Patents Assigned to Nippon Telegraph & Telephone Corporation
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Patent number: 5157148Abstract: Fluorine-containing alicyclic or aromatic cyclic compounds represented by the formula ##STR1## wherein M is a divalent organic group comprising at least one substituted or unsubstituted alicyclic hydrocarbon group or a divalent organic group comprising at least two substituted or unsubstituted aromatic hydrocarbon group, the alicyclic hydrocarbon group or aromatic hydrocarbon group may be linked by O, S or CH.sub.2, or may form a condensed ring, X is ##STR2## Y is H or CH.sub.3, n is zero or a positive number, are useful as an effective component of the adhesive composition.Type: GrantFiled: October 18, 1990Date of Patent: October 20, 1992Assignees: Daikin Industries, Ltd., Nippon Telegraph and Telephone CorporationInventors: Akira Ohmori, Yoshiki Shimizu, Motonobu Kubo, Kouzaburou Nakamura, Tohru Maruno, Norio Murata, Hideo Kobayashi
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Patent number: 5156663Abstract: An apparatus for fushion splicing optical fiber with three pairs at clamps; the outermost pair of clamps has one rotatable clamp mechanism that is manually operated and a second rotatable clamp mechanism that is operated by a motor. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.Type: GrantFiled: April 16, 1991Date of Patent: October 20, 1992Assignees: Fujikura Ltd., Nippon Telegraph & Telephone CorporationInventors: Keinichiro Itoh, Takeshi Yamada, Tsutomu Onodera, Mikio Yoshinuma, Yasuyuki Kato
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Patent number: 5157755Abstract: A hermetically coated optical fiber comprising a core made of glass, a cladding made of quartz glass surrounding the core the outermost layer of which glass contains fluorine, and a carbon layer surrounding the fluorine-containing glass layer, which optical fiber has good initial strength and fatigue characteristics.Type: GrantFiled: October 15, 1991Date of Patent: October 20, 1992Assignees: Sumitomo Electric Industries, Ltd., Nippon Telegraph and Telephone CorporationInventors: Masaharu Ooe, Yoichi Ishiguro, Gotaro Tanaka, Nobuyuki Yoshizawa
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Patent number: 5155737Abstract: A wide band distributed Bragg reflector having a reflectivity extremely greater than that of a narrow band distributed Bragg reflector mirror portion on the output side of a bistable type wavelength conversion device is arranged on the incident side. The input light in TM polarization mode is used as an input signal light and the wavelength conversion is performed by tuning the narrow band distributed Bragg reflection mirror portion on the output side from which an output light in TE polarization mode outgoes perpendicularly to the input light. The input signal light and the output signal light are polarized in such a manner that they are perpendicular to one another and, therefore, the device can be realized as a one-directional device. The use of any isolator is not required.Type: GrantFiled: November 6, 1991Date of Patent: October 13, 1992Assignee: Nippon Telegraph & Telephone CorporationInventors: Masahiro Ikeda, Osamu Mikami, Hiroshi Yasaka, Mitsuru Naganuma, Shingo Uehara, Katsuhiko Kurumada
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Patent number: 5155759Abstract: A control method for a cordless telephone system including a main apparatus connected to a telephone line and having a line control function, a plurality of stationary apparatuses connected to the main apparatus and each having a radio transmitter/receiver, and portable telephones capable of communicating with the stationary apparatuses through a radio channel. When the main apparatus receives a simultaneous calling request signal from one portable telephone through a given stationary apparatus, it transmits a simultaneous calling request signal to whichever of the other portable telephones are not in use through corresponding stationary apparatuses.Type: GrantFiled: May 17, 1991Date of Patent: October 13, 1992Assignees: NEC Corporation, Nippon Telegraph and Telephone Corporation, K.K. ToshibaInventors: Noboru Saegusa, Toshihiro Hara, Hideki Toyama, Yuji Ohta, Shoji Fuse, Koji Ono
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Patent number: 5151757Abstract: A heterojunction field-effect transistor includes a first electron transit channel formation semiconductor layer formed on a substrate and consisting of a compound semiconductor, a first electron supply semiconductor layer formed on the first electron transit channel formation semiconductor layer and consisting of a compound semiconductor, a gate electrode, a source electrode, and a drain electrode formed on the first electron supply semiconductor layer, and a second electron transit channel formation semiconductor layer formed between the substrate and the first electron transit channel formation semiconductor layer.Type: GrantFiled: October 24, 1991Date of Patent: September 29, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Takatomo Enoki, Naoteru Shigekawa, Kunihiro Arai
