Patents by Inventor Takao Naito

Takao Naito 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).

  • Patent number: 8369442
    Abstract: A transmitter modulator that is operable to modulate signals according to multiple modulation formats includes a first modulator, a second modulator, and a polarization beam combiner. The first modulator encodes a first signal according to a first modulation format. The second modulator encodes a second signal according to a second modulation format, the first signal orthogonally polarized with respect to the second signal. The polarization beam combiner combines the first signal and the second signal for transmission.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: February 5, 2013
    Assignee: Fujitsu Limited
    Inventors: Olga I. Vassilieva, Takao Naito
  • Patent number: 8347006
    Abstract: In certain embodiments, minimizing interconnections in a multi-shelf switching system includes receiving a map describing the switching system, where the switching system comprises shelves and input/output (I/O) points. The map is transformed to yield a graph comprising nodes and edges. A node represents an I/O point, and a node weight represents a number of interface cards of the I/O point represented by the node. An edge between a node pair represents traffic demand between the I/O points represented by the node pair, and an edge weight represents the amount of the traffic demand represented by the edge. The graph is partitioned to yield a groups that minimize interconnection traffic among the shelves, where each group represents a shelf of the multi-shelf switching system.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: January 1, 2013
    Assignee: Fujitsu Limited
    Inventors: Qiong Zhang, Paparao Palacharla, Xi Wang, Takao Naito
  • Patent number: 8340515
    Abstract: A method is provided for dispersion compensation of an optical signal communicated in an optical network. The method may include receiving an optical signal comprising a plurality of channels. The method may further include filtering at least one channel from the plurality of channels. The method may also include analyzing the at least one channel of the plurality of channels to measure optical dispersion in the at least one channel. The method may additionally include compensating for optical dispersion based on the measured dispersion.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: December 25, 2012
    Assignee: Fujitsu Limited
    Inventors: Alexander Umnov, Takao Naito, Niranjan Hanumanna
  • Patent number: 8335438
    Abstract: According to particular embodiments, a signal communicated from a transmitter to a receiver is received. A frequency offset estimate of the signal is determined. The frequency offset estimate indicates a frequency difference between the transmitter and the receiver. The frequency offset estimate is provided as feedback. A next frequency offset is compensated for according to the feedback.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: December 18, 2012
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Takao Naito
  • Patent number: 8299816
    Abstract: A data processing apparatus includes a reconfigurable circuit capable of reconfigurating partially a circuit configuration: and a reconfiguration controlling unit that controls a reconfiguration of the circuit configuration of the reconfigurable circuit. The reconfiguration controlling unit reconfigurates a plurality of partial circuits, which constitute one pipeline and are reconfigurated simultaneously on the reconfigurable circuit, on the reconfigurable circuit in sequence from a head partial circuit of the pipeline, and starts sequentially the reconfigurated partial circuits from a head.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: October 30, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kazuo Yamada, Takao Naito
  • Publication number: 20120269452
    Abstract: An image data processing apparatus includes the following elements. A lossless compression device performs lossless compression. A configuration controller performs control so that a first configuration including a first line memory set and a decompression circuit set and a second configuration including a second line memory set are selectively set in a reconfigurable circuit. A maximum size determining device determines the maximum size of lines of the compressed image data. An output controller performs control so that, when the maximum size is equal to or smaller than a predetermined threshold, the first configuration is set and the compressed image data is output to an image processing circuit via the first line memory set, and so that, when the maximum size is greater than the predetermined threshold, the second configuration is set and the non-compressed image data is output to the image processing circuit via the second line memory set.
    Type: Application
    Filed: November 14, 2011
    Publication date: October 25, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takao NAITO, Kazuo YAMADA
  • Patent number: 8284479
    Abstract: A system for optical communication including an optical amplifier card configured to receive a plurality of pump laser modules. The optical amplifier card includes a receptacle configured to receive the pump laser module, a connector configured to couple the pump laser module to the optical amplifier card, a monitor configured to measure at least the optical output power of the pump laser module, and a pump combiner communicatively coupled to the monitor. The pump combiner is configured to receive a signal from the monitor indicating a drop in the output power of a first pump laser module below a threshold level, and, in response to the signal, switch the optical amplifier card from using the optical power of the first pump laser module to using the optical power of a second pump laser module without substantially affecting normal operation of the optical amplifier card.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: October 9, 2012
    Assignee: Fujitsu Limited
    Inventors: Youichi Akasaka, Takao Naito
  • Patent number: 8218975
    Abstract: A demodulator comprises an input splitter, optical device sets, and couplers. The input splitter splits an input signal comprising symbols to yield a number of signals. A first optical device set directs a signal of along a first path. A second optical device set directs another signal along a second path to yield a delayed signal. At least a portion of the second path is in free space. A path length difference between the first path and the second path introduces a delay between the first signal and the second signal. A coupler receives a portion of the signal and a portion of the delayed signal to generate interference, where the interference indicates a phase shift between a phase corresponding to a symbol and a successive phase corresponding to a successive symbol.
