Magnetic Brush Patents (Class 399/267)
  • Patent number: 10852661
    Abstract: A developing apparatus includes a sleeve for carrying a developer including toner and magnetic carrier, the sleeve having a plurality of grooves extending in a longitudinal direction; a magnet provided inside the sleeve, a non-magnetic regulating member, provided spaced from the sleeve, wherein an amount M/S (mg/mm2) of the developer carried on a unit area of the sleeve after passing by the regulating member, a gap SB (mm) between a free end of the regulating member and the sleeve, a density G (mg/mm3) of the developer, and a groove ratio ? which is a ratio of the grooves in the surface of the sleeve satisfy, 0.1?M/S (mg/mm2)?0.5, 0.2?SB (mm), and m/S (mg/mm2)×1/4??×{SB (mm)+D (mm)}×G (mg/mm3)<M/S (mg/mm2).
    Type: Grant
    Filed: July 11, 2017
    Date of Patent: December 1, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomoyuki Sakamaki, Mitsuhiro Furukawa
  • Patent number: 10795304
    Abstract: An image forming apparatus, detachably connected to a consumable product including a plurality of function units integrated with each other, includes an acquisition unit that acquires a life of each of the plurality of function units and a setting unit that sets an operation in a case where each acquired life reaches a preset value.
    Type: Grant
    Filed: August 1, 2018
    Date of Patent: October 6, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kazutaka Shinagawa
  • Patent number: 10768552
    Abstract: A developing device includes a rotatable developing sleeve to carry and feed a developer including toner and a carrier toward a developing region, and a magnetic field generating portion provided inside the developing sleeve and having a developing magnetic pole for forming the developing region. The developing magnetic pole is disposed opposite to a closest position of the image bearing member to the developing sleeve. A ratio of an 80%-value-width of magnetic flux density of the developing magnetic pole with respect to a normal direction of the developing sleeve to a half peak width of the magnetic flux density of the developing magnetic pole with respect to the normal direction is 0.65 or more.
    Type: Grant
    Filed: August 1, 2018
    Date of Patent: September 8, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomoyuki Sakamaki, Yuta Okuyama
  • Patent number: 10545428
    Abstract: A force for warping a regulating blade is imparted to the regulating blade in such a manner that a gap between a developer bearing member supported by a development frame member and the regulating blade attached to an attaching portion of the development frame member falls within a predetermined range over a longitudinal direction of the developer bearing member. The regulating blade is fixed to the attaching portion in a state in which the regulating blade is warped by the force imparted to the regulating blade and the gap is within the predetermined range over the longitudinal direction of the developer bearing member.
    Type: Grant
    Filed: May 22, 2018
    Date of Patent: January 28, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventors: Teruaki Tsurusaki, Masafumi Takahashi, Shunichi Koga, Tomohiro Shiomi
  • Patent number: 10503091
    Abstract: A carrier for electrostatic image development includes: resin-coated magnetic particles each including a magnetic particle and a resin layer that covers the magnetic particle; and strontium titanate particles composed of primary particles having an average circularity of 0.82 to 0.94 and an 84% cumulative circularity of more than 0.92.
    Type: Grant
    Filed: September 4, 2018
    Date of Patent: December 10, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Yosuke Tsurumi, Moegi Iguchi, Shintaro Anno, Toshiaki Hasegawa
  • Patent number: 10303078
    Abstract: An image forming apparatus includes: a first image forming unit that includes a first image holding member and a first developing unit, the first developing unit accommodating a first developer that includes a first toner and a first carrier; a first transfer unit; a second image forming unit that is disposed downstream of the first image forming unit in a traveling direction of a transfer medium and includes a second image holding member and a second developing unit, the second developing unit accommodating a second developer that includes a second toner and a second carrier; and a second transfer unit, in which a volume resistivity of the first carrier is higher than a volume resistivity of the second carrier, and a volume average particle diameter of the first carrier is more than a volume average particle diameter of the second carrier.
