Patents by Inventor Shinichiro Yagi

Shinichiro Yagi 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: 7083890
    Abstract: A toner is used in an image forming process employing a toner recycling system and contains at least a modified polyester resin, a coloring agent, and a releasing agent. The toner has a volume-average particle diameter Dv, a number-average particle diameter Dn and a shape factor SF-1, wherein Dv is in a range from 4.0 ?m to 6.0 ?m, the ratio Dv/Dn of Dv to Dn is in a range from 1.00 to 1.30, and the shape factor SF-1 is in a range from 140 to 200.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: August 1, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Toshiki Nanya, Naohito Shimota, Maiko Kondo, Shinichiro Yagi, Hiroto Higuchi, Fumihiro Sasaki, Takahiro Honda, Junichi Awamura
  • Publication number: 20060154168
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.61 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Application
    Filed: December 12, 2005
    Publication date: July 13, 2006
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7056638
    Abstract: The present invention is directed to a toner for electrophotography that exhibits excellent hot offset resistance, storability, and glossiness and can obtain a high image-resolution and highly detailed images when used for energy saving apparatuses or as a color toner. The present invention is also directed to a developer, image-forming apparatus, and process cartridge containing such toner, and image-forming process using such toner. The toner of the present invention contains a resin and wax. The wax is dispersed within the resin in a shaped of fine particles to form a toner particle. In the toner particle, more dispersed wax particles are existed in a surface portion of the toner particle than a centric portion of the toner particle.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: June 6, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Toshiki Nanya, Fumihiro Sasaki, Shigeru Emoto, Shinichiro Yagi, Hiroto Higuchi, Naohiro Watanabe, Tadao Takikawa
  • Patent number: 7056636
    Abstract: A dry toner contains at least a toner binder, organic fine particles, a colorant, a wax, a charge control agent, and an external additive. The wax is concentrated in the vicinity of a toner core including the toner binder, colorant and wax. The organic fine particles adhere to the surface of the toner core to form a base toner-particle, the fine particle of charge control agent adhere to the surface of the base toner-particle, and the external additive is located on the surface thereof.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: June 6, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shinichiro Yagi, Shigeru Emoto, Tomoyuki Ichikawa, Naohito Shimota, Maiko Kondo, Tadao Takikawa
  • Patent number: 7029816
    Abstract: An image formation method includes the steps of charging the surface of an electrophotographic photoconductor, exposing the charged photoconductor to a light image to form a latent electrostatic image on the photoconductor, developing the latent electrostatic image using a two-component developer containing a toner and a carrier to obtain a toner image, and transferring the toner image to an image receiving material directly or via an intermediate transfer member, with the photoconductor showing a surface friction coefficient of 0.40 or less, and the toner having toner particles with an average circularity of 0.930 or more.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: April 18, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Sasaki, Mitsuo Aoki, Yasuaki Iwamoto, Naohito Shimota, Kazuyuki Yazaki, Hiroaki Matsuda, Hiroshi Nakai, Kumi Hasegawa, Shinichiro Yagi, Hiroto Higuchi, Akemi Sugiyama
  • Publication number: 20060024606
    Abstract: A carrier containing a core material and a resin coating layer located overlying the surface of the core material. The resin coating layer contains resin and electroconductive particles having an oil absorption amount of from 10 to 300 ml/100 g. The electroconductive particle contains a base material particle and an electroconductive coating layer located overlying the surface of the base material particle. The electroconductive coating layer contains an underlayer containing tin dioxide and an upper layer containing indium oxide and tin dioxide, located overlying the underlayer.
    Type: Application
    Filed: July 27, 2005
    Publication date: February 2, 2006
    Inventors: Kohsuke Suzuki, Tomio Kondoh, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20050250036
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80° C. (G?80) and a storage modulus at 180° C. (G?180) is from 100 to 1,000.
