Patents by Inventor Takaaki Ikegami

Takaaki Ikegami 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).

  • Patent number: 8798487
    Abstract: An image forming apparatus having an image bearing member, a charger to charge the surface of the image bearing member, an irradiator to irradiate the image bearing member to form the latent image, a developing device to develop the latent electrostatic image with toner to obtain a visible image, a transfer device to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member, and a voltage detector to measure a first surface voltage and a second surface voltage under different conditions, and a life expectancy identification device to identify whether or when the expected working life of the image bearing member has come to the end based on a comparison of the first surface voltage and the second surface voltage.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: August 5, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Takaaki Ikegami, Michio Kimura
  • Patent number: 8472818
    Abstract: An image carrier deterioration degree evaluating apparatus for evaluating a degree of deterioration of an image carrier of an image forming apparatus, the image carrier deterioration degree evaluating apparatus including: an image deletion detecting unit that detects image deletion by obtaining latent image information written on the image carrier; an image deletion reducing unit that performs a process of reducing image deletion when the image deletion detecting unit detects image deletion, and an image carrier deterioration degree evaluating unit that drives the image deletion detecting unit and the image deletion reducing unit alternately one or more times each, and evaluates a degree of deterioration of the image carrier by using the latent image information obtained one or more times by the image deletion detecting unit.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: June 25, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Jun Yamane, Yasushi Nakazato, Kohji Ue, Masahide Yamashita, Mikiko Imazeki, Yasuo Suzuki, Michio Kimura, Takaaki Ikegami, Yoshiaki Kawasaki, Hideo Nakamori, Akihiro Sugino
  • Publication number: 20130011147
    Abstract: A degradation level estimating device for estimating degradation level of a photoreceptor of an image forming apparatus performing at least a charging process, an optical image writing process, a developing process, and a transferring process in which a toner image on the photoreceptor is transferred onto a receiver while applying a charge to the photoreceptor. The degradation level estimating device includes a charge dependence detector to detect charge quantity dependence of a charge property of the photoreceptor in the charging process on the quantity of the charge applied to the photoreceptor in the last transferring process by subjecting the photoreceptor to the processes plural times without performing the optical image writing process, followed by the charging process, while changing the quantity of the charge and measuring the charge property of the photoreceptor. The degradation level estimating device estimates the degradation level of the photoreceptor based on the charge quantity dependence.
    Type: Application
    Filed: May 8, 2012
    Publication date: January 10, 2013
    Inventors: Michio KIMURA, Takaaki IKEGAMI, Tomoharu ASANO
  • Patent number: 8349529
    Abstract: 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): where R1-3 each represent hydrogen, halogen or (un)substituted C1-6 alkyl, and n is 1 or 2, where R1-2 each represent C1-6 alkyl and R3-6 each represent hydrogen, halogen or (un)substituted C1-6 alkyl, where R8-33 each represent hydrogen, C1-4 alkyl, C1-4 alkoxy, or (un)substituted phenyl, and may be identical or different, where A and B each represent a group represented by formula (i) or (ii), and may be identical or different: —CH2X??formula (i) —CH2CH2Y??formula (ii) where X and Y each represent an (un)substituted aromatic group.
    Type: Grant
    Filed: May 12, 2010
    Date of Patent: January 8, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Shimoyama, Takaaki Ikegami, Eiji Kurimoto, Kohsuke Yamamoto, Tetsuya Sakuma, Toshihiko Koizumi, Hajime Suzuki, Hideki Nakamura
  • Patent number: 8278016
    Abstract: An electrophotographic photoconductor including an electroconductive support and a photoconductive layer provided thereon, wherein the photoconductive layer includes a charge generating material, an electron transporting material and a hole transporting material, the electron transporting material being a diphenoquinone compound represented by formula (1) described herein, the hole transporting material being a compound represented by formula (2) described herein.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: October 2, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Shimoyama, Eiji Kurimoto, Takaaki Ikegami, Kohsuke Yamamoto, Tadayoshi Uchida, Takumi Shinohara, Hajime Suzuki
  • Patent number: 8263297
    Abstract: 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 R1 and R2 each represent a substituted or unsubstituted alkyl group, alkoxy group, aryl group or heterocyclic group, provided that R1 and R2 are different, where R3 to R5 each 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.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: September 11, 2012
    Assignees: Ricoh Company, Ltd., Yamanashi Electronics Co., Ltd.