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Patent number: 5151693Abstract: A central station generates and transmitted data of a transmission format. The transmission format includes an I/B bit indicating permission or inhibition of a new transmission of a next transmission timing of terminal stations, an R/N bit indicating reception or non-reception of a signal at the central station, and partial data produced from data received at the central station in accordance with a predetermined rule. One or plural of the terminal stations transmit the signal containing signal-length data W to the central station. The terminal station starts new transmission when the I/B bit indicates the permission of transmission. The central station determines and transmits the I/B bit, the R/N bit, and the partial data in accordance with the reception of the signal-length data W and the data transmitted from the terminal station. The terminal station determines whether or not a signal has been correctly received at the central station, in accordance with the R/N bit and the partial data.Type: GrantFiled: September 18, 1990Date of Patent: September 29, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Seizo Onoe, Narumi Umeda
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Patent number: 5149350Abstract: An apparatus for fusion splicing optical fibers has one rotatable clamp mechanism that is manually operated and a second rotatable clamp mechanism that is operated by a motor. A three position stopper functions in the first position as a stopper against the optical fibers when the optical fibers are moved toward each other and in the second position as a mirror for reflecting an image of respective end faces of the optical fibers. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.Type: GrantFiled: December 26, 1990Date of Patent: September 22, 1992Assignees: Fujikura Ltd., Nippon Telegraph & Telephone CorporationInventors: Kenichiro Itoh, Takeshi Yamada, Tsutomu Onodera, Mikio Yoshinuma, Yasuyuki Kato
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Patent number: 5147434Abstract: An apparatus for fusion splicing optical fibers has one rotatable clamp mechanism that is manually operated, a second rotatable clamp mechanism that is operated by a motor and a twist preventing means removably coupled to the apparatus with an arm member. A rapid fine adjustment of the alignment of the polarization maintaining optical fibers can be made.Type: GrantFiled: April 16, 1991Date of Patent: September 15, 1992Assignees: Fujikura Ltd., Nippon Telegraph & Telephone CorporationInventors: Kenichiro Itoh, Takeshi Yamada, Tsutomu Onodera, Mikio Yoshinuma, Yasuyuki Kato
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Patent number: 5146214Abstract: Mobile stations are classified into a first grouped station which is portable, and a second ungrouped station which is carried by a vehicle. A grouped station receives a part of the time slots of a paging channel relating to the group which the station belongs, and an ungrouped station receives all the time slots of a paging channel. A base station having a plurality of buffer cells (1-n) relating to each group, stores the queue of the paging signals in each buffer cell, and broadcasts the content of each buffer cell in the related time slot of the paging channel. A paging signal for a grouped station is stored in the related buffer cell, and a paging signal for an ungrouped station is stored in the buffer cell which has the shortest queue. Thus, a grouped station saves battery power because of intermittently receiving a paging signal, while keeping a short waiting time for an ungrouped station, and small call loss ratio.Type: GrantFiled: November 13, 1990Date of Patent: September 8, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Tomoyuki Yamada, Seizo Onoe
