Fujitsu Corporation

Showa Denko K.k.

Tetsuo Wada

Hiroaki Tomofuji

Takuji Maeda

Hideki Kobayashi

Tetsuhiko Yamaguchi

Taizo Maeda

Tatsuo Nagayoshi

Kazuhiro Suzuki

Kazuo Yamane

Hirofumi Inoue

Takeshi Sakamoto

Yuji Miyaki

Masakazu Mori

Yasushi Tateno

Hiroyuki Iwaki

Yoshinori Ohkuma

Yoshinori Tochiki

Kazumaro Takaiwa

Toshihisa Kyouno

Yoshiaki Shibayama

Yoshihisa Funami

Tomokazu Umezawa

Mina Saito

Akinori Nishiie

Eiichi, Deceased Yoshida

The thermosetting resin composition according to the present invention includes a resin (A) containing two or more carboxyl groups and having a polyurethane structure, a strongly basic nitrogen-containing heterocyclic compound having pKa of 10.0 to 14.0 as a curing accelerator (B) and a curing agent (C). A cured product of the thermosetting resin composition is used as an insulating protective film for printed wiring boards, flexible printed wiring boards, chip-on-films, etc. The thermosetting resin composition of the invention has improved low-temperature curability and instantaneous curability, can realize tack-free property, can simultaneously realize low warpage property and electrical insulation property, does not contaminate a curing oven and the like by outgassing during heating, has a sufficient pot life, can form excellent cured products and insulating protective films, and can form solder resists and insulating protective films at low cost with good productivity.

Thermosetting resin composition

An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.

Optical transmission system with automatic signal level adjustment and startup functions

An optical multiplex communication system includes a transmission part and a receiving part, wherein the transmission part includes a transmission quality detecting part which measures and transmits a transmission quality information for the channels based on a request from the transmission part; the receiving part includes a variable optical attenuation part controls the optical signal level for the channels, an optical level setting part controls the variable optical attenuation part based on a setting value, a setting control part adding the setting value to the optical level setting part based on a request for setting.

Optical multiplex communication system, optical transmission apparatus, and control method of optical multiplex communication

Disclosed is a wavelength-division multiplexing optical transmission system in which an optical lossy medium, optical amplifiers and Raman amplifiers for compensating for loss in the optical lossy medium are cascade-connected. The system includes power-level equalizing means for equalizing optical power levels input to an optical amplifier of a succeeding stage by adjusting excitation ratio of a Raman amplifier; optical-SNR equalizing means for adjusting power levels at a transmitting end to equalize optical SNRs at a receiving end; and correction-value acquisition means for acquiring a correction value that represents an amount of change in power of each wavelength before and after optical-SNR equalization control. At control for equalizing power levels by a Raman amplifier, the power-level equalizing means performs equalization control using the correction value that represents the amount of change in power of each wavelength before and after optical-SNR equalization control the previous time, and the optical-SNR equalizing means subsequently performs optical-SNR equalization control.

Wavelength-division multiplexing optical transmission system and repeater station therein

The present invention relates to an optical level control method for use in an optical transmission system. In the system, a WDM terminal comprises a multiplexing/demultiplexing unit, an amplifier, an up-direction OSC light transmitting/receiving unit, an up-direction multiplexer, an up-direction branching unit, an amplifier and an APR control unit, and a repeater comprises an up-direction branching unit, an OSC light transmitting/receiving unit, an amplifier, an up-direction multiplexer, a down-direction branching unit, an amplifier, a down-direction multiplexer and an APR control unit. In this configuration, a flexible optical output level control in connection with variation in WDM light level, a selective value irrespective of occurrence of an error stemming from the passage of time and avoidable malfunctions are respectively capable. In addition, a trouble retrieving operator can eliminate the possibility of being exposed to the WDM light.