    Type: Grant
    Filed: April 24, 2018
    Date of Patent: May 28, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Shintaro Anno, Yasuaki Hashimoto, Takuro Watanabe, Hiroaki Saijo, Fusako Kiyono
  • Patent number: 10234793
    Abstract: A development device includes a magnetic field generation unit having a developing magnetic pole S2, a magnetic pole N2, and a magnetic pole N1. The magnetic poles N2 and N1 are disposed adjacent to the magnetic pole S2, at positions downstream and upstream of the magnetic pole S2 in a rotation direction of a sleeve, respectively. The magnetic pole N2 is configured to have a larger magnetic flux density and full width half maximum in a normal direction of the sleeve and have a smaller inter-pole distance from the developing magnetic pole than the magnetic pole N1, so that the rising position of magnetic brushes of developer is shifted in the upstream direction, and the magnetic brushes come into contact with a photosensitive drum more suitably.
    Type: Grant
    Filed: March 2, 2018
    Date of Patent: March 19, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuta Okuyama, Tomoyuki Sakamaki
  • Patent number: 10175608
    Abstract: A developing device includes a developing roller, a conveyor roller and a developer stirring unit. The developing roller is arranged to face a photoconductive drum at a predetermined developing position. The developing roller includes a fixed first magnet and a first sleeve. The conveyor roller is arranged to face the developing roller at a predetermined facing position. The conveyor roller includes a fixed second magnet and a second sleeve. The developer stirring unit stirs the developer and supplies the developer to the conveyor roller. The first magnet includes a first magnetic pole composed of a predetermined magnetic pole and a second magnetic pole arranged downstream of and adjacent to the first magnetic pole and having the same polarity as the first magnetic pole. The developer is transferred from the developing roller to the conveyor roller after passing through a repulsive magnetic field formed by the first and second magnetic poles.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: January 8, 2019
    Assignee: Kyocera Document Solutions Inc.
    Inventors: Kenichi Tamaki, Tamotsu Shimizu, Akifumi Yamaguchi
  • Patent number: 10088776
    Abstract: A developing device includes a developer bearer including a magnetic field generator, a developer regulator disposed opposite the developer bearer across a regulation gap, a developer containing compartment disposed below the developer bearer, and a conveying screw disposed in the developer containing compartment and including a shaft having a diameter greater than a radius of the conveying screw. On a cross section perpendicular to an axial direction of the conveying screw, a developer scooping pole of the magnetic field generator to scoop the developer from the developer containing compartment onto the developer bearer is disposed between the regulation gap and a bisector dividing an angle extending from a first line, which connects a center of the developer bearer and a center of the conveying screw, to a second line, which connects the center of the developer bearer and the regulation gap, in a rotation direction of the developer bearer.
    Type: Grant
    Filed: September 28, 2016
    Date of Patent: October 2, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Hosokawa, Shinji Tamaki, Keiichi Yoshida, Ichiro Kadota, Shunji Katoh
  • Patent number: 10042283
    Abstract: A developing device includes a developing roller, a toner supply roller, a regulating blade, a casing, and a cleaning member. The developing roller supplies a toner to the image carrier in a region opposed to an image carrier. The toner supply roller is located opposed to the developing roller. The toner supply roller forms a magnetic brush made of a two-component developer including a magnetic carrier and a toner on an outer peripheral surface to supply a toner to the developing roller in a region opposed to the developing roller. The regulating blade is located opposed to the toner supply roller at a predetermined interval. The casing houses the developing roller, the toner supply roller, and the regulating blade. The cleaning member reciprocates along a longitudinal direction of the regulating blade so as to remove a toner accumulated on a top surface of the regulating blade.
    Type: Grant
    Filed: July 5, 2017
    Date of Patent: August 7, 2018
    Assignee: Kyocera Document Solutions Inc.
    Inventor: Yuji Kamiyama
  • Patent number: 10018943
    Abstract: A developing sleeve includes first axially extending groove portions which satisfy D1?2R and W1?2R, where 2R is a volume-average particle size of a carrier, D1 is a maximum depth of each first groove portion and W1 is a width an opening of each first groove portion with respect to a circumferential direction of the developing sleeve, and second axially extending groove portions. Each second groove portion satisfies D2<2R, where 2R is the volume-average particle size of the carrier and D2 is a maximum depth of each second groove portion. Each or a plurality of the second groove portions are disposed between the first groove portions with respect to the circumferential direction of the developing sleeve.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: July 10, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Tomoyuki Sakamaki
  • Patent number: 9846388
    Abstract: A developing device includes a storage portion, a developer carrying member, a stirring portion, a layer thickness restricting portion, and a guide portion. The guide portion is disposed between the stirring portion and the layer thickness restricting portion. The stirring portion faces the developer carrying member with a first gap between them. The layer thickness restricting portion faces the developer carrying member with a second gap between them. The guide portion includes a first guide surface and a second guide surface. On the first guide surface, convex portions or concave portions are formed. The first guide surface faces the stirring portion with, between them, a third gap that is a passage through which the developer passes toward the first gap. The second guide surface faces the developer carrying member with, between them, a fourth gap that is a passage through which the developer passes toward the second gap.
