515876Abstract: An X-ray absorber layer in the form of single layer of high melting point metal such as Ta, W is formed with granular crystal grains on a mask substrate, so that an internal stress of the layer is reduced. A fine pattern is formed from the absorber layer by reactive sputter etching using CBrF.sub.3 gas as an etchant, so that an X-ray absorber pattern is formed on the mask substrate. The X-ray lithography mask thus fabricated has a fine pattern such as submicron pattern with a high degree of pattern contrast and a high dimensional accuracy.Type: GrantFiled: July 15, 1983Date of Patent: May 7, 1985Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Hideo Yoshihara, Akira Ozawa, Misao Sekimoto, Toshiro Ono
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Patent number: 4511642Abstract: Photo-fixing heat-sensitive recording media which comprise diazonium salts, couplers and/or basic materials, all of these components being insoluble or sparingly soluble in water. At least one of these components is present in the media in the form of a fine powder. The coupler may be a coupler which has a basic group therein and serves as both a coupler and a basic material.Type: GrantFiled: February 9, 1983Date of Patent: April 16, 1985Assignees: Nippon Telegraph and Telephone Public Corp., Tomoegawa Paper Manufacturing Co., Ltd.Inventors: Kensaku Higashi, Haruhiko Yano, Hirotsugu Sato, Ken Sukegawa, Yuji Ooba
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Patent number: 4508251Abstract: A cable pulling/feeding apparatus comprises a fixed base, a cable pulling/feeding unit having a drive/brake unit for pulling or feeding a cable, a sensor supported on the fixed base so as to be movable in both directions in which the cable is pulled and fed for detecting a load imposed between the cable pulling/feeding unit and the fixed base and for generating an electric signal dependent on the load as detected, and structure for determining a load applied to the drive/brake unit in response to the electric signal when the cable is pulled or fed.Type: GrantFiled: October 26, 1982Date of Patent: April 2, 1985Assignees: Nippon Telegraph and Telephone Public Corp., Showa Electric Wire & Cable Co.Inventors: Kazuhiro Harada, Yuzoh Tsuchiya, Nobuo Sekiguchi, Toshio Ishikawa
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Patent number: 4490007Abstract: Optical fiber alignment mechanism comprising at least an optical fiber, at least three rigid members with a circular cross section, which are arranged to surround said optical fiber and of which each is in tangential contact with said optical fiber as well as with two other rigid members, and a plastic member molded in a plug like shape to contain said fiber and rigid members in lump, the outer surface of said plastic member allowing said rigid members to be exposed tangentially at least at three portions thereon.Type: GrantFiled: September 18, 1979Date of Patent: December 25, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventor: Hisashi Murata
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Patent number: 4480156Abstract: In addition to the telephone signal input and output terminals, a unit circuit is provided with novel input and output interfaces, and m echo canceller unit circuits are connected to each other in cascade with data buses in order to cancel the echoes of an m-times echo path delay.Type: GrantFiled: November 9, 1981Date of Patent: October 30, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Kenzo Takahashi, Takashi Sakamoto
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Patent number: 4479910Abstract: Disclosed are methods for production of plastic optical fiber connectors specifically for production of plastic plug ferrules employable for plastic optical fiber connectors, wherein improvements are realized to decrease the production cost thereof, to enable accurate finished dimension thereof, to enhance the advantage of mass production thereof, and to decrease the connection loss thereof.Type: GrantFiled: April 13, 1982Date of Patent: October 30, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Takashi Kurokawa, Tetsuo Yoshizawa, Shigeo Nara
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Patent number: 4463034Abstract: Heat-sensitive magnetic transfer element for printing a magnetic image to be recognized by a magnetic ink character reader (MICR), comprising a heat-resisting foundation and a heat-sensitive transferring layer provided on the foundation, the transferring layer which includes a ferromagnetic substance powder and has a melting point of 50.degree. to 120.degree. C. being readily melted and transferred on a receiving paper in the form of magnetic image by a thermal printer.Type: GrantFiled: March 15, 1982Date of Patent: July 31, 1984Assignees: Nippon Telegraph & Telephone Public Corp., Fuji Kagakushi Kogyo Co., Ltd.Inventors: Yukio Tokunaga, Yasuhisa Ikeda, Tadao Seto, Yoshikazu Shimazaki
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Patent number: 4463366Abstract: A field effect transistor device is constituted by a semiinsulating substrate consisting of a compound semiconductor, an N type semiconductor layer formed on the substrate, a plurality of P type semiconductor gate regions aligned along a straight line and extending through the semiconductor layer to reach the substrate, source and drain electrodes disposed on the semiconductor layer on the opposite sides of the drain regions, a gate electrode having an ohmic contact with the gate regions and having a Schottky contact with the semiconductor layer interposed between the gate regions. Two gate regions on the opposite ends of the array are in contact with the boundary region of the transistor.The field effect transistor device is useful for fabricating an integrated circuit and consumes less electric power. Further it reduces dispersion in the gate pinch off voltage and can be prepared at a high yield.Type: GrantFiled: June 20, 1980Date of Patent: July 31, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Yasunobu Ishii, Kazuyoshi Asai, Katsuhiko Kurumada
