Ricoh Company, Ltd.

Semiconductor Energy Laboratory Co., Ltd.

Hiroshi Nagame

Narihito Kojima

Yohta Sakon

Hidetoshi Kami

Hiroshi Ikuno

Ryuta Takeichi

Akiyo Nakajima

Hiroshi Tamura

Tetsuro Suzuki

Naohiro Toda

Ryoichi Kitajima

Shunpei Yamazaki

Tatsuya Niimi

Shigenori Hayashi

Maiko Kondo

Yoshiaki Kawasaki

Katsuichi Ohta

Takashi Rokutanzono

Akiyo Namiki

Nozomu Tamoto

Akihiko Matsuyama

Eiji Kurimoto

Yukiko Iwasaki

Hiroyuki Fushimi

Yukio Ide

Mitsuru Seto

Ryohichi Kitajima

Yuka Miyamoto

Shinji Nousho

Naoki Hirose

Jun Aoto

Shinji Nohsho

Masao Yoshikawa

Kohichi Ohshima

Noriya Ishida

Junichi Takeyama

Minoru Umeda

Mari Sasaki

Kouichi Ohshima

Shinji Nosho

Yoshiaki Kwasaki

Maiko Kondoh

An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.0% by mass calculated from the following equation (1): 

Toner, developer, toner container and latent electrostatic image carrier, and process cartridge, image forming method, and image forming apparatus using the same

An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.0% by mass calculated from the following equation (1): where SF-2 denotes a shape factor of the toner.

An electrophotographic photoconductor includes an electroconductive substrate, a photoconductive layer arranged over the electroconductive layer with or without the interposition of an undercoat layer, and a surface top layer containing a crosslinkable resin arranged over the photoconductive layer, the photoconductive layer includes a charge generation layer containing a charge generating material, and a charge transport layer containing a charge transporting material, in which the surface top layer is substantially free from hydroxyl groups and residual uncured portions.

Electrophotographic photoconductor, preparation method thereof, electrophotographic apparatus and process cartridge

An image forming apparatus, including an electrophotographic photoreceptor including: an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protective layer overlying the photosensitive layer and serving as an outermost layer, wherein the protective layer has an average abraded thickness not greater than 1 &#x3bc;m after the electrophotographic image forming apparatus produces 100,000 images; a charger charging the electrophotographic photoreceptor; an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; a transferer transferring the toner image onto a transfer sheet; and a cleaner cleaning a surface of the electrophotographic photoreceptor, wherein the cleaner comprises a cleaning brush impregnated with a resin.

Image forming apparatus and image forming method

An image forming apparatus includes a photoconductor having a surface with a frictional resistance ranging from 45 gram-force to 200 gram-force, a 10-point average roughness RzJIS ranging from 0.1 mm to 1.5 mm or a maximum height Rz of 2.5 mm. Image formation is performed by the image forming apparatus to allow irregular-shaped toner or spherical toner to be cleaned off efficiently and any background stain on a copied sheet to be prevented. A lubricant is applied to the photoconductor so as to form a nonuniform film thereon, which prevents the frictional resistance from abnormally lowering, thus suppressing image degradation.

Measurement of frictional resistance of photoconductor against belt in image forming apparatus, process cartridge, and image forming method

An electrophotographic photoreceptor including a photosensitive layer on an electroconductive substrate, wherein nitrate ion is present on the surface of the photosensitive layer in an amount of from 50 to 300 &#x3bc;g per 1 mof the surface of the photosensitive layer when the nitrate ion is determined by an ion chromatographic method. Preferably a material having a fluorine atom and a carbon atom or a fatty acid metal salt such as zinc stearate is further present on the surface of the photosensitive layer such that the F/C ratio is from 0.05 to 0.5 or the Zn/C ratio is from 0.001 to 0.1. An image forming apparatus using the photoreceptor is also provided.

