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: 7381511
    Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer; and optionally a protective layer, wherein an outermost layer thereof includes a filler, an organic compound having an acid value of from 10 to 700 mg KOH/g and at least one compound selected from the group consisting of compounds having the following formulae (1) and (2): wherein R1 (R3) and R2 (R4) independently represent a substituted or an unsubstituted aromatic hydrocarbon group, or a substituted or an unsubstituted alkyl group, and optionally share bond connectivity to form a heterocyclic group including a nitrogen atom; Ar1 (Ar3) and Ar2 (Ar4) independently represent a substituted or a unsubstituted aromatic ring group; k (K) and m (M) independently represent 0 or an integer of from 1 to 3, wherein k (K) and m (M) are not 0 at the same time; and n (n?) represents an integer of from 1 to 3.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: June 3, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takaaki Ikegami, Tomoyuki Shimada, Yasuo Suzuki, Nozomu Tamoto, Hidetoshi Kami, Yuuji Takana
  • Patent number: 7314693
    Abstract: The present invention relates to an electrophotographic photoconductor comprising a photoconductive layer, a protective layer, and a conductive support, wherein the protective layer is disposed as the outermost layer of the photoconductive layer, and 20% by volume to 60% by volume of fine particles of fluorine-contained resin and at least one compound selected from amine aromatic compounds and hydroxy aromatic compounds are incorporated into the protective layer. According to the present invention, high durability may be achieved, image degradation such as lags may be controlled from the increase of residual potential and decrease of charging, and high quality images may be formed stably even after the prolonged and repeated usage. The present invention also relates to an electrophotographic process, an electrophotographic apparatus and a process cartridge for the electrophotographic apparatus which utilize the electrophotographic photoconductor respectively.
    Type: Grant
    Filed: September 13, 2004
    Date of Patent: January 1, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takaaki Ikegami, Shinji Nohsho, Eiji Kurimoto, Hidetoshi Kami, Akihiro Sugino, Yasuyuki Yamashita, Hideo Nakamori, Takeshi Takada
  • Publication number: 20070287083
    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: Application
    Filed: June 13, 2007
    Publication date: December 13, 2007
    Inventors: Masanobu Gondoh, Akihiro Sugino, Hideo Nakamori, Shinji Nohsho, Tomoyuki Shimada, Takaaki Ikegami
  • Publication number: 20070231733
    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: Application
    Filed: April 3, 2007
    Publication date: October 4, 2007
    Inventors: Takeshi Takada, Takaaki Ikegami
  • Patent number: 7267916
    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 a particulate fluorine-containing resin, and wherein a primary particle of the particulate fluorine-containing resin and a secondary particle formed of agglomerated primary particles thereof, which are projected from a surface of the outermost layer and have an average particle diameter of from 0.15 to 3 ?m, are present in an area ratio not less than 10% based on total surface area of the outermost layer.
    Type: Grant
    Filed: July 19, 2004
    Date of Patent: September 11, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Sugino, Shinji Nousho, Takaaki Ikegami, Eiji Kurimoto, Hideo Nakamori, Hidetoshi Kami, Yasuyuki Yamashita
  • Publication number: 20070117033
    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: Application
    Filed: November 21, 2006
    Publication date: May 24, 2007
    Inventors: Akihiro SUGINO, Takaaki Ikegami, Takeshi Takada, Kazukiyo Nagai
  • Patent number: 7220522
    Abstract: A photoreceptor including a photosensitive layer including a specific diamine compound, or a photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate; and optionally a protective layer located overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, an organic compound having an acid value of from 10 to 700 mgKOH/g and a specific diamine compound. An image forming method, an image forming apparatus and a process cartridge using the photoreceptor are also provided. A method for manufacturing the photoreceptor including the steps of preparing a coating liquid including the filler, the organic compound, the specific diamine compound and an antioxidant; and coating the coating liquid is also provided.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: May 22, 2007
    Assignee: Ricoh Company Limited
    Inventors: Takaaki Ikegami, Tomoyuki Shimada, Yasuo Suzuki
  • Patent number: 7212777
