Ricoh Company, Ltd.

Mitsuaki Hirose

Akihiro Sugino

Yoshiaki Kawasaki

Tomoharu Asano

Hideo Nakamori

Nozomu Tamoto

Noboru Toriu

Daisuke Inoue

Yoshiki Yanagawa

Keisuke Shimoyama

Kenji Komito

Yohichi Kitagawa

Masayuki Ukigaya

Hiroshi Yamada

Yohta Sakon

Akio Kosuge

Hiroshi Ikuno

Makoto Yasuda

Masahiro Ohmori

Tetsuya Toshine

Tadayoshi Uchida

Hideki Nakamura

Daisuke Kubo

Hiroshi Hashiguchi

Shuya Sugimoto

Kaori Harada

Susumu Muramatsu

Katsuo Kuribayashi

Shoichi Wakabayashi

A toner is provided. The toner comprises toner particles each comprising a toner base particle and an external additive. The toner base particle comprises a binder resin and a colorant. The toner satisfies the following conditions (a) and (b):

Toner, developer, toner accommodating unit, image forming apparatus, and image forming method

A toner is provided. The toner comprises toner base particles, resin particles adhered to surfaces of the toner base particles, and an external additive adhered to the surfaces of the toner base particles. The toner base particles each comprising a binder resin, a colorant, and a wax. The toner has a storage elastic modulus G' of 4.0×10or less at 70° C. An embedment degree of the external additive is from 15% to 40%, as the embedment degree is measured by stirring 10 g of the toner and 20 g of a carrier in a 50-mL vial at 67 Hz for 60 minutes using a rocking mill.

Toner, method for manufacturing the toner, toner accommodating unit, image forming apparatus, and image forming method

An electrophotographic photoconductor is provided that includes a conductive substrate, an undercoat layer overlying the conductive substrate, and a photosensitive layer overlying the undercoat layer. The undercoat layer contains zinc oxide particles and a binder resin and has a volume resistivity of 0.03&#xd7;10&#x3a9;&#xb7;cm or less in an electrical field of 5 V/&#x3bc;m at a temperature of 23 degrees C. and a relative humidity of 55%. The photosensitive layer contains a compound represented by the following general formula (1): where each of Rto Rindependently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.

Electrophotographic photoconductor, image forming apparatus, and process cartridge

Provided is an electrophotographic photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, wherein the undercoat layer and the photoconductive layer are provided over the conductive support in the order of reciting, wherein the undercoat layer contains at least metal oxide particles, a binder, and a salicylic acid derivative such as 4-methylsalicylic acid, wherein the metal oxide particles have a volume resistivity of 1&#xd7;10&#x3a9;&#xb7;cm or higher but 1&#xd7;10&#x3a9;&#xb7;cm or lower, wherein the undercoat layer has a volume resistivity of 0.001&#xd7;10&#x3a9;&#xb7;cm or higher but 0.02&#xd7;10&#x3a9;&#xb7;cm or lower, and wherein the undercoat layer has a thickness of 2 micrometers or greater but 20 micrometers or less.

A photoconductor is provided. The photoconductor includes a cylindrical conductive support, a water-repellent resin film, a coating film, and a flange. The cylindrical conductive support has an end part having an inner circumferential surface having a surface roughness Rz of from 3 to 10 &#x3bc;m. The water-repellent resin film is on the inner circumferential surface of the end part of the cylindrical conductive support. The coating film is on an outer circumferential surface of the cylindrical conductive support. The flange has a cylindrical fitting part having an outer circumferential surface secured to the inner circumferential surface of the end part of the cylindrical conductive support.

Photoconductor, image forming apparatus, process cartridge, and method of manufacturing photoconductor

In a photoreceptor including an electroconductive substrate; a photosensitive layer; and a protective layer, the protective layer includes a crosslinked resin having a residual group of a polycarboxylic acid compound and a group having the below-mentioned formula (10), and at least one of a compound having the below-mentioned formula (2) and a compound having the below-mentioned formula (3). wherein each of R5 and R6 independently represents a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms. wherein each of Rand Rindependently represents a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, and Zrepresents a vinylene group, a divalent aromatic hydrocarbon group having 6 to 14 carbon atoms, or a 2,5-thiophenediyl group. wherein each of Arand Arindependently represents an aromatic group having 6 to 14 carbon atoms, Zrepresents a divalent aromatic hydrocarbon group having 6 to 14 carbon atoms, and each of Rand Rindependently represents a hydrogen atom, or a methyl group.

Photoreceptor, method for preparing photoreceptor, and image forming apparatus and process cartridge using the photoreceptor

An image forming apparatus, including a photoreceptor; a charger; an irradiator; an image developer; a transferer; a fixer; and a cleaning blade formed of a strip-shaped elastic blade, removing a powder from the surface of the photoreceptor passing an edge line of the blade while contacting thereto, wherein the photoreceptor includes a crosslinked resin surface layer formed of at least one of an acrylic resin and a methacrylic resin, and the cleaning blade includes a contact point with the photoreceptor, including a substrate; a mixed layer formed of at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.

