Konica Corporation

Konica Minolta Business Technologies, Inc.

Konica-minolta Holdings, Inc.

Takeo Oshiba

Akihiko Itami

Kazuhisa Shida

Tomoo Sakimura

Yohko Kitahara

Yoshihiko Etoh

Masahiko Kurachi

Satoshi Uchino

Okushi Okuyama

Yoshiaki Takei

Asao Matsushima

Nobuaki Kobayashi

Kouichi Sugama

Masahiro Anno

Hiroshi Yamazaki

Naoto Abe

Toyoko Shibata

Hirofumi Hayata

Shinya Obara

Fumitaka Mochizuki

Yoshio Takizawa

Shinichi Suzuki

Akira Kinoshita

Masao Asano

Osamu Sasaki

Naohiro Hirose

Ryuichi Hiramoto

Tomoko Suzuki

Katsumi Matsuura

Eiichi Sakai

Yoshihiko Eto

Kimiyuki Itou

So Matsuya

Chikusa Fukumoto

Naoto Abew

Syozo Mitsui

Provide is an electrophotographic photoreceptor exhibiting excellent evenness of halftone images together with fine line reproduction, and an image forming method thereof, as to a photoreceptor in which an oxytitanium phthalocyanine pigment having a maximum diffraction peak at a Bragg angle (2&#x3b8;&#xb1;0.2&#xb0;) of 27.2&#xb0; in CuK&#x3b1; X-ray diffraction. Also disclosed is an electrophotographic photoreceptor possessing a body having cylindrical conductive support provided thereon photosensitive layer containing oxytitanium phthalocyanine pigment having maximum diffraction peak at a Bragg angle (2&#x3b8;&#xb1;0.2&#xb0;) of 27.2&#xb0; in CuK&#x3b1; X-ray diffraction, and flanges jointed at both ends of the body, wherein at least one of flanges is fitted with driving shaft having drive hole having at least 3 sides, and a ratio B/A of cross-sectional area B of engaging part of rotation shaft to rotate the electrophotographic photoreceptor with respect to cross-sectional area A of the drive hole is 0.890-0.998.

Electrophotographic photoreceptor and image forming method

An electrophotographic image forming method is disclosed. The method includes steps of conveying a developer comprising a toner to a developing zone by a developing roller, and developing an electrostatic latent image formed on an electrostatic latent image carrying member by the developer, and the developing roller has an electroconductive shaft and a resin layer provided around the shaft, the resin layer comprises a surface layer containing silicone copolymer resin as the principal component and a layer containing resin-silica hybrid composite as a principal component provided directly under the surface layer.

Image forming method using the same

An objective is to provide a developing roller in which increase of residual potential is inhibited during repetitive operation without deteriorating adhesion to an elastic layer, scattering and leakage of toner are prevented, appropriate elasticity is exhibited and a resin layer capable of preventing uneven charging of toner and image unevenness is prepared, and also to provide a image forming method employing the developing roller. Disclosed is a developing roller possessing an elastic layer made of silicone rubber provided around a conductive shaft, and a resin layer further provided on the elastic layer, wherein the resin layer contains polyurethane resin-silica hybrid as a principal component.

Developing roller and image forming method employing the same

A developing roller comprising: a shaft comprising an aluminum alloy; and a coating layer directly formed on a periphery of the shaft, the coating layer comprising a conducting agent and a binder comprising a resin, wherein the aluminum alloy comprises 0.2 to 0.8% by mass of silicon and 0.05 to 1.5% by mass of maganese, based on the total mass of the aluminum alloy.

Electrophotograph developing roller and developing apparatus employing the same

An objective is to provide a developing roller in which increase of residual potential is inhibited during repetitive operation without deteriorating interlayer adhesion, and prepared is a layer immediately below the surface capable of preventing fog caused by toner scattering, accompanied with a surface layer capable of preventing stains formed from foreign matters adhered to the surface, as well as preventing image unevenness since toner electrification is even under the presence of appropriate elasticity, and also to provide a image forming method employing the developing roller. Disclosed is a developing roller possessing an elastic layer made of silicone rubber provided around a conductive shaft, and a plurality of resin layers further provided on the elastic layer, wherein an outermost surface layer among the resin layers comprises silicone copolymerization polyurethane; and a layer immediately below the surface layer comprises a polyurethane resin-silica hybrid.

