Hitachi, Ltd.

Other

Hitachi Cable, Inc.

Hitachi Communication Technologies, Ltd.

Shinji Sakano

Naoki Chinone

Kazuhisa Uomi

Junya Kosaka

Hiroyoshi Matsumura

Makoto Okai

Hitoshi Nakamura

Toshio Katsuyama

Tsukuru Ohtoshi

Hiroaki Inoue

Shinji Tsuji

Akihiko Oka

Hiroshi Yamaguchi

Shoji Shukuri

Tohru Ishitani

Takayuki Suzuki

Tomonobu Tsuchiya

Koji Ishida

Fumikazu Itoh

Keiya Saito

Masao Tamura

Tsuneo Ichiguchi

Yoshiaki Ikoma

Ichiro Yokota

Makoto Takahashi

Masahiro Aoki

Hideaki Tsushima

Tatemi Ido

Makoto Suzuki

Hirohisa Sano

Kazuo Aida

Atsushi Takai

Shinji Sasaki

Masahito Togami

Ryuji Ishii

Yuichi Nonaka

Yasushi Sawada

Yoshiaki Sato

Toshiyuki Matsuda

Katutoshi Saito

Kanji Tabeya

Masahito Hirokawa

Yoshinori Yamada

Masaki Miyagami

A plural camera images capturing and processing apparatus includes a plurality of cameras that capture images of a plurality of adjacent imaging regions which overlap each other, a plurality of laser devices that give a marker to each common imaging region in which imaging regions overlap each other, an imaging control unit that controls each camera and each laser device and acquires a markerless image group to which no marker is given and a marker-given image group to which the marker is given, a non-visible light image processing unit that calculates a correction parameter, which is information for aligning the inclinations, sizes, and positions of the imaging regions, on the basis of the marker-given image group, and a visible light image processing unit that composes the markerless image group to generate a composite image, on the basis of the correction parameter.

Plural camera images capturing and processing apparatus, and composite imaging method

A service providing server transmits service information to a wireless communication terminal via a wireless base station. The service information includes AP identification information of AP software necessary to execute each of a plurality of wireless services, and a utilization priority level of the AP software. The wireless communication terminal receives the service information and displays the name of AP that has the highest priority level in the service information (S). If an application menu is selected in this state (S), the name of the AP that has the next highest priority level is displayed (S). If executing AP software is selected (S) while the name of the AP is being displayed, this AP software is started up (S).

Information providing server and wireless communication terminal

An acoustic echo canceller system having a filter with high suppression performance of acoustic echo, generated by using microphone array having a plurality of microphone elements, judging a band where only a speaker sound is present, based on phase difference among microphones, and carrying out adaptation of an adaptive filter for only such a band.

Acoustic echo canceller system

A television phone adapter which permits an ordinary analog telephone to switch between being a telephone with a video function and a telephone without a video function. The television phone adapter includes a telephone adapter unit that detects dial operation of an analog telephone connected to a router with an IP telephone function, a video adapter unit that connects and disconnects a video connection using an IP network, sends a video taken by a camera to a communication partner and outputs a video received from the communication partner to a displaythrough the video connection in the connected state. A translation table stores correspondence between dial operation and a setting content. A main control unit controls connection and disconnection of the video connection by the video adapter unit, according to setting/content items corresponding to dial numbers or dial tones detected by the telephone adapter unit, when the control content translation table stores the setting/content items corresponding to the dial numbers or tones detected by the telephone adapter unit.

Television phone adaptor

A medium-scale IP telecommunications network is configured in a low-cost optical network with good reliability and expandability. A physical configuration example has a center node-and eight local nodes-through-connected in one OADM ring--. The logical configuration is a star configuration with the central node-at its origin with all traffic passing through the center node-. The local nodes-through-are connected to the central node-by wavelength-unit optical channels or optical paths &#x3bb;through &#x3bb;. Channels are added as required. Initially, for example, the center node-and the local node-are connected by &#x3bb;, but &#x3bb;can added when the need arises. Since the logical star network is limited to approximately two add/drop optical channels at local nodes, costs are reduced by using inexpensive filters (e.g., dielectric interference film filters or fiber Bragg reflectors) that are capable of extracting only the specific wavelength of the optical channel. High reliability is provided through the use of optical switches for correction of fiber transmission path failures.