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Patent number: 4460413Abstract: A pattern utilized to prepare a diffraction grating, or an element of a semiconductor device, for example a silicon island, or a device isolation pattern or a semiconductor element, such as a MOS FET, is formed by the steps of forming an oxidizable region of a predetermined pattern on a substrate and oxidizing the oxidizable region for forming an oxide region pattern in at least a portion of the sidewalls of the oxidizable region. The resulting pattern, which is extremely fine and formed at a low cost, has a sufficiently large height with respect to its width. Furthermore the pattern can be formed at a relatively low temperature.Type: GrantFiled: December 17, 1981Date of Patent: July 17, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Kazuo Hirata, Masatoshi Oda
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Patent number: 4458261Abstract: An insulated gate type transistor has a nonsaturating current characteristic as well as a saturating current type characteristic. P.sup.+, N, N.sup.+ or N.sup.+, P, P.sup.+ regions are juxtaposed in the horizontal direction in a semiconductor layer formed on an insulating layer. A gate electrode is provided on a portion of the N or P region through a gate insulating film, and the thickness of the N or P region beneath the gate electrode is less than .pi./2 times of a Debye length inherent to the semiconductor constituting the active region.Type: GrantFiled: September 21, 1981Date of Patent: July 3, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventor: Yasuhisa Omura
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Patent number: 4437168Abstract: A real-time, on-line communication control unit is installed between a host computer and a plurality of terminals or between two host computers for the process of communication control. A plurality of basic processes relating to the communication control process are performed simultaneously by a corresponding plurality of basic processors which operate at the same time.Type: GrantFiled: January 23, 1981Date of Patent: March 13, 1984Assignee: Nippon Telegraph & Telephone Public Corp. of 1-6Inventors: Masahide Yamashita, Hikaru Oku, Masato Maruyama
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Patent number: 4434224Abstract: In a method of pattern formation according to this invention, an organic polymer resist material is simultaneously used with an inorganic resist material, i.e., a first desired pattern consisting of the organic polymer resist material layer is formed on a substrate material, then the whole surface thereof is covered with the inorganic resist material layer, a second desired pattern is then formed with the inorganic resist material layer, and then the resulting second desired pattern is transferred to the organic polymer resist material. According to the invention, mask alignment can automatically be effected by detecting reflected light from an alignment mark on the substrate, formation of a relief including large and small patterns is also easily carried out, throughput can also be increased. The method of the invention may be combined with various process steps, so that such combined method is applicable for deep and shallow etching, formation of an interlayer insulation film, and lift-off method.Type: GrantFiled: January 29, 1982Date of Patent: February 28, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Akira Yoshikawa, Akitsu Takeda, Osamu Ochi, Tomoko Hisaki, Yoshihiko Mizushima
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Patent number: 4426434Abstract: An electrophotographic photoreceptor comprises an electrically conductive substrate, a layer of charge generating material which chloroaluminium phthalocyanine and chloroaluminium monochlorophthalocyanine are evaporated in a vacuum over the electrically conductive substrate and the evaporated film of chloroaluminium phthalocyanine and chloroaluminium monochlorophthalocyanine are treated by an organic solvent selected from the group consisting tetrohydrofurane, methanol, acetone, methyl ethyl ketone, .alpha.-chloronaphthalene, pyridine, a layer of charge transport material overcoated the layer of charge generating material. The electrophotographic photoreceptor and the preparation thereof is disclosed to apply for use in a laser printing machine in which a light of laser diode or light emission diode is used as a light source.Type: GrantFiled: June 14, 1982Date of Patent: January 17, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Koichi Arishima, Takeshi Okada, Akiyuki Tate, Hiroaki Hiratsuka
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Patent number: 4424974Abstract: An improved ferro fluidic seal assembly having a cylindrical permanent magnet, a pair of ring-shaped yokes coupled coaxially with said magnet, and a fresh fluid storage containing ferro magnetic fluid mounted in a room defined by said magnet and yokes. Said fresh fluid storage is composed of a resilient elongated member like a stainless steel belt adapted and fixed in a circular shape along the surface of the magnet, and supplies fresh fluid to the clearance gaps defined between said yokes and a rotational body to seal said clearance gaps.Type: GrantFiled: July 28, 1982Date of Patent: January 10, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Yasunaga Mitsuya, Kunio Hoshiya, Shigemitsu Oguchi, Reizo Kaneko