Patents Assigned to Nippon Telephone & Telegraph Corporation
  • Patent number: 9160458
    Abstract: An optical signal detection circuit (10) includes an amplification circuit (11) that differentially amplifies an electrical signal (Tout) corresponding to the pulse train of an optical signal (Pin) and outputs a differential output signal (Aout), and a comparator (12) that compares the voltage value of the positive-phase signal of the differential output signal (Aout) with the voltage value of the negative-phase signal and outputs a pulsed comparison output signal (Cout) corresponding to the comparison result. The amplification circuit (11) includes a current addition circuit (11E) that adjusts a DC load current to generate a positive-phase signal (Aout+) and a negative-phase signal (Aout?) of the differential output signal (Aout) in accordance with an adjusted voltage value from an external adjusted voltage source (Vadj) and adjusts the DC bias of the positive-phase signal (Aout+) and the DC bias of the negative-phase signal (Aout?).
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: October 13, 2015
    Assignee: NIPPON TELEPHONE AND TELEGRAPH CORPORATION
    Inventors: Hiroshi Koizumi, Masafumi Nogawa, Yusuke Ohtomo
  • Patent number: 7868701
    Abstract: A gain switching determination circuit (250) compares/determines a comparative input voltage (Vc) from an inter-stage buffer (230) with a first hysteresis characteristic, and outputs a gain switching signal (SEL) based on the comparison/determination result to first and second transimpedance amplifier core circuits (210, 220), thereby switching the gains of the core circuits. This obviates holding a comparison input voltage with long response time in a level holding circuit for gain switching determination, which allows instantaneous gain switching determination and instantaneous response corresponding to burst data.
    Type: Grant
    Filed: August 3, 2005
    Date of Patent: January 11, 2011
    Assignees: Nippon Telephone and Telegraph Corporation, NTT Electronics Corporation
    Inventors: Makoto Nakamura, Yohtaro Umeda, Jun Endou, Yuji Akatsu, Yuuki Imai, Masatoshi Tobayashi, Yoshikazu Urabe, Hatsushi Iizuka, Eiji Hyodo
  • Patent number: 7673145
    Abstract: This invention includes an image quality priority level decision processing unit (40) which evaluates the magnitude of an image quality of each of a plurality of first image data formed from biometric images associated with the same target on the basis of a specific index having the relationship of a monotone function with authentication accuracy of biometric authentication, and outputs each of the first image data upon adding a priority level thereto on the basis of the evaluation result, a first image storage (6, 81) unit which stores each of the first image data having a priority level added thereto from the image quality priority level decision processing unit (40), a second image storage unit (8, 61) which stores second image data used for comparison/collation with the first image data, an image collation unit (7) which compares/collates the second image data stored in the second image storage unit (8, 61) with the first image data stored in the first image storage unit (6, 81) and outputs the comparison
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: March 2, 2010
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventors: Takahiro Hatano, Satoshi Shigematsu, Hiroki Morimura, Namiko Ikeda, Yukio Okazaki, Katsuyuki Machida, Mamoru Nakanishi
  • Patent number: 7557674
    Abstract: Four SP4T switches (31-34) are grouped in twos to form two switch pairs. First conductive lines (411-414, 421-424) are arranged in fours between the SP4T switches (31, 34; 32, 33) constituting the switch pairs. Each of four second conductive lines (51-54) connects to a corresponding one of different conductive lines of the first conductive lines which connect to the respective switch pairs. The first and second conductive lines are arranged on a dielectric layer having a lower surface on which a ground conductor (6) is formed. The dielectric, layer has a two-layer structure. The first conductive lines are arranged on the first dielectric layer as a lower layer. The second conductive lines are arranged on the second dielectric layer as an upper layer. This arrangement makes it possible to attain a reduction in the size of a matrix switch and a reduction in loss and allow broadband operation.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: July 7, 2009
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventor: Hideki Kamitsuna
  • Patent number: 7505644
    Abstract: An optical memory medium (2) has cores (21) each constituting a planar optical waveguide and clads (22) sandwiching each core, and has a data image (203) in which data is recorded as a scattering factor and a pair of positioning marks (201, 202) which are scattering factors required for positioning at an interface between a core (21) and a clad (22) or in the core (21). A read light (103) travels while spreading in the core (21) and scatters and interferes by the data image (203), and data is reproduced from a data reproduction light (1031) generated by this scattering and interference. A pair of positioning lights (101, 102) are caused to enter the core (21) with offsets with respect to the read light (103) in opposite directions along a thickness direction of the core (21), and scatter and interfere at the pair of positioning marks (201, 202).
