Ricoh Company, Ltd.

Yamanashi Electronics Co., Ltd.

Hideki Nakamura

Eiji Kurimoto

Hajime Suzuki

Tadayoshi Uchida

Toshihiko Koizumi

Keisuke Shimoyama

Takaaki Ikegami

Kohsuke Yamamoto

Noboru Toriu

Tetsuya Sakuma

Takeshi Takada

Mitsuaki Hirose

Hiroki Orii

Tsuyoshi Ueda

Shuya Sugimoto

Kaori Harada

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

A photoconductor is used for an image-forming apparatus, and the photoconductor has a surface including irregularities having an arithmetic average roughness of 0.1 &#x3bc;m or more and 0.5 &#x3bc;m or less in a cycle length from 867 to 1,654 &#x3bc;m.

Photoconductor, image-forming apparatus, and cartridge

An electrophotographic photoconductor including: an electroconductive substrate; an intermediate layer; and a photoconductive layer, the intermediate layer and the photoconductive layer being on the electroconductive substrate, wherein the intermediate layer includes an inorganic pigment and a binder resin, wherein a volume ratio of the inorganic pigment in the intermediate layer is 30% by volume to 50% by volume, wherein the inorganic pigment comprises titanium oxide and a content of the titanium oxide in the inorganic pigment is 70% by mass to 90% by mass, wherein the inorganic pigment has a specific surface area of 70 m/g to 140 m/g, and wherein the intermediate layer has a volume resistivity at an electrical field intensity of 2.5&#xd7;10V/cm of 5&#xd7;10&#x3a9;&#xb7;cm to 1&#xd7;10&#x3a9;&#xb7;cm.

Electrophotographic photoconductor, electrophotographic apparatus and process cartridge

An electrophotographic photoconductor including a conductive substrate and a photoconductive layer thereover, wherein the photoconductive layer contains a charge generation agent and a charge transport agent represented by General Formula (A-I), (B-I) or (C-I), and an amine compound represented by General Formula (II):    

Electrophotographic photoconductor, and electrophotographic method, electrophotographic apparatus and process cartridge containing the electrophotographic photoconductor

An electrophotographic photoconductor including a conductive support and a photosensitive layer, wherein the photosensitive layer contains a charge generation agent, a charge transport agent and a binder resin, and wherein the charge generation agent contains an asymmetric disazo pigment represented by General Formula (I), the charge transport agent contains a triphenylamine compound represented General Formula (IX), and the mass ratio of the charge transport agent to the binder resin is 0.3 to 2.0,  where Rand Reach represent a substituted or unsubstituted alkyl group, alkoxy group, aryl group or heterocyclic group, provided that Rand Rare different,  where Rto Reach represent hydrogen, a halogen atom, an alkyl group having 1 to 6 carbon atoms, which may have a substituent, an alkoxy 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 and electrophotographic apparatus

An electrophotographic photoreceptor which can respond to a reduction in diameter of photoreceptor and a process having high circumferential speed, due to the demand in the miniaturization and increase in the speed of copiers and printers. The photoreceptor has high sensitivity in long-wavelength region, and is free from deterioration of electric characteristics even after repeated use, and is highly stable. The electrophotographic photoreceptor has a conductive support member and a photosensitive layer laminated thereon, which includes at least a charge-generating agent, a charge-transfer agent, and a binder resin. The charge-generating agent is oxytitanium phthalocyanine, which has a Bragg angle (2&#x3b8;&#xb1;0.2&#xb0;) providing a maximum peak at 27.2&#xb0; in the X-ray diffraction spectra using CuK&#x3b1; as a radiation source.

Electrophotographic photoreceptor and electrophotographic apparatus

Growing community of inventors

Yamanashi, Japan

Hideki Nakamura