    Type: Grant
    Filed: December 31, 2009
    Date of Patent: July 10, 2012
    Assignee: Fujitsu Limited
    Inventors: Cechan Tian, Takao Naito
  • Publication number: 20120134022
    Abstract: In accordance with one embodiment of the present disclosure, an optical signal bidirectional transmission system comprises a bi-directional port configured to receive and output optical beams, an input port configured to receive beams and an output port configured to output beams, and only one birefringent crystal. A first beam manipulation system configured to adjust polarization of the beams, and direct the beams from the bi-directional port to the birefringent crystal. A second beam manipulation system configured to adjust polarization of the beams, and direct the beams from the input port to the birefringent crystal. The birefringent crystal is configured to direct the beams received from the first beam manipulation system such that the beams may exit the second beam manipulation system through the output port and direct the beams received from the second beam manipulation system such that the beams may exit the first beam manipulation system through the bi-directional port.
    Type: Application
    Filed: November 30, 2010
    Publication date: May 31, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Alexander Umnov, Takao Naito
  • Publication number: 20120093507
    Abstract: A system and method are provided for dynamically reconfiguring an optical circuit between a first node and a second node of a communication network. The system and method may include establishing a scheduling window for receiving a plurality of optical traffic demands, classifying the plurality of optical traffic demands into at least a set of bandwidth adjustable demands and a set of fixed bandwidth demands, provisioning a first set of provisioned wavelengths from the plurality of wavelengths to carry the set of fixed bandwidth demands during the scheduling window, allocating the bandwidth remaining on the first set of provisioned wavelengths to the set of bandwidth adjustable demands, and if necessary, provisioning a second set of provisioned wavelengths from the plurality of wavelengths to carry the bandwidth required by the set of bandwidth adjustable demands that could not be allocated to the first set of provisioned wavelengths.
    Type: Application
    Filed: October 15, 2010
    Publication date: April 19, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Xi Wang, Qiong Zhang, Paparao Palacharla, Takao Naito
  • Publication number: 20120096122
    Abstract: A method for facilitating remote downloading, in accordance with particular embodiments, includes receiving, at a proxy server maintained by a wireless service provider, a remote download request. The remote download request is relayed to the proxy server via at least one component of a wireless service provider's network. The remote download request includes an address associated with at least one file hosted by a remote server. The method also includes downloading the at least one file from the remote server to the proxy server. Upon detecting a presence of the endpoint, the method includes transferring the at least one file from the proxy server to the endpoint via a femto base station associated with the endpoint.
    Type: Application
    Filed: October 13, 2010
    Publication date: April 19, 2012
    Applicant: Fujitsu Limited
    Inventors: Chenxi Zhu, Wei-Peng Chen, Takao Naito
  • Publication number: 20120082458
    Abstract: According to one embodiment, a system for transmitting an optical signal comprises a traffic distribution circuit configured to distribute traffic to a plurality of wavelength division multiplexer (WDM) modules. The system further comprises a first WDM module and a second WDM module. The first and second WDM modules each comprise a plurality of tunable optical transmitters, with each transmitter associated with a different wavelength band of a plurality of wavelength bands. Each transmitter in the first and second WDM modules is also tuned to transmit optical signals in channels included within the associated wavelength band of the transmitter. The first and second WDM modules each comprise a multiplexer configured to combine the optical signals transmitted from the plurality of transmitters into optical signals. The system further comprises a cyclic multiplexer configured to combine the optical signals from the first and second WDM modules into an optical output signal.
    Type: Application
    Filed: September 30, 2010
    Publication date: April 5, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Martin Bouda, Inwoong Kim, Takao Naito
  • Publication number: 20120082448
    Abstract: In accordance with an embodiment, a method for sparing channels in a wavelength division multiplexing (WDM) transponder comprises transmitting network traffic, over a plurality of active channels, wherein each active channel is associated with an active transmitter. Determining that one or more active transmitters have failed and switching traffic from the channels associated with the failed transmitters to first spare channels, wherein the first spare channels are associated with a plurality of first spare transmitters included in a first spare WDM module. Switching traffic from the channels associated with the failed transmitters to second spare channels. The second spare channels are associated with a plurality of second spare transmitters included in a second spare WDM module to allow for a plurality of active transmitters to fail before requiring immediate replacement of an active WDM module with at least one failed transmitter.
