Patents by Inventor Hiroto Higuchi

Hiroto Higuchi 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).

  • Publication number: 20060204883
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Application
    Filed: March 20, 2006
    Publication date: September 14, 2006
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Publication number: 20060177756
    Abstract: A toner formed of a toner composition containing a resin and a plasticizer, wherein the following relationships (1) and (2) are satisfied: Tg2r>Tg2t (1), and Tg1t?Tg2t>Tg1r?Tg2r (2), wherein Tg1r represents the peak of the resin for the first temperature rise and Tg2r represents the peak of the resin for the second temperature rise when a differential scanning calorimeter (DSC) measurement is performed for the resin, Tg1t represents the peak of the toner comprising the resin for the first temperature rise and Tg2t represents the peak of the toner comprising the resin for the second temperature rise when a differential scanning calorimeter (DSC) measurement is performed for the toner.
    Type: Application
    Filed: January 26, 2006
    Publication date: August 10, 2006
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Hiroto Higuchi
  • 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: 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: 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: 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: 20060063081
    Abstract: It is an object of the present invention to provide a toner that can sustain favorable transferability and cleaning ability for prolonged periods; prevent photoconductor filming; exhibit no variation in image nonuniformity or external additive immersion induced by developer agitation at the time of use; excels in stability with flowability and charge stability over prolonged periods. Therefore, provided is the toner of which the quantity of aggregate of residual external additives found on the sieve of 635-mesh and 452 cm2 of mesh area, after 0.2 g of the toner on the sieve is blasted with air at a blow pressure of 0.2 MPa from 160 mm above the sieve while being air-suctioned at a suction force of 5 mmHg, and then air-suctioned at a suction force of 20 mmHg, is 4,500 or less and 5 or more.
    Type: Application
    Filed: September 16, 2005
    Publication date: March 23, 2006
    Inventors: Tsuneyasu Nagatomo, Akihiro Kotsugai, Hiroshi Yamashita, Masayuki Ishii, Hiroto Higuchi, Osamu Uchinokura, Satoshi Mochizuki, Fumihiro Sasaki, Hisashi Nakajima, Hideki Sugiura, Yasuo Asahina, Shinya Nakayama, Koichi Sakata, Tomoyuki Ichikawa, Takuya Saito, Sonoh Matsuoka
  • Publication number: 20060024097
    Abstract: A fixer fixing a toner including a binder resin and a colorant on a recording medium upon application of at least one of heat and pressure, including: a fixing member fixing the toner on the recording medium; a pressurizing member pressurizing the toner thereon; and a cleaning member collecting the toner from the fixing member or the pressurizing member onto the cleaning member, wherein a storage modulus of the toner collected on the cleaning member is larger than a storage modulus thereof before fixed.
    Type: Application
    Filed: August 2, 2005
    Publication date: February 2, 2006
    Inventors: Hiroshi Yamada, Junichi Awamura, Tomomi Suzuki, Hiroto Higuchi, Naohito Shimota, Masami Tomita, Fumihiro Sasaki, Toshiki Nanya
  • 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
  • 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
  • Patent number: 6934484
    Abstract: In a copier which is an image-forming apparatus comprising a photoconductor 1, a developing apparatus 4, transfer apparatus 5 which transfers a toner image formed on the photoconductor 1 to a transfer material by heat and pressure using a transfer roller 52, and a fixing apparatus which fixes the toner image transferred to the transfer material, on the transfer material, a heater 56, temperature detection apparatus 57 and temperature control apparatus are provided which controls the temperature to within a range of from the glass transition temperature (Tg) to the softening temperature (Tm) of the toner, and lower than the fixing temperature of the fixing apparatus 7.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: August 23, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Hiroto Higuchi, Shinya Nakayama, Maiko Kondo, Bing Shu, Yasushi Koichi, Tadashi Kasai, Yutaka Takahashi
  • 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
  • Patent number: 6924073
    Abstract: A toner for developing an electrostatic latent image, comprising a colorant, a releasing agent and a binder resin, wherein said binder resin comprises a first, non-linear resin, a second, linear resin, and a modified wax comprising a wax moiety and a vinyl polymer moiety having an ester group content of 8 to 30% by weight based on the weight of the vinyl polymer moiety.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: August 2, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Mitsuo Aoki, Fumihiro Sasaki, Naohito Shimota, Kumi Hasegawa, Bing Shu, Maiko Kondo, Shinya Nakayama
  • Patent number: 6911289
    Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: June 28, 2005
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • 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: 6873814
    Abstract: A developing device including a developer containing magnetic toner grains and includes a main pole for development disposed in a sleeve. Flux density generated by the magnetic pole in a direction normal to the surface of the sleeve outside of the surface has an attenuation ratio of 50% or above. The toner grains have a weight mean grain size of 6.0 ?m to 8.0 ?m while the toner grains having grain sizes of 5 ?m and below occupy 40% to 80% of the entire developer. The toner grains have magnetization strength of 10 emu/g to 25 emu/g in a magnetic field of 5 kOe or magnetization strength of 7 emu/g to 20 emu/g in a magnetic field of 1 kOe. The toner grains reduce toner scattering and image defects despite that they are magnetic, thereby implementing ultrahigh resolution.
    Type: Grant
    Filed: November 1, 2002
    Date of Patent: March 29, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Tokuya Ohjimi, Fumihiro Sasaki, Hiroto Higuchi, Maiko Kondo, Toshio Koike, Atsushi Sampe, Masayuki Yamane, Kunihiro Ohyama, Junichi Sano, Takeyoshi Sekine
  • Patent number: 6856774
    Abstract: A developing device developing a latent image on a latent image carrier with a developer, and including a casing having an opening facing the latent image carrier and a developer carrier. Also included is a magnetic field generating device including a first magnetic pole generating a magnetic field causing the developer to rise on the developer carrier in a form of a magnet brush in a developing region, and a second magnetic pole generating a magnetic field at a downstream side of the first magnetic pole in a rotating direction of the developer carrier. Further, a toner-scattering restraining device is provided on an end portion of the casing at the downstream side of the developing region, and a magnetic member provided on a side of the toner-scattering restraining device facing the latent image carrier. A peak of a magnetic flux density set by the second magnetic pole in its normal direction is located outside of the opening.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: February 15, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Sampe, Takeyoshi Sekine, Masayuki Yamane, Tokuya Ohjimi, Junichi Sano, Toshio Koike, Fumihiro Sasaki, Hiroto Higuchi, Maiko Kondo, Kunihiro Ohyama
  • Patent number: 6856781
    Abstract: An image forming apparatus including a photoconductor, and a developing unit having a developing sleeve for carrying a developer and a developer regulating plate for regulating the amount of the developer carried on the sleeve, wherein the developer is composed of a carrier and a toner, wherein that portion of the toner which has a particle diameter of 2.0-4.0 ?m accounts for 30-70% of a total number thereof, and wherein the developer regulating plate is grounded so that when the developing sleeve is applied with a bias voltage, an electric field is formed between the developer regulating plate and the developing sleeve, whereby toner deposits on the developing sleeve are transferred to the developer regulating plate.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: February 15, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Matsuda, Yasuaki Iwamoto, Hiroshi Nakai, Hiroto Higuchi, Bing Shu, Maiko Kondo, Fumihiro Sasaki