    Abstract: An image forming apparatus including an image bearing member to bear a latent electrostatic image, an irradiation device and developing device to develop a toner latent electrostatic image on the image bearing member, a cleaning blade to remove toner particles remaining on the image bearing member, and a transfer device to transfer the toner image formed on the image bearing member to a recording material. The image forming apparatus satisfies relationships (1) and (2): (1) 0.10< or =Dm3/V< or =3.41, wherein Dm represents a weight average particle diameter of the toner and V represents a circumference velocity of the image bearing member; and (2) Tave< or =1.40 kgf·cm, wherein Tave represents the average of a torque T of the image bearing member when the torque is measured for 15 seconds while the cleaning blade is in contact with the image bearing member.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: May 1, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino
  • Patent number: 7177583
    Abstract: An image forming apparatus including a photoreceptor having an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protection layer including an inorganic filler in an amount of from 3 to 25% by weight based on total weight of the protection layer and a binder resin, and overlying the photosensitive layer. The apparatus further including a charger, an irradiator, an image developer, and a transferer transferring a toner image onto a transfer material. The apparatus also includes a cleaner cleaning the photoreceptor, including a rotatable core and a looped brush fiber provided on the surface of the rotatable core so as to contact the photoreceptor. A top of the looped brush fiber is positioned on an upstream side from a root of the looped brush fiber relative to a rotating direction of the rotatable core.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: February 13, 2007
    Assignee: Ricoh Company Limited
    Inventors: Eiji Kurimoto, Ryohichi Kitajima, Yoshiaki Kawasaki, Akihiro Sugino, Takaaki Ikegami
  • Patent number: 7112392
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate and a photosensitive layer on the electroconductive substrate, wherein the photosensitive layer includes at least a compound having a substituted or unsubstituted alkylamino group and a charge transport material, and wherein an oxidation potential (Eox1) of the substituted or unsubstituted alkylamino group and an oxidation potential (Eox2) of the charge transport material satisfy the following relationship (I): Eox1?Eox2??0.2.
    Type: Grant
    Filed: February 24, 2004
    Date of Patent: September 26, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Takaaki Ikegami, Yasuo Suzuki
  • Publication number: 20060199092
    Abstract: An electrostatic latent image bearer, including a substrate and a photosensitive layer located overlying the substrate, wherein an outermost layer of the electrostatic latent image bearer includes a binder resin and an electroconductive particulate material, wherein the electroconductive particulate material has the following formula: MxSbyOz wherein M represents a metallic element; and x, y and z represent molar ratios for respective elements.
    Type: Application
    Filed: March 3, 2006
    Publication date: September 7, 2006
    Inventors: Akihiro Sugino, Takaaki Ikegami, Takeshi Takada
  • Publication number: 20060141378
    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: Application
    Filed: December 27, 2005
    Publication date: June 29, 2006
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino
  • Patent number: 7031650
    Abstract: An image forming apparatus including a photoreceptor having an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protection layer including an inorganic filler in an amount of from 3 to 25% by weight based on total weight of the protection layer and a binder resin, and overlying the photosensitive layer. The apparatus further including a charger, an irradiator, an image developer, and a transferer transferring a toner image onto a transfer material. The apparatus also includes a cleaner cleaning the photoreceptor, including a rotatable core and a looped brush fiber provided on the surface of the rotatable core so as to contact the photoreceptor. A top of the looped brush fiber is positioned on an upstream side from a root of the looped brush fiber relative to a rotating direction of the rotatable core.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: April 18, 2006
    Assignee: Ricoh Company Limited
    Inventors: Eiji Kurimoto, Ryohichi Kitajima, Yoshiaki Kawasaki, Akihiro Sugino, Takaaki Ikegami
  • Patent number: 7018755
    Abstract: An electrophotographic photoconductor having at least a photosensitive layer on a conductive support, wherein the electrophotographic photoconductor comprising, in the outermost layer thereof: a filler, an organic compound having an acid value of 10–400 mgKOH/g, and at least one of compounds represented by the following general formulas 1 and 2: where R1, R2 are substituted or unsubstituted alkyl groups or aromatic hydrocarbon rings, and may be identical or different. R1, R2 may also be bonded together to form a substituted or unsubstituted heterocycle containing a nitrogen atom. R3, R4, R5 are substituted or unsubstituted alkyl or alkoxy groups, or halogen atoms. Ar is a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocycle. n is an integer in the range 2 to 4, and k, l, m are respectively integers in the range 0 to 3. X is an oxygen atom, or a sulfur atom.
