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).
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Publication number: 20150078777Abstract: A developing device includes a developing roller including a base and a surface layer formed on the base, the surface layer including a polyurethane resin having a fluorine group and a polyfunctional isocyanurate structure, a toner storage chamber being partially in contact with the developing roller and to support the developing roller, and a sealing member provided at opposed ends of an end portion of the toner storage chamber in a rotating axis direction of the developing roller, and to seal in toner moving to the end portion of the toner storage chamber, the sealing member before use having a coefficient of static friction in a range of from 0.08 to 0.19.Type: ApplicationFiled: September 2, 2014Publication date: March 19, 2015Inventors: Keiichiro Juri, Hideaki Yasunaga
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Publication number: 20150078790Abstract: Provided is a developing device, including: a toner having an average circularity of from 0.880 to 0.960; and a developing roller configured to rotate while carrying the toner, wherein the developing roller has on a surface thereof, a plurality of streaky grooves each formed in a circumferential direction, and a plurality of steps each formed in a direction of a rotation axis.Type: ApplicationFiled: September 12, 2014Publication date: March 19, 2015Inventors: Yoshimichi ISHIKAWA, Tsuyoshi NOZAKI, Tomoharu MIKI, Yuta TAKEUCHI, Hideaki YASUNAGA, Keiichiro JURI
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Publication number: 20140321888Abstract: A developing roller, including: a shaft containing a metal; an elastic layer on a circumference of the shaft; and a surface layer on a circumferential surface of the elastic layer, wherein the surface layer contains: a polyurethane which is a reaction product between a fluoroethylene vinyl ether copolymer and an isocyanurate form of an isocyanate; and particles having an average primary particle diameter of 5 nm to 30 nm, and wherein the polyurethane has a peak intensity ratio of a NCO group to a hydroxyl group of 5.6 to 8.8 in an infrared absorption spectrum obtained by an attenuated total reflection method.Type: ApplicationFiled: April 23, 2014Publication date: October 30, 2014Applicant: RICOH COMPANY, LTD.Inventors: Hideaki Yasunaga, Keiichiro Juri, Yuta Takeuchi, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Tomoharu Miki
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Publication number: 20140212184Abstract: A developing roller to bear toner thereon is provided. The developing roller includes a cylindrical electroconductive substrate; an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and a toner bearing layer located on a peripheral surface of the electroconductive elastic layer. The toner bearing layer includes a polyurethane resin, which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110. The toner bearing layer has a water contact angle of from 135° to 155°, and a static friction coefficient of from 0.10 to 0.15.Type: ApplicationFiled: January 22, 2014Publication date: July 31, 2014Applicant: RICOH COMPANY, LTD.Inventors: Keiichiro Juri, Hideaki Yasunaga, Chiyoshi Nozaki
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Patent number: 8526864Abstract: An image developer, including a developer container containing a developer developing a latent image on a latent image bearer; a developer bearer bearing the developer, located close to or contacting the latent image bearer; and a developer feeding and collection roller feeding the developer onto the developer bearer and scraping the developer therefrom, rotating while contacting thereto with pressure, wherein the developer feeding and collection roller includes an inner layer formed of an electroconductive foamed rubber; and an outer layer formed of an insulative foamed rubber, and wherein the following relationship is satisfied: ??T wherein ? represents a compression amount of the pressure of the developer feeding and collection roller to the developer bearer; and T represents a thickness of the outer layer, and wherein an offset voltage having a polarity opposite to that of the charged developer is applied to the developer feeding and collection roller.Type: GrantFiled: March 25, 2011Date of Patent: September 3, 2013Assignee: Ricoh Company, Ltd.Inventors: Shuuichi Nakagawa, Chiyoshi Nozaki, Hideaki Yasunaga, Keiichiro Juri
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Publication number: 20130058685Abstract: A developing roller including: a core metal; and an elastic layer formed on an outer circumference of the core metal, wherein an outermost surface of the developing roller is roughened, and wherein a difference between a maximum value and a minimum value of indentation power is 10% to 21%, wherein the indentation power is measured by a micro-indentation test at 120 locations with 3 degrees apart on a circumference of the developing roller, which is at a center of the developing roller with respect to a longitudinal direction.Type: ApplicationFiled: August 30, 2012Publication date: March 7, 2013Inventors: Keiichiro JURI, Hideaki Yasunaga
