Patents by Inventor Maiko Kondo

Maiko Kondo 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: 6813461
    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: February 26, 2004
    Date of Patent: November 2, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Patent number: 6811944
    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: February 26, 2004
    Date of Patent: November 2, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Publication number: 20040209181
    Abstract: A toner for developing latent electrostatic images is in the form of particles prepared by dissolving or dispersing each component of a composition in an organic solvent to form a solution or dispersion, the composition containing at least a resin reactive with a compound having an active hydrogen group, a compound having an active hydrogen group, a coloring agent, a releasing agent, and a graft polymer C of a polyolefin resin A on which a vinyl resin B has been at least partially grafted; dispersing the solution or dispersion in an aqueous medium; reacting the reactive resin with the compound having an active hydrogen group; removing the organic solvent during or after the step of reacting; and washing and drying particles formed by removing the organic solvent.
    Type: Application
    Filed: January 21, 2004
    Publication date: October 21, 2004
    Inventors: Hiroto Higuchi, Masami Tomita, Fumihiro Sasaki, Shigeru Emoto, Naohito Shimota, Maiko Kondo, Takahiro Honda, Junichi Awamura, Shinichiro Yagi, Toshiki Nanya, Tadao Takikawa
  • Patent number: 6790575
    Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: September 14, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Sasaki, Hiroaki Matsuda, Bing Shu, Maiko Kondo, Hiroshi Nakai, Hiroto Higuchi, Yasuaki Iwamoto, Yoshihiro Suguro, Hiroyuki Yoshikawa, Masahide Yamashita, Kazuyuki Yazaki
  • Publication number: 20040166429
    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: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Publication number: 20040166428
    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: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Publication number: 20040146795
    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 &mgr;m to 6.0 &mgr;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: Application
    Filed: January 20, 2004
    Publication date: July 29, 2004
    Inventors: Shigeru Emoto, Toshiki Nanya, Naohito Shimota, Maiko Kondo, Shinichiro Yagi, Hiroto Higuchi, Fumihiro Sasaki, Takahiro Honda, Junichi Awamura
  • Publication number: 20040142265
    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: Application
    Filed: November 14, 2003
    Publication date: July 22, 2004
    Inventors: Masami Tomita, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shinichiro Yagi, Shigeru Emoto, Tomoyuki Ichikawa, Naohito Shimota, Maiko Kondo, Tadao Takikawa
  • Publication number: 20040126147
    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 &mgr;m, and includes fine particles having a circle equivalent diameter not greater than 2 &mgr;m in an amount not greater than 20% by number.
    Type: Application
    Filed: September 22, 2003
    Publication date: July 1, 2004
    Inventors: Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Shinichiro Yagi, Masami Tomita, Shigeru Emoto, Naohito Shimota, Hiroto Higuchi, Tomoyuki Ichikawa
  • Publication number: 20040076443
    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: Application
    Filed: August 1, 2003
    Publication date: April 22, 2004
    Inventors: Koji Suzuki, Mitsuo Aoki, Hiroto Higuchi, Shinya Nakayama, Maiko Kondo, Bing Shu, Yasushi Koichi, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20040053154
    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 &mgr;m to 7 &mgr;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 0.6 &mgr;m to 2.0 &mgr;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: June 27, 2003
    Publication date: March 18, 2004
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 6699632
    Abstract: An image forming toner is provided, including at least: a binder resin; a colorant; and a release agent, wherein a volume-average particle diameter of the toner measured by a Coulter counter is from 5 to 8 &mgr;m; the content of the toner having a volume-average particle diameter of not greater than 5 &mgr;m is 60 to 75% by number; and the content of the toner having a number-basis circle-equivalent particle diameter of from 0.6 to 3 &mgr;m measured by a flow-type particle image analyzer is not greater than 25%.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: March 2, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroaki Matsuda, Hiroshi Nakai, Bing Shu, Maiko Kondo