    Type: Application
    Filed: September 30, 2010
    Publication date: April 5, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Martin Bouda, Takao Naito
  • Patent number: 8144626
    Abstract: According to particular embodiments, determining disjoint paths includes receiving a graph representing a network comprising nodes and links. The graph is transformed such that the number of intermediate nodes of a path indicates the number of regenerators for the path. A set of seed paths from a source node to a destination node of the transformed graph is generated. For each seed path, a shortest path from the source node to the destination node is determined to yield one or more pairs of disjoint paths from the source node to the destination node. An optimized pair of disjoint paths is selected, where the optimized pair of disjoint paths has an optimized number of regenerators.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: March 27, 2012
    Assignee: Fujitsu Limited
    Inventors: Qiong Zhang, Xi Wang, Paparao Palacharla, Takao Naito
  • Publication number: 20120066347
    Abstract: A method for facilitating remote downloading includes receiving, at a home media gateway associated with at least a first endpoint, a remote download request generated by a web browser running on the first endpoint. The remote download request is relayed to the home media gateway via at least one component of a wireless service provider's network. The wireless service provider provides user authentication for the remote download request. The remote download request includes an address associated with at least one file hosted by a remote server. The method also includes downloading the at least one file from the remote server to the home media gateway. The method further includes, upon detecting a presence of the first endpoint, uploading the at least one file from the home media gateway to the endpoint.
    Type: Application
    Filed: September 14, 2010
    Publication date: March 15, 2012
    Applicant: Fujitsu Limited
    Inventors: Chenxi Zhu, Wei-Peng Chen, Takao Naito
  • Publication number: 20120063768
    Abstract: Methods and systems are provided for cancellation of chromatic dispersion combined laser phase noise. A method may include measuring a differential of laser phase noise using two optical pilot signals, the pilot signals each having a different optical frequency, or using an optical carrier and a pilot signal. The method may also include determining an approximate laser phase noise present in an optical system based on the measured differential of laser phase noise. The method may further include compensating for laser phase noise based on the determined approximate laser phase noise.
    Type: Application
    Filed: September 10, 2010
    Publication date: March 15, 2012
    Inventors: Inwoong Kim, Takao Naito, Olga I. Vassilieva
  • Patent number: 8107815
    Abstract: In one embodiment, a method for providing wireless communications utilizing a passive optical network (PON) is disclosed. The method includes receiving, at a PON, downstream packets from a base station destined for a mobile station, and transmitting the downstream packets to wireless transceivers associated with PON. The method also includes receiving, at the first wireless transceiver communicatively coupled to a first optical network terminal (ONT), the downstream packets from the first ONT and transmitting a first wireless signal comprising the downstream packets to a first cell. The method also includes receiving, at a second wireless transceiver communicatively coupled to a second ONT, the downstream packets from the second ONT and transmitting a second wireless signal comprising the downstream packets to a second cell.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: January 31, 2012
    Assignee: Fujitsu Limited
    Inventors: Youichi Akasaka, Takao Naito, Satoshi Mizutani
  • Publication number: 20110320770
    Abstract: An internal buffer is provided for a DRP core. A selector SEL switches input/output destination of the DRP core between external memory and an internal buffer. Control software executed by a CPU core receives information a pipeline of configurations for a sequence of target processing and generates combinations as to whether the processing result is transferred between the configurations via the external memory or via the internal buffer as transfer manners. Next, for each manner, bandwidth and performance of the external memory used by the DRP core in the manner are calculated. The manner of the best performance satisfying a previously specified bandwidth restriction is selected among the manners and the selector SEL is switched in accordance with the manner.
    Type: Application
    Filed: December 8, 2010
    Publication date: December 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Kazuo YAMADA, Takao NAITO
  • Publication number: 20110317205
    Abstract: A print image processing apparatus, includes N image processing circuits; a selection unit that estimates, every N pages, a necessary time corresponding to each of (i) a page-based parallel method for allocating image processing of the N pages to the image processing circuits in units of pages to perform the image processing of the N pages in parallel, and (ii) a paginal-object-based parallel method for allocating image processing of each single page to the image processing circuits in units of objects to perform the image processing of the objects of each single page in parallel, and selects one of the page-based parallel method and the paginal-object-based parallel method such that the estimated necessary time corresponding to the selected one of the parallel methods is shorter than the estimated necessary time; and an allocation unit that allocates image processing of the N pages to the N image processing circuit, respectively.
    Type: Application
    Filed: October 26, 2010
    Publication date: December 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takao NAITO, Kazuo YAMADA
  • Patent number: 8041229
    Abstract: A system for optoelectrical communication includes a transmitter configured to transmit optical signals. It also includes a pluggable form factor module. The module includes an input port, an output port, and a receiver configured to convert optical signals received at the input port into electrical signals. The system further includes an optoelectrical connector coupled to the module and the transmitter. The connector includes an embedded fiber coupled to the transmitter and configured to transmit the optical signals from the transmitter to the output port of the module. The connector also includes electrical contacts configured to receive the electrical signals from the receiver. The system includes a cage in a pluggable form factor configured to house the module and the connector, wherein the transmitter is positioned outside the cage.
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: October 18, 2011
    Assignee: Fujitsu Limited
    Inventors: Alexander Umnov, Dung Q. Tran, Takao Naito