Electrophotographic photoreceptor and image forming apparatus using the photoreceptor

An image-forming apparatus which includes an image developer configured to develop a latent electrostatic image and to have a developer, a developer bearing member which has a magnet therein, has the developer on a surface thereof, and rotates with carrying the developer, and a developer limiting member which faces the developer bearing member, and controls an amount of the developer, and a latent electrostatic image support configured to contain a filler in its outermost layer. In the image-forming apparatus, the developer is a double-component developer which contains a magnetic carrier and a toner, the magnetic carrier has a coating layer which is formed of a binder resin having particles retained on a surface of the magnetic carrier, and a ratio of a particle diameter Dof the particles to a film thickness hof the binder resin satisfies a relation of: 1&#x3c;D/h

Image-forming apparatus and image-forming process-cartridge

An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &#x3c3;&#x2266;D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &#x3bc;m wide when a portion of a cross section of the photoreceptor of 100 &#x3bc;m wide is divided into the 20 segments, and &#x3c3; represents a standard deviation of the 20 maximum thicknesses.

Electrophotographic photoreceptor, method for manufacturing the photoreceptor, and image forming method and apparatus using the photoreceptor

An electrophotographic drum-shaped photoconductor has an electroconductive support and a photoconductive layer formed thereon, with a lubricating material being applied to the surface thereof in the shape of a plurality of bands spaced therebetween, constituting band-shaped lubricating material applied areas, extending along a circumference of the drum-shaped photoconductor in the direction perpendicular or substantially perpendicular to an axis of rotation of the drum-shaped photoconductor. An electrophotographic image formation method and an image forming apparatus employing the above-mentioned drum-shaped photoconductor are also disclosed.

Electrophotographic drum-shaped photoconductor and image forming method and apparatus using the same

An image forming apparatus including a photoreceptor configured to bear an electrostatic latent image while rotating in a direction, wherein the photoreceptor includes an electroconductive substrate, a photosensitive layer located overlying the substrate, and a protective layer located overlying the photosensitive layer and including a filler; a latent image former configured to form the electrostatic latent image on the photoreceptor; an image developer configured to develop the electrostatic latent image with a developer including a toner; an image transfer device configured to transfer the toner image onto a receiving material; a cleaner configured to remove the toner remaining on the surface of the photoreceptor while contacting the surface of the photoreceptor; and a surface condition controller configured to control a surface condition of the photoreceptor.

Electrophotographic image forming method and apparatus

An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &sgr;&lE;D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &mgr;m wide when a portion of a cross section of the photoreceptor of 100 &mgr;m wide is divided into the 20 segments, and &sgr; represents a standard deviation of the 20 maximum thicknesses.

An electrophotographic photoreceptor including a photosensitive layer on an electroconductive substrate, wherein nitrate ion is present on the surface of the photosensitive layer in an amount of from 50 to 300 &mgr;g per 1 m of the surface of the photosensitive layer when the nitrate ion is determined by an ion chromatographic method. Preferably a material having a fluorine atom and a carbon atom or a fatty acid metal salt such as zinc stearate is further present on the surface of the photosensitive layer such that the F/C ratio is from 0.05 to 0.5 or the Zn/C ratio is from 0.001 to 0.1. An image forming apparatus using the photoreceptor is also provided.

An electrophotographic photoreceptor including an electroconductive substrate and a photoreceptive layer, which is formed overlying the substrate, wherein the photoreceptive layer includes a charge carrier generation layer including a charge carrier generation material and a charge carrier transport layer including a charge carrier transport material, and wherein when an electric field of from 2.5&times;10 V/cm to 5.5&times;10 V/cm is applied to the charge carrier transport layer, the relationship, t /&mgr; &lE;1.5&times;10 V&middot;s/m, is satisfied, wherein t represents a thickness of the charge carrier transport layer and &mgr; represents a charge mobility of the charge carrier transport layer.

Electrophotographic photoreceptor and electrophotographic image forming method and apparatus using the photoreceptor

A lubricity-imparting unit for imparting lubricity to a surface of an electrophotographic photoconductor, which is in contact with the surface of the photoconductor, wherein at least a surface of the lubricity-imparting unit which comes into contact with the surface of the photoconductor includes a flexible lubricating material, and has a length at least capable of covering an image formation region of the electrophotographic photoconductor lengthwise. An image formation apparatus and an image formation method using this lubricity-imparting unit are described.

Unit for imparting lubricity to electrophotographic photoconductor, electrophotographic image formation apparatus including the unit, and image formation method using the apparatus

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Numazu, Japan

Hiroshi Nagame