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: March 17, 2009
    Assignee: Nippon Telephone & Telegraph Corporation
    Inventors: Yoshiaki Kurokawa, Shogo Yagi, Akinori Furuya, Masahiro Endo, Tadayuki Imai, Hiroshi Yoshikawa
  • Patent number: 7430233
    Abstract: A spread-spectrum demodulator includes a spreading code generating section, correlation value computing section, data signal demodulating section, peak signal detecting section, and spreading code generation control section. The spreading code generating section generates a spreading code for correlating with a received spread signal. The correlation value computing section computes a correlation value between the spread signal and the spreading code output from the spreading code generating section. The data signal demodulating section detects the peak of an output from the correlation value computing section and demodulates a data signal on the basis of the detected peak. The peak signal detecting section detects the peak of the output from the correlation value computing section. The spreading code generation control section changes the shifting direction of the spreading code relative to the spread signal every time a peak is detected by the peak signal detecting section.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: September 30, 2008
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventors: Kenji Suzuki, Mamoru Ugajin, Tsuneo Tsukahara
  • Patent number: 7412229
    Abstract: The button apparatus is an apparatus provided for, for example, a vending machine and to be touched and pressed with the body of a user who wants to purchase a commodity from the vending machine. By pressing down the button apparatus, the user can purchase a required commodity from the vending machine. The button apparatus has a conductive pusher, an insulator, a switch, and a transceiver. A user wearing a wearable computer and a user's transceiver touches and presses down the pusher, to separately establish communication between the transceiver and the user's transceiver through the conductive pusher and the body of the user, as well as communication of providing a press signal.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: August 12, 2008
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventors: Katsuyuki Ochiai, Mitsuru Shinagawa, Hiroyoshi Togo, Tadashi Minotani
  • Patent number: 7256062
    Abstract: In a semiconductor photo-detector of the present invention, a first semiconductor layer, a second semiconductor layer having, and a photo-absorption part composed of a photo-absorption layer sandwiched between these layers are disposed on a substrate, at least the photo-absorption layer is formed at a position apart inwardly by a finite length from an end surface of the substrate, an end surface of the second semiconductor layer and the substrate or the end surface of the substrate is provided with a light incident facet angled inwardly as it separates from the surface of the second semiconductor or the surface of the substrate.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: August 14, 2007
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventor: Hideki Fukano
  • Patent number: 6934331
    Abstract: A moving image brightness variation compensation method for encoding digital moving images for transmission and storage, and for image processing when editing moving images, the moving image brightness variation compensation method comprising a step of compensating for overall brightness variations by correcting a luminance value x of each pixel according to the formula DC·x+DB, wherein DB is a parameter indicating a gain change and DC is a parameter indicating a contrast change, the parameters representing overall luminance changes between a reference image plane and an image plane being processed.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: August 23, 2005
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventors: Kazuto Kamikura, Hiroshi Watanabe, Hirohisa Jozawa
  • Patent number: 6263089
    Abstract: A method and an equipment extracts image features from an image sequence in which frames indicating images are time-sequentially arranged with respect to time. The equipment includes a unit for inputting the image sequence, a unit for acquiring a motion trajectory of an image contour of a target included within a region defined by an arbitrary spatial range and time range within the input image sequence, as three-dimensional volume data drawn within a spatiotemporal space in which each of the frames is time-sequentially stacked, a unit for acquiring a plane histogram of one of tangent planes tangent to the motion trajectory and partial planes which may be included in the motion trajectory, and a unit for measuring temporal features and spatial features of the image from the acquired plane histogram. The three-dimensional volume data is obtained by forming difference images among the frames arranged in the time sequence and stacking the formed difference images.
    Type: Grant
    Filed: October 1, 1998
    Date of Patent: July 17, 2001
    Assignee: Nippon Telephone and Telegraph Corporation
    Inventors: Kazuhiro Otsuka, Tsutomu Horikoshi, Satoshi Suzuki
  • Patent number: 6108467
    Abstract: A small-size large-capacity optical switch in which the switch switching control structure is simple and the switch switching efficiency is excellent. A plurality of fiber accommodating grooves (4) are formed on a grooved board (1) and stationary side optical fibers (5) are held and aligned in the fiber accommodating grooves (4) to form a fiber array unit (8). The fiber array units (8) are laminated with a space therebetween. A master fiber (10) is arranged so as to correspond to the fiber array unit (8) of each stage and the master fiber (10) of each stage is supported and secured by a common master fiber supporter (12). Movement of the master fiber supporter (12) is controlled by fiber movement control means (13) only in a direction in which the fiber accommodating grooves (4) are aligned.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: August 22, 2000
    Assignees: The Furukawa Electric Co. Ltd., Nippon Telephone and Telegraph Corporation
    Inventors: Seiichi Naraoka, Makoto Okuda, Yoshitaka Enomoto
  • Patent number: 6045271
    Abstract: A ferrule for an optical connector wherein the work efficiency of the manufacture is increased by reducing the time necessary for grinding and the reliability of the connection of the optical connectors is improved. A front end surface (2) of a ferrule (1) comprises a flat surface (16) vertical to the central axes of optical fiber insertion holes (3) and a slanting surface (15). A step (17) is provided at the upper end of a slanting surface (15) and the flat surface (16) protrudes frontward by the step (17) with respect to the slanting surface (15). The optical fiber insertion holes (3) open at the slanting surface (16) and pin engagement holes (4) are provided on both sides of the optical fiber insertion holes (3).
