Patents by Inventor Kazuoki Fuwa

Kazuoki Fuwa 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: 7867680
    Abstract: A non-magnetic toner including a binder resin including a first resin, a second resin, a third resin; a colorant; and a wax, wherein the first resin is a hybrid resin including an amorphous condensation polymerization unit and a radical polymerization unit in its molecular frame, and the second and third resins are non-hybrid resins including condensation polymerization units, wherein each of the first, second and third resins has a glass transition temperature (Tg) and a softening point (Tm) satisfying the following relationships: Tg of first resin<Tg of second resin<Tg of third resin, which is from 70 to 80° C., and Tm of second resin<Tm of third resin<Tm of first resin, and wherein the binder resin includes the first resin in an amount of from 10 to 20% and the third resin of from 25 to 45% by weight.
    Type: Grant
    Filed: January 5, 2009
    Date of Patent: January 11, 2011
    Assignee: Ricoh Company Limited
    Inventors: Yoshihiro Mikuriya, Kazuoki Fuwa, Hiroaki Katoh, Yoshitaka Sekiguchi, Hideaki Yasunaga, Masayuki Hagi
  • Patent number: 7820348
    Abstract: To provide a toner recovery apparatus including: a toner transporting duct; and an endless toner transporting belt; wherein the toner transporting belt is rotated in a loop form in such a way that it descends in a region where the outer circumferential surface faces a ceiling surface of the toner transporting duct and that it rises in a region where the outer circumferential surface of the toner transporting belt faces a bottom surface of the toner transporting duct, the toner recovery apparatus transports the residual toner to the outlet by holding the toner by the convex parts, spaces formed between convex parts and the bottom surface of the toner transporting duct, and the toner comprises a binding resin, releasing agent, coloring material and external additive, and torque T (mNm) measured by torque measurement method using a conical rotor in a space ratio of 50% to 60% is 1.0 to 2.5.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: October 26, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Hagi, Yoshihiro Mikuriya, Yoshitaka Sekiguchi, Hideaki Yasunaga, Hiroaki Kato, Kazuoki Fuwa, Masahide Inoue, Yoshiyuki Shimizu
  • Patent number: 7817946
    Abstract: The present invention provides a developing device that allows for maintaining the conveyance amount of a toner within a certain definite range. A developing device 12 of the present invention is provided with a toner conveying unit 13 configured to convey a first toner and a controlling member 15 configured to control the thickness of a toner layer formed with the first toner conveyed by the toner conveying unit 13, wherein a second toner provided with a charged amount per unit mass that differs from a charged amount per unit mass of the first toner is applied over the surface of the controlling member 15.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: October 19, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Murakami, Masahide Inoue, Masayuki Hagi, Takuya Kadota, Yoshihiro Mikuriya, Katsunori Kurose, Hideaki Yasunaga, Hiroaki Kato, Yoshimichi Ishikawa, Kazuoki Fuwa
  • Publication number: 20100167196
    Abstract: To provide a toner recovery apparatus including: a toner transporting duct; and an endless toner transporting belt; wherein the toner transporting belt is rotated in a loop form in such a way that it descends in a region where the outer circumferential surface faces a ceiling surface of the toner transporting duct and that it rises in a region where the outer circumferential surface of the toner transporting belt faces a bottom surface of the toner transporting duct, the toner recovery apparatus transports the residual toner to the outlet by holding the toner by the convex parts, spaces formed between convex parts and the bottom surface of the toner transporting duct, and the toner comprises a binding resin, releasing agent, coloring material and external additive, and torque T (mNm) measured by torque measurement method using a conical rotor in a space ratio of 50% to 60% is 1.0 to 2.5.
