Kyocera Mita Corporation

Kyocera Document Solutions Inc.

Mita Industrial Co., Ltd.

Kazunari Hamasaki

Yuko Iwashita

Daisuke Kuboshima

Keiji Maruo

Kazutaka Sugimoto

Jun Azuma

Yukimasa Watanabe

Yasufumi Mizuta

Keizo Kimoto

Yoshio Inagaki

Norio Nakai

Eiichi Miyamoto

Hideki Okada

Fumio Sugai

Sakae Saito

Hirofumi Kawaguchi

Tetsuya Ichiguchi

Hiroshi Takemoto

Hisakazu Honma

Syoji Itsumi

Shiho Kuboshima

Mikio Kakui

Yuichi Yoshida

Susumu Hiroshima

Akihiko Kawahara

Yasuhiro Oishi

Ayako Yashima

Nobuko Akiba

Mitsuo Ihara

Kazuaki Ezure

An electrophotographic photosensitive member includes a conductive substrate, an intermediate layer provided on the conductive substrate, and a photosensitive layer provided on the intermediate layer. The intermediate layer contains a specific polyamide resin and specific inorganic particles. The specific inorganic particles each include a metal oxide particle and a surface treatment layer covering at least a part of the surface of the metal oxide particle. The surface treatment layers contain a component derived from an organic siloxane compound and at least one of aluminum oxide and silica. The specific polyamide resin includes a first repeating unit derived from an aliphatic dicarboxylic acid with a carbon number of at least 8 and no greater than 20 and a second repeating unit derived from a diamine compound with a cycloalkane structure.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a compound represented by chemical formula (1-1) or (1-2). The photosensitive layer further contains an n-type pigment. The n-type pigment is preferably an azo pigment or a perylene pigment. 

An electrophotographic photosensitive member includes a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is 0.05 milliseconds or longer and 0.85 milliseconds or shorter. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to decay of a surface potential of the photosensitive layer from +800 V to +400 V. The pulse light has an intensity that allows the surface potential of the photosensitive layer to decay to +200 V from +800 V after 400 milliseconds elapse from the irradiation of the surface of the photosensitive layer charged to +800 V with the pulse light. The photosensitive layer has a Martens hardness at 50&#xb0; C. of at least 160 N/mm.

An electrophotographic photosensitive member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, an additive, and a binder resin. An optical response time is in a range from 0.05 milliseconds to 0.85 milliseconds. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to surface potential decay of the photosensitive layer from +800 V to +400 V. An optical intensity of the pulse light is set so that the surface potential of the photosensitive layer becomes +200 V from +800 V after 400 milliseconds from pulse light irradiation of the surface of the photosensitive layer charged to the +800 V. The additive includes either of both an ultraviolet absorbing agent and an antioxidant.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is at least 0.05 milliseconds and no greater than 0.85 milliseconds. The binder resin includes a polycarbonate resin including a repeating unit represented by general formula (1) shown below and a repeating unit represented by general formula (2) shown below. 

A method of manufacturing a positively-charged single-layer electrophotographic photoreceptor including the steps of: producing a photosensitive layer application liquid containing a good solvent with respect to a binding resin and at least one organic solvent having a boiling point of 70&#xb0; C. or higher; and forming a photosensitive layer by coating a photosensitive layer support base having a wall thickness of 0.7 mm or less, with the photosensitive layer application liquid and then drying the photosensitive layer application liquid.

Method of manufacturing positively-charged single-layer electrophotographic photoreceptor, positively-charged single-layer electrophotographic photoreceptor, and image forming apparatus

Disclosed is a positively-charged single-layer electrophotographic photoreceptor in which a photosensitive layer containing at least a binding resin and a charge transporting material is provided on a photosensitive layer support base with a wall thickness of 0.7 mm or less, wherein when the charge transporting material is solely constituted by a hole transporting material, a content of the hole transporting material is 110 parts by mass or less with respect to 100 parts by mass of the binding resin, and when the charge transporting material is constituted by a hole transporting material and an electron transporting material, a content of the hole transporting material is 130 parts by mass or less and a content of the electron transporting material is 5 parts by mass or more with respect to 100 parts by mass of the binding resin.