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: April 4, 2000
    Assignees: The Furukawa Electric Co. Ltd., Nippon Telephone and Telegraph Corporation
    Inventors: Naoko Shimoji, Jun Yamakawa, Ken Kanai, Shinji Nagasawa
  • Patent number: 5363072
    Abstract: In a power amplifying apparatus which has a high-frequency power divider and combiner and two to four parallel-operated power amplifiers, in which a change is made in the number of the parallel-operated power amplifiers so as to adjust output power, there are provided a power dividing circuit D.sub.1 having a transmission line Wd.sub.51 serving as an impedance transformer set in such a manner that the power loss is minimized by assigning an intermediate number 3 between 2 and 4 both of which indicate the number of divisions, and having four output terminals, and a power combining circuit S.sub.1 having a transmission line Ws.sub.51 serving as an impedance transformer set in such a manner that the power loss is minimized by assigning the intermediate number 3 indicative of the number of combinations, and having four input terminals.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: November 8, 1994
    Assignees: Japan Radio Co., Ltd., Nippon Telephone & Telegraph Corporation, NTT Mobile Communication Network Inc.
    Inventors: Hironori Sakamoto, Akira Ito, Toshio Nojima
  • Patent number: 5249185
    Abstract: A small and economical voice packet assembling/disassembling (PAD) apparatus, which comprises only one packet assembler/disassembler for a plurality of channels. The packet assembler receives coded voice data from a plurality of CODECs provided for each channel, and assembles voice packets by using the coded voice data. The packet disassembler disassembles voice packets to coded voice data and supplies them to a plurality of CODECs provided for each channel.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: September 28, 1993
    Assignees: Nippon Telephone and Telegraph Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shin Kanno, Tsukasa Tsujimura, Masatsugu Yano, Hidenori Aoyagi, Hiroshi Kawawata
  • Patent number: 5104694
    Abstract: A selected chemical vapor deposition method includes the steps of arranging a substrate having a silicon surface and an insulator surface in a reaction chamber, supplying a gas consisting of a silicon hydride in said reaction chamber to reduce and remove a native oxide film on said silicon surface by said gas, and supplying a source gas in said reaction chamber to selectively form a film on only said silicon surface.
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: April 14, 1992
    Assignee: Nippon Telephone & Telegraph Corporation
    Inventors: Kunio Saito, Yoshinobu Arita, Takao Amazawa
  • Patent number: 4833702
    Abstract: In a wide area cordless telephone system, a wide service area is divided into a plurality of local service areas identified respectively by unique codes. Each local area has home position portable cordless telephones to which telephone numbers are permanently assigned and can accommodate roaming non-home position telephones belonging to other local areas. Each telephone receives a pre-registration polling signal from one of access units located at key points and returns a pre-registration response signal if a unique code contained in the received polling signal mismatches a stored area code. A controller in each local area assigns a reserved telephone number, if available, to a roaming telephone in response to such a response signal and registers this cordless telephone in memory. The controller then transmits an acknowledgement signal indicating the completion of a registration. The registered telephone responds to it by returning a post-registration signal which is monitored by the controller.
    Type: Grant
    Filed: May 13, 1988
    Date of Patent: May 23, 1989
    Assignees: NEC Corporation, Nippon Telephone and Telegraph Corporation
    Inventors: Kenji Shitara, Akio Sasaki, Yoshitoshi Murata
  • Patent number: RE37272
    Abstract: There is provided an information processing apparatus of a code-compressed image information for use in a facsimile apparatus or an electronic file. This apparatus comprises: an image memory to store the coded image data; a printer to print the image data; a counter to read out the data from the memory and to count the number of lines of the image data; and a controller to control the printer so as to allow the image data to be divided and printed in response to the count value of the counter. The size data of the image data is compared with the count value and when they coincide, the controller controls the printer. If the image data exceeds the line number of one standard scale recording sheet, the printer is controlled so as to divide and record the image data on two or more recording cut sheets.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: July 10, 2001
    Assignees: Nippon Telephone and Telegraph Corporation, Canon Kabushiki Kaisha
    Inventors: Hiroshi Ochi, Nobuji Tetsutani, Tetsuji Yamamoto, Hiroshi Nobuta