    Type: Grant
    Filed: March 1, 2017
    Date of Patent: December 19, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Koji Suenami, Yukihiro Mori
  • Patent number: 9829829
    Abstract: A developing device includes a developing roller, a conveyor roller, a developer stirring unit and a development bias applying unit. The developing roller is arranged to face a photoconductive drum at a predetermined developing position and supplies the toner. The conveyor roller is arranged to face the developing roller at a predetermined facing position and supplies the developer to the developing roller. The development bias applying unit applies development biases to the first sleeve of the developing roller and the second sleeve of the conveyor roller during a developing operation of developing the electrostatic latent image on the photoconductive drum with the toner. The development bias applying unit applies the development biases such that a shifting electric field to move the toner on the first sleeve of the developing roller toward the second sleeve of the conveyor roller is formed at the facing position during the developing operation.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: November 28, 2017
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Eiji Gyotoku, Akihiro Watanabe, Norio Kubo, Minoru Wada, Ryo Taniguchi, Yasushi Imanishi, Takahiro Okubo
  • Patent number: 9703237
    Abstract: A multipolar magnet is arranged inside a developer bearing member. A partitioning wall is arranged such that an apex position thereof is located between the developer bearing member and a first conveying member, and is extended up to a position which is located below an upper end position of a zone. A plurality of concaved portions is formed on the surface of the developer bearing member at an interval. Each of the plurality of concaved portions has such an opening shape that a maximum diameter of an inscribed circle is equal to or greater than a diameter of an average grain size of a carrier, and is formed such that the carrier with the average grain size is able to enter each of the concaved portions by a depth that is equal to or greater than a radius thereof.
    Type: Grant
    Filed: September 21, 2015
    Date of Patent: July 11, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Akihiro Noguchi
  • Patent number: 9658573
    Abstract: A developing unit includes a developer carrier, and first and second chambers to collect and circulate developer. A partition separates the first and second chambers and has first communication portion disposed more downstream in the second chamber and a second communication portion disposed more upstream in the second chamber. A first conveying member is disposed in the first chamber, and a second conveying member is disposed in the second chamber and includes a spiral blade portion, a reverse spiral blade portion helically wound in an opposite direction of the spiral blade portion and disposed downstream of the spiral blade portion, and a discharging portion provided downstream of the reverse spiral blade. An upstream end of the first communication portion is positioned farther than a downstream end of the second communication portion from a center of the developer carrier in a rotational axis direction of the developer carrier.
    Type: Grant
    Filed: February 3, 2016
    Date of Patent: May 23, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Fumiyoshi Saito
  • Patent number: 9366989
    Abstract: An image forming apparatus includes at least one image bearer; multiple developing devices to develop the latent images with developers including toner and carrier into a toner image; multiple developer supply devices to supply the developers to the multiple developing devices, respectively; and a fixing device to fix the toner image on a sheet of recording media. When one of the multiple developing devices positioned at a shortest distance from an outline of the fixing device is referred to as a first developing device, and one of the multiple developer supply devices that supplies developer to the first developing device is referred to as a first developer supply device, the first developer supply device is greater in percentage by weight of carrier in developer supplied to the first developing device than rest of the multiple developer supply devices.
    Type: Grant
    Filed: January 5, 2015
    Date of Patent: June 14, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Ito, Ken Yoshida, Keiko Matsumoto, Yoichi Sakurai, Daisuke Takahashi
  • Patent number: 9280094
    Abstract: A developer unit for a dual component development electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. An auger is positioned to convey developer mix in the reservoir toward the outer surface of a magnetic roll on a front of the housing. A ledge on an inner surface of the housing extends axially with respect to the magnetic roll along a front of the reservoir. The ledge is positioned upstream from a trim bar and downstream from a pickup pole of the magnetic roll with respect to the operative rotational direction of the magnetic roll. The ledge has a concave curved inner surface that is open to the reservoir and extends from near the trim bar to near a front side of the auger.