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Patent number: 8329371Abstract: A non-magnetic toner, including a binder resin; a wax present dispersing in the toner in the shape of a particle; and a colorant, wherein the wax having a particle diameter not less than 2.0 ?m and less than 3.0 ?m is not less than 20% and less than 40% by number based on total number thereof; the wax has a mode value not less than 1.5 ?m and less than 2.0 ?m in a frequency distribution of 0.1 ?m width; and the following relationship is satisfied: 45<XZ/Y<62 wherein X represents a softening point (° C.) of the toner; Y represents a volume-average particle diameter (?m) of the toner; and Z represents a total parts by weight of the wax included in 100 parts by weight of the toner.Type: GrantFiled: December 21, 2007Date of Patent: December 11, 2012Assignee: Ricoh Company, Ltd.Inventors: Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Katoh, Kazuoki Fuwa, Masayuki Hagi, Masahide Inoue
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Publication number: 20120237270Abstract: A developing roller including: an electrically-conductive base; an elastic layer formed on an outer circumference of the electrically-conductive base; and a toner bearing layer formed on the elastic layer, wherein the toner bearing layer contains a polyurethane resin having an isocyanurate structure, and wherein the polyurethane resin has a ratio A/B of 1.0 to 10.0 where A denotes absorbance attributed to C?O of cyanurate and B denotes absorbance attributed to C?O of urethane in an infrared absorption spectrum of the polyurethane resin obtained by an ATR method.Type: ApplicationFiled: March 16, 2012Publication date: September 20, 2012Inventors: Keiichiro JURI, Chiyoshi Nozaki, Hideaki Yasunaga, Shuuichi Nakagawa
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Patent number: 8192910Abstract: 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: GrantFiled: June 24, 2009Date of Patent: June 5, 2012Assignee: Ricoh Company, LimitedInventors: Hiroaki Katoh, Naoki Nakatake, Masayuki Hagi, Yoshitaka Sekiguchi, Kazuoki Fuwa, Yoshihiro Mikuriya, Hideaki Yasunaga
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Patent number: 8103199Abstract: A developing device including a developing roller facing an image bearing member and a toner layer thickness control member to control an amount of a toner adhered to the developing roller, so that an electrostatic latent image formed on the image bearing member is developed with the toner to form a toner image. The following relationships are satisfied: 0.08×100.3×Dv<Ra<0.18×100.3×Dv, 2.0<(Ra/RSm)×100<4.0, and 8<Rz<15, where Dv (?m) is a volume average particle diameter of the toner, Ra (?m) is an arithmetical mean roughness of the developing roller in a longitudinal direction, Rz (?m) is a ten-point mean roughness of the developing roller in a longitudinal direction, and RSm (?m) is a mean length of roughness curve elements of the developing roller.Type: GrantFiled: January 24, 2008Date of Patent: January 24, 2012Assignee: Ricoh Company LimitedInventors: Hideaki Yasunaga, Masayuki Hagi, Yoshihiro Mikuriya, Yoshitaka Sekiguchi, Hiroaki Katoh, Kazuoki Fuwa, Masahide Inoue
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Patent number: 8053154Abstract: A toner for electrostatic charge development is provided where the toner comprises a colorant and a resin and contains an organic boron compound represented by a following chemical formula (A) as a charge controlling agent, further the toner is treated with an inorganic fine particle and at least one of the inorganic particles is a magnesium silicate compound represented by a following general formula [2] is provided. wherein X is an alkali metal, R1, R2, R3 or R4 each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom. MgxSiyO(x+2y)??[2] wherein x and y are integers.Type: GrantFiled: March 2, 2007Date of Patent: November 8, 2011Assignee: Ricoh Company, Ltd.Inventors: Takuya Kadota, Masayuki Hagi, Yoshihiro Mikuriya, Katsunori Kurose, Hiroaki Kato, Atsushi Yamamoto, Yoshimichi Ishikawa, Masahide Inoue, Minoru Nakamura, Hideaki Yasunaga
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Patent number: 8043779Abstract: To provide a pulverized toner excellent in the releasing ability and cleaning ability, and an image-forming apparatus for one-component developer, and a process cartridge using the pulverized toner. The pulverized toner contains a toner base particle containing at least a binder resin, a colorant, and a releasing agent, the mass ratio of the releasing agent to the binder resin is 3.0% to 6.0%, the adhesive force among the pulverized toners at 25° C. to 55° C. is 20 g to 80 g, and the pulverized toner is used for the image-forming apparatus for one-component developer containing the cleaning unit configured to dispose an elastic blade adjacent to the surface of the image bearing member so as to clean the surface.Type: GrantFiled: March 9, 2007Date of Patent: October 25, 2011Assignee: Ricoh Company, Ltd.Inventors: Hideaki Yasunaga, Hiroaki Kato, Masayuki Hagi, Katsunori Kurose, Yoshihiro Mikuriya, Yoshimichi Ishikawa, Atsushi Yamamoto, Takuya Kadota