Positively-charged single-layer electrophotographic photoreceptor and image forming apparatus

Disclosed is a positively-charged electrophotographic photoreceptor which uses a tubular photosensitive layer support base with a wall thickness of (t), wherein (t) is 0.7 mm or less, a chamfer angle (a) of an end surface of the photosensitive layer support base is 30&#xb0; or more and 60&#xb0; or less with respect to a longitudinal tangent of a surface of a tubular photosensitive layer support base, and an outer end surface-tail edge surface width (b) of the tubular photosensitive layer support base is 0.05 mm or more.

Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (&#x3bb;) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 &#x3bc;mor less.

Monolayer type photoconductor and image forming device

The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a prede mulas (A) and (B). The electrophotographic photoreceptor prevents image defect termined additive. The hole transport agent satisfies the following for from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. 

Electrophotographic photoreceptor and image forming apparatus

Provided are an electrophotographic photoconductor which shows a small variation in sensitivity and exhibits a high sensitivity even at a small amount of light exposure and a tandem-system color image forming device provided with the electrophotographic photoconductor. A positive charging type electrophotographic photoconductor for use in a tandem-system color image forming device including a drum type electrophotographic photoconductor, a rotation speed of which is (70) rpm or more, and a color image forming device provided with the electrophotographic photoconductor, wherein, when Vb (V) denotes a sensitivity in the case where an amount of light exposure per unit area is 0.6 &#x3bc;J/cmand Va (V) denotes a sensitivity in the case where an amount of light exposure per unit area is 1.5 &#x3bc;J/cm, a sensitivity ratio represented by Vb/Va is adjusted to a value of below (2).

Electro photographic photoconductor and color image forming apparatus

There is provided a tandem color image forming apparatus and the like, which is capable of suppressing the generation of black spots during a continuous image forming process, even though a non-magnetic single-component developer is used and a cleaner-less type is adopted. The color image forming apparatus is a tandem type that includes a plurality of image carriers and a cleaner-less type that does not include a blade cleaner, wherein the resistance per square centimeter of a base body of an image carrier using for at least a black developer among the plurality of image carriers, or the resistance per square centimeter of the base body through an intermediate layer is set in a range of 1&#xd7;10to 1&#xd7;10&#x3a9; or more.

Color image forming apparatus and color image forming method

The present invention provides a monolayer type electrophotographic photoconductor which can effectively suppress the generation of an exposure memory and exhibits high sensitivity and an image forming apparatus using the monolayer type electrophotographic photoconductor. In an electrophotographic photoconductor which has a monolayer type photoconductive layer including at least a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin on a substrate, the charge generating agent contains oxo-titanyl phthalocyanine crystal, the electron transfer agent has a reduction potential thereof set to a value which falls within a range from &#x2212;0.97 to &#x2212;0.83 V, and the reflection absorbance (A/&#x2212;) of the photoconductive layer with respect to light having a wavelength of 700 nm, a film thickness (d/m) of the photoconductive layer, and the concentration (C/weight %) of the oxo-titanyl phthalocyanine crystal of the photoconductive layer (100 weight %) satisfy a following formula (1).&#x3e;1.75&#xd7;10&#x2003;&#x2003;(1)

Electrophotographic photoconductor having titanyl phthalocyanine and image forming apparatus

The present invention provides an electrophotographic photoconductive member comprising a substrate, and a photoconductive layer containing a hole transferring material, a charge generating material and a binder resin, wherein a value (IV/OV value) in which the inorganic value is divided by the organic value of the binder resin is 0.36 or more and the hole transferring material contains an amine compound represented by the following general formula (1): 

Electrophotographic photoconductive member and image forming apparatus

An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate. The hole-transfer agent has a solubility of 5 to 35% by weight with respect to triglyceride oleate and the photosensitive layer contains a compound represented by the following general formula (1) as an additive: 

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Osaka, Japan

Kazunari Hamasaki