    Type: Grant
    Filed: February 10, 2015
    Date of Patent: March 8, 2016
    Assignee: Lexmark International, Inc.
    Inventors: Michael Brian Bacelieri, Robert Dan Bennett, III, Gary Allen Denton, Katherine Marie Gilliam, Elliott Vincent Jernigan, Matthew Lee Rogers, Dominique Renee Rowe, Courtney Harrison Soale
  • Patent number: 9268263
    Abstract: A development device wherein a magnetic force distribution of a developer bearing member in a longitudinal direction at positions at which a magnetic flux density of a low magnetic field area is minimal in the peripheral direction of the developer bearing member is set such that a difference between a maximum magnetic flux density in a range from a maximum position at which an attenuation rate of the magnetic flux density is maximal to a 30 mm distant position toward the center of the developer bearing member and a magnetic flux density on a further center side of the developer bearing member than the range is 3 mT or less, and an absolute value of the magnetic flux density of a further outer side in the longitudinal direction of the developer bearing member than the maximum position is set to 3 mT or less.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: February 23, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Ariizumi, Takanori Iida, Shinya Suzuki, Ryohei Terada, Ichiro Katsuie, Shoji Naruge, Masahiro Ootsuka
  • Patent number: 9250573
    Abstract: An image forming apparatus includes: a developer carrying member (sleeve) including a magnet and grooves; and an image bearing member (drum). The electrostatic image on the drum is developed with a developer. When a linear speed of the sleeve is Vs, a linear speed of the drum is Vd, a peripheral speed ratio of the sleeve to the drum is ?=Vs/Vd, a radius of the sleeve is Rs, a radius of the drum is Rd, a distance of a rectilinear line connecting a most upstream point and a most downstream point in the developing region with respect to the circumferential direction is Lnip, a pitch of the grooves of the sleeve is p, and an arbitrary natural number is n, the following relationship is satisfied: (1?0.05)×np?2[?×Rd×arcsin(Lnip/2Rd)?Rs×arcsin(Lnip/2Rs)]?(1+0.05)×np.
    Type: Grant
    Filed: May 21, 2015
    Date of Patent: February 2, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Atsushi Matsumoto
  • Patent number: 9244386
    Abstract: A developing device includes a first developer holder and a second developer holder. The first developer holder is disposed so as to face an image holding member and rotates so as to move in a direction opposite to a direction of movement of the image holding member at a first facing portion. The second developer holder is disposed downstream from the first developer holder in the direction of movement of the image holding member so as to face the image holding member and rotates so as to move in the same direction as the image holding member moves at a second facing portion. A value obtained by dividing an amount of developer per unit area held on the first developer holder by a shortest distance between the image holding member and the first developer holder is approximately in a range from 1.00×103 kg/m3 to 1.60×103 kg/m3.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: January 26, 2016
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Kunihiko Sato, Yoko Miyamoto, Yoshiya Mashimo, Masaaki Takahashi, Sakon Takahashi, Nobumasa Furuya, Kazuhiko Arai
  • Patent number: 9188890
    Abstract: Disclosed is a method for managing the triboelectric charge potential of a two-component xerographic developer over a wide range of variables. In particular, the present embodiments uses the addition of second and third carrier particles to a developer comprising toner particles and first carrier particles to adjust the tribo electric charge potential of the developer. Various parameters (system responses), including Vmag, laser power, relative humidity, toner and carrier age, and image scan data, are used to determine the requisite amounts of the second and third carrier to achieve a desired shift in tribo electric charge potential of the developer.
    Type: Grant
    Filed: September 17, 2014
    Date of Patent: November 17, 2015
    Assignee: XEROX CORPORATION
    Inventor: James A. Winters
  • Patent number: 9188904
    Abstract: An electro-photographic print system or method for regulating a supply of toner based on a required toner amount.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: November 17, 2015
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Jeffrey Harold Luke
  • Patent number: 9158226
    Abstract: An image forming apparatus includes a first image forming unit and a second image forming unit, wherein the first image forming unit is arranged on a downstream side of the second image forming unit in a traveling direction of a transfer medium, the first developing unit contains a first developer containing a first toner and a first carrier, the second developing unit contains a second developer containing a second toner and a second carrier, and a ratio of a resistance value of the first carrier to a resistance value of the second carrier is within a range of from 4.0×10?5 to 9.7×10?1.
