Fuji Electric Co., Ltd.

Tokai Carbon Company, Ltd.

Tetsuya Saitoh

Hideo Shimizu

Takeshi Kobayashi

Tomoaki Kirino

Makoto Sekiyama

A method for producing a surface-treated carbon black particle aqueous dispersion that exhibits excellent blackness and dispersibility, exhibits excellent storage stability, suppresses feathering, exhibits an excellent discharge capability and rubfastness (quick-drying capability), and suppresses metal corrosion when used in an aqueous black pigment (colorant) ink, is disclosed. The method for producing a surface-treated carbon black particle aqueous dispersion includes providing an aqueous dispersion of oxidized carbon black particles obtained by forming acidic hydroxyl groups on a surface of carbon black particles having a DBP absorption of 120 cm/100 g or more, neutralizing 5% or more and less than 50% of the acidic hydroxyl groups with a polyvalent cation, and neutralizing the remainder of the acidic hydroxyl groups with a monovalent cation.

Method for producing aqueous dispersion of surface-treated carbon black particles and aqueous dispersion of surface-treated carbon black particles

An optical star coupler that distributes the optical signal radiated from an optical fiber uniformly across the mixing means and couples the distributed optical signal efficiently to the other optical fibers. The optical star coupler includes: a bundling means including a plurality of optical fibers, the ends thereof being bundled, a flat plane formed by polishing the end faces of the optical fibers, and a light reflector formed on a part of the flat plane; a mixing means including a waveguide, the first end face thereof contacting with the flat plane and wide enough to cover the cores of the optical fibers; and a diffuser-reflector means arranged on the second end face of the waveguide.

Optical star coupler

A light beam from an optical fiber held by a waveguide support is guided to an illuminated region of a light-receiving section. A light beam from one light-deflecting device inside this region is reflected by a reflecting surface and passed as a light beam through a second light-deflecting device in another illuminated region to arrive at a second optical fiber. A light beam from the second optical fiber takes the reverse route to the foregoing route. In this way, various light-deflecting devices in one illuminated region are optically coupled to light-deflecting devices in other illuminated regions with substantially equal optical coupling strength. Further for equalizing light-beam intensities and minimizing optical dispersion loss, lenses may be included with the light-deflecting devices.

A light beam from an optical fiber held by waveguide support is guided to an illuminated region of a light-receiving section. A light beam from one light-deflecting device inside this region is reflected by a reflecting surface and passed as a light beam through a second light-deflecting device in another illuminated region to arrive at a second optical fiber. A light beam from the second optical fiber takes the reverse route to the foregoing route. In this way, various light-deflecting devices in one illuminated region are optically coupled to light-deflecting devices in other illuminated regions with substantially equal optical coupling intensity.

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Tokyo, Japan

Tetsuya Saitoh