Mita Industrial Co., Ltd.

Sharp Kabushiki Kaisha Corporation

Akihiko Kawahara

Yasufumi Mizuta

Eiichi Miyamoto

Satoshi Katayama

Mikio Kakui

Hiroaki Iwasaki

Yasuyuki Hanatani

Kazushige Morita

Kazuya Ishida

Tomoko Kanazawa

Tatsuhiro Morita

Takahiro Teramoto

Tadashi Nakamura

Kiyofumi Morimoto

Kazunari Hamasaki

Nariaki Tanaka

Koichi Toriyama

Hirofumi Kawaguchi

Masayuki Sakamoto

Kaname Nakatani

Tadayuki Sawai

Yoshihide Shimoda

Yoshio Inagaki

Rikiya Matsuo

Ayako Yashima

Makoto Kurokawa

Toru Nishikawa

Hiroko Ishibashi

Kazuya Korematu

Tomomi Nakamura

A non-magnetic single component developing device that is included in combination with a photoreceptor in an image forming apparatusof the electro-photographic system. The non-magnetic single component developing device includes a developing roller, a supplying roller, a doctor, a toner bath and a stirring blade. The supplying roller contains a rubber foam at least in its surface layer portion, the rubber foam including closed cells and open cells and having a foam ratio (porosity) of 0.75 to 0.85 and an average foam cell diameter of 350 to 500 &#x3bc;m.

Non-magnetic single component developing device

An organic electrophotographic receptor comprising at least an undercoating layer, an electric charge generating layer, and an electric charge transferring layer which are laminated in said order, wherein a coating fluid for forming said electric charge generating layer comprising an electric charge generating material, a binding resin, a silicon oil having a surface tension of 22 mN/m or less, and an organic solvent is stored inside a tank and a photosensitive base supported by a chucking device is dipped into said coating tank so as to form said electric charge generating layer.

Coating fluid for electric charge generating layer, organic electrophotographic receptor, and method to manufacturing the same

Highly sensitive and highly durable electrophotographic photoreceptors which generate faultless images can be produced by forming the under-coating layer on the conductive support and forming the photoreceptive layer on the layer. The under-coating layer contains dendritic titanium oxide. The under-coating layer contains the dendritic titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide, of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s), and an alcohol soluble polyamide resin.

Electrophotographic photoreceptor, process for production thereof, and

The object of the invention is to provide a highly characteristic and lesser defective image using an electrophotographic photoreceptor which can be produced with a better coating property and which is highly sensitive and hardly loses the electrostatic stability during repeated use. A water-soluble or water/alcohol-soluble polyvinyl acetal and an inorganic pigment are involved in an underlayer provided between a conductive support and a photoconductive layer. Particularly, it is favorable to use titanium oxide as the inorganic pigment, make the ratio of polyvinyl acetal/titanium oxide 1/9-9/1 by weight, make the underlayer 0.5-5 .mu.m in thickness, use the titanium oxide of which the surface is treated with alumina, use the titanium oxide of which the titanium oxide component is 95% by weight or lower and of which the surface is treated with alumina, use the polyvinyl acetal of which the sodium ion concentration is 40 ppm or lower, and use the photo-conductive layer which contains a vinyl chloride-vinyl acetate type copolymer. As for a dispersing medium for coating the underlayer, water/alcohol=1/9-7/3 (ratio by weight) is selected. The aforementioned photoreceptor is applied to an image-forming apparatus using an inversion development process.

Electrophotographic photoreceptor

An object of the invention is to provide a highly characteristic image using an electrophotographic photoreceptor of which a charge-generating layer can be produced with a better coating property and which is highly sensitive and electrostatically highly stable in repeated use. The charge-generating layer of a function-separated type photoreceptor contains a n-type non-metallic phthalocyanine and a copolymer of vinyl chloride-vinyl acetate type. Particularly, the ratio of the .tau.-type non-metallic phthalocyanine to the copolymer of vinyl chloride-vinyl acetate type is fixed at 1/3-3/1 by weight. The thickness of the charge-generating layer is fixed at 0.1-0.6 .mu.m. As the copolymer of vinyl chloride-vinyl acetate type, copolymers of vinyl chloride-vinyl acetate, vinyl chloride-vinyl acetate-maleic acid, or vinyl chloride-vinyl acetate-vinyl alcohol are selected. Particularly, it is favorable to select those containing at least 10% by weight of the vinyl alcohol component. The charge-generating layer is formed with a liquid coating material using a ketone solvent as dispersant. The aforementioned photoreceptor is applied to an image-forming apparatus using an inversion development process.

Electrophotographic photoreceptor, process for producing the same, and

A photosensitive material for electrophotography, wherein the charge-generating agent comprises a P-type charge-generating pigment and an N-type charge-generating pigment in combination, at least part of these pigments being present in the form of aggregates in the photosensitive layer. The photosensitive material will assume the form of either a single dispersion type or a laminated layer type, and exhibits very high carrier generation efficiency, strikingly improved sensitivity on the side of long wavelengths, excellent balance in the spectral sensitivity and property after repetitively used, and can hence be effectively used for forming image by the electrophotography.

Photosenstive material for electrophotography

Photosensitive material for electrophotography

An azo compound represented by the following general formula IA and an electrophotographic photosensitive member comprising a photosensitive layer containing the azo compound: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different from each other and indicate a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a carboxy group, an alkoxy carbonyl group, an acyl group, an aryl group, a halogen group or a cyano group, respectively; R.sup.14 indicates a hydrogen atom, a halogen group, an alkyl group, an alkoxy group, an aryl group, an amine group, a cyano group, a nitro group or a sulfoxide group; and A indicates a coupler residue having an acceptor property.

Electrophotographic photosensitive member having a photosensitive layer

An azo compound represented by the following general formula IA and an electrophotographic photosensitive member comprising a photosensitive layer containing the azo compound: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different from each other and indicate a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a carboxy group, an alkoxy carbonyl group, an acyl group, an aryl group, a halogen group or a cyano group, respectively; R.sup.14 indicates a hydrogen atom, a halogen group, an alkyl group, an alkoxy group, an aryl group, an amino group, a cyano group, a nitro group or a sulfoxide group; and A indicates a coupler residue having an acceptor property.

Electrophotographic member having an azo compound with diphenoquinone

Bisazo compounds which contain a diphenoquinone tetraazo component and

An electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and a methyl-butyl etherified melamine-formaldehyde resin in an amount of from 0.1 to 30 parts by weight per 100 parts by weight of the non-volatile solid components of the thermosetting silicone resin, an electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and an acrylic copolymer having an average molecular weight of 6,000 or less in an amount of from 0.1 to 30 parts by weight per 100 parts by weight of the non-volatile solid components of the thermosetting silicone resin, and an electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer containing a thermosetting silicone resin, a methyl etherified melamine-formaldehyde resin and/or a methyl-butyl mixed etherified melamine-formaldehyde resin in an amount of from 0.1 to 50 parts by weight per 100 parts by weight of the non-volatile solid components of the thermosetting silicone resin, and a thermoplastic resin in an amount of from 1 to 11 wt % to a total amount of the non-volatile solid components of the thermosetting silicone resin and the methyl etherified melamine-formaldehyde resin and/or the methyl-butyl mixed etherified melamine-formaldehyde resin.

Electrophotographic photosensitive element comprising a surface

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Nara, Japan

Akihiko Kawahara