    Type: Grant
    Filed: January 26, 2015
    Date of Patent: October 13, 2015
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Shintaro Anno, Fusako Kiyono, Emi Matsushita, Hiroki Ohmori, Shuji Sato
  • Publication number: 20150139699
    Abstract: A developing apparatus includes a developer carrying member; and a magnetic member provided inside the carrying member and having magnetic poles arranged circumferentially, wherein on a center axis of the carrying member outside an end of the magnetic member, there is a region in which a magnetic flux density of a first magnetic polarity converges toward zero; and wherein a ratio of a volume, per unit length, of a portion of the magnetic member which has a surface magnetic pole of a second magnetic polarity which is different from the first magnetic polarity in a longitudinal end portion to that in a longitudinally central portion is smaller than a ratio of a volume of a portion of the magnetic member which has a surface magnetic pole of the first magnetic polarity in a longitudinal end portion to that in a longitudinally central portion.
    Type: Application
    Filed: December 11, 2014
    Publication date: May 21, 2015
    Inventors: Tomoyuki Sakamaki, Takanori Iida
  • Publication number: 20150071683
    Abstract: A developing device includes: a developer carrying member; a first chamber; a second chamber; a partition wall; a communicating portion; and a feeding member, provided rotatably in the first chamber, for feeding the developer in the first chamber. In a circulation path, the feeding member includes a first region corresponding to a developer coating region of the developer carrying member and a second region, provided downstream of the first region with respect to a feeding direction of the feeding member, corresponding to a region outside the developer coating region of the developer carrying member. Feeding power per unit driving time of the feeding member is set at a smaller value in the first region than in the second region.
    Type: Application
    Filed: April 26, 2013
    Publication date: March 12, 2015
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kyosuke Takahashi, Atsushi Matsumoto
  • Patent number: 8958729
    Abstract: A magnet roller includes a roller-shaped body constructed of a magnetic field generating material, a first support rod provided to a first axial end of the body; and a second support rod provided to a second axial end of the body. At least one of the first and second support rods is constructed of a nonmagnetic material and includes a projecting part projecting outside the body from an end face of the body and a buried part united to the projecting part and positioned inside the body. The buried part includes a reduced-area portion smaller than a base end of the projecting part adjacent to the buried part in cross-sectional area perpendicular to an axial direction of the first and second support rods.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: February 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Innami, Noriyuki Kamiya, Masayuki Ohsawa, Yoshiyuki Takano, Hiroya Abe
  • Patent number: 8948662
    Abstract: A two-component developer includes toner and a magnetic carrier. The two-component developer is used in a developing device including a circular cylindrical developer transporting member that is disposed so as to be separated by 125 ?m to 250 ?m from a latent image carrier that rotates. The two-component developer is used so as to satisfy a condition in which a width of a region where a magnetic brush contacts a surface of the latent image carrier is in a range of from 1.0 mm to 2.25 mm, and a condition in which a developer density of the region where the magnetic brush contacts the surface of the latent image carrier is in a range of from 0.75×10?6 to 1.50×10?6 g/m3.
    Type: Grant
    Filed: May 7, 2013
    Date of Patent: February 3, 2015
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takashi Ochi, Yasuaki Watanabe, Tomoyuki Yoshii, Jun Abe, Takayuki Yamashita, Toji Tokutsu
  • Patent number: 8934818
    Abstract: An image forming apparatus includes a controller that controls rotational driving of a magnetic roller and rotational driving of a developing roller. The controller is capable of performing a toner collecting mode when no image formation is performed. In the toner collecting mode, the magnetic roller and the developing roller are intermittently rotated in a direction reverse to a direction in which the magnetic roller and the developing roller are rotated during image formation, then the magnetic roller is made to rotate in a forward direction, and then, the magnetic roller is rotated in a backward direction.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: January 13, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Takashi Eiki
  • Patent number: 8929781
    Abstract: A developing device includes a first developer carrier that carries developer on a peripheral surface thereof; a second developer carrier that carries the developer on a peripheral surface thereof; a supplying section that supplies the developer to the peripheral surface of the first developer carrier; a layer thickness regulating member that regulates a layer thickness of the developer supplied to the peripheral surface of the first developer carrier by the supplying section; a first transfer magnetic pole disposed in an interior of the first developer carrier; a second transfer magnetic pole disposed in an interior of the second developer carrier; a first downstream magnetic pole disposed in the interior of the first developer carrier; and a second downstream magnetic pole disposed in the interior of the second developer carrier.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: January 6, 2015
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Sakae Yoshioka, Shinichiro Fujimori, Masanori Kato
  • Publication number: 20140369720
    Abstract: A developing apparatus used in an image forming apparatus including a developer bearing member configured to develop a latent image formed on an image bearing member and rotate together with the image bearing member so that opposed surfaces thereof rotate in the same direction, an interval guarantee member configured to maintain a distance between the developer bearing member and the image bearing member by coming into abutment with the developer bearing member and the image bearing member, and a biasing member configured to bias the interval guarantee member toward the upstream side in the direction of rotation of the developer bearing member by applying an elastic force generated by elastic deformation on the interval guarantee member.