    Type: Application
    Filed: December 1, 2003
    Publication date: November 10, 2005
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Patent number: 6947692
    Abstract: A method for developing an electrostatic latent image, including forming a magnet brush of a developer including a toner and a carrier on a developing sleeve including a main magnet and auxiliary magnets; and developing the electrostatic latent image with the magnet brush to form a toner image at a rubbing region, wherein the magnetic flux density in a normal line direction, half width, and attenuation ratio of the main magnet and the angle between the main magnet and auxiliary magnets are specified, and the magnetic sleeve has specific grooves thereon, and wherein the toner has a volume average particle diameter of from 4.0 to 7.0 ?m, and includes fine particles having a circle equivalent diameter not greater than 2 ?m in an amount not greater than 20% by number.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: September 20, 2005
    Assignee: Ricoh Company Limited
    Inventors: Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Shinichiro Yagi, Masami Tomita, Shigeru Emoto, Naohito Shimota, Hiroto Higuchi, Tomoyuki Ichikawa
  • Patent number: 6936390
    Abstract: A toner for developing an electrostatic image, including a colorant, a binder resin comprising a modified polyester, and fine resin particles having a weight average particle diameter of 50 to 300 nm and being present on an outer surface of the toner, wherein the toner has a BET specific surface area of 1.5 to 4.0 m2/g.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: August 30, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Masami Tomita, Shigeru Emoto, Hiroshi Yamada, Shinichiro Yagi, Naohiro Watanabe, Tadao Takigawa
  • Publication number: 20050186498
    Abstract: A toner is provided that contains a binder resin; a colorant; a release agent; and an external additive, wherein the toner has an average circularity of from 0.940 to 0.965 and a crater having a depth of from 0.02 to 0.1 ?m, and wherein the crater has an amount of the external additive larger than an average amount thereof on the toner, along with a two-component developer containing the toner and an image forming apparatus using the toner.
    Type: Application
    Filed: February 22, 2005
    Publication date: August 25, 2005
    Inventors: Takahiro Honda, Masami Tomita, Toshiki Nanya, Fumihiro Sasaki, Shigeru Emoto, Hiroto Higuchi, Hiroshi Yamada, Shinichiro Yagi, Tomomi Suzuki, Junichi Awamura, Naohito Shimota
  • Publication number: 20050180786
    Abstract: An image forming apparatus including an image bearing member; a charger; a light irradiator; a developing device; a transfer device; an imagebearingmember's cleaner; anda fixing device, wherein the fixing device includes a fixing member configured to fix a toner image upon application of heat and pressure thereto; a pressing member configured to press the recording material toward the fixing member; and a cleaning member configured to clean a surface of the fixing member and/or the pressing member, wherein the cleaning member has an outermost layer including a reactive material which increases viscoelasticity of a binder resin of the toner by reacting with the binder resin.
    Type: Application
    Filed: February 16, 2005
    Publication date: August 18, 2005
    Inventors: Hiroshi Yamada, Fumihiro Sasaki, Shigeru Emoto, Jun Okamoto, Shinji Ohtani, Hiroto Higuchi, Naohito Shimota, Shinichiro Yagi, Junichi Awamura, Tomomi Suzuki, Masami Tomita, Toshiki Nanya, Yoshiki Yamaguchi
  • Publication number: 20050164114
    Abstract: A toner for developing an electrostatic image which has a small particle size essential for attaining a high-quality image, and can output a high-quality image excellent in frictional charging property and free from scumming. The toner for developing an electrostatic image has the volume average particle diameter of 2.0 ?m to 7.1 ?m and the surface condition of the toner is in scab form.
    Type: Application
    Filed: December 28, 2004
    Publication date: July 28, 2005
    Inventors: Shinichiro Yagi, Hiroshi Yamada, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Shigeru Emoto, Masami Tomita, Toshiki Nanya, Tadao Takikawa
  • Patent number: 6916587
    Abstract: A toner including at least a binder resin; a colorant; and a charge controlling agent, in which the binder resin includes at least a polyester resin having a molecular weight distribution such that components having a molecular weight not greater than 500 are included in an amount of 4% by weight and at least a peak is present in a range of from 3,000 to 9,000 when measured by Gel Permeation Chromatography. In addition, the binder resin does not include a tetrahydrofuran-insoluble compound and the charge controlling agent is a resin charge controlling agent including at least units obtained from a monomer including a sulfonate group; an aromatic monomer including an electron absorption group; and an acrylic ester and/or a methacrylic ester monomer.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: July 12, 2005
    Assignee: Ricoh Company Limited
    Inventors: Hiroyuki Fushimi, Toshiki Nanya, Osamu Uchinokura, Shinichiro Yagi, Kohki Katoh
  • Patent number: 6902857
    Abstract: A method for forming an electrophotographic image and a device for forming an image on a transfer material by the steps for charging, exposing, developing and transferring, and recovering the toner remained untransferred in the step for cleaning by recovering, wherein the toner used in the step for developing has a total surface area ratio Z of additive, which is calculated by Z=(Ht·Wt)/(H·W), satisfies 0.5?Z?1.5, the electrophotographic photoconductor used comprises at least a photosensitive layer and a filler-containing protective layer provided on a conductive support in that order, and the angle of repose of the toner to the protective layer surface of the electrophotographic photoconductor is 30° or less.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: June 7, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Naohito Shimota, Tatsuya Niimi, Satoshi Mochizuki, Hiroaki Matsuda, Tomomi Tamura
  • Patent number: 6902858
    Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 ?m.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: June 7, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Mochizuki, Naohito Shimota, Hiroaki Matsuda, Shinichiro Yagi, Tomomi Tamura, Tatsuya Niimi
  • Publication number: 20050112488
    Abstract: A toner is provided that contains a particulate toner material (mother toner) having an average circularity of from 0.93 to 0.99, and including a modified polyester resin and a colorant; and an external additive in an amount of from 0.3 to 5.0 parts by weight per 100 parts by weight of the mother toner, wherein the toner has a melting viscosity of from 70 to 140 Pa·s at 160° C., a weight-average particle diameter of from 3 to 7 ?m, a ratio thereof to a number-average particle diameter of from 1.91 to 1.25, wherein particles satisfy at least one of (I) and (II): (I) particles having a diameter of 4 ?m or less in an amount less than 10% by number; or (II) particles having a diameter of 8 ?m or more in an amount less than 2% by volume, along with a one or two component developer containing the toner, a cartridge containing the toner, an image forming method using the toner and an image forming apparatus using the toner.
