Fuji Xerox Co., Ltd.

Xerox Corporation

Koji Bando

Takahiro Suzuki

Hirofumi Nakamura

Hidemi Nukada

Sadao Okano

Seiji Ashiya

Masanori Murase

Masahiko Hodumi

Katsumi Nukada

Taketoshi Hoshizaki

Mitsuhide Nakamura

Nan-Xing Hu

Wataru Yamada

Masahiro Iwasaki

Kazuhiro Koseki

Shigeto Hashiba

Kenta Ide

Yu Qi

Ah-Mee Hor

Kenny-Tuan Dinh

Takayuki Yamashita

Takashi Yamada

Masahiko Miyamoto

Giuseppa Baranyi

Ryosaku Igarashi

Kazuya Hongo

Yoshiyuki Ono

Makoto Takemoto

Ichiro Takegawa

Michael E Zak

Hitoshi Takimoto

Yukiko Kamijo

Tetsuya Ezumi

Michiko Aida

Toru Asahi

Kaori Iemula

Yasuhiro Nida

An electrophotographic photoreceptor including a conductive substrate and a photosensitive layer provided on a surface of the conductive substrate, an outermost layer of the photosensitive layer containing a crosslinked product formed from at least one charge transporting material having at least one substituent selected from the group consisting of &#x2014;OH, &#x2014;OCH, &#x2014;NH, &#x2014;SH, and &#x2014;COOH and at least one selected from a guanamine compound or a melamine compound, the content of the at least one charge transporting material being at least about 90% by weight, and the content of the at least one selected from the guanamine compound or the melamine compound being from about 0.1% by weight to about 5% by weight.

Electrophotographic photoreceptor, process cartridge and image forming apparatus

According to an aspect of the invention, an electrophotographic photoreceptor including a conductive substrate and a photosensitive layer provided on a surface of the conductive substrate is provided. In the electrophotographic photoreceptor, an outermost layer of the photosensitive layer containing a crosslinked product formed from at least one charge transporting material having at least one substituent selected from the group consisting of &#x2014;OH, &#x2014;OCH, &#x2014;NH, &#x2014;SH, and &#x2014;COOH, an acidic substance, and at least one compound selected from the group consisting of compounds represented by the following formula (A) and compounds represented by the following formula (B). 

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An image carrier includes a conductive base material and a photosensitive layer formed on the base material. The photosensitive layer has an outermost surface layer that contains particles having a number-averaged particle sphericality represented by Formula (1) of approximately 0.7 or less: sphericality=4&#x3c0;A/L(1), where &#x3c0; represents the circular constant, A represents the projection area of the particle, and L represents the peripheral length of the projected particle image.

Image carrier, process cartridge and image-forming apparatus

An electrophotographic photoreceptor has at least an undercoat layer and a photosensitive layer formed on a conductive substrate, wherein the undercoat layer contains metal oxide fine particles and an electron acceptor compound having a group reactive with the metal oxide fine particles. A process cartridge and an electrophotographic apparatus use the electrophotographic photoreceptor.

Electrophotographic photoreceptor, process cartidge and electrophotographic apparatus

A charging roller including: a support; an elastic layer provided on the outer peripheral surface of the support, and having a ground-finished outer peripheral surface; and a surface layer formed to cover the outer peripheral surface of the elastic layer and that has a thickness of about 2 &#x3bc;m to about 10 &#x3bc;m from the outer peripheral surface of the elastic layer, and a proportion of water absorbed in the total of the elastic layer and the surface layer, after storage for 48 hours in an environment having a temperature of 10&#xb0; C. and a humidity of 15% RH, and after storage for 48 hours in an environment having a temperature of 28&#xb0; C. and a humidity of 85% RH, being about 2% to about 8% by weight, being about 2% to about 8% by weight.

Charging roller, electrophotographic process cartridge, and image forming apparatus

The invention provides an image forming apparatus comprising at least: an electrophotographic photoreceptor comprising at least a conductive substrate and a photosensitive layer provided on the conductive substrate; a charging device; an exposure device; a developing device; and a transfer device, wherein the exposure device is of a multi beam exposure system which has a surface emitting laser array having two or more light-emitting elements as an exposure light source and which scan the electrophotographic photoreceptor with plural light beams thereby forming electrostatic latent image, and wherein the outermost layer in the electrophotographic photoreceptor, positioned most distant from the conductive substrate, contains a silicon-containing resin containing at least a charge transporting compound or a characteristic group derived from a charge transporting compound, and having a structure in which bonds formed by crosslinking of an O atom with neighboring Si atoms are formed three dimensionally.