Provided are a developing roller for non-magnetic single component development and a developing method employing the developing, by which toner can be stably conveyed in any external environment, and the stable toner conveyance and charging amount can also be acquired. Also disclosed is a developing roller possessing a spindle and provided around an outer circumference of the spindle, at least an elastic layer (innermost layer), a resistance adjusting layer (intermediate layer) formed on the elastic layer and a surface layer (outermost layer) formed on the resistance adjusting layer, wherein the intermediate layer possesses a layer containing carbon black in a resin, a content of a polycyclic aromatic hydrocarbon in the carbon black is at most 10 ppm, and a volume resistance (Rv) of all the layers provided around the outer circumference of the spindle is 1.0&#xd7;10&#x2212;1.0&#xd7;10&#x3a9;&#xb7;cm.

Developing roller and developing method thereof

An image forming method which can provides excellent cleaning property, no occurrence of unusual noise or curling of a blade, and a high quality image. The method includes forming a latent image on a cylindrical electrophotographic photoconductor including a mass additive therein; and developing the latent image with a developer comprising a toner, wherein the toner comprises a ratio (Dv50/Dp50) of a 50% volume particle size (Dv50) to a 50% number particle size (Dp50) of 1.0 to 1.15, a ratio (Dv75/Dp75) of a cumulative 75% volume particle size (Dv75) from a larger volume particle size to a cumulative 75% number particle size (Dp75) from a larger number particle size of 1.0 to 1.20, and the number of toner particles having a particle size of 0.7&#xd7;(Dp50) or less in an amount of not greater than 10 number %.

Image forming method

An image forming method is disclosed. The method comprises processes in which a latent image on an electrophotographic photoreceptor is developed employing a developer material, and after transferring the visualized toner image to a recording material, the remaining toner on said photoreceptor is removed employing an elastic body cleaning blade. The electrophotographic photoreceptor comprises a surface layer containing a charge transportable polysiloxane hardenable resin, and said developer material comprises a fatty acid metal salt.

An electrophotographic photoreceptor is disclosed. The charge transport material comprising a mixture of stereoisomers as a charge transport material and glass transition point Tgb of the binder resin of the charge transport layer and glass transition point Tgl of the charge transport layer satisfy100&#xb0; C.&#x3c;1&#x3c;(bothandin &#xb0; C.). An image forming method employing the photoreceptor is also disclosed.

Organic photoreceptor and image forming method

An electrophotographic photoreceptor is disclosed. The charge transport material comprising a mixture of stereoisomers as a charge transport material and glass transition point Tgb of the binder resin of the charge transport layer and glass transition point Tg1 of the charge transport layer satisfy100&#xb0; C.&#x3c;Tg1 &#x3c;Tgb (both Tgb and Tg1 in &#xb0; C.). An image forming method employing the photoreceptor is also disclosed.

A method of forming a toner image is disclosed. The photoreceptor is installed so that the center axis of the cylinder is to be almost horizontal, front edge of the cleaning blade is pressed against surface of the photoreceptor at the top, ratio of width of the photosensitive layer of the photoreceptor to length of the cylindrical electroconductive substrate is 80/100 to 99/100, and a number ratio of toner particles having a shape coefficient of 1.2 to 1.6 is at least 65 percent in the toner particles.

An electrophotographic image carrier is disclosed. The image carrier has a photoreceptor made from a photoreceptive layer and a resin layer. The resin layer is made of a siloxane resin having a cross-linked structure, and contains an anti-oxidant.

Electrophotographic image carrier and image forming apparatus, image forming method and processing cartridge using it

An electrophotographic photoreceptor is disclosed. The photoreceptor has a difference in ionization potential between the photosensitive layer and the hardenable resinous layer of not more than 0.4 eV, and a response time T defined in the specification is not more than 0.25 second. An image forming method and apparatus employing the photoreceptor are also disclosed.

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Tokyo, Japan

Takeo Oshiba