Fujitsu Corporation

Ricoh Company, Ltd.

Fujitsu Telecom Networks Limited

Takehiro Fujita

Yasushi Sugaya

Motoyoshi Sekiya

Satoru Okano

Shigeru Ishii

Miki Onaka

Futoshi Izumi

Hiroaki Tomofuji

Ichiro Nakajima

Tatsuya Tsuzuki

Taizo Maeda

Toshiki Honda

Hidezumi Natori

Takahumi Terahara

Kenji Watanabe

Tomoaki Takeyama

Tomoyuki Suzuki

Shogo Nakamura

Ryosuke Goto

Daisuke Arai

Takuya Miyashita

Hideki Kobayashi

Kimio Uekama

Hiroki Oi

Koji Tanonaka

Akihisa Kawaguchi

Tomoki Shimohira

An optical wavelength multiplexing transmission device includes: a demultiplexer configured to demultiplex a wavelength multiplexing signal for each wavelength band from a multiplexed signal that includes wavelength multiplexing signals in a plurality of the wavelength bands; a processor configured to detect an optical power value of each wavelength multiplexing signal for each wavelength band; calculate a compensation amount used to compensate a tilt of the wavelength multiplexing signal, by using the optical power value and a predetermined calculation expression; and compensate the tilt of the wavelength multiplexing signal, based on the compensation amount; and a multiplexer configured to multiplex each wavelength multiplexing signal compensated by the processor and output the wavelength multiplexing signal to a transmission line.

Optical wavelength multiplexing transmission device and optical wavelength multiplexing transmission method

An information processing apparatus, a meeting system, and a method. The information processing apparatus registers material to be distributed to a participant of a meeting, controls an output device to output the material, acquires meeting progress information indicating progress of the meeting and additional information added by the participant to the material, and generates meeting result information that indicates meeting result based on the material, the meeting progress information, and the additional information.

Information processing apparatus, meeting system, and method

A sheet conveying device, which is included in an image forming apparatus, includes a pair of rotary bodies configured to convey a sheet and correct a positional deviation of the sheet, a pair of downstream side sheet conveying bodies disposed downstream from the pair of rotary bodies in a sheet conveying direction and configured to convey the sheet, and a detector configured to detect separation of the pair of rotary bodies. The pair of rotary bodies moves the sheet by moving from a home position on a sheet conveyance passage through which the sheet passes. The pair of rotary bodies moves to the home position while the pair of downstream side sheet conveying bodies is conveying the sheet, in response to detection of the separation of the pair of rotary bodies by the detector.

Sheet conveying device and image forming apparatus incorporating the sheet conveying device

A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

Optical wavelength multiplexing transmission apparatus and optical wavelength multiplexing transmission method

A sheet conveying device, which is included in an image forming apparatus, includes a pair of rollers configured to convey a sheet in a sheet conveyance passage, a detector configured to optically detect an attitude of the sheet, one of a rotation device to rotate the pair of rollers in a direction parallel to a plane of the sheet and a moving device to move the pair of rollers in a width direction, and a controller configured to correct the attitude of the pair of rollers at a time interval, based on a detection result obtained by the detector. The controller performs the correcting operation by setting, according to reflectance of the sheet, at least one of a light emission time of the detector, the time interval of the correcting operation, light emission intensity of the detector and a conveying speed of the sheet.

A series of conveyance paths to convey a recording medium is formed across a printer and a post-processing device in a printing system. The printing system includes: a detection unit that detects that the post-processing device has entered a predetermined state; and a paper feeding control unit that limits the number of recording media fed to the conveyance path, when it is not detected that the post-processing device has entered the predetermined state, based on the number of recording media conveyable to the post-processing device after the post-processing device enters the predetermined state.

Printing system

A measuring device includes an identifying unit configured to identify a design value of a central frequency of spectrum of an optical signal for each of sub-channels, the optical signal being formed in Nyquist pulse, the sub-channels forming a super-channel in wavelength division multiplexing communication; and a measurer configured to measure the power of the optical signal in a band for each of the sub-channels, the identified design value of the central frequency of the band being a central frequency of the band, the band being narrower than a frequency band of a corresponding one of the sub-channels.