    Type: Application
    Filed: June 11, 2014
    Publication date: December 18, 2014
    Inventor: Hiroki Ogino
  • Publication number: 20140356030
    Abstract: A developing device includes a developer bearer, a magnetic field generator provided inside the developer bearer, a casing including an opening to partly expose a surface of the developer bearer, and a lateral end cover to cover an axial end portion of the exposed surface of the developer bearer. The lateral end cover includes a wide portion extending more to an axial inner side of the developer bearer than a downstream portion of the lateral end cover positioned downstream from the wide portion in a direction of rotation of the developer bearer. A downstream end of the wide portion is downstream from an upstream end of the development range in the direction of rotation of the developer bearer.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 4, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yoshiyuki Fukuda, Yoshio Hattori, Sho Akiyama, Noriyuki Kimura
  • Publication number: 20140348543
    Abstract: An image forming apparatus includes an image forming section including an image carrier and a developing device, and a developer recovery mechanism. The developing device includes, a developer carrier, and a developer discharge portion. The image forming section incorporates a developing device employing a first developing method where toner is caused to adhere to the image carrier by a magnetic brush formed on the developer carrier, or a developing device having a toner carrier between the developer carrier and the image carrier, and employing a second developing method where a toner layer is formed on the toner carrier by a magnetic brush formed on the developer carrier, and toner is caused to adhere to the image carrier by the toner layer formed on the toner. These developing devices, in the image forming section, each have a same positional relationship between the developer discharge portion and an image-carrier rotation shaft.
    Type: Application
    Filed: April 21, 2014
    Publication date: November 27, 2014
    Applicant: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Masahiro KASHIMOTO, Hiroaki OHASHI
  • Patent number: 8891991
    Abstract: A developing device includes first and second magnet members respectively including first and second transfer magnetic poles that have different polarities, that generate a magnetic force for transferring a developer from a first developer-transporting member to a second developer-transporting member, and that are located at positions where the developer-transporting members come close to each other, wherein (B1×B2)/L2 is less than about 400 where L represents a distance (mm) between an outer peripheral surface portion of the first developer-transporting member, the portion facing the first transfer magnetic pole, and an outer peripheral surface portion of the second developer-transporting member, the portion facing the second transfer magnetic pole, and B1 and B2 (mT) respectively represent maximum magnetic flux densities of the first and second transfer magnetic poles in a normal line direction on outer peripheral surfaces of the first and second developer-transporting members.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: November 18, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Sakae Yoshioka, Shinichiro Fujimori, Masanori Kato
  • Publication number: 20140334851
    Abstract: In accordance with one embodiment, a developing apparatus comprises a developing roller configured to hold developing agent and face to an image carrier; a housing configured to store the developing agent and support the developing roller; and a first gap adjusting section configured inside the housing at the downstream side of an opening end part of the housing in a rotation direction of the developing roller, and configured to protrude from an inner wall of the housing at the side parts in an axis direction of the developing roller.
    Type: Application
    Filed: March 28, 2014
    Publication date: November 13, 2014
    Applicants: TOSHIBA TEC KABUSHIKI KAISHA, KABUSHIKI KAISHA TOSHIBA
    Inventor: Takao Izumi
  • Patent number: 8831486
    Abstract: A developing device includes a case for housing a developer, a magnetic roller, an agitating member, a layer thickness restricting member and a plurality of projection members. The magnetic roller is arranged in the case, includes a rotary shaft and magnetically carries the developer on a circumferential surface. The agitating member is arranged to face the magnetic roller in the case, includes a shaft center and a screw forming portion arranged around the shaft center. The layer thickness restricting member restricts the layer thickness of the developer to a predetermined thickness. The plurality of projection members are arranged along a rotation axis direction of the magnetic roller to face the circumferential surface of the magnetic roller at a side upstream of the layer thickness restricting member in a rotating direction of the magnetic roller and comes into contact with the developer carried on the magnetic roller.
