Patents Assigned to NEC
  • Patent number: 7688501
    Abstract: At an optical transmission system that uses plural light sources for Raman amplification, even when a failure occurred in a pumping light source in one of the light sources for Raman amplification, the signal light output level and its wavelength characteristic are not deteriorated at the final stage, and the number of components in the system is not made to be large and the cost of the system is not made to be high. This optical transmission system is provided. At an optical transmission system using “n” light sources for Raman amplification, a first to “n?1”th light sources for Raman amplification do not provide spare pumping light sources, and an “n”th light source for Raman amplification provides the spare pumping light sources. When a pumping light source in one of the “n” light sources for Raman amplification had a failure, the spare pumping light source in the “n”th light source for Raman amplification corresponding to the failure occurred pumping light source is worked.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: March 30, 2010
    Assignee: NEC Corporation
    Inventor: Ryu Yokoyama
  • Patent number: 7688140
    Abstract: Disclosed is a differential amplifier circuit that comprises: a first differential pair of a first conductivity type having an input pair connected to respective input terminals and an output pair connected to a load-element pair; a second differential pair of a second conductivity type having an input pair connected to the respective input terminals and an output pair connected to a load-element pair; a first output transistor connected between a first power supply and an output terminal and having a control terminal connected to a first output of the first differential pair; and a second output transistor connected between a second power supply and the output terminal and having a control terminal connected to a first output of the second differential pair.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: March 30, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Tachio Yuasa
  • Patent number: 7686465
    Abstract: A key input device includes a key input section, mode switching section, key backlight, and key backlight lighting control section. The key input section inputs characters by key input in a plurality of character input modes. The mode switching section switches a plurality of character input modes. The key backlight is placed on a lower surface of the key input section and is lighted in a plurality of colors. The key backlight lighting control section changes the lighting color of the key backlight in accordance with switching of character input modes. A cell phone is disclosed.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: March 30, 2010
    Assignee: NEC Corporation
    Inventor: Akihito Okayasu
  • Patent number: 7688143
    Abstract: Disclosed is a variable gain circuit including a gain change region in which the gain is changed substantially exponentially as a function of a control voltage. The gain is changed in the gain change region substantially exponentially based on a function {(1+x)2+K}/{1?x}2+K}, where x is a control voltage and K is a parameter of K?1. The parameter K of the function is about equal to 0.21. The denominator and the numerator of the function are proportionate to driving currents of OTAs (operational transconductance amplifiers). Or, the denominator and the numerator of the above function are constituted by output currents of a MOS differential pair and a quadritail cell that includes four transistors driven by a common tail current. Outputs of two of the transistors, receiving a differential input voltage, are connected in common and outputs of the other two of the transistors, receiving the common mode voltage of the differential input voltage, are connected in common.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: March 30, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Katsuji Kimura
  • Patent number: 7688134
    Abstract: The present invention solves characteristic deterioration caused by peaking and a ground inductance, and provides a transimpedance amplifier capable of achieving a higher gain and a wider band. For this purpose, the transimpedance amplifier is configured to include a feedback circuit having two or more extreme frequencies and having a filter characteristic which is flat with respect to frequencies in a frequency region not more than a smallest extreme frequency among the extreme frequencies, which is flat with respect to frequencies in a frequency region not less than a largest extreme frequency among the extreme frequencies, and which has at least one negative inclination portion with respect to frequencies in a frequency region between the smallest and largest extreme frequencies.
    Type: Grant
    Filed: July 24, 2006
    Date of Patent: March 30, 2010
    Assignee: NEC Corporation
    Inventors: Masahiro Tanomura, Kouji Matsunaga
  • Patent number: 7688547
    Abstract: A head cleaning mechanism for a read/write device includes an arm with serially connected arm members that supports a cleaning component. The arm members fold as the arm is wound about a shaft formed on a guide plate which guides a stud attached to the arm as it is wound in a dead space of a corner of the device.
    Type: Grant
    Filed: May 10, 2006
    Date of Patent: March 30, 2010
    Assignee: NEC Corporation
    Inventor: Atsushi Tanaka
  • Publication number: 20100072578
    Abstract: A semiconductor chip which includes an element forming region formed over a substrate, a scribe line region which surrounds the element forming region, and a structure provided locally inside the scribe line region in at least one corner area of the semiconductor chip. The element forming region and the scribe line region include a plurality of interlayer dielectric films laminated over the substrate. The structure is constituted of corner pads sandwiching at least one of the interlayer dielectric films vertically in the direction of lamination, and vias interconnecting the corner pads.