Image forming apparatus

An apparatus for forming an image is provided that can sufficiently prevent occurrence of nibbled images without any damage of the photoreceptor and the intermediate transfer body, whereby good image quality can be stably obtained for a long period of time. In an apparatus for forming an image having an intermediate transfer body, the surface of the photoreceptor has a dynamic hardness of 8&times;10 N/m or more, and the surface of the intermediate transfer body has a dynamic hardness larger than that of the surface of the photoreceptor, and a difference between the dynamic hardness of the surface of the photoreceptor and the dynamic hardness of the surface of the intermediate transfer material is 2&times;10 N/m or less.

Apparatus for forming image

An electrophotographic photoreceptor having, between an electroconductive substrate and a photosensitive layer, an interlayer which contains fine metal oxide particles and a binder resin and which, when an electric field of 10 V/m is applied thereto at 28&deg; C. and 85% RH, has a volume resistivity of from 10 to 10 &OHgr;&middot;cm and, when an electric field of 10 V/m is applied thereto at 15&deg; C. and 15% RH, has a volume resistivity which is up to 500 times the volume resistivity thereof as measured when an electric field of 10 V/m is applied thereto at 28&deg; C. and 85% RH.

Electrophotographic photoreceptor, processes for producing the same, process cartridge, and electrophotographic apparatus

A method for determining a termination time of the step of dispersing a coating composition for a photosensitive layer, containing a binder resin, a powdery charge generating material and a solvent, is disclosed, which comprises (i) providing coating (I) on a substrate by coating the coating composition, following by drying, (ii) providing coating (II) on a substrate by dispersing the coating composition using a dispersion medium to fine the powdery charge generating material, followed by drying, (iii) measuring absorbances of coating (I) at two wavelengths within a short wavelength region and a long wavelength region, respectively, of the spectral absorption wavelength of the charge generating material, (iv) measuring absorbances of coating (II) at the two wavelengthes within the short wavelength region and the long wavelength region, respectively, and (v) calculating spectral absorbance ratios of coatings (I) and (II), respectively, from the following equation: ##EQU1## wherein the dispersing of the coating composition is terminated when the ratio of the spectral absorbance ratio of coating (II) to that of coating (I) exceed a predetermined value.

Method for determining termination time of the step of dispersing a

An electrophotographic photoreceptor comprising a conductive substrate having thereon a photosensitive layer as the uppermost layer, in which the photosensitive layer contains two charge transporting materials different in ionization potential, a charge transporting material having a higher ionization potential is present in the amount equimolar to or in an amount less than the equimolar amount to the other charge transporting material having a lower ionization potential. A laminate type electrophotographic photoreceptor comprising a conductive substrate having thereon a charge generating layer and a charge transporting layer, in which the charge generating layer comprises a binder resin and a charge generating material dispersed therein, the charge transporting layer comprises a binder resin and at least two charge transporting materials including a first charge transporting material and a second charge transporting material, the amount of the first charge transporting material is at least 60 wt % based on the total amount of the charge transporting materials, the difference between the highest ionization potential and the lowest ionization potential the charge transporting materials is not more than 0.4 eV, provided that (1) the ionization potentials of all the charge transporting materials are lower than the ionization potential of the charge generating material, or (2) the ionization potential of the first charge transporting material is lower than the ionization potential of the charge generating material, and the ionization potential of the second charge transporting material is higher than the ionization potential of the charge generating material by at least 0.2 eV.

Electrophotographic photoreceptor

A novel method for preparing an electrophotographic photoreceptor is disclosed, which comprises laminating a charge generating layer and a charge transporting layer in this order on an electrically conductive substrate via an undercoating layer, wherein the coating solution for said undercoating layer contains an alkoxide coupling agent represented by formula (I), an aliphatic alcohol solvent containing at least the same number of carbon atoms as in the alkoxy group in said alkoxide coupling agent, and at least one compound selected from the group consisting of aromatic solvents, ethylene glycols and propylene glycols:

Method for preparing an electrophotographic photoreceptor

A novel electrophotographic photoreceptor is disclosed, comprising an undercoating layer provided on an electrically conductive substrate having thereon a light-sensitive layer, wherein the undercoating layer is obtained by coating a solution of a composition comprising zirconium and silicon or a solution of a mixture of a zirconium acetyl acetonate compound and a silane coupling agent, the silicon content in the composition comprising zirconium and silicon is in the range of 5 to 35 mol % based on the total amount of zirconium and silicon, and the hardened undercoating layer obtained from the zirconium acetyl acetonate compound and silane coupling agent is a layer having a hardening degree of 1.2 or less.

Electrophotographic photoreceptor having a zirconium and

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Kanagawa, Japan

Koji Bando