Patents by Inventor Seizo Kitagawa
Seizo Kitagawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20220197161Abstract: Provided are a photoconductor for electrophotography that has sufficiently high sensitivity and excellent potential stability during repeated printing in various environments, and does not cause problems, such as deterioration of gradation or generation of memory images, especially when applied to monochrome high-speed printers and small medium-speed tandem color printers, as well as a method of manufacturing the photoconductor for electrophotography, and an electrophotographic equipment.Type: ApplicationFiled: December 10, 2021Publication date: June 23, 2022Applicant: FUJI ELECTRIC CO., LTD.Inventors: Seizo KITAGAWA, Shinjiro SUZUKI, Hiroshi EMORI, Kazuki NEBASHI
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Patent number: 11143976Abstract: A photoconductor for electrophotography includes a base member; an anodic oxide coating provided on the base member and having a film thickness of 2 to 10 ?m; an interlayer provided on the anodic oxide coating and containing a vinyl chloride-vinyl acetate copolymer resin and having a film thickness of 0.02 to 0.3 ?m; and a photosensitive layer including a charge transport layer formed on the interlayer and containing a charge transport material and a first resin binder, and a charge generation layer laminated on the charge transport layer and containing a charge generation material, a hole transport material, a first electron transport material that is a naphthalenetetracarboxylic diimide compound, a second electron transport material that is an azoquinone compound, a diphenoquinone compound, or a stilbenequinone compound and that has a mobility of 17×10?8 cm2/V·s or more, and a second resin binder.Type: GrantFiled: January 3, 2020Date of Patent: October 12, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventors: Seizo Kitagawa, Kazuya Saito, Kazuki Nebashi, Hiroshi Emori, Masaru Takeuchi
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Patent number: 11036151Abstract: An electrophotographic photoreceptor, including a photosensitive layer formed on an electroconductive substrate. The photosensitive layer includes a charge-generating material and an electron-transporting material, and the electron-transporting material includes first and second electron-transporting materials. A difference in lowest unoccupied molecular orbital (LUMO) energy between the first electron-transporting material and the charge-generating material is in a range from 1.0 to 1.5 eV, and a difference in LUMO energy between the second electron-transporting material and the charge-generating material is in a range from 0.6 to 0.9 eV. A ratio of mass of the second electron-transporting material to a total of mass of the first electron-transporting material and the mass of the second electron-transporting material is in a range from 3 to 40%.Type: GrantFiled: April 1, 2020Date of Patent: June 15, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventors: Seizo Kitagawa, Kazuya Saito, Shinjiro Suzuki, Toshiki Takeuchi
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Patent number: 10962893Abstract: An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer arranged on the conductive substrate and containing, as a charge generating material, any one material selected from the group consisting of titanyl phthalocyanines, metal-free phthalocyanines, chlorogallium phthalocyanines and hydroxygallium phthalocyanines; and, as an electron transporting material, a naphthalene tetracarboxylic acid diimide compound represented by Formula (1) below, where R1 and R2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkylene group, an alkoxy group, an alkyl ester group, a phenyl group optionally having a substituent, a naphthyl group optionally having a substituent, or a halogen element; and R1 and R2 are optionally the same or different: The photoreceptor realizes a stable print density even in a low-temperature environment by suppressing a reduction in print density that is caused by potential fluctuation of the photoreceptor in the low-temperatType: GrantFiled: June 27, 2018Date of Patent: March 30, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventors: Shinjiro Suzuki, Seizo Kitagawa, Yuji Ogawa
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Patent number: 10747129Abstract: Provided is a photoconductor for electrophotography having high sensitivity, low residual potential, and good wear resistance and contamination resistance, and that is less likely to cause light-induced fatigue and filming, and also exhibits good potential stability before and after repeated printing, even without a surface protective layer formed on a photosensitive layer. Provided also are a process of producing the photoconductor and an electrophotographic apparatus.Type: GrantFiled: July 26, 2019Date of Patent: August 18, 2020Assignee: FUJI ELECTRIC CO., LTD.Inventors: Fengqiang Zhu, Shinjiro Suzuki, Seizo Kitagawa