    Type: Application
    Filed: September 14, 2009
    Publication date: March 25, 2010
    Applicant: NEC Electronics Corporation
    Inventor: Hiroyuki Kunishima
  • Publication number: 20100072625
    Abstract: A semiconductor device includes a semiconductor substrate which includes a functional circuit, a trunk wiring which passes through a portion near a position immediately above a center portion of the functional circuit, a power supply pad which is connected to an end of the trunk wiring and placed at a layer level which is same as a layer level where the trunk wiring is placed, and a connection wiring which connects a substantially center portion of the functional circuit and the trunk wiring.
    Type: Application
    Filed: August 13, 2009
    Publication date: March 25, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventor: Tetsuya Katou
  • Publication number: 20100076580
    Abstract: A semiconductor integrated circuit design method, includes modeling a layer thickness of a wiring by a function including as independent variables, a percentage of surface area of the wiring in a first two-dimensional region where the wiring is formed, and a percentage of surface area for elements other than the wiring in a second two-dimensional region, and designing the wiring based on the wiring modeled.
    Type: Application
    Filed: September 11, 2009
    Publication date: March 25, 2010
    Applicant: NEC Electronics Corporation
    Inventor: Hiroshi Kitahara
  • Publication number: 20100074358
    Abstract: A method for sparse channel estimation in MIMO OFDM systems with a plurality of subchannels having the same sparsity structure is presented. The inventive method comprises initializing a plurality of residual vectors and observation generating matrices modeling the channel, sending a pilot signal for each subcarrier, converting the pilot signals to tap positions, detecting an optimal tap position, updating the residual vectors by removing the one residual vector having the optimal tap position, updating the generating matrices in accordance with the optimal residual vector, calculating weighted residuals based on the updated residual vectors, and repeating the steps, except initializing, until a stopping condition is met, wherein the updated observation matrices estimate the sparse channel. In one embodiment, the observation generating matrices are omitted. In one embodiment, multiple vectors are removed during one iteration.
    Type: Application
    Filed: March 1, 2009
    Publication date: March 25, 2010
    Applicant: NEC Laboratories America, Inc.
    Inventors: Mohammad A. Khojastepour, Krishna S. Gomadam
  • Publication number: 20100077371
    Abstract: A semiconductor integrated circuit includes multiple cells each containing transistors. The transistors include a gate and diffusion layers. The multiple cells are adjacently formed in a first direction perpendicular to the gate. The distance between the cell border and the adjacent and corresponding diffusion layer, the first direction, is the same.
    Type: Application
    Filed: November 23, 2009
    Publication date: March 25, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventor: Naohiro Kobayashi
  • Publication number: 20100076913
    Abstract: Systems and methods are disclosed to find dynamic social networks by applying a dynamic stochastic block model to generate one or more dynamic social networks, wherein the model simultaneously captures communities and their evolutions, and inferring best-fit parameters for the dynamic stochastic model with online learning and offline learning.
    Type: Application
    Filed: November 25, 2008
    Publication date: March 25, 2010
    Applicant: NEC LABORATORIES AMERICA, INC.
    Inventors: Tianbao Yang, Yun Chi, Shenghuo Zhu, Yihong Gong
  • Publication number: 20100074289
    Abstract: A two-wavelength semiconductor laser 1 includes an n-type GaN substrate 101, an n-type GaAs substrate 201 disposed on a predetermined face of the n-type GaN substrate 101, a blue-violet laser 100 provided on one of faces of the n-type GaN substrate 101 and including a multi-quantum well active layer 105, and a red laser 200 provided on one of faces of the n-type GaAs substrate 201 and including a multi-quantum well active layer 205. The blue-violet laser 100 and the red laser 200 emit laser beams having wavelengths different from each other. The blue-violet laser 100 and the red laser 200 are disposed so that their cavity length directions are almost parallel with each other. The cavity length of the blue-violet laser 100 is shorter than that of the red laser 200.
    Type: Application
    Filed: September 8, 2006
    Publication date: March 25, 2010
    Applicant: NEC CORPORATION
    Inventors: Ryuji Kobayashi, Shigeo Sugou
  • Publication number: 20100076768
    Abstract: Disclosed is a speech synthesizing apparatus including a segment selection unit that selects a segment suited to a target segment environment from candidate segments, includes a prosody change amount calculation unit that calculates prosody change amount of each candidate segment based on prosody information of candidate segments and the target segment environment, a selection criterion calculation unit that calculates a selection criterion based on the prosody change amount, a candidate selection unit that narrows down selection candidates based on the prosody change amount and the selection criterion, and an optimum segment search unit than searches for an optimum segment from among the narrowed-down candidate segments.