    Type: Grant
    Filed: September 11, 2012
    Date of Patent: September 9, 2014
    Assignee: Kyocera Document Solutions Inc.
    Inventor: Tetsuya Toichi
  • Patent number: 8824932
    Abstract: A development device includes a developer container, a developer carrier, exposed partly from a casing, facing a latent image carrier in a development area, a magnetic field generator inside the developer carrier, having multiple magnetic poles including a conveyance pole to convey the developer downstream from the development area to a developer release portion, a developer agitator, and a developer regulator. A predetermined gap is kept between an outer surface of the developer carrier and an inner wall of the casing downstream from an opening of the casing, upstream from a developer release portion, in a direction in which the developer carrier rotates. Multiple recesses are formed in the outer surface of the developer carrier at a pitch in a circumferential direction shorter than half a width of a magnetic flux density of the developer conveyance pole in a direction perpendicular to an axial direction of the developer carrier.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: September 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsumi Masuda, Takamasa Ozeki, Nobuyuki Taguchi, Yuuki Satoh, Toshiki Hayashi, Kyohta Koetsuka, Toshio Kojima, Masayuki Ohsawa, Noriyuki Kamiya, Takumi Terasaka
  • Patent number: 8824936
    Abstract: The image forming apparatus is an image forming apparatus including an image bearing member, a developing device, a transfer device, and a cleaning device. The developing device includes a toner bearing member having a surface subjected to alumite treatment. Toner that is used in the image forming apparatus is magnetic mono-component developer including magnetic toner particles containing at least binder resin and iron-containing magnetic powder, and an external additive to be externally added to the magnetic toner particles. The external additive is formed from inorganic fine particles which have been subjected to surface treatment with a tin-containing compound and an antimony-containing compound. In the image forming apparatus, the ratio of antimony to iron of the toner that has been removed by the cleaning device is double or more the ratio of antimony to iron of the toner before being conveyed by the toner bearing member.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: September 2, 2014
    Assignee: Kyocera Document Solutions Inc.
    Inventor: Takeshi Arakawa
  • Patent number: 8824938
    Abstract: An image forming apparatus, wherein the packing density at a closest point where the first peripheral surface and the second peripheral surface are the closest to each other is within a range from 0.3 to 0.4; wherein a maximum magnetic flux density of a principal magnetic pole for generating the magnetic field for development is located in an upstream side from the closest point with respect to the specified direction and at a point where the packing density is equal to or greater than 0.2; and wherein a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in a downstream side from the closest point with respect to the specified direction is equal to or less than ½ of a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in the upstream side.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: September 2, 2014
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Kanji Nakayama, Masayasu Haga, Tomohisa Yoshida, Wataru Onoda, Narutaka Yoshida, Noboru Ito
  • Patent number: 8818219
    Abstract: An image forming apparatus includes a developer containing part, a developer mixer, a mixer drive motor, a magnetic sleeve, a sleeve drive motor, a mixer rotation speed determination part and a motor drive controller. The developer containing part contains a two-component developer including a toner and a carrier. The developer mixer is provided in the developer containing part, agitates the two-component developer, and charges the toner and the carrier. The mixer rotation speed determination part determines the mixer rotation speed of the mixer drive motor according to a supply amount of the toner supplied to the developer containing part from a toner cartridge by driving of a toner supply motor. The motor drive controller independently performs rotation control of the sleeve drive motor and the mixer drive motor, and rotates and controls the mixer drive motor at the mixer rotation speed determined by the mixer rotation speed determination part.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: August 26, 2014
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Hiromichi Mitamura
  • Patent number: 8811854
    Abstract: A developing apparatus includes a developing container for accommodating developer including magnetic particles, a developer carrying member, rotatably provided in the developing container, for carrying the developer to a region where the developer carrying member is opposed to image bearing member, and a magnet stationarily provided in the developer carrying member, having a pair of magnetic poles of the same polarity adjacent to each other in a circumferential direction of the developer carrying member. In addition, a magnet member extends at each of longitudinal end portions of the developer carrying member within a circumferential range opposed to and between a half-peak width zone of one of the magnetic poles and a half-peak width zone of the other one of the magnetic poles. A side of the magnet member opposed to the developer carrying member is magnetized only to a polarity which is the same as the polarity of the pair of magnetic poles.