Optical network

A wavelength converter and a wavelength division-multiplexing optical communication apparatus automatically generate clock signals of a specified frequency that match send/receive digital signals and regenerates timing for the send/receive digital signals. The wavelength converter includes: optical/electrical signal converters (A,B) that convert input optical signals into electric digital signals; clock generator circuits (A,B) that automatically identify the transmission mode for digital signals and generate phase-synchronized clocks of a specified frequency that match the signal transmission mode; timing regeneration circuits (A,B) that regenerate clock timing for the digital signals based upon the phase-synchronized clocks from the clock generator circuits; and electric/optical converters (A,B) that convert the digital signals from the timing regeneration circuits into optical signals of a specified wavelength.

Transponder and wavelength division-multiplexing optical transmission equipment

To ensure transmission in a flexible optical network system, a digital test signal generation/comparison circuit is incorporated in an electrical signal processing portion of a transponder. The optical network system provides transparent wavelength-division multiplex service regardless of the signal type in client optical signals. Prior to connecting a client optical line to the optical system, a selective insertion unit and a selective extraction unit enable quality assessment of the client optical line.

Optical network system with quality control function

High performance optical add/drop multiplexer and optical wavelength multiplexing network

A variable attenuator is inserted into an optical input part and a feedback control is performed so that an optical input to an amplifying optical fiber becomes constant. Further, a control for changing a total optical output and an optical input to the amplifying optical fiber is performed on the basis of channel number information obtained from a supervisory signal. When light to/from an intermediate optical component is detected and the absence of the component is detected, pumping is suppressed, thereby avoiding occurrence of an optical surge at the time of connection of the optical component and a signal indicative of detachment of the optical component is generated.

Optical fiber amplifier and optical transmission system using the same

An optical transmission system having a transmitter which generates an optical signal and amplifies the optical signal, a receiver which receives a transmitted optical signal, and an optical fiber which receives and transmits amplified optical signal from the transmitter to the receiver. The optical fiber is a single-mode optical fiber and has an end face to be optically coupled through physical contact with another optical fiber. A transparent film made of a material having a melting temperature higher than a melting temperature of a material of the single-mode optical fiber is formed on the end face of the single-mode optical fiber.

Optical fiber and method for coupling optical fibers

In a light amplification apparatus in which a part of a light output from a light amplification medium is transmitted through a branching means to a light detection means so that light power of the light output is detected by the light detection means whereby at least one of an excitation source and a return means is controlled through a control means so that light branch from a branching means is returned as a return light to the light amplification medium through the branching means again in a state in which light power is adjusted by the return means, and, as a result, the light power of the light output from the light amplification medium can be kept in a desired value while the occurrence of a light surge is suppressed, a light amplification medium control method and a light amplification apparatus wherein a signal light input can be amplified while the occurrence of a light surge is suppressed by a simple structure and with good control response, and a system using the same.

Light amplification medium control method, light amplification apparatus and system using the same

An optical amplifier controlling method and optical amplifier system which are simple in composition, maintain the S/N ratio of an optical signal output, have high control responsiveness, suppress the generation of a light surge, and amplify the optical signal, and a system using the method and amplifier system. The optical amplifier system includes an optical amplifier unit which is supplied with energy by pumping light and amplifies with the supplied energy an optical signal inputted to the amplifier unit. The optical amplifier system includes a gain control unit for controlling the gain of the amplifier system depending on the strength of the optical signal inputted to the amplifier system such that the amplifier has a maximum gain at a predetermined value of the strength of the optical signal inputted in the optical amplifier system and an area of a positive gain of not more than the maximum gain for a strength of the optical signal of not more than the predetermined value.

Optical amplifier unit control methods, optical amplifier systems and systems which use the methods and amplifier systems

A single-mode optical fiber for outputting high-power light wherein a diameter of a mode field at an output end of the optical fiber is made large to thereby lower a light power density. Material higher in thermal conductivity or melting temperature than material of the optical fiber is coated on the end face of the fiber. A thickness of the coating film is set to cause light wavelength to be phase-shifted by &frac14; of the wavelength to reduce reflection at the connecting end face. The same type of optical fiber is used as a party optical fiber to be connected therewith.

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Kamakura, Japan

Shinji Sakano