Ricoh Company, Ltd.

Ricoh UK Products Ltd.

Fumitoshi Murakami

Nobuyasu Makino

Mutsumi Takahashi

Makoto Hirai

Tohru Suganuma

Masakazu Nakada

Eiichi Masushio

Colin Weaver

David Roberts

Tsutomu Kagawa

An air classifier contains a cylindrical casing provided with at an upper part thereof a feed port to feed high pressure air and a powder material, an umbrella-shaped center core in the casing, and an umbrella-shaped separator core arranged downstream of the center core in the casing and including an opening at center thereof. The air classifier has a configuration containing a dispersion chamber to disperse the powder material, being surrounded by an inner wall of the upper part casing and the center core, and a classification chamber to classify the powder material into fine and coarse powders by centrifugation, being surrounded by the center core, separator core and inner wall of the casing. In the dispersion chamber provided are a louver ring containing guide slats circularly arranged at regular intervals, and a space encircling the louver ring and serving as flow passage of the air and powder material.

Air classifier

A toner manufacturing process, includes: melting a kneaded composition, to thereby obtain a melted composition; and spraying the melted composition with a high pressure gas, to thereby form a fine particle. The kneaded composition is selected from the group consisting of the following &#x3c;1&#x3e;, &#x3c;2&#x3e; and &#x3c;3&#x3e;: &#x3c;1&#x3e; a first kneaded composition including a binder resin, a colorant, and a charge controlling agent, &#x3c;2&#x3e; a second kneaded composition including a binder resin, a colorant, a charge controlling agent, and a releasing agent, and &#x3c;3&#x3e; a third kneaded composition including a binder resin, a magnetic agent, a charge controlling agent, and a releasing agent.

Toner, process of manufacturing toner, developer, toner container, process cartridge, image forming apparatus, and image forming process

A toner includes toner particles which have a binder resin and a colorant. The toner has a weight average particle diameter of from 4 to 7 &#x3bc;m and includes toner particles having a circle equivalent diameter of from 0.6 to 2.0 &#x3bc;m in an amount not greater than 5% by quantity, toner particles having a particle diameter of from 3.17 to 4.00 &#x3bc;m in an amount of from 10 to 40% by quantity, toner particles having a diameter of from 4.00 to 5.04 &#x3bc;m in an amount of from 20 to 40% by quantity, and toner particles having a diameter not less than 12.7 &#x3bc;m in an amount of from 0 to 1.0% by weight. The toner satisfies the following relationship: 1.04&#x2266;D/D&#x2266;1.30, wherein Drepresents the weight average particle diameter and Drepresents a number average particle diameter of the toner.

Toner, developer, image forming method, image forming apparatus and toner manufacturing method

A fluidized bed pulverizing and classifying apparatus is disclosed having a vessel that includes a pulverizing section having a pulverizing nozzle spraying compressed air to pulverize a powder, a classifying section located over the pulverizing section, including a classifying rotor classifying the powder, and a fluidized bed. The vessel also contains a supply of secondary air.

Fluidized bed pulverizing and classifying apparatus, and method of pulverizing and classifying solids

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Fuji, Japan

Fumitoshi Murakami