Patents by Inventor Hideaki Yasunaga

Hideaki Yasunaga 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: 7838193
    Abstract: A toner including toner particles including a binder resin, a colorant and a release agent, and an external additive including a first particulate inorganic material having a formula of MgxSiyOx+2y where each of x and y is an integer, and a number average secondary particle diameter of from 0.02 ?m to 2 ?m, wherein the first atomic ratio (Mg/Si)s in a surface portion of the first particulate inorganic material is not greater than (preferably less than) the second atomic ratio (Mg/Si)e in the entire first particulate inorganic material. Alternatively, a toner including toner particles including a binder resin and a colorant, and an external additive which includes a particulate inorganic material having a formula of MgxSiyOx+2y where each of x and y is an integer and which has a surface treated with a fatty acid.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: November 23, 2010
    Assignee: Ricoh Company Limited
    Inventors: Masayuki Hagi, Takuya Kadota, Hiroaki Katoh, Atsushi Yamamoto, Katsunori Kurose, Yoshihiro Mikuriya, Masahide Inoue, Hideaki Yasunaga, Minoru Nakamura, Yoshimichi Ishikawa, Hiroyuki Murakami
  • Patent number: 7833686
    Abstract: A toner kit containing at least a black toner, a yellow toner, a magenta toner and a cyan toner, wherein these toners have at least the binder resin, the colorant and the charge controlling agent having the molecular structure containing K+ as the counterion, when the K+ intensity detected by the fluorescent X ray on the surface of the black toner is Kk, the K+ intensity detected by the fluorescent X ray on the surface of the yellow toner is Ky, the K+ intensity detected by the fluorescent X ray on the surface of the magenta toner is Km and the K+ intensity detected by the fluorescent X ray on the surface of the cyan toner is Kc, the following formulae: Kk<Ky, Kk<Km and Kk<Kc are fulfilled is provided.
    Type: Grant
    Filed: December 26, 2006
    Date of Patent: November 16, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Kadota, Minoru Nakamura, Masayuki Hagi, Yoshihiro Mikuriya, Katsunori Kurose, Hideaki Yasunaga, Hiroaki Kato, Yoshimichi Ishikawa, Atsushi Yamamoto, Masahide Inoue
  • 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
  • Patent number: 7749671
    Abstract: To provide a toner containing at least a toner base containing a binder resin and a colorant, and an inorganic fine particle, wherein the inorganic fine particle contains a compound oxide expressed by the following Composition Formula (1): [M1]aSibOc??Composition Formula (1) where “M1” represents a metal element selected from Sr, Mg, Zn, Co, Mn and Ce, “a” and “b” each represents an integer of 1 to 9 and “c” represents an integer of 3 to 9, wherein an average primary particle diameter of the compound oxide is 0.02 ?m to 1.5 ?m, and an average secondary particle diameter of the compound oxide is 0.08 ?m to 3.5 ?m, where the secondary particle is an aggregate of the primary particles.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: July 6, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Masahide Inoue, Chiyoshi Nozaki, Minoru Nakamura, Masayuki Hagi, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Hiroaki Kato, Takuya Kadota, Katsunori Kurose, Hideaki Yasunaga, Yoshimichi Ishikawa
  • 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
  • Patent number: 7695885
    Abstract: A negatively-chargeable non-magnetic one-component developer for developing an electrostatic latent image using a contact DC-bias development method, having a capacitance of 1.05×10?12 to 1.25×10?12 F, a volume resistivity of 5.0×1010 to 5.0×1012 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a contact DC-bias development method, the developer has a capacitance of 1.30×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 5.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a non-contact DC/AC-bias development method, the developer has a capacitance of 1.45×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 1.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: April 13, 2010
    Assignee: Ricoh Company Limited
    Inventors: Hideaki Yasunaga, Minoru Nakamura, Masayuki Hagi, Takuya Kadota, Hiroaki Katoh, Yoshihiro Mikuriya, Katsunori Kurose, Atsushi Yamamoto, Masahide Inoue
  • 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
  • Patent number: 7556904
    Abstract: It is an object of the present invention to provide a toner containing toner particles and inorganic fine particles wherein the inorganic fine particles are externally added to the toner particles which contain a binder resin and a colorant and at least one type of the inorganic fine particles is a compound oxide having a relative permittivity measured at 1 MHz of 2 to 10 and a volume resistivity of 1011?·cm or more and an image forming method using the toner.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: July 7, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Kadota, Masahide Inoue, Yoshihiro Mikuriya, Katsunori Kurose, Masayuki Hagi, Minoru Nakamura, Hiroaki Kato, Atsushi Yamamoto, Hideaki Yasunaga
  • Patent number: 7556906
    Abstract: A toner is provided including a colorant; a resin composition (A) comprising at least one binder resin and a hydrocarbon wax having a melting point of 70-90° C. in an amount of from 6 to 30% by weight based on total weight of resin composition (A), and having a softening point (T1/2(A)) of from 120 to 150° C.; and a resin composition (B) having a softening point (T1/2 (B)) of from 100 to 130° C., wherein a weight ratio of the resin composition (A) to the resin composition (B) is from 10/90 to 45/55, and the following relationship is satisfied: T1/2(A)?T1/2(B)+3; and the use of the toner in an image forming method, an image forming apparatus, and a process cartridge.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: July 7, 2009
    Assignee: Ricoh Company Limited
    Inventors: Hiroaki Katoh, Masayuki Hagi, Takuya Kadota, Yoshihiro Mikuriya, Katsunori Kurose, Atsushi Yamamoto, Masahide Inoue, Minoru Nakamura, Chiyoshi Nozaki, Tsuyoshi Nozaki, Hideaki Yasunaga
  • 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
  • Patent number: 7550242
    Abstract: A toner having a core containing a colorant, a release agent and a binder resin (A), and a shell containing a binder resin (B), the shell overlying the core, wherein the binder resin (A) contains a resin having a polyester skeleton, the binder resin (B) contains a vinyl copolymer resin, and a weight ratio of the shell to the core is from 0.05 to 0.5, and wherein the toner has a volume average particle diameter of from 3 to 8 ?m; a toner manufacturing method of such the toner can be used in an image forming apparatus and in a process cartridge.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: June 23, 2009
    Assignee: Ricoh Company Limited
    Inventors: Tsuyoshi Nozaki, Chiyoshi Nozaki, Minoru Nakamura, Atsushi Yamamoto, Hideaki Yasunaga
  • 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