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Patent number: 5145508Abstract: A method for preparing a homogenous fluoride glass containing high purity BaF.sub.2 through the CVD process using a gaseous mixture containing a barium .beta.-diketonate complex service as a first starting material and represented by the following general formula (1) of: ##STR1## where (i) R and R' are each --C(CH.sub.3).sub.3 ; or (ii) R is CH.sub.2 CH.sub.2 CH.sub.3 and R' is --C(CH.sub.3).sub.3 ; or (iii) R and R' are each CF.sub.3 ;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent. Further provided is a process for preparing a perform for a fluoride optical fiber which is low in transmission loss, by depositing the fluoride glass over the interior wall of a cylindrical tube or the wall of rod-like glass substrate through the CVD process following by collapsing.Type: GrantFiled: March 11, 1991Date of Patent: September 8, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Kazuo Fujiura, Yasutake Ohishi, Michiya Fujiki, Terutoshi Kanamori, Shiro Takahashi
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Patent number: 5145793Abstract: A method for manufacturing a solar cell which includes at least a first GaAs layer of a first conductivity type and a second GaAs layer of a second conducitivity type sequentially formed on a first main surface of an Si substrate of the first conductivity type, a first electrode formed on a second main surface opposite to the first main surface of the Si substrate and a second electrode formed on the second GaAs layer. The method includes a first step of forming a layer comprising a material having a thermal expansion coefficient smaller than that of Si on the second main surface of the Si substrate at a temperature close to room temperature and a second step of sequentially forming the first and second GaAs layers on the first main surface of the Si substrate.Type: GrantFiled: April 12, 1991Date of Patent: September 8, 1992Assignees: Mitsubishi Denki Kabushiki Kaisha, Nippon Telegraph and Telephone CorporationInventors: Takahiko Oohara, Yoshiro Ohmachi, Yoshiaki Kadota, Kotaro Mitsui, Nobuyoshi Ogasawara, Takashi Nishimura
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Patent number: 5144574Abstract: To markedly improve the computational speed of A.times.B modulo N computation as compared with the prior-art Baker's method where A denotes a multiplicand; B denotes a multiplier; and N denotes a modulus, the number of multiply-additions and division (modular) substractions is reduced on the basis of any given same higher radix number r. In practice, the modular subtracters c(k)N are previously determined on the basis of the partial products b(k-1)A at the succeeding processing stage (k-1) to reduce the absolute value of the partial remainder R(k) down to a value less than a modulus N, so that bit overflow from a predetermined computational range can be prevented. For instance, when the partial product b(k)A at the succeeding processing stage (k-1) is large, the modular subtracter c(k)N at the current stage (k) is also determined large.Type: GrantFiled: July 16, 1991Date of Patent: September 1, 1992Assignee: Nippon Telegraph and Telephone CorporationInventor: Hikaru Morita
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Patent number: 5144428Abstract: A method and an apparatus for decoding image signals capable of achieving a reproduction of the image signals with a high image quality by using a relatively low speed inverse orthogonal transform device.Type: GrantFiled: August 15, 1991Date of Patent: September 1, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Hidenori Okuda, Shigeki Masaki
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Patent number: 5140695Abstract: In a mobile communication system between a mobile station and a telephone network through a base station which assigns a communication channel so that it satisfies required communication quality or D/U ratio, said base station comprises a moving speed detector (22) for measuring moving speed of the mobile station, and a D/U ratio generator (22A) responsive of output of said moving speed detector (22) for providing said required communication quality. The required communication quality depends upon the moving speed of a mobile station, and a communication channel is selected to be the minimum quality channel as far as it satisfies said required communication quality. Thus, the communication quality is always higher than the requested threshold quality level, and the effective reuse of frequencies is improved.Type: GrantFiled: September 18, 1990Date of Patent: August 18, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Shuji Yasuda, Yoshiaki Nakajima, Seizo Onoe