    Inventors: Takaaki Ikegami, Takeshi Takada, Toshihiko Koizumi, Hideki Nakamura, Hajime Suzuki, Keisuke Shimoyama, Kohsuke Yamamoto, Eiji Kurimoto
  • Publication number: 20120183310
    Abstract: An image forming apparatus having an image bearing member, a charger to charge the surface of the image bearing member, an irradiator to irradiate the image bearing member to form the latent image, a developing device to develop the latent electrostatic image with toner to obtain a visible image, a transfer device to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member, and a voltage detector to measure a first surface voltage and a second surface voltage under different conditions, and a life expectancy identification device to identify whether or when the expected working life of the image bearing member has come to the end based on a comparison of the first surface voltage and the second surface voltage.
    Type: Application
    Filed: January 11, 2012
    Publication date: July 19, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Tomoharu Asano, Takaaki Ikegami, Michio Kimura
  • Patent number: 8097393
    Abstract: An image forming apparatus at least containing an electrophotographic photoconductor, a latent electrostatic image forming unit, a developing unit, a transferring unit, and a fixing unit, wherein a glass transition temperature of an outermost layer of the electrophotographic photoconductor is 100° C. or more, wherein the toner is obtained by dissolving and/or dispersing the toner material containing at least an active hydrogen group-containing compound and a polymer reactive with the active hydrogen group-containing compound in an organic solvent to form a solution and/or a dispersion, emulsifying and/or dispersing the solution and/or the dispersion in an aqueous medium containing resin fine particles, allowing the active hydrogen group-containing compound and the polymer reactive with the active hydrogen group-containing compound to react in the aqueous medium, and removing the organic solvent, wherein a glass transition temperature of the resin fine particles is 65° C. to 85° C.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: January 17, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takada, Takaaki Ikegami
  • Publication number: 20110286777
    Abstract: A lubricant for use in an image forming apparatus, which contains a lubricant material and at least one of diamine compounds represented by chemical structure 1, 2, and 3, where R1 and R2 independently represent an alkyl group optionally having a substitution group and an aromatic hydrocarbon group optionally having a substitution group, one of R1 and R2 is an aromatic hydrocarbon group optionally having a substitution group, R1 and R2 optionally share bond connectivity to form a heterocyclic ring containing a nitrogen atom, and Ar represents an aromatic hydrocarbon group optionally having a substitution group, where R3 and R4 independently represent an alkyl group having one to four carbon atoms optionally substituted by an aromatic hydrocarbon group, R3 and R4 optionally share bond connectivity to form a heterocyclic ring containing a nitrogen atom, Ar1 and Ar2 independently represent a substituted or a non-substituted aromatic ring group, l and m each, independently, represent an integer of
    Type: Application
    Filed: May 13, 2011
    Publication date: November 24, 2011
    Inventors: Akihiro SUGINO, Takaaki Ikegami, Keisuke Shimoyama, Tomoharu Asano, Hiroshi Ikuno, Mitsuaki Hirose
  • Publication number: 20110170884
    Abstract: An image carrier deterioration degree evaluating apparatus for evaluating a degree of deterioration of an image carrier of an image forming apparatus, the image carrier deterioration degree evaluating apparatus including: an image deletion detecting unit that detects image deletion by obtaining latent image information written on the image carrier; an image deletion reducing unit that performs a process of reducing image deletion when the image deletion detecting unit detects image deletion, and an image carrier deterioration degree evaluating unit that drives the image deletion detecting unit and the image deletion reducing unit alternately one or more times each, and evaluates a degree of deterioration of the image carrier by using the latent image information obtained one or more times by the image deletion detecting unit.