    Type: Grant
    Filed: October 18, 2011
    Date of Patent: August 19, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsuya Nose
  • Publication number: 20140205325
    Abstract: A developing unit includes a casing, a developer carrier, a developer conveying path, a developer conveying member, and a layer thickness regulator. The developer carrier is driven to rotate in the casing and carries a toner on the circumferential surface. The developer conveying member is located in the developer conveying path and driven to rotate so as to convey the developer in a second direction and to supply the toner to the developer carrier. The layer thickness regulator is spaced from the developer carrier, and regulates a layer thickness of the developer supplied to the developer carrier. The developing unit is configured to satisfy a condition of 2.0<Vd/Vs<7.0, where Vd denotes a circumferential velocity of the developer carrier and Vs denotes a circumferential velocity of the developer conveying member.
    Type: Application
    Filed: January 15, 2014
    Publication date: July 24, 2014
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Tamotsu Shimizu, Shizuka Okada, Takefumi Yotsutsuji, Akifumi Yamaguchi
  • Publication number: 20140193179
    Abstract: An image forming apparatus supplies toner to an electrostatic latent image on a circumferential surface of a photosensitive rotating member to develop the electrostatic latent image, and includes: a photosensitive unit including the photosensitive rotating member and a pair of support frames rotatably supporting the photosensitive rotating member at axial ends thereof; a developing unit including a developing sleeve that is longer in a rotational axis direction thereof than an element tube of the photosensitive rotating member in a rotational axis direction thereof, and a pair of bearings provided outward from axial ends of the element tube and rotatably holding the developing sleeve at axial ends thereof; and a forcing member relatively forcing the developing unit toward the photosensitive unit to bring the bearings into abutment with the respective support frames, such that a gap between the developing sleeve and the photosensitive rotating member is maintained at a predetermined value.
    Type: Application
    Filed: December 17, 2013
    Publication date: July 10, 2014
    Applicant: KONICA MINOLTA, INC.
    Inventors: Yasuaki TOMODA, Naoki NONOYAMA, Yoshitaka KURODA
  • Patent number: 8744322
    Abstract: A developing device includes a developing member including a scooping pole generating the magnetic lines of force to scoop up a developer, rotating while holding the developer scooped up by the scooping pole on a surface thereof, and supplying the developer to an image holding body to develop the electrostatic latent image, and an agitation transport unit that is disposed at a position where a developer used for development and separated and falling from the developing member is received, rotates about a rotating shaft extending along a rotating shaft of the developing member, agitates the developer, and transports the agitated developer to a scoop position, wherein the scooping pole is disposed on the downstream side of a line, which connects the rotating shaft of the developing member with the rotating shaft of the agitation transport unit, in a rotation direction of the developing member.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: June 3, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Takuya Iwamura
  • Publication number: 20140140733
    Abstract: In a development device, a developer carrier arranged in a housing containing a one-component developer has a circumferential surface carrying the developer. A developer conveying path includes one conveying path along the developer carrier in a first direction and another conveying path in a second direction opposite to the first direction. The developer is circulated and conveyed between the conveying paths. A developer conveying member is arranged in the one conveying path and rotationally driven to convey the developer along the first direction and to supply the developer to the developer carrier. A layer thickness adjusting member is arranged at a distance from the circumferential surface to adjust a layer thickness of the developer supplied to the developer carrier. The developer carrier has a circumferential speed Vd and the developer conveying member has a circumferential speed Vs so that a circumferential speed ratio Vd/Vs satisfies a relationship represented by 1.3?Vd/Vs?5.0.
    Type: Application
    Filed: November 19, 2013
    Publication date: May 22, 2014
    Applicant: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu SHIMIZU, Shizuka OKADA, Takefumi YOTSUTSUJI, Akifumi YAMAGUCHI
  • Patent number: 8693929
    Abstract: An image forming apparatus for forming a toner image on a print medium with a developer composed of