    Type: Grant
    Filed: September 23, 2003
    Date of Patent: March 28, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Takaaki Ikegami, Tomoyuki Shimada, Yasuo Suzuki, Nozomu Tamoto, Hidetoshi Kami
  • Publication number: 20060056893
    Abstract: An image forming apparatus including a photoreceptor having an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protection layer including an inorganic filler in an amount of from 3 to 25% by weight based on total weight of the protection layer and a binder resin, and overlying the photosensitive layer. The apparatus further including a charger, an irradiator, an image developer, and a transferer transferring a toner image onto a transfer material. The apparatus also includes a cleaner cleaning the photoreceptor, including a rotatable core and a looped brush fiber provided on the surface of the rotatable core so as to contact the photoreceptor. A top of the looped brush fiber is positioned on an upstream side from a root of the looped brush fiber relative to a rotating direction of the rotatable core.
    Type: Application
    Filed: November 7, 2005
    Publication date: March 16, 2006
    Inventors: Eiji Kurimoto, Ryohichi Kitajima, Yoshiaki Kawasaki, Akihiro Sugino, Takaaki Ikegami
  • Publication number: 20050201778
    Abstract: An image forming apparatus containing an image bearing member to bear a latent electrostatic image, a charging device to irradiate the image bearing member with light, a developing device to develop the latent electrostatic image on the image bearing member with a toner, a cleaning device having a cleaning blade to remove toner particles remaining on the image bearing member, and a transfer device to transfer the toner image formed on the image bearing member to a recording material. The image forming apparatus satisfies the following relationships (1) and (2): (1) 0.10< or =Dm3/V< or =3.41, wherein Dm represents a weight average particle diameter of the toner and V represents a circumference velocity of the image bearing member; and (2) Tave< or =1.40 kgf·cm, wherein Tave represents the average of a torque T of the image bearing member when the torque is measured for 15 seconds while the cleaning blade is in contact with the image bearing member.
    Type: Application
    Filed: February 25, 2005
    Publication date: September 15, 2005
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino
  • Publication number: 20050130050
    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: Application
    Filed: December 8, 2004
    Publication date: June 16, 2005
    Inventors: Takeshi Takada, Takaaki Ikegami, Akihiro Sugino
  • Publication number: 20050118518
    Abstract: The present invention relates to an electrophotographic photoconductor comprising a photoconductive layer, a protective layer, and a conductive support, wherein the protective layer is disposed as the outermost layer of the photoconductive layer, and 20% by volume to 60% by volume of fine particles of fluorine-contained resin and at least one compound selected from amine aromatic compounds and hydroxy aromatic compounds are incorporated into the protective layer. According to the present invention, high durability may be achieved, image degradation such as lags may be controlled from the increase of residual potential and decrease of charging, and high quality images may be formed stably even after the prolonged and repeated usage. The present invention also relates to an electrophotographic process, an electrophotographic apparatus and a process cartridge for the electrophotographic apparatus which utilize the electrophotographic photoconductor respectively.
    Type: Application
    Filed: September 13, 2004
    Publication date: June 2, 2005
    Inventors: Takaaki Ikegami, Shinji Nohsho, Eiji Kurimoto, Hidetoshi Kami, Akihiro Sugino, Yasuyuki Yamashita, Hideo Nakamori, Takeshi Takada
  • Publication number: 20050105942
    Abstract: An image forming apparatus including a photoreceptor having an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protection layer including an inorganic filler in an amount of from 3 to 25% by weight based on total weight of the protection layer and a binder resin, and overlying the photosensitive layer. The apparatus further including a charger, an irradiator, an image developer, and a transferer transferring a toner image onto a transfer material. The apparatus also includes a cleaner cleaning the photoreceptor, including a rotatable core and a looped brush fiber provided on the surface of the rotatable core so as to contact the photoreceptor. A top of the looped brush fiber is positioned on an upstream side from a root of the looped brush fiber relative to a rotating direction of the rotatable core.
    Type: Application
    Filed: December 23, 2004
    Publication date: May 19, 2005
    Inventors: Eiji Kurimoto, Ryohichi Kitajima, Yoshiaki Kawasaki, Akihiro Sugino, Takaaki Ikegami
  • Publication number: 20050053853
    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 a particulate fluorine-containing resin, and wherein a primary particle of the particulate fluorine-containing resin and a secondary particle formed of agglomerated primary particles thereof, which are projected from a surface of the outermost layer and have an average particle diameter of from 0.15 to 3 ?m, are present in an area ratio not less than 10% based on total surface area of the outermost layer.
    Type: Application
    Filed: July 19, 2004
    Publication date: March 10, 2005
    Inventors: Akihiro Sugino, Shinji Nousho, Takaaki Ikegami, Eiji Kurimoto, Hideo Nakamori, Hidetoshi Kami, Yasuyuki Yamashita