    Type: Application
    Filed: January 7, 2011
    Publication date: July 14, 2011
    Applicant: Ricoh Company, Limited
    Inventors: Jun Yamane, Yasushi Nakazato, Kohji Ue, Masahide Yamashita, Mikiko Imazeki, Yasuo Suzuki, Michio Kimura, Takaaki Ikegami, Yoshiaki Kawasaki, Hideo Nakamori, Akihiro Sugino
  • Patent number: 7964327
    Abstract: An electrophotographic photoreceptor, including an electroconductive substrate; and a photosensitive layer, located overlying the electroconductive substrate, wherein an outermost layer of the electrophotographic photoreceptor includes an amine compound and a charge transport material, and wherein the amine compound includes an amine site having an electrostatic potential with a dimensionless unit not greater than ?0.27.
    Type: Grant
    Filed: June 13, 2007
    Date of Patent: June 21, 2011
    Assignee: Ricoh Company Ltd.
    Inventors: Masanobu Gondoh, Akihiro Sugino, Hideo Nakamori, Shinji Nohsho, Tomoyuki Shimada, Takaaki Ikegami
  • Patent number: 7879519
    Abstract: This invention relates to image bearing member and an image forming apparatus that employs the image bearing member. The image bearing member contains an electroconductive substrate; a charge generation layer; a charge transport layer; a cross-linking surface protective layer, and a monomer having one radical polymerizable functional group with a charge transport structure. The cross-linking surface protective layer is formed by curing a monomer having at least three radical polymerizable functional groups without a charge transport structure. For the image bearing member, the ratio of the layer thickness of the cross linking surface protective layer to the layer thickness of the charge transport layer is from 0.7 to 1.3.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: February 1, 2011
    Assignee: Ricoh Company Limited
    Inventors: Naohiro Toda, Yoshiki Yanagawa, Takaaki Ikegami, Makoto Yasuda, Takeshi Orito
  • Patent number: 7851114
    Abstract: An electrostatic latent image bearing member is provided including a substrate and a photosensitive layer located overlying the substrate, wherein the outermost layer of the electrostatic latent image bearing member includes a cross-linked resin formed from a cross-linking reaction between a charge transport polyol having a specific formula and an isocyanate compound; and the use of the electrostatic latent image bearing member in an image forming apparatus, a process cartridge, and an image forming method.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: December 14, 2010
    Assignee: Ricoh Company Limited
    Inventors: Akihiro Sugino, Takaaki Ikegami, Takeshi Takada, Kazukiyo Nagai
  • Publication number: 20100290807
    Abstract: 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): where R1-3 each represent hydrogen, halogen or (un)substituted C1-6 alkyl, and n is 1 or 2, where R1-2 each represent C1-6 alkyl and R3-6 each represent hydrogen, halogen or (un)substituted C1-6 alkyl, where R8-33 each represent hydrogen, C1-4 alkyl, C1-4 alkoxy, or (un)substituted phenyl, and may be identical or different, where A and B each represent a group represented by formula (i) or (ii), and may be identical or different: —CH2X ??formula (i) —CH2CH2Y ??formula (ii) where X and Y each represent an (un)substituted aromatic group.