  • Patent number: 6667141
    Abstract: An image forming method and apparatus, wherein a surface of a photoconductor is charged with a contact-type charging roller having a surface roughness of 2-40 &mgr;m, and exposed imagewise to form an electrostatic latent image thereon, the latent image being developed with a toner, transferred to a transfer member and fixed, and wherein the toner comprises a colorant, and a binder resin containing a tetrahydrofuran-soluble component having such a molecular weight distribution that at least one peak having a half width not greater than 15,000 is present between 1,000 and 10,000 when measured by gel permeation chromatography.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: December 23, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuaki Iwamoto, Fumihiro Sasaki, Hiroaki Matsuda, Hiroshi Nakai, Hiroto Higuchi, Bing Shu, Maiko Kondo
  • Publication number: 20030165760
    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: Application
    Filed: December 27, 2002
    Publication date: September 4, 2003
    Inventors: Hiroto Higuchi, Mitsuo Aoki, Fumihiro Sasaki, Naohito Shimota, Kumi Hasegawa, Bing Shu, Maiko Kondo, Shinya Nakayama
  • Patent number: 6593048
    Abstract: A two-component developer includes at least a magnetic toner and a magnetic carrier. The magnetic toner has magnetic particles coated with a carbon black layer. The magnetic toner adheres to the magnetic carrier due to the magnetic interaction.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: July 15, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Sasaki, Yasuaki Iwamoto, Hiroaki Matsuda, Hiroshi Nakai, Hiroto Higuchi, Hyou Shu, Maiko Kondo
  • Publication number: 20030108362
    Abstract: A developing device of the present invention uses 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 &mgr;m to 8.0 &mgr;m while the toner grains having grain sizes of 5 &mgr;m and below occupy 40 number % to 80 number % 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, image reproducibility.
    Type: Application
    Filed: November 1, 2002
    Publication date: June 12, 2003
    Inventors: Tokuya Ohjimi, Fumihiro Sasaki, Hiroto Higuchi, Maiko Kondo, Toshio Koike, Atsushi Sampe, Masayuki Yamane, Kunihiro Ohyama, Junichi Sano, Takeyoshi Sekine
  • Publication number: 20030099481
    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: Application
    Filed: November 26, 2002
    Publication date: May 29, 2003
    Inventors: Atsushi Sampe, Takeyoshi Sekine, Masayuki Yamane, Tokuya Ohjimi, Junichi Sano, Toshio Koike, Fumihiro Sasaki, Hiroto Higuchi, Maiko Kondo, Kunihiro Ohyama
  • Publication number: 20030082472
    Abstract: A toner including at least a binder resin; a colorant; a charge controlling agent; and a wax (B), in which the charge controlling agent comprises a compound selected from the group consisting of: an aromatic oxycarboxylic acids, derivatives of aromatic oxycarboxylic acid, salts of aromatic oxycarboxylic acids and salts of derivatives of aromatic oxycarboxylic acids; and a zirconium compound (A), and in which the zirconium compound (A) and the wax (B) have a weight ratio (A/B) satisfying the following relationship:
    Type: Application
    Filed: May 21, 2002
    Publication date: May 1, 2003
    Inventors: Maiko Kondo, Yasuaki Iwamoto, Fumihiro Sasaki, Hiroto Higuchi, Bing Shu, Yasushi Koichi
  • Publication number: 20030073021
    Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.
    Type: Application
    Filed: March 21, 2002
    Publication date: April 17, 2003
    Inventors: Fumihiro Sasaki, Hiraoki Matsuda, Bing Shu, Maiko Kondo, Hiroshi Nakai, Hiroto Higuchi, Yasuaki Iwamoto, Yoshihiro Suguro, Hiroyuki Yoshikawa, Masahide Yamashita, Kazuyuki Yazaki
  • Publication number: 20020159797
    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 &mgr;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: Application
    Filed: February 20, 2002
    Publication date: October 31, 2002
    Inventors: Hiroaki Matsuda, Yasuaki Iwamoto, Hiroshi Nakai, Hiroto Higuchi, Bing Shu, Maiko Kondo, Fumihiro Sasaki