    Type: Application
    Filed: March 12, 2010
    Publication date: July 1, 2010
    Inventors: Masayuki Hagi, Yoshihiro Mikuriya, Yoshitaka Sekiguchi, Hideaki Yasunaga, Hiroaki Kato, Kazuoki Fuwa, Masahide Inoue, Yoshiyuki Shimizu
  • Patent number: 7727694
    Abstract: A toner including toner particles including a binder resin, and a colorant, and an external additive present on a surface of the toner particles, wherein the external additive includes a silica having an average primary particle diameter of from 100 to 500 nm and a BET specific surface area of from 800 to 1000 m2/g. An image forming method including forming an electrostatic image on an image bearing member; developing the electrostatic image with the toner to form a toner image; and transferring the toner image on to a receiving material. An image forming apparatus including an image bearing member bearing an electrostatic image; a developing device developing an electrostatic image with the toner to form a toner image on the image bearing member; a transfer device transferring the toner image to a receiving material; and a fixing device fixing the toner image on the receiving material.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: June 1, 2010
    Assignee: Ricoh Company Limited
    Inventors: Hiroyuki Murakami, Masahide Inoue, Masayuki Hagi, Takuya Kadota, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Katoh, Yoshimichi Ishikawa, Kazuoki Fuwa
  • Patent number: 7720428
    Abstract: To provide a toner recovery apparatus including: a toner transporting duct; and an endless toner transporting belt; wherein the toner transporting belt is rotated in a loop form in such a way that it descends in a region where the outer circumferential surface faces a ceiling surface of the toner transporting duct and that it rises in a region where the outer circumferential surface of the toner transporting belt faces a bottom surface of the toner transporting duct, the toner recovery apparatus transports the residual toner to the outlet by holding the toner by the convex parts, spaces formed between convex parts and the bottom surface of the toner transporting duct, and the toner comprises a binding resin, releasing agent, coloring material and external additive, and torque T (mNm) measured by torque measurement method using a conical rotor in a space ratio of 50% to 60% is 1.0 to 2.5.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: May 18, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Hagi, Yoshihiro Mikuriya, Yoshitaka Sekiguchi, Hideaki Yasunaga, Hiroaki Kato, Kazuoki Fuwa, Masahide Inoue, Yoshiyuki Shimizu
  • Publication number: 20100009282
    Abstract: An image forming method, including charging the surface of an electrostatic latent image bearer by a charger; irradiating the surface of the electrostatic latent image bearer to form an electrostatic latent image thereon; developing the same with a toner to form a toner image; transferring the toner image onto a recording medium; and fixing the toner image thereon, wherein the charger is a charging roller contacting the electrostatic latent image bearer to charge the same, having a ten-point surface roughness of 5 to 30, and the toner includes a binder resin, a colorant, a release agent and an external additive including a composite oxide including titanium oxide in an amount of 80 to 95% by weight and silicon oxide, having a core-shell structure formed of a core including the titanium oxide and a shell including the silicon oxide and has a BET specific surface area of 50 to 100 m2/g.
    Type: Application
    Filed: June 24, 2009
    Publication date: January 14, 2010
    Inventors: Hiroaki KATOH, Naoki Nakatake, Masayuki Hagi, Yoshitaka Sekiguchi, Kazuoki Fuwa, Yoshihiro Mikuriya, Hideaki Yasunaga
  • Patent number: 7587159
    Abstract: Provided is an image forming method that comprises a charging step, an exposing step, a developing step, an intermediate transfer step and a secondary transfer step, wherein the diameter R (mm) of a secondary transfer roller used in the secondary transfer step and the distance A (mm) between a nip center of the secondary transfer roller and a site where paper contacts with a secondary transfer belt at ingress side satisfy the following relation, and the charge amount Q (?C/g) of the toner going into the secondary transfer step satisfies the following relation. R/40<A<R/15 15/A2<Q<35/A2.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: September 8, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuoki Fuwa, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Kato, Yoshitaka Sekiguchi, Yoshie Iwakura
  • Publication number: 20090186291
    Abstract: A non-magnetic toner including a binder resin including a first resin, a second resin, a third resin; a colorant; and a wax, wherein the first resin is a hybrid resin including an amorphous condensation polymerization unit and a radical polymerization unit in its molecular frame, and the second and third resins are non-hybrid resins including condensation polymerization units, wherein each of the first, second and third resins has a glass transition temperature (Tg) and a softening point (Tm) satisfying the following relationships: Tg of first resin<Tg of second resin<Tg of third resin, which is from 70 to 80° C., and Tm of second resin<Tm of third resin<Tm of first resin, and wherein the binder resin includes the first resin in an amount of from 10 to 20% and the third resin of from 25 to 45% by weight.