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Publication number: 20200225594Abstract: An electrophotographic photoreceptor, including a photosensitive layer formed on an electroconductive substrate. The photosensitive layer includes a charge-generating material and an electron-transporting material, and the electron-transporting material includes first and second electron-transporting materials. A difference in lowest unoccupied molecular orbital (LUMO) energy between the first electron-transporting material and the charge-generating material is in a range from 1.0 to 1.5 eV, and a difference in LUMO energy between the second electron-transporting material and the charge-generating material is in a range from 0.6 to 0.9 eV. A ratio of mass of the second electron-transporting material to a total of mass of the first electron-transporting material and the mass of the second electron-transporting material is in a range from 3 to 40%.Type: ApplicationFiled: April 1, 2020Publication date: July 16, 2020Applicant: FUJI ELECTRIC CO., LTD.Inventors: Seizo KITAGAWA, Kazuya SAITO, Shinjiro SUZUKI, Toshiki TAKEUCHI
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Publication number: 20200142328Abstract: A photoconductor for electrophotography, including an electroconductive base member, an anodic oxide coating provided on the electroconductive base member, an interlayer provided on the anodic oxide coating, and a photosensitive layer including a charge transport layer formed on the interlayer, and a charge generation layer laminated on the charge transport layer. The charge transport layer contains a charge transport material and a first resin binder. The charge generation layer contains a charge generation material, a hole transport material, an electron transport material, and a second resin binder. The anodic oxide coating has a film thickness of 2 ?m or more and 10 ?m or less. The interlayer contains a vinyl chloride-vinyl acetate copolymer resin, and has a film thickness of 0.02 ?m or more and 0.3 ?m or less.Type: ApplicationFiled: January 3, 2020Publication date: May 7, 2020Applicant: FUJI ELECTRIC CO., LTD.Inventors: Seizo KITAGAWA, Kazuya SAITO, Kazuki NEBASHI, Hiroshi EMORI, Masaru TAKEUCHI
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Publication number: 20190346780Abstract: Provided is a photoconductor for electrophotography having high sensitivity, low residual potential, and good wear resistance and contamination resistance, and that is less likely to cause light-induced fatigue and filming, and also exhibits good potential stability before and after repeated printing, even without a surface protective layer formed on a photosensitive layer. Provided also are a process of producing the photoconductor and an electrophotographic apparatus.Type: ApplicationFiled: July 26, 2019Publication date: November 14, 2019Applicant: FUJI ELECTRIC CO., LTD.Inventors: Fengqiang ZHU, Shinjiro SUZUKI, Seizo KITAGAWA
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Patent number: 10429752Abstract: Provided is a positively charged electrophotographic photoconductor, a manufacturing method thereof, and an electrophotographic apparatus using the same. The positively charged electrophotographic photoconductor includes an electroconductive support and a single layer-type photosensitive layer provided thereon including a charge generation material, a hole transport material, an electron transport material, and a mixed binder resin. Alternately, the positively charged electrophotographic photoconductor includes an electroconductive support; a charge transport layer provided on the electroconductive support and containing at least a hole transport material, and a binder resin; and a charge generation layer provided on the charge transport layer and including at least a charge generation material, a hole transport material, an electron transport material, and a mixed binder resin.Type: GrantFiled: August 30, 2018Date of Patent: October 1, 2019Assignee: FUJI ELECTRIC CO., LTD.Inventors: Seizo Kitagawa, Toshiki Takeuchi, Kazuya Saito
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Patent number: 10416579Abstract: An electrophotographic photoreceptor which, even when mounted on a high-image-quality monochrome high-speed printer or tandem color printer including a cleaner-less process of a non-magnetic single-component contact development system using a polymerized toner, inhibits the generation of fine black spots or color spots and suppresses the occurrence of toner filming during the initial printing under a high-temperature and high-humidity environment and thereby stably attains a high image quality in a variety of environments.Type: GrantFiled: July 25, 2018Date of Patent: September 17, 2019Assignee: FUJI ELECTRIC CO., LTD.Inventors: Toshiki Takeuchi, Seizo Kitagawa, Kazuya Saito
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Publication number: 20180373172Abstract: Provided is a positively charged electrophotographic photoconductor that provides a stable high-quality image in any environment, a manufacturing method thereof, and an electrophotographic apparatus using the same. The positively charged electrophotographic photoconductor includes an electroconductive support; and a single layer-type photosensitive layer provided on the electroconductive support and including a charge generation material, a hole transport material, an electron transport material and a binder resin. Alternately, the positively charged electrophotographic photoconductor includes an electroconductive support; a charge transport layer provided on the electroconductive support and containing at least a hole transport material and a binder resin; and a charge generation layer provided on the charge transport layer and including at least a charge generation material, a hole transport material, an electron transport material and a binder resin.Type: ApplicationFiled: August 30, 2018Publication date: December 27, 2018Applicant: FUJI ELECTRIC CO., LTD.Inventors: Seizo KITAGAWA, Toshiki TAKEUCHI, Kazuya SAITO