    Type: Application
    Filed: October 8, 2004
    Publication date: May 26, 2005
    Inventors: Hiroshi Yamada, Masami Tomita, Toshiki Nanya, Fumuhiro Sasaki, Shigeru Emoto, Naohito Shimota, Shinichiro Yagi, Hiroto Higuchi, Tomomi Suzuki, Junichi Awamura, Takahiro Honda
  • Patent number: 6852462
    Abstract: A toner comprising: a binder resin which is at least a resin selected from the group consisting of modified polyester resins and unmodified polyester resins; and a colorant; the product toner having a volume-average particle diameter (Dv) to a number-average particle diameter (Dn) ratio (Dv/Dn) ranging from 1.00 to 1.30, and the toner having a shape factor SF-1 ranging from 140 to 200.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: February 8, 2005
    Assignee: Ricoh Company Limited
    Inventors: Shigeru Emoto, Tsunemi Sugiyama, Hiroshi Yamashita, Shinichiro Yagi, Masami Tomita, Hiroshi Yamada, Naohiro Watanabe, Toshiki Nanya
  • Patent number: 6849369
    Abstract: Toner particles including a binder resin; a colorant; and a particulate resin which is present at least on a surface of the toner particles and which has a glass transition temperature of form 50 to 90° C., wherein a ratio (Dv/Dn) of a volume average particle diameter (Dv) of the toner particles to a number average particle diameter (Dn) thereof is from 1.00 to 1.40 and the surface of the toner particles is covered with the particulate resin at a covering ratio of from 1 to 90 %. A method for manufacturing the toner particles is provided. A developer including a toner including the toner particles is provided. A developing method using a toner including the toner particles is provided. A toner container containing the toner particles is provided.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: February 1, 2005
    Assignee: Ricoh Company, Limited
    Inventors: Shinichiro Yagi, Masami Tomita, Toshiki Nanya, Shigeru Emoto, Hiroshi Yamada, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Tadao Takigawa
  • Publication number: 20040229147
    Abstract: A toner composition including toner particles including at least a binder resin; and a colorant, wherein the toner composition satisfies at least one of the following relationships (1) and (2):
    Type: Application
    Filed: March 5, 2004
    Publication date: November 18, 2004
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Shinichiro Yagi, Shigeru Emoto, Junichi Awamura, Naohito Shimota, Masami Tomita, Toshiki Nanya, Takahiro Honda, Maiko Kondo
  • Patent number: 6818370
    Abstract: A toner for developing an electrostatic latent image, containing a colorant and a binder resin composed of two different resins (A) and (B), wherein resin (A) is substantially free of tetrahydrofuran insolubles, is selected from polyester resins and polyol resins and has such a molecular weight distribution according to gel permeation chromatography that (a) a main peak is present in a molecular weight of 3000 to 9,000 and (b) that portion of resin (A) having a molecular weight of 500 or less accounts for 4% or less based on a total weight of resin (A), wherein resin (B) is substantially free of tetrahydrofuran insolubles and is a polyester resin containing a diol component represented by the formula (1): and wherein the weight ratio of resin (A) to resin (B) is in the range of 60:40 to 85:15.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: November 16, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Osamu Uchinokura, Hiroyuki Fushimi, Kohki Katoh, Shinichiro Yagi, Toshiki Nanya