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Patent number: 8041270Abstract: 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<Log10 R<5.70??(1) 8.00<Log10 Z<10.70??(2) ?6.25*Log10 R+37.5<Log10 Z<?6.25*Log10 R+45.6??(3) wherein R represents a resistivity of the developing roller and Z represents an impedance of the pulverized toner.Type: GrantFiled: March 14, 2008Date of Patent: October 18, 2011Assignee: Ricoh Company, LimitedInventors: Hideaki Yasunaga, Masayuki Hagi, Yoshihiro Mikuriya, Hiroaki Katoh, Kazuoki Fuwa, Masahide Inoue, Yoshitaka Sekiguchi, Satoshi Ogawa
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Publication number: 20110243616Abstract: An image developer, including a developer container containing a developer developing a latent image on a latent image bearer; a developer bearer bearing the developer, located close to or contacting the latent image bearer; and a developer feeding and collection roller feeding the developer onto the developer bearer and scraping the developer therefrom, rotating while contacting thereto with pressure, wherein the developer feeding and collection roller includes an inner layer formed of an electroconductive foamed rubber; and an outer layer formed of an insulative foamed rubber, and wherein the following relationship is satisfied: ??T wherein ? represents a compression amount of the pressure of the developer feeding and collection roller to the developer bearer; and T represents a thickness of the outer layer, and wherein an offset voltage having a polarity opposite to that of the charged developer is applied to the developer feeding and collection roller.Type: ApplicationFiled: March 25, 2011Publication date: October 6, 2011Applicant: RICOH COMPANY, LTD.Inventors: Shuuichi NAKAGAWA, Chiyoshi Nozaki, Hideaki Yasunaga, Keiichiro Juri
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Patent number: 8021814Abstract: 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: GrantFiled: March 19, 2008Date of Patent: September 20, 2011Assignee: Ricoh Company LimitedInventors: Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Katoh, Kazuoki Fuwa, Yoshitaka Sekiguchi, Satoshi Ogawa, Masahide Inoue
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Patent number: 8007973Abstract: A full-color toner kit including yellow, magenta, and cyan toners each including a benzimidazolone, a naphthol, and a copper phthalocyanine colorants, respectively, and resins (A) and (B) each of which having a polyester skeleton and containing a wax, and a resin (C) having a polyester skeleton and containing no wax. Each of the toners has a softening point of from 125° C. to 135° C. The following relationships are satisfied: Ts(A)<Ts(B), Ay+5?Am?Ay+15, and Ac+5?Am?Ac+15, wherein Ts(A) and Ts(B) (° C.) each represent softening points of the resin (A) and (B), respectively, and Ay, Am, and Ac each represent ratios (% by weight) of the amount of the resin (A) to total amount of the resins (A) and (B) in the yellow, magenta, cyan toners, respectively.Type: GrantFiled: December 27, 2007Date of Patent: August 30, 2011Assignee: Ricoh Company, LimitedInventors: Kazuoki Fuwa, Yoshihiro Mikuriya, Masayuki Hagi, Hideaki Yasunaga, Hiroaki Katoh, Yoshitaka Sekiguchi
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Patent number: 7981593Abstract: A toner including toner particles including a resin, a colorant, a wax, and a charge controlling agent, and an external additive, wherein the toner satisfies the relationships (1) 0.15×Q?2?T?0.15×Q?0.15, and (2) 1.0?T?2.5, wherein Q represents the charge of the toner in units of ?C/g, and T represents the torque of the toner in units of mN·m determined by a method using a cone-shaped rotor while controlling a space ratio of the toner at 58%. A developer including the toner and a carrier. An image forming apparatus including an image bearing member, a transfer device, a fixing device and a double side image forming unit, and using the toner, wherein the receiving material includes moisture in an amount of not greater than 5% by weight after the toner image on the first side is fixed.Type: GrantFiled: September 14, 2007Date of Patent: July 19, 2011Assignee: Ricoh Company LimitedInventors: Hiroaki Katoh, Hideaki Yasunaga, Kazuoki Fuwa, Yoshihiro Mikuriya, Masayuki Hagi, Masahide Inoue
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Patent number: 7979010Abstract: 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: GrantFiled: December 23, 2008Date of Patent: July 12, 2011Assignee: Ricoh Company, Ltd.Inventors: Kazuoki Fuwa, Yoshihiro Mikuriya, Hideaki Yasunaga, Yoshitaka Sekiguchi, Hiroaki Kato
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Patent number: 7970323Abstract: 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: GrantFiled: March 5, 2008Date of Patent: June 28, 2011Assignee: Ricoh Company, Ltd.Inventors: Hiroaki Katoh, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Yoshitaka Sekiguchi, Kazuoki Fuwa, Masahide Inoue
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Patent number: 7873300Abstract: 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?106.3??Relationship (2).Type: GrantFiled: August 5, 2008Date of Patent: January 18, 2011Assignee: Ricoh Company LimitedInventors: Kazuoki Fuwa, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Katoh, Yoshitaka Sekiguchi, Satoshi Ogawa