    Type: Application
    Filed: February 15, 2008
    Publication date: March 25, 2010
    Applicant: NEC CORPORATION
    Inventors: Masanori Kato, Reishi Kondo, Yasuyuki Mitsui
  • Publication number: 20100076736
    Abstract: A statistical SPICE model parameter calculation method in which it is possible to create a variation model having high accuracy and size dependency. A principal component analysis is performed, for respective device sizes, of a measurement of an element characteristic value of a semiconductor device on which multipoint measurement is performed (principal component analysis process). A statistical SPICE model parameter that reproduces variation of an element characteristic value for a plurality of device sizes is calculated based on a result of the principal component analysis obtained for each of the device sizes and predetermined device size dependency (parameter calculation process).
    Type: Application
    Filed: September 23, 2009
    Publication date: March 25, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventor: TAKASHI SHIMIZU
  • Publication number: 20100074303
    Abstract: A wireless communication apparatus comprises a local generator for generating a local signal having a frequency equal to the central frequency of the band group; a first down converter for down-converting a wireless signal in each of the bands into an IF signal; a hopping complex filter for removing an image signal in the frequency range of a band to pass therethrough, among down-converted signals, said hopping complex filter having filter characteristics changeable depending on the hopping between the bands; and a second down converter for converting an IF signal of a band which does not contain said central frequency into a baseband signal in a predetermined frequency range about a DC level.
    Type: Application
    Filed: November 2, 2007
    Publication date: March 25, 2010
    Applicant: NEC CORPORATION
    Inventor: Akio Tanaka
  • Publication number: 20100073982
    Abstract: Disclosed herewith is a semiconductor device having an SRAM cell array capable of easily evaluating the performance of transistors and the systematic fluctuation of wiring capacity/resistance. In order to form an inversion circuit required to form a ring oscillator, a test cell is disposed at each of the four corners of the SRAM cell array and the ring oscillator is operated while charging/discharging the subject bit line. Concretely, the ring oscillator is formed on a memory cell array and the ring oscillator includes test cells disposed at least at the four corners of the memory cell array respectively. At this time, a wiring that is equivalent to a bit line is used to connect the test cells to each another.
    Type: Application
    Filed: July 8, 2009
    Publication date: March 25, 2010
    Applicant: NEC Electronics Corporation
    Inventors: Shinobu Asayama, Toshio Komuro
  • Publication number: 20100072609
    Abstract: Provided is a socket for semiconductor integrated circuit allowing a semiconductor integrated circuit to be analyzed easily. The socket for semiconductor integrated circuit according to the invention is used by mounting a package thereon. The socket for semiconductor integrated circuit includes: a socket main body which covers both a front-side surface and a back-side surface of the package and is provided with a window formed above either of the two surfaces of the package; bottom-side socket pins provided corresponding respectively to package balls of the package; upper-side socket pins provided corresponding respectively to the package balls of the package at the time when the package is mounted upside down; and wirings which electrically connect the bottom-side socket pins to the corresponding upper-side socket pins, respectively.
    Type: Application
    Filed: November 24, 2009
    Publication date: March 25, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventor: Toshiki Fukumoto
  • Publication number: 20100076963
    Abstract: Provided is an index making device for lightening a load on a network and an information-providing server. The index making device (2) comprises information acquiring means (201) for acquiring the reference information, which is acquired by a terminal device (5) demanding an information providing device (4) for sending specific information via a network (1), and the reference history information which contains the reference target information for discriminating the place where that reference information is stored, and index making means (202) for making an index for retrieving the reference information from the reference history information and the reference information, which were acquired by that information acquiring means.
    Type: Application
    Filed: February 18, 2008
    Publication date: March 25, 2010
    Applicant: NEC CORPORATION
    Inventor: Naoto Kiuchi
  • Publication number: 20100076749
    Abstract: A language processing system according to the present invention includes: an input device 1 that receives an input of an input document; and a unit selecting dictionary 22 that selects a document-information-attached user dictionary that is a user dictionary to which document information is attached. The unit selecting dictionary 22 selects the dictionary, based on the degree of similarity between the input document input from the input unit 1 and the document information attached to the document-information-attached user dictionary. The language processing system further includes a document-information-attached user dictionary storage unit 31 that stores the document-information-attached user dictionary. One or more sentences are attached as the document information to the document-information-attached user dictionary.
    Type: Application
    Filed: February 22, 2008
    Publication date: March 25, 2010
    Applicant: NEC CORPORATION
    Inventors: Seiya Osada, Kiyoshi Yamabana, Jinan Xu, Takahiro Ikeda, Kunihiko Sadamasa