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Publication number: 20180329318Abstract: An electrophotographic photoreceptor which, even when mounted on a high-image-quality monochrome high-speed printer or tandem color printer including a cleaner-less process of a non-magnetic single-component contact development system using a polymerized toner, inhibits the generation of fine black spots or color spots and suppresses the occurrence of toner filming during the initial printing under a high-temperature and high-humidity environment and thereby stably attains a high image quality in a variety of environments. The electrophotographic photoreceptor is a positively-chargeable electrophotographic photoreceptor which includes, on a conductive support, a single layer-type photosensitive layer that contains a charge generation material, a hole transport material, an electron transport material, and a binder resin. The charge generation material contains at least a titanyl phthalocyanine, and a contact angle between the surface of an outermost layer and water is in a range of 81° to 87°.Type: ApplicationFiled: July 25, 2018Publication date: November 15, 2018Applicant: FUJI ELECTRIC CO., LTD.Inventors: Toshiki TAKEUCHI, Seizo KITAGAWA, Kazuya SAITO
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Publication number: 20180307147Abstract: An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer arranged on the conductive substrate and containing, as a charge generating material, any one material selected from the group consisting of titanyl phthalocyanines, metal-free phthalocyanines, chlorogallium phthalocyanines and hydroxygallium phthalocyanines; and, as an electron transporting material, a naphthalene tetracarboxylic acid diimide compound represented by Formula (1) below, where R1 and R2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkylene group, an alkoxy group, an alkyl ester group, a phenyl group optionally having a substituent, a naphthyl group optionally having a substituent, or a halogen element; and R1 and R2 are optionally the same or different: The photoreceptor realizes a stable print density even in a low-temperature environment by suppressing a reduction in print density that is caused by potential fluctuation of the photoreceptor in the low-temperatType: ApplicationFiled: June 27, 2018Publication date: October 25, 2018Applicant: FUJI ELECTRIC CO., LTD.Inventors: Shinjiro SUZUKI, Seizo KITAGAWA, Yuji OGAWA
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Patent number: 9904186Abstract: A layered, positively-charged electrophotographic photoreceptor, a method for manufacturing the photoreceptor and an electrophotographic apparatus using the photoreceptor are disclosed. The layered, positively-charged electrophotographic photoreceptor includes a conductive support on which is provided a sequential stack composed of a charge transport layer containing at least a first hole transport material and a first binder resin; and a charge generation layer containing at least a charge generation material, a second hole transport material, an electron transport material, and a second binder resin, wherein the charge generation layer and the charge transport layer have a total amount of residual solvents that is 50 ?g/cm2 or less. The photoreceptor is highly sensitive, highly durable, and has excellent image qualities including low image defects from cracks generated due to image memory or contact contamination.Type: GrantFiled: August 5, 2011Date of Patent: February 27, 2018Assignee: FUJI ELECTRIC CO., LTD.Inventors: Seizo Kitagawa, Yasushi Tanaka, Shinjiro Suzuki, Hiroshi Emori, Kazuki Nebashi
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Patent number: 9671705Abstract: An electrophotographic photoconductor includes a conductive support; and a photoconductive layer that contains at least a charge generation material, a hole transport material, an electron transport material and a binder resin, and that is provided on the conductive support, wherein the photoconductive layer has an outermost layer that contains a charge generation material, a hole transport material, an electron transport material, a binder resin and a highly branched polymer that is obtained by polymerizing, in the presence of a polymerization initiator, a monomer having, in a molecule, two or more radically polymerizable double bonds and a monomer having, in a molecule, a long-chain alkyl group or an alicyclic group and at least one radically polymerizable double bond. The electrophotographic photoconductor exhibits superior operational stability and stably high image quality, without problems with image memory, a contact member, or image defects due to cracks caused by contamination by oils/fats or sebum.Type: GrantFiled: August 10, 2015Date of Patent: June 6, 2017Assignee: FUJI ELECTRIC CO., LTD.Inventors: Seizo Kitagawa, Shinjiro Suzuki, Hiroshi Emori