Image forming apparatus and process cartridge

A photoreceptor including an electroconductive substrate; a photosensitive layer, which is located overlying the electroconductive substrate and which includes a charge generation material, a charge transport material having no radical polymerizability, a binder resin having no radical polymerizability, and a crosslinked polymer including a unit obtained from a first radically polymerizable monomer having three or more functional groups and no charge transport structure and a unit obtained from a second radically polymerizable monomer having a charge transport structure; and an outermost layer, which is located on the photosensitive layer and which includes a crosslinked polymer including a unit obtained from a third radically polymerizable monomer having three or more functional groups and no charge transport structure and a unit obtained from a fourth radically polymerizable monomer having a charge transport structure. An image forming method and apparatus, and a process cartridge using the photoreceptor.

Electrophotographic photoreceptor, method for preparing the electrophotographic photoreceptor, and image forming method and apparatus and process cartridge using the electrophotographic photoreceptor

A photoreceptor including an electroconductive substrate; a photosensitive layer on the electroconductive substrate; and a protection layer on the photosensitive layer, wherein the protection layer includes a radical polymerizable compound having three or more radical polymerizable groups without a charge transportable group, a monofunctional radical polymerizable compound having a specific charge transportable group and a non-radical polymerizable compound having a specific charge transportable group.

Photoreceptor, process cartridge and image forming apparatus

A method of manufacturing an image bearing member including forming a charge generation layer overlying an electroconductive substrate, forming a charge transport layer overlying the charge generation layer, the charge transport layer including a charge transport material having a molecular weight of from 600 to 900 and a binder resin, and forming a protection layer overlying the charge transport layer by applying a liquid application containing a polymerizable compound having a charge transport structure, a polymerizable compound having no charge transport structure, a filler, a polycarboxylic acid compound, and cyclopentanone and curing the polymerizable compound having a charge transport structure, and the polymerizable compound having no charge transport structure.

Method of manufacturing image bearing member, image bearing member, and image forming apparatus

An image bearing member including an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protection layer overlying the photosensitive layer, the photosensitive layer containing a diamine compound represented by the chemical structure 1, more of the diamine compound being disposed on the photosensitive layer side than the surface side relative to the midpoint in a depth direction of the protection layer:  

Image bearing member, image forming apparatus, and process cartridge

The present invention provides an image forming apparatus which is equipped with at least a latent electrostatic image forming unit, a developing unit, a transferring unit, and a fixing unit, wherein the transferring unit is configured to apply a positive electric potential to a visible image formed on the latent electrostatic image bearing member via a recording medium, the latent electrostatic image member has a surface layer which comprises a hardened material hardened by irradiating at least a trifunctional or more radical polymerizable compound having no charge transporting structure, a radical polymerizable compound having a charge transporting structure, and a reactive silicone compound having any one of an acryloyloxy group and a methacryloyloxy group, and the concentration of the reactive silicone compound is varied in between the surface part and the innerlayer part of the surface layer.

Image forming apparatus, image forming method, and process cartridge

An image forming apparatus including an image bearing member having an electroconductive substrate on which are provided at least a photosensitive layer and a protection layer, in that sequence, a charging device that charges the surface of the image bearing member to form a latent electrostatic image thereon, a development device that develops the latent electrostatic image with a development agent containing toner to obtain a developed toner image, a cleaning device that removes toner remaining on the surface of the image bearing member and a lubricant material applicator that applies a lubricant material to the surface of the image bearing member, the protection layer containing a cured resin and a filler and the surface form of the protection layer having an arithmetical mean waviness Wa of from 0.05 to 0.3 &#x3bc;m and an average length WSm of profile elements of from 0.5 to 1.5 mm, which are obtained from a waviness profile obtained by filtering a coarse component with a &#x3bb;c profile filter of 0.25 mm and filtering a wavelength component longer than a waviness with a &#x3bb;f profile filter of 2.5 mm.

Image forming apparatus, process cartridge, and image bearing member

There is provided a temperature control unit for an electrophotographic photoconductor substrate, containing a stretchable membrane member which is detachably disposed in a hollow space of the cylindrical substrate, wherein the membrane member is configured to sequentially stretch until reaching the deepest part of the hollow space of the cylindrical substrate as a result of an introduction of a refrigerant therein to closely contact with an entire inner wall of the cylindrical substrate, and to sequentially shrink to the original shape thereof as a result of a release of the refrigerant therefrom, so that the membrane member is detachably disposed in the hollow space, and wherein the membrane member is configured to make a heat transfer between a surface of the cylindrical substrate and the refrigerant via the membrane member closely contacted with the inner surface of the cylindrical substrate, to control a surface temperature of the cylindrical substrate.

Temperature control unit for electrophotographic photoconductor substrate

An electrophotographic photoreceptor, including:

Electrophotographic photoreceptor and method of preparing the photoreceptor, and image forming method, image forming apparatus and process cartridge therefor using the photoreceptor

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Shizuoka, Japan

Mitsuaki Hirose