Measuring device, measurement method, and transmission system

A transmitter to be added or reduced turns ON/OFF an optical output. A relay station and a receiving terminal station acquire the amount of fluctuation of the optical output of the received signal light when the optical output of the added transmitter is turned ON and OFF. From the amount of fluctuation of the optical output, the number of wavelengths after the addition or reduction is acquired. Without an OSC signal, each station may be informed of the number of wavelengths. Therefore, the configuration for transmitting and receiving the OSC signal is not requested, thereby reducing the total cost, appropriately controlling the gain of the optical amplifier, and successfully maintaining transmission quality.

Wavelength division multiplexing transmission device

An optical receiving device includes: an optical amplifier configured to amplify a wavelength multiplexed optical signal; a demultiplexer configured to demultiplex the amplified wavelength multiplexed signal into optical signals of a plurality of wavelengths; optical receivers configured to regenerate the demultiplexed optical signals; error correction units configured to correct a bit error in the regenerated optical signals; and main control unit. The control unit adjusts RXDTV of the optical receiver for receiving optical signals of a given wavelength to the optimal value in the state where the gain of the optical amplifier is lowered from that of a normal operation such that the occurrence of bit errors in the optical signals of the other wavelengths does not exceed the correction capability of the error correction unit.

Optical receiving device

There is provided a method of determining transmission quality of a path in an optical communication network system obtained by connecting a plurality of networks, the method including: acquiring a value representing transmission performance corresponding to a network condition of each of spans in the path in the optical communication network system; and determining the transmission quality of the path on the basis of the acquired value representing transmission performance corresponding to the network condition of each of spans.

Transmission quality determination method, transmission path selection method and network management system

A transmission system is provided with a transmission apparatus that outputs an ASE light from a transmission light amplifier and with a reception apparatus provided with: a tilt detection unit that detects the optical strength levels of at least two probe lights having different wavelengths from a received ASE light; and a reception light amplifier that performs a first-order tilt correction on light to be output in a linear manner so as to reduce the difference in the optical strength level of the two probe lights detected by the tilt detection unit.

Transmission system and method of correcting tilt of the transmission system

An optical apparatus includes a first optical amplifier for adjusting an output value to a constant level; an optical signal processor located before the first optical amplifier and processing the optical signal; a second optical amplifier located before the optical signal processor and subjected to automatic gain control for adjusting a gain constant; and a controller detecting a level of the optical signal at an output of the second optical amplifier. The controller adjusts a level of an output value of the first optical amplifier such that the level of the optical signal at the output of the second optical amplifier is held at the optimum value if the detected level of the optical signal differs from an optimum value, compensates for a loss caused in the optical signal processor and maintains the level of the optical signal at the output of the second optical amplifier at the optimum value.

Optical transmission device

An optical transmission system includes an optical transmitter that sends signal light to a transmission path, an optical receiver that receives the signal light from the transmission path, and an optical amplifier that is provided on the transmission path and that amplifies the signal light, the optical amplifier being configured to control a gain characteristic of the optical amplifier such that a power of signal light having a wavelength included within a wavelength range in which polarization hole burning occurs is higher than a power of another signal light having a wavelength outside the wavelength range.

Optical transmission system

A WDM optical transmission system includes a plurality of optical nodes optically coupled by a transmission line, a processor that is operative to calculate an amount of adjustment of a reception level capable of increasing an optical signal-to-noise ratio for each channel of the WDM light reaching the optical node positioned at a receiving end of the unit section based on information on amplification operation of the WDM light in at least one optical-amplification repeating node disposed on the optical transmission line in the unit section, and to adjust a power level corresponding to each channel of the WDM light transmitted on the transmission line from the optical node positioned at a transmission end of the unit section in accordance with a calculation result of the calculation.

WDM optical transmission system and control method thereof

There is provided a WDM transmission apparatus including a calculator being operable to calculate an optical signal level of a wavelength after wavelength demultiplexing based on information of OSNR, an amplifier controller being operable to compensate for the optical signal levels of all the wavelengths after wavelength demultiplexing to become a target level based on an optical signal level calculated by the calculator, and an deviation corrector being operable to correct a deviation of an optical signal level between each wavelength based on the optical signal level calculated by the calculator.

Growing community of inventors

Kawasaki, Japan

Takehiro Fujita