Canon Kabushiki Kaisha

Canon Kasei Kabushiki Kaisha

Mitsuru Okuda

Yoshinobu Ogawa

Ryo Sugiyama

Hiroshi Imasaka

Satoshi Fukuzawa

Erika Umeki

Kazutoshi Ishida

Jun Miura

Yuji Sakurai

Kazuhiro Okubo

Takaaki Shinkawa

Masayuki Takahashi

Erika Uematsu

Hiroshi Morishita

Masayuki Hashimoto

Sinya Tokitou

To provide a developer regulating member which can generate a uniform frictional charge even on a developer having a small size. A developer regulating member for regulating the thickness of the layer of a developer carried on the surface of a developer carrier, having: a regulating portion contacting with the developer, wherein the regulating portion includes a thermoplastic acrylic resin, and the thermoplastic acrylic resin has a first endothermic peak having a peak top at +50&#xb0; C. or more and a second endothermic peak having a peak top at +20&#xb0; C. or less on the differentiation curve of a DSC curve obtained when the temperature is raised from &#x2212;100&#xb0; C. to 150&#xb0; C. at a rate of temperature rise of 20.0&#xb0; C./min using differential scanning calorimetry (DSC).

Developer regulating member, developing device, process cartridge and electrophotographic image forming apparatus

A developing apparatus includes a developer carrying member, a developing frame member to rotatably supporting the developer carrying member, and a regulating member provided on the developing frame member and regulating developer carried on the developer carrying member. The regulating member includes a projecting part projected towards the developer carrying member and having an abutting part that abuts the developer carrying member, and an opposing surface facing the developer carrying member. The opposing surface is positioned on an upstream side of the projecting part and arranged to connect the projecting part with a distal end of the regulating member at a free end side of the regulating member. In addition, the opposing surface is a surface having no point of reverse curve, and the distance between the opposing surface and the developer carrying member is constant or decreasing with distance from the projecting part.

Developing apparatus having a projecting regulating member and process cartridge

A developing apparatus includes a developer carrying roller rotatable in a first rotating direction, and a developer regulating member which controls a thickness of a developer layer carried on a surface of the developer carrying roller. The developer regulating member has a developer layer thickness regulating part abutting with the surface of the developer carrying roller and a projecting part. The projecting part extends towards an upstream side in the first rotating direction from the abutting part, and a non-contacting gap is formed between the projecting part and the surface of the developer carrying roller. The projecting part has a concave shape at a side facing the developer carrying roller that follows an arc-shaped surface of the developer carrying roller and forms a portion having a gap width H and a continuous length L.

Developing apparatus having multi-part regulating member, process cartridge and electrophotographic image forming apparatus

The developing apparatus includes a developer carrying roller rotatable in a first rotating direction, and a developer regulating member which regulates a thickness of a developer layer carried on the developer carrying roller, wherein at least a part of the developer regulating member is in pressure contact with a surface of the developer carrying roller to form an abutting portion between the developer carrying roller and the developer regulating member, the abutting portion having an abutting width W in a circumferential direction of the developer carrying member of 1.0 to 5.0 mm, wherein in the abutting portion, an abutting pressure has a maximum value in a first area, the first area having a width of 20% or less of the abutting width W from an upstream edge of the abutting portion in the rotating direction, and wherein an abutting pressure in a second area is 0.08 to 0.18 MPa.

Developing apparatus, process cartridge and electrophotographic image forming apparatus

The developing apparatus includes: a developing roller rotatable in a first rotation direction; and a developer regulating member, wherein the developing roller includes: a substrate; an electro-conductive elastic layer on the substrate; and insulating domains on the electro-conductive elastic layer, wherein the electro-conductive elastic layer has a certain Martens hardness, the developing roller has a surface including surfaces of the insulating domains and a surface of the electro-conductive elastic layer, which is uncovered with the insulating domains at a certain area ratio, wherein the developer regulating member comprises: an abutting portion which is in contact with the surface of the developing roller, and a certain projection portion extending to an upstream side from the abutting portion in the first rotation direction, the developing apparatus has a certain gap between a side of the projection portion facing to the developing roller, and the surface of the developing roller.

Developing apparatus, electrophotographic process cartridge, and electrophotographic image forming apparatus

A developer quantity control blade is provided which can sufficiently impart charge to toner and which allows bleeding of a material from a blade member to be suppressed even in application of a voltage. The developer quantity control blade includes a supporting member and a blade member, wherein the blade member is composed of a thermoplastic elastomer composition including a block copolymer having a polyamide structure and a polyether structure, and an ion conductive agent; in the blade member, a quantity of an extraction component to be extracted with methyl isobutyl ketone as a solvent is 0.5% by mass or more and 2.4% by mass or less; and a quantity of a molecule having a molecular weight of 5000 or less in the extraction component is 70% by mass or more.

Developer quantity control blade having blade member composed of a thermoplastic elastomer composition and image forming apparatus

This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Process for producing conductive rubber roller, and roller for electrophotographic apparatus

A process for producing a conductive rubber roller having a conductive core material and a rubber layer provided thereon. The rubber layer contains at least acrylonitrile rubber, epichlorohydrin rubber and a blowing agent, and has a gas generation rate of from 2 ml/g&#xb7;min to 4 ml/g&#xb7;min at 170&#xb0; C. to 230&#xb0; C. The process has a vulcanizing and foaming step of vulcanizing and foaming the rubber layer by using a microwave vulcanizing furnace which provides hot air and irradiation with microwaves. A temperature of a heating atmosphere in the microwave vulcanizing furnace in the vulcanizing and foaming step is so controlled that a ratio of initial vulcanizing time T10 to initial foaming time Tp10, T10/Tp10, of the rubber layer is from 1 or more to less than 3 and the T10 is within 90 seconds.

A process produces a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press fitted into the foamed rubber tube without using any adhesive.

In a conductive rubber roller including a conductive support and a rubber layer, the rubber layer includes a component (A), an epichlorohydrin rubber containing 40 mol % or more of ethylene oxide, and a component (B), an acrylonitrile butadiene rubber component having an acrylonitrile content of 20% by weight or less. The component (A) is in a proportion of 5 or more to less than 25 in weight ratio, based on a total weight of the components (A) and (B).

Growing community of inventors

Suntou-gun, Japan

Mitsuru Okuda