    Type: Application
    Filed: January 5, 2009
    Publication date: July 23, 2009
    Inventors: Yoshihiro MIKURIYA, Kazuoki Fuwa, Hiroaki Katoh, Yoshitaka Sekiguchi, Hideaki Yasunaga, Masayuki Hagi
  • Publication number: 20090169270
    Abstract: Provided is an image forming apparatus including at least a latent image bearing member, a latent electrostatic image forming unit, a developing unit which includes at least a developing roller and a supply roller, and a transfer unit, wherein both of a diameter R (mm) of the developing roller and a diameter R? (mm) of the supply roller are 12 mm or less; the toner contains at least a binder resin, a wax, and a colorant with the wax having a melting point of 75° C. or less; an amount of the wax exposed on a surface of the toner is 10 mg/g to 30 mg/g; and when a diameter (mm) of the developing roller is represented by R the toner has a torque T (mNm) satisfying the inequation, 20/R<T<27/R, at a void rate of 58% as measured by a torque measurement method using a conical rotor.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Inventors: Kazuoki FUWA, Yoshihiro Mikuriya, Hideaki Yasunaga, Yoshitaka Sekiguchi, Hiroaki Kato
  • Publication number: 20090162772
    Abstract: An image forming method, including forming an electrostatic latent image on a latent image bearer; forming a thin layer of a toner on a developing roller with a thin-layer forming member; and feeding the toner with the developing roller to the electrostatic latent image to develop the electrostatic latent image, wherein the toner is a pulverized toner, including a binder resin; a wax; and an inorganic particulate material, and wherein the following relationships (1) to (3) are satisfied: 300?v?100??(1) 10?R?5??(2) R2/12?A?150/v??(3) wherein v represents a peripheral speed of the developing roller; R represents a diameter of the developing roller; and A represents an exposure of the wax on the surface of the toner.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 25, 2009
    Inventors: Kazuoki FUWA, Shinobu Fujiki, Yutaka Naitoh, Yasuhide Ohkubo, Shin Murayama
  • Publication number: 20090117481
    Abstract: A toner for one-component developer, including a mother toner including a binder resin including a polyester resin as a main component, a colorant and a release agent; and an external additive in an amount of from 2.5 to 5.0 parts by weight per 100 parts by weight of the mother toner, wherein the toner includes a hexane-extracted volume of from 10 to 40 mg/g and has a cohesion of from 50 to 90%.
    Type: Application
    Filed: September 30, 2008
    Publication date: May 7, 2009
    Inventors: Hideaki YASUNAGA, Yoshihiro Mikuriya, Masayuki Hagi, Yoshitaka Sekiguchi, Hiroaki Katoh, Kazuoki Fuwa
  • Publication number: 20090052952
    Abstract: An image forming apparatus including an image bearing member including a tube, the image bearing member to bear a latent electrostatic image, a development device including a pulverized toner including a resin, a coloring agent and a releasing agent component, the development device to develop the latent electrostatic image with the toner to form a visualized image on the image bearing member, a transfer device to transfer the visualized image to a recording medium, a fixing device including a fixing member, the fixing device to fix the visualized image on the recording medium and an elastic blade to remove the toner on the surface of the image bearing member, wherein the toner has a void ratio of from 52 to 58% and a toner torque of from 1.0 to 2.5 mNm according to a torque measuring method using a circular conical rotor and the following relationships (1) to (4) are satisfied: 45?WA?60 ??Relationship (1) 2×WA?40?50×T?2×WA+5 ??Relationship (2) 1.2?t?2.
    Type: Application
    Filed: August 25, 2008
    Publication date: February 26, 2009
    Inventors: Hiroaki KATOH, Naoki Nakatake, Hideaki Yasunaga, Kazuoki Fuwa, Yoshihiro Mikuriya, Masayuki Hagi
  • Publication number: 20090041511
    Abstract: A single component development device including a toner including a resin, a coloring agent, a wax, a charge control agent and an inorganic particulate, a development roller to bear the toner on the surface of the development roller and transfer the toner to an image bearing member and a thin layer forming member to regulate a thickness of the layer of the toner while in contact with the surface of the development roller via the toner borne thereon, wherein a regulating pressure A between the thin layer forming member and the development roller is from 25 to 60 (N/m), a content Z (weight %) of the charge control agent satisfies the following relationship (1) and an average dispersion particle diameter D (nm) of the charge control agent satisfies the following relationship (2): 0.029×A?0.150>Z>0.013×A?0.013 ??Relationship (1) D<6.3×A?106.
    Type: Application
    Filed: August 5, 2008
    Publication date: February 12, 2009
    Inventors: KAZUOKI FUWA, MASAYUKI HAGI, YOSHIHIRO MIKURIYA, HIDEAKI YASUNAGA, HIROAKI KATOH, YOSHITAKA SEKIGUCHI, SATOSHI OGAWA
  • Publication number: 20080304875
    Abstract: A developing device including a developer bearing member configured to feed a developer to an image bearing member; a developer supplying member, which is contacted with the developer bearing member at a first nip while opposed thereto and which is configured to supply the developer to the developer bearing member; and a developer layer forming member, which is contacted with the developer bearing member at a second nip located on the downstream side from the first nip relative to the rotation direction of the developer bearing member to form the layer of the developer on the developer bearing member, wherein the developer is a nonmagnetic one component developer, and the distance between the front edge of the second nip and the rear edge of the first nip relative to the rotation direction of the image bearing member is greater than 0.8 mm and less than 2.0 mm.
    Type: Application
    Filed: March 5, 2008
    Publication date: December 11, 2008
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroaki Katoh, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Yoshitaka Sekiguchi, Kazuoki Fuwa, Masahide Inoue
  • Publication number: 20080279591
    Abstract: The present invention is to provide a nonmagnetic one-component toner containing a colorant, and a binder resin, wherein metal oxide fine particles are fixed on a toner surface with an adhesion strength of 95% to 99%, the toner has a direct current resistance of 1E7 ?·cm to 1E9 ?·cm, and an electrostatic capacity of 1.0E-12F to 1.5E-11F.