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Patent number: 9665019Abstract: An electrophotographic photoconductor includes a conductive support; a charge generation layer provided on the conductive support; and a charge transport layer containing a charge transport material, a binder resin, and a highly branched polymer having a long-chain alkyl group or an alicyclic group, provided on the charge generation layer as an outermost layer. The electrophotographic photoconductor has excellent contamination resistance against sebum or the like, stable electrical characteristics even upon repeated use, as well as superior transfer resistance and gas resistance. A method for producing the electrophotographic photoconductor is disclosed, as well as an electrophotographic apparatus including the electrophotographic photoconductor.Type: GrantFiled: August 10, 2015Date of Patent: May 30, 2017Assignee: FUJI ELECTRIC CO., LTD.Inventors: Shinjiro Suzuki, Ikuo Takaki, Seizo Kitagawa, Hiroshi Emori
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Publication number: 20150346614Abstract: An electrophotographic photoconductor includes a conductive support; a charge generation layer provided on the conductive support; and a charge transport layer containing a charge transport material, a binder resin, and a highly branched polymer having a long-chain alkyl group or an alicyclic group, provided on the charge generation layer as an outermost layer. The electrophotographic photoconductor has excellent contamination resistance against sebum or the like, stable electrical characteristics even upon repeated use, as well as superior transfer resistance and gas resistance. A method for producing the electrophotographic photoconductor is disclosed, as well as an electrophotographic apparatus including the electrophotographic photoconductor.Type: ApplicationFiled: August 10, 2015Publication date: December 3, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Shinjiro SUZUKI, Ikuo TAKAKI, Seizo KITAGAWA, Hiroshi EMORI
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Publication number: 20150346619Abstract: An electrophotographic photoconductor includes a conductive support; and a photoconductive layer that contains at least a charge generation material, a hole transport material, an electron transport material and a binder resin, and that is provided on the conductive support, wherein the photoconductive layer has an outermost layer that contains a charge generation material, a hole transport material, an electron transport material, a binder resin and a highly branched polymer that is obtained by polymerizing, in the presence of a polymerization initiator, a monomer having, in a molecule, two or more radically polymerizable double bonds and a monomer having, in a molecule, a long-chain alkyl group or an alicyclic group and at least one radically polymerizable double bond. The electrophotographic photoconductor exhibits superior operational stability and stably high image quality, without problems with image memory, a contact member, or image defects due to cracks caused by contamination by oils/fats or sebum.Type: ApplicationFiled: August 10, 2015Publication date: December 3, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Seizo KITAGAWA, Shinjiro SUZUKI, Hiroshi EMORI
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Patent number: 9081313Abstract: An electrophotographic photoconductor including, in the order recited: a conductive substrate; an undercoat layer provided on the conductive substrate; and a photoconductive layer provided on the undercoat layer and containing at least a phthalocyanine compound as a charge generation material and, as a resin binder, a polyvinyl acetal resin composed of a repeating unit represented by formula (1): where, in formula (1), R is a hydrogen atom, a methyl group, an ethyl group or a propyl group; x, y and z represent mol % of the respective structural units, where x+y+z=100; n is an integer from 1 to 5; a degree of acetalization (x+z) is 86 to 99 mol %; and a molar ratio (x:z) of the structural units is 95:5 to 50:50.Type: GrantFiled: February 14, 2012Date of Patent: July 14, 2015Assignee: FUJI ELECTRIC CO., LTD.Inventors: Kazuki Nebashi, Shinjiro Suzuki, Seizo Kitagawa
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Patent number: 9081319Abstract: Provided is an electrophotographic photoconductor that has good coating solution stability and metal oxide dispersibility, is free of image defects including ground fogging and black spots, and affords good image characteristics in various environments, as well as a manufacturing method therefore and a device including the same. The electrophotographic photoconductor includes a conductive substrate; an undercoat layer; and a photosensitive layer. The undercoat layer contains, as a main component, a resin obtained by polymerizing, as starting materials, an aromatic dicarboxylic acid, at least one aliphatic dicarboxylic acid having 8 or more carbon atoms, and at least one diamine having a cycloalkane structure, and further contains a metal oxide. The aromatic dicarboxylic acid in the resin is present in an amount that ranges from 0.1 to 10 mol %, and the resin has an acid value and a base value that are each no greater than 10 KOH mg/g.Type: GrantFiled: December 14, 2009Date of Patent: July 14, 2015Assignee: FUJI ELECTRIC CO., LTD.Inventors: Shinjirou Suzuki, Yoichi Nakamura, Ikuo Takaki, Seizo Kitagawa, Kazuki Nebashi