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Patent number: 5138704Abstract: A control method for processing elements (PE) in a parallel processing system, such as an array processor, in which data processing is carried out with data transfer between the PEs, and wherein the data transfer between the PEs is performed simultaneously with the data operations in the PEs to improve the processing speed of the parallel processing system. Three buffer memories are respectively connected to a data input path from one data procesing apparatus, a data output path to another data processing apparatus, and data paths for transmitting data from or to the data operation unit in the data processing apparatus itself having these three buffer memories.Type: GrantFiled: October 31, 1990Date of Patent: August 11, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Junichi Takahashi, Takashi Kimura
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Patent number: 5136629Abstract: A radio communication system of a multi-channel access type in which an idle one of a plurality of radio channels is detected to perform transmission and reception of voice signals, data signals or the like. In the present system, in the case where a base unit receives an incoming call from a wired line, the base unit transmits to a plurality of radio terminal units a speech channel designation signal as well as a representative radio terminal designation signal specifying a representative radio terminal unit from the plurality of radio terminal units, and when receiving a channel switching completion signal from the representative radio terminal unit, the base unit transmits a signal for generation of ringing tones to the plurality of radio terminal units at the same time to cause the plurality of radio terminal units to generate the ringing tones at the same time.Type: GrantFiled: December 12, 1989Date of Patent: August 4, 1992Assignees: Nippon Telegraph and Telephone Corporation, NEC Corporation, Kabushiki Kaisha ToshibaInventors: Hideki Toyama, Yuji Ohta, Noboru Saegusa, Yukihiro Shimura, Shoji Fuse, Koji Ono
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Patent number: 5136673Abstract: An optical cable has a center member, around which a plurality of coated optical fibers are tightly stranded. Each optical fiber is given uneven strains in its longitudinal direction. Adhesive resin is applied to surround each of the coated optical fibers and binds each of them to the center member to make an integral optical unit when cured.Type: GrantFiled: May 28, 1991Date of Patent: August 4, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Nobuyuki Yoshizawa, Tsuneo Horiguchi, Koushi Ishihara, Tetsuro Yabuta, Toshio Kurashima, Hidenobu Tada
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Patent number: 5136628Abstract: A video telephone for transmitting video data of a still picture through an audio signal line includes an image pickup tube for picking up a picture of the still picture, an A/D (analog-to-digital) converter for converting the analog output picked up by the image pick-up tube to the form of a digital signal, a memory for storing the output of the A/D converter as video data, a modulating circuit for modulating the video data stored in the memory into a modulated signal of an occupied frequency band corresponding to a transmission band of the signal line, a circuit for transmitting the modulated output of the modulating circuit to the signal line, a circuit for generating a synchronizing pulse and a frequency-dividing circuit for frequency-dividing the color subcarrier signal to provide signals necessary for the A/D converter, the memory, and the modulating circuit, wherein the video data is a signal which results from thinning the picked-up output at a predetermined ratio.Type: GrantFiled: June 24, 1988Date of Patent: August 4, 1992Assignees: Nippon Telegraph and Telephone Corporation, Sony CorporationInventors: Shoji Araki, Yukinobu Takano, Tadahisa Yamamoto, Noriyuki Uchiumi
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Patent number: 5136303Abstract: A pair of bands are each secured at one end to one side of a case wherein a radio receiver is housed, and a monopole antenna having a length of 0.005.lambda. has one end connected to the feeding point of the radio receiver and its other end exposed to the outside of the case to form a contact portion for contact with the human body. A first helical antenna is supported to the one of the bands lengthwise thereof and is connected at one end to the feeding point. A second helical antenna is supported to the other band lengthwise thereof and is connected at one end to the common potential point of the radio receiver. The first and second helical antennas resonate, as one antenna, with the wavelength .lambda. used by the radio receiver, and their pitch P and helix area A are selected so that P<500A/.lambda. and P>150A/.lambda..Type: GrantFiled: February 19, 1991Date of Patent: August 4, 1992Assignee: Nippon Telegraph and Telephone CorporationInventors: Keizo Cho, Kenichi Kagoshima, Kouichi Tsunekawa, Hitoshi Itakura