Canon Kabushiki Kaisha

Momosuke Takaichi

Hitoshi Kanda

Kazuhiko Omata

Satoshi Mitsumura

Kazuyuki Miyano

Tadashi Sato

Takeshi Naka

Tsuneo Nakanishi

Yosuke Ata

Saki Tominaga

Kiyoshi Kanai

A developing roller has a conductive shaft member, a conductive elastic layer formed around the shaft member in a thickness of 0.5 mm to 6.0 mm, and a surface layer. The elastic layer contains carbon black and silicone rubber. The carbon black is in a content of 7% to 17% by mass and has at least two peaks in its particle size number distribution. The minimum diameter peak center in the particle size number distribution is within the range of 10 nm to 40 nm. The elastic layer has density within the range of 1.01 g/cmto 1.07 g/cm. Where the ratios of carbon atoms to silicon atoms (C/Si), in the vicinity of the surface of the elastic layer, at depths of 100 &#x3bc;m and 200 &#x3bc;m from the surface of the elastic layer are represented by X, Y and Z, respectively, the X, Y and Z satisfy a specific relationship.

Developing roller, process for producing developing roller, process cartridge and image forming apparatus

Coarsely crushed toner particles comprising at least a binder resin and a colorant are effectively pulverized by a mechanical pulverizer including a generally cylindrical rotor rotating about an axis and a stator surrounding the rotor with a minute gap from the rotor. Each of the outer wall of the rotor and the inner wall of the stator is provided with a plurality of grooves which extend generally in parallel with the rotation axis of the rotor and are formed of a wave-shaped plurality of projections and intervening recesses. Each recess on at least one of the rotor and the stator is provided with a flat-shaped bottom between a forward corner and a rear corner adjacent a forward slope and a rear slope respectively, with respect to the rotation direction. One corner (rear corner on the rotor or forward corner on the stator) of the two corners receiving an intense flow of the pulverized feed together with conveying air is provided with a dull angle between the adjacent slope and the flat-bottomed surface for effective pulverization.

Toner production system

A pneumatic pulverizer comprises an accelerating tube for carrying and accelerating powder to be pulverized with high-pressure gas and a pulverizing chamber for pulverizing the powder to be pulverized. The back end of the accelerating tube is provided with a pulverization powder feed port for feeding powder to be pulverized to the accelerating tube, the pulverizing chamber has an impact member having an impact surface opposed to the opening plane of the outlet of the accelerating tube, the and a side wall against which the powder to be pulverized that has been pulverized by the impact member collides to further pulverize. The closest distance from the side wall to a margin of the impact member, is shorter than the closest distance from the front wall of the pulverizing chamber opposed to the impact surface to the margin of the impact member, to prevent pulverized powder from fusing, coagulating, and getting coarser, and prevent localized abrasion of an impact surface the impact member and the accelerating tube.

Pneumatic impact pulverizer, fine powder production apparatus, and toner

A pneumatic pulverizer comprises an accelerating tube for carrying and accelerating powder to be pulverized with high-pressure gas and a pulverizing chamber for pulverizing the powder to be pulverized. The back end of the accelerating tube is provided with a pulverization powder feed port for feeding powder to be pulverized to the accelerating tube, the pulverizing chamber has an impact member having an impact surface opposed to the opening plane of the outlet of the accelerating tube, and a side wall against which the powder to be pulverized that has been pulverized by the impact member collides to further pulverize. The closest distance from the side wall to a margin of the impact member is shorter than the closest distance from the front wall of the pulverizing chamber opposed to the impact surface to the margin of the impact member to prevent pulverized powder from fusing, coagulating, and getting coarser, and prevent localized abrasion of an impact surface the impact member and the accelerating tube.

Pneumatic impact pulverizer system

Growing community of inventors

Nagareyama, Japan

Momosuke Takaichi