    Type: Application
    Filed: August 23, 2007
    Publication date: November 13, 2008
    Inventors: Hideaki Yasunaga, Hiroaki Kato, Kazuoki Fuwa, Masayuki Hagi, Yoshihiro Mikuriya, Takuya Kadota, Hiroyuki Murakami, Yoshimichi Ishikawa, Katsunori Kurose
  • Publication number: 20080233506
    Abstract: A toner useful for an oilless fixing method, includes a binder resin; a colorant; and 2.0 to 4.5% by weight of a wax which is soluble in n-hexane, based on a total weight of the toner, wherein the wax is dispersed in the toner, the wax forming wax domain particles (DA) comprising wax domain particles (DS) exposed at a surface of the toner and wax domain particles (DI) encapsulated in the toner and not exposed at the surface of the toner, wherein a weight of the DS is greater than a weight of the DI, wherein the toner from which the DS have been eluted with n-hexane comprises vestigial concavities having an area of 0.01 ??m2 or more on the surface of the toner in an amount of from 1 to 7 pcs/4 ?m2, and wherein 60% or more by number of the DA having a particle diameter of 200 nm or more have a spindle or cylindrical shape having an aspect ratio of 4 or more.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 25, 2008
    Inventors: Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Katoh, Kazuoki Fuwa, Yoshitaka Sekiguchi, Satoshi Ogawa, Masahide Inoue
  • Publication number: 20080226356
    Abstract: An image developer using a one-component developer, Including a developing roller visualizing an electrostatic latent image formed on an image bearer with a pulverized toner; and a feed roller feeding the pulverized toner to the developing roller while contacting thereto, wherein the pulverized toner includes a parent toner; a wax; and an external additive comprising an additive having a number-average particle diameter of from 20 to 60 nm and adhering to the surface of the parent toner at an adherence strength of from 50 to 70%, and wherein the following relationships (1) to (3) are satisfied: 4.70<Log10R<5.70 ??(1) 8.00<Log10Z<10.70 ??(2) ?6.25*Log10R+37.5<Log10Z<?6.25*Log10R+45.6 ??(3) wherein R represents a resistivity of the developing roller and Z represents an impedance of the pulverized toner.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 18, 2008
    Inventors: Hideaki YASUNAGA, Masayuki Hagi, Yoshihiro Mikuriya, Hiroaki Katoh, Kazuoki Fuwa, Masahide Inoue, Yoshitaka Sekiguchi, Satoshi Ogawa
  • Publication number: 20080227009
    Abstract: A developing device including a developing roller and a developer layer forming member for forming a layer of a one component developer on the roller. The developing device satisfies the relationships (1) 20<X<65?14?, and (2) 12.7??25>Q/M>13.1??44.5, wherein X represents the ratio (% by weight) of the wax present on the surface of the developer to the total of the wax therein; ? represents the angle formed by a tangent line to the member at a point B, which is the center of the contact zone of the member contacted with the roller, and another tangent line at a point A thereof 0.5 mm apart from the point B toward the tip of the member, wherein ? is 0 to ?/2 radian; and Q/M represents the charge quantity (?C/g) of the toner per unit weight.
    Type: Application
    Filed: February 7, 2008
    Publication date: September 18, 2008
    Inventors: Kazuoki FUWA, Masayuki HAGI, Yoshihiro MIKURIYA, Hideaki YASUNAGA, Hiroaki KATOH, Yoshitaka SEKIGUCHI, Satoshi OGAWA
  • Publication number: 20080199234
    Abstract: To provide a toner recovery apparatus including: a toner transporting duct; and an endless toner transporting belt; wherein the toner transporting belt is rotated in a loop form in such a way that it descends in a region where the outer circumferential surface faces a ceiling surface of the toner transporting duct and that it rises in a region where the outer circumferential surface of the toner transporting belt faces a bottom surface of the toner transporting duct, the toner recovery apparatus transports the residual toner to the outlet by holding the toner by the convex parts, spaces formed between convex parts and the bottom surface of the toner transporting duct, and the toner comprises a binding resin, releasing agent, coloring material and external additive, and torque T (mNm) measured by torque measurement method using a conical rotor in a space ratio of 50% to 60% is 1.0 to 2.5.
    Type: Application
    Filed: January 22, 2008
    Publication date: August 21, 2008
    Inventors: Masayuki HAGI, Yoshihiro Mikuriya, Yoshitaka Sekiguchi, Hideaki Yasunaga, Kiroaki Kato, Kazuoki Fuwa, Masahide Inoue, Yoshiyuki Shimizu