    Type: Application
    Filed: May 12, 2010
    Publication date: November 18, 2010
    Inventors: Keisuke SHIMOYAMA, Takaaki Ikegami, Eiji Kurimoto, Kohsuke Yamamoto, Tetsuya Sakuma, Toshihiko Koizumi, Hajime Suzuki, Hideki Nakamura
  • Publication number: 20100233602
    Abstract: An electrophotographic photoconductor including a conductive substrate, and a photosensitive layer formed on the conductive substrate, wherein the photosensitive layer contains at least a charge generation agent, a specific charge transfer agent and a specific antioxidant.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kohsuke Yamamoto, Takaaki Ikegami, Eiji Kurimoto, Keisuke Shimoyama, Hideki Nakamura, Toshihiko Koizumi, Hajime Suzuki
  • Patent number: 7781134
    Abstract: A photoreceptor is provided having an electroconductive substrate and a photosensitive layer located overlying the electroconductive substrate, wherein an outermost layer of the photoreceptor contains a binder resin, wherein the binder resin solution satisfies the following relationship 2?(T0?T400)/C wherein T0 represents a initial transmittance (%) at 400 nm of the binder resin solution; T400 represents a transmittance (%) at 400 nm of the binder resin solution which has been allowed to settle for 400 hours under conditions of 23° C. and 40% RH; and C represents the concentration of the binder resin solution; and an image forming method, an image forming apparatus and a process cartridge including the photoreceptor.
    Type: Grant
    Filed: December 27, 2005
    Date of Patent: August 24, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino
  • Publication number: 20090311616
    Abstract: An electrophotographic photoconductor including an electroconductive support and a photoconductive layer provided thereon, wherein the photoconductive layer includes a charge generating material, an electron transporting material and a hole transporting material, the electron transporting material being a diphenoquinone compound represented by formula (1) described herein, the hole transporting material being a compound represented by formula (2) described herein.
    Type: Application
    Filed: June 9, 2009
    Publication date: December 17, 2009
    Inventors: Keisuke SHIMOYAMA, Eiji KURIMOTO, Takaaki IKEGAMI, Kohsuke YAMAMOTO, Tadayoshi UCHIDA, Takumi SHINOHARA, Hajime SUZUKI
  • Publication number: 20090136260
    Abstract: 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 R1 and R2 each represent a substituted or unsubstituted alkyl group, alkoxy group, aryl group or heterocyclic group, provided that R1 and R2 are different, where R3 to R5 each 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.
    Type: Application
    Filed: November 25, 2008
    Publication date: May 28, 2009
    Applicants: RICOH COMPANY, LTD,, YAMANASHI ELECTRONICS CO., LTD.
    Inventors: Takaaki IKEGAMI, Takeshi Takada, Toshihiko Koizumi, Hideki Nakamura, Hajime Suzuki, Keisuke Shimoyama, Kohsuke Yamamoto, Eiji Kurimoto
  • Publication number: 20080292981
    Abstract: This invention relates to image bearing member and an image forming apparatus that employs the image bearing member. The image bearing member contains an electroconductive substrate; a charge generation layer; a charge transport layer; a cross-linking surface protective layer, and a monomer having one radical polymerizable functional group with a charge transport structure. The cross-linking surface protective layer is formed by curing a monomer having at least three radical polymerizable functional groups without a charge transport structure. For the image bearing member, the ratio of the layer thickness of the cross linking surface protective layer to the layer thickness of the charge transport layer is from 0.7 to 1.3.
    Type: Application
    Filed: February 14, 2008
    Publication date: November 27, 2008
    Inventors: Naohiro Toda, Yoshiki Yanagawa, Takaaki Ikegami, Makoto Yasuda, Takeshi Orito
  • Patent number: 7391994
    Abstract: Disclosed is an image forming apparatus for lowering friction coefficient and lowering surface energy of photoconductor surface in particular, which comprises an electrophotographic photoconductor, charging unit, light exposure unit, developing unit, transferring unit, and fixing unit, the electrophotographic photoconductor comprises a photosensitive layer on a conductive support and fluoropolymer fine particles at the outermost layer, a part of the fluoropolymer fine particles are exposed above the surface of the outermost layer in configurations of primary particles and secondary particles formed by flocculation of plural primary particles, and sum of area ratios of particles in the configurations of the primary particles and the secondary particles, each particles having an average diameter D of 0.15 ?m?D?3.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: June 24, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino