Patents by Inventor Michitaka Sasaki

Michitaka Sasaki 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: 9116468
    Abstract: A powder storage container capable of preventing erroneous opening of a powder loading port. The powder storage container includes a powder storage part configured to store a developer used for image forming, a powder discharge part provided on one end part of the powder storage part to discharge the developer stored in the powder storage part, a gripping part protruding through an end face of the one end part side of the powder storage part, a powder loading port causing an inner space of the powder storage part and an outer portion of the powder storage part to communicate with each other, and a sealing member capable of sealing the powder loading port. The powder loading port is enclosed by the gripping part.
    Type: Grant
    Filed: March 29, 2012
    Date of Patent: August 25, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Seiji Terazawa, Atsushi Inoue, Kaori Mitsuishi, Yuki Oshikawa, Tadashi Hayakawa, Michitaka Sasaki, Hiroyuki Iwasa
  • Publication number: 20140029973
    Abstract: A powder storage container capable of preventing erroneous opening of a powder loading port. The powder storage container includes a powder storage part configured to store a developer used for image forming, a powder discharge part provided on one end part of the powder storage part to discharge the developer stored in the powder storage part, a gripping part protruding through an end face of the one end part side of the powder storage part, a powder loading port causing an inner space of the powder storage part and an outer portion of the powder storage part to communicate with each other, and a sealing member capable of sealing the powder loading port. The powder loading port is enclosed by the gripping part.
    Type: Application
    Filed: March 29, 2012
    Publication date: January 30, 2014
    Inventors: Seiji Terazawa, Atsushi Inoue, Kaori Mitsuishi, Yuki Oshikawa, Tadashi Hayakawa, Michitaka Sasaki, Hiroyuki Iwasa
  • Patent number: 8064795
    Abstract: An electrophotographic image forming apparatus, including a photoreceptor, a charger charging the surface of the photoreceptor, an irradiator irradiating the surface of the photoreceptor with imagewise light to form an electrostatic latent image thereon, an image developer developing the electrostatic latent image with a developer including a toner to form a toner image on the surface of the photoreceptor, and a transferer transferring the toner image onto a transfer material, wherein the photoreceptor includes an electroconductive substrate, and a photosensitive layer overlying the electroconductive substrate and including a charge generation material and a specific charge transport material.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: November 22, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Shimoyama, Eiji Kurimoto, Michitaka Sasaki, Shin-ichi Kawamura
  • Publication number: 20110111335
    Abstract: To provide an electrophotographic photoconductor that has a layer containing a compound represented by the following general formula (1), and an image forming apparatus using the electrophotographic photoconductor.
    Type: Application
    Filed: November 5, 2010
    Publication date: May 12, 2011
    Inventors: Keisuke SHIMOYAMA, Eiji Kurimoto, Takeshi Orito, Tatsuya Niimi, Shinichi Kawamura, Yoshiki Yanagawa, Michitaka Sasaki
  • Patent number: 7871747
    Abstract: To provide an electrophotographic photoconductor that has a layer containing a compound represented by the following general formula (1), and an image forming apparatus using the electrophotographic photoconductor. where R1 and R2 independently represent any one of a hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group and substituted or unsubstituted aralkyl group, and R3, R4, R5, R6, R7, R8, R9 and R10 independently represent any one of a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group and substituted or unsubstituted aralkyl group.
    Type: Grant
    Filed: September 12, 2006
    Date of Patent: January 18, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Shimoyama, Eiji Kurimoto, Takeshi Orito, Tatsuya Niimi, Shinichi Kawamura, Yoshiki Yanagawa, Michitaka Sasaki
  • Patent number: 7862969
    Abstract: The present invention provides an image bearing member that includes: a photoconductor; and a heating unit which heats the photoconductor, wherein the photoconductor includes: a support; a charge generating layer on the support, a charge transport layer, and a crosslinked charge transport layer in this order, wherein the crosslinked charge transport layer includes a reaction product of a radically polymerizable compound with three or more functional groups which does not have a charge transporting structure, and a radically polymerizable compound with one functional group, which compound has a charge transporting structure.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: January 4, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuo Suzuki, Kohichi Ohshima, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20100260515
    Abstract: An electrophotographic image forming apparatus, including a photoreceptor, a charger charging the surface of the photoreceptor, an irradiator irradiating the surface of the photoreceptor with imagewise light to form an electrostatic latent image thereon, an image developer developing the electrostatic latent image with a developer including a toner to form a toner image on the surface of the photoreceptor, and a transferer transferring the toner image onto a transfer material, wherein the photoreceptor includes an electroconductive substrate, and a photosensitive layer overlying the electroconductive substrate and including a charge generation material and a specific charge transport material.
    Type: Application
    Filed: May 10, 2010
    Publication date: October 14, 2010
    Inventors: Keisuke SHIMOYAMA, Eiji Kurimoto, Michitaka Sasaki, Shin-ichi Kawamura
  • Patent number: 7662533
    Abstract: An image forming method including: forming an electrostatic latent image on an image bearing member; developing the latent image with a toner; transferring the toner image onto a receiving material; and fixing the toner image. The image bearing member includes a substrate, and a charge generation layer, a charge transport layer and a crosslinked charge transport layer, wherein the crosslinked charge transport layer includes a compound obtained from radical polymerizable monomers including a monomer having three or more functional groups and no charge transport structure and a monomer having one functional group and a charge transport structure. The toner includes a binder resin, a colorant, and a release agent, wherein tetrahydrofuran-soluble components of the binder resin have a molecular weight distribution such that at least one peak is observed in a range of from 1,000 to 10,000 and the half-width of the molecular weight distribution curve is not greater than 15,000.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: February 16, 2010
    Assignee: Ricoh Company Limited
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Patent number: 7550238
    Abstract: An image forming process using an electrostatic latent image carrier containing a support and a photoconductive layer including: a charge generating layer, a charge transportable layer, and a cross-linked charge transportable layer which are disposed on the support in this order and the cross-linked charge transportable layer comprises a compound produced by the reaction between a trifunctional or more functional radical-polymerizable compound having no charge transportable structure, and a monofunctional radical-polymerizable compound having a charge transportable structure, and a toner produced in the form of particles by producing an adhesive base material through reacting a compound having an active hydrogen group with a polymer which can be reacted with the above-noted compound having an active hydrogen group in an aqueous medium.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: June 23, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Patent number: 7517625
    Abstract: An image forming apparatus including: an electrophotographic photoreceptor; a non-contact charger located close to the electrophotographic photoreceptor, charging the electrophotographic photoreceptor; an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; and a transferer transferring the toner image onto a transfer material, wherein the electrophotographic photoreceptor comprises: an electroconductive substrate; a charge generation layer located overlying the electroconductive substrate; a charge transport layer located overlying the charge generation layer; and a crosslinked charge transport layer, located overlying the charge transport layer, wherein the crosslinked charge transport layer is formed by hardening a radical polymeric monomer having three or more functional groups without a charge transport structu
    Type: Grant
    Filed: September 6, 2005
    Date of Patent: April 14, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuo Suzuki, Michitaka Sasaki, Tetsuro Suzuki, Kohichi Ohshima
  • Publication number: 20070212625
    Abstract: The present invention provides an image bearing member that includes: a photoconductor; and a heating unit which heats the photoconductor, wherein the photoconductor includes: a support; a charge generating layer on the support, a charge transport layer, and a crosslinked charge transport layer in this order, wherein the crosslinked charge transport layer includes a reaction product of a radically polymerizable compound with three or more functional groups which does not have a charge transporting structure, and a radically polymerizable compound with one functional group, which compound has a charge transporting structure.
    Type: Application
    Filed: January 10, 2007
    Publication date: September 13, 2007
    Inventors: Yasuo Suzuki, Kohichi Ohshima, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20070059619
    Abstract: To provide an electrophotographic photoconductor that has a layer containing a compound represented by the following general formula (1), and an image forming apparatus using the electrophotographic photoconductor.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 15, 2007
    Inventors: Keisuke Shimoyama, Eiji Kurimoto, Takeshi Orito, Tatsuya Niimi, Shinichi Kawamura, Yoshiki Yanagawa, Michitaka Sasaki
  • Publication number: 20070059039
    Abstract: An electrophotographic image forming apparatus, including a photoreceptor, a charger charging the surface of the photoreceptor, an irradiator irradiating the surface of the photoreceptor with imagewise light to form an electrostatic latent image thereon, an image developer developing the electrostatic latent image with a developer including a toner to form a toner image on the surface of the photoreceptor, and a transferer transferring the toner image onto a transfer material, wherein the photoreceptor includes an electroconductive substrate, and a photosensitive layer overlying the electroconductive substrate and including a charge generation material and a specific charge transport material.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 15, 2007
    Inventors: Keisuke Shimoyama, Eiji Kurimoto, Michitaka Sasaki, Shin-ichi Kawamura
  • Publication number: 20060093955
    Abstract: An image forming method including forming a toner image on an image bearing member; transferring the toner image onto a receiving material; and then cleaning the surface of the image bearing member with a cleaning member while applying a voltage to the cleaning member such that the cleaning member electrostatically attracts toner particles remaining on the image bearing member, wherein the image bearing member has, as an outermost layer, a crosslinked charge transport layer comprising a crosslinked resin including at least one unit obtained from at least one radical polymerizable polyfunctional monomer having three or more radical polymerizable functional groups and no charge transport structure, and a unit obtained from a radical polymerizable functional monomer having one or more radical polymerizable functional groups and a charge transport structure. An image forming apparatus and a process cartridge using the image forming method are also provided.
    Type: Application
    Filed: October 31, 2005
    Publication date: May 4, 2006
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20060068308
    Abstract: An image forming process is provided, which is consisting of forming step for forming a latent electrostatic image on a photoconductor, developing step, transferring step, and fixing step, wherein the photoconductor contains the crosslinked charge transporting layer containing a cured product formed from at least a radical polymerizable compound having three or more functionalities and no charge transport structure, and a radical polymerizable compound having one functionality and a charge transport structure, wherein the developer includes a toner and a carrier, the carrier has core particles and a coating layer for coating the core particles, the content of the core particles having a particle diameter of smaller than 44 ?m in the carrier is 70% by mass or more, and the content of the core particles having a particle diameter of smaller than 22 ?m in the carrier is 7% by mass or less, a mass average particle diameter of the carrier (Dw) is 25 ?m to 45 ?m, and a ratio (Dw/Dp) of Dw to a number average partic
    Type: Application
    Filed: September 20, 2005
    Publication date: March 30, 2006
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20060051689
    Abstract: An image forming apparatus including: an electrophotographic photoreceptor; a non-contact charger located close to the electrophotographic photoreceptor, charging the electrophotographic photoreceptor; an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; and a transferer transferring the toner image onto a transfer material, wherein the electrophotographic photoreceptor comprises: an electroconductive substrate; a charge generation layer located overlying the electroconductive substrate; a charge transport layer located overlying the charge generation layer; and a crosslinked charge transport layer, located overlying the charge transport layer, wherein the crosslinked charge transport layer is formed by hardening a radical polymeric monomer having three or more functional groups without a charge transport structure a
    Type: Application
    Filed: September 6, 2005
    Publication date: March 9, 2006
    Inventors: Yasuo Suzuki, Michitaka Sasaki, Tetsuro Suzuki, Kohichi Ohshima
  • Publication number: 20060014096
    Abstract: An image forming method including: charging an electrophotographic photoreceptor including: an electroconductive substrate; and a photosensitive layer comprising a crosslinked surface layer on a surface thereof, which is located overlying the electroconductive substrate, irradiating the electrophotographic photoreceptor with imagewise light to form an electrostatic latent image thereon; developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; transferring the toner image onto a transfer material; and fixing the toner image on the transfer material, wherein the photosensitive layer is sensitive to light having a wavelength of from 400 to 450 nm, and the crosslinked surface layer is formed by crosslinking and hardening a radical polymerizing monomer having three or more functional groups without a charge transport structure and a radical polymerizing compound having one functional group with charge transport structure.
    Type: Application
    Filed: June 27, 2005
    Publication date: January 19, 2006
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20050287465
    Abstract: An image forming method including: forming an electrostatic latent image on an image bearing member; developing the latent image with a toner; transferring the toner image onto a receiving material; and fixing the toner image. The image bearing member includes a substrate, and a charge generation layer, a charge transport layer and a crosslinked charge transport layer, wherein the crosslinked charge transport layer includes a compound obtained from radical polymerizable monomers including a monomer having three or more functional groups and no charge transport structure and a monomer having one functional group and a charge transport structure. The toner includes a binder resin, a colorant, and a release agent, wherein tetrahydrofuran-soluble components of the binder resin have a molecular weight distribution such that at least one peak is observed in a range of from 1,000 to 10,000 and the half-width of the molecular weight distribution curve is not greater than 15,000.
    Type: Application
    Filed: June 24, 2005
    Publication date: December 29, 2005
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Publication number: 20050238987
    Abstract: The object of the present invention is to provide an image forming process which can form a stable image for a long term without causing an image blur, an image failure in the form of a stripe or a dot, and an image fluctuation due to an environmental fluctuation.
    Type: Application
    Filed: April 21, 2005
    Publication date: October 27, 2005
    Inventors: Kohichi Ohshima, Yasuo Suzuki, Tetsuro Suzuki, Michitaka Sasaki
  • Patent number: 6271310
    Abstract: A polypropylene composition which contains 0.01 to 5 parts by weight of an olefin (co)polymer (a) having an intrinsic viscosity of 15 to 100 dl/g, 100 parts by weight of a propylene homopolymer (b) having an intrinsic viscosity of 0.2 to 10 dl/g, and 28 to 300 parts by weight of an ethylene/propylene copolymer (c) having an intrinsic viscosity of 0.2 to 10 dl/g, and in which the ratio of the melt flow rate of the homopolymer (b) to that of the copolymer (c), MFRPP/MFRRC, is 0.3 to 4 and the product of the ratio of the intrinsic viscosity of the copolymer (c) to that of the homopolymer (b), [&eegr;]RC/[&eegr;]PP, and the weight ratio of the amount of the homopolymer (b) to that of the copolymer (c), WPP/WRC, is in the range of from 0.2 to 3.0. The composition has high melt tension, high crystallization temperature, and excellent thermal stability, and yields a molded article having excellent transparency, reduced molding shrinkage, and excellent resistance to whitening by impact or bending.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: August 7, 2001
    Assignee: Chisso Corporation
    Inventors: Chikashi Okayama, Takanori Nakashima, Akira Yamauchi, Jun Saito, Michitaka Sasaki