Optical level control method

A controlling apparatus and a controlling method for a wavelength division multiplexing optical amplifier to reduce the controlling error due to noise light included in the monitoring light. The controlling apparatus branches, by a photocoupler, a portion of WDM signal light amplified by a light level controlling part and separates the branched light into groups of even-numbered channel components and odd-numbered channel components using a wavelength channel separate filter. Monitor signals corresponding to the light powers of the even-numbered group and odd-numbered group, respectively, are generated by respective photoelectric converting parts and LPF's. One of the monitor signals, which corresponds to one of the even-numbered group and the odd-numbered group, is selected by a monitor signal selecting/controlling part and then sent to a comparator. The control apparatus conducts feedback controlling in accordance with the output signal of the comparator, so that the light level controlling part conducts to ALC (automatic level control) operate.

Controlling apparatus and controlling method for wavelength division multiplexing optical amplifier

An optical communication system according to the present invention includes an optical transmission device and a repeater. The repeater has an automatic level controller for performing average level constant control to an optical signal transmitted from the optical transmission device. The optical transmission device has an average level detector for detecting an average level detection signal of the optical signal transmitted to the repeater, and the average level detector transmits the average level detection signal to the repeater. When the automatic level controller of the repeater detects an average level detection signal, the automatic level controller performs average level constant control for the optical signal with reference to the average level detection signal.

Optical communication system and optical signal control method therefor

The present invention aims at providing a controlling apparatus and a controlling method for a wavelength division multiplexing optical amplifier to reduce the controlling error due to the affection of noise light included in the monitoring light to be used for controlling the wavelength division multiplexing optical amplifier, to thereby realize precise controlling of the optical amplifier. To this end, the controlling apparatus for a wavelength division multiplexing optical amplifier according to the present invention: branches, by a photocoupler, a portion of WDM signal light amplified by a light level controlling part; and separates the thus branched light into groups of even-numbered channel components and odd-numbered channel components making use of a wavelength channel separate filter. Further, monitor signals corresponding to the light powers of the even-numbered group and odd-numbered group, respectively, are generated by respective photoelectric converting parts and LPF's. Moreover, that one of the monitor signals, which corresponds to one of the even-numbered group and the odd-numbered group, is selected by a monitor signal selecting/controlling part and then sent to a comparator. The controlling apparatus conducts feedback controlling in accordance with the output signal of the comparator, so that the light level controlling part conducts to ALC (automatic level control) operate.

An optical transmission system having a linear repeater section that performs linear amplification of an optical signal, in which some functional redundancy is introduced to improve the reliability of long-distance signal transmission. The optical transmission line is segmented by regenerative repeater devices into a plurality of linear repeater sections, in each of which a plurality of linear optical amplifiers are deployed. The regenerative repeater devices have a signal regeneration unit that regenerates the received optical signals to compensate for their deterioration. The present invention eliminates RSOH termination and insertion functions from the regenerative repeater devices connected to at least one end of each linear repeater section. Further, the present invention deploys a signal regeneration unit in parallel with a linear optical amplifier within each linear repeater section. Still further, the present invention adds another signal regeneration unit to the existing signal regeneration unit as part of each regenerative repeater device connected to at least one end of each linear repeater section.

Optical transmission system

A collagen powder is obtained by wet-pulverizing a purified animal tissue consisting mainly of collagen in water at a collagen concentration of 1-30% by weight at a water temperature of not more than 37.degree. C. and a pH value of 2-8, tanning treating the pulverized tissue at a pH level of 2-7 with a polyvalent metal tanning agent to obtain a stabilized wet collagen product, dehydrating the wet collagen product at a pH level of 4-8, and then drying and pulverizing the dehydrated product into a powder. This powder can be used as an additive for modifying paints, artificial leathers, molding materials and the like based on synthetic resins such as thermoplastic resins. The materials obtained with this powder have an excellent appearance, feel, and moisture-absorbing and moisture-releasing properties.

Process for producing collagen powder

Disclosed is a collagen powder having a good dispersion stability, in which the content of particles having a particle size smaller than 40 .mu.m is at least 85% by weight, the water absorption is 120 to 300%, and the apparent bulk density is 0.10 to 0.30 g/cc. This collagen powder is advantageously used for a leather-like surface layer-forming agent and a leather-like molded article.

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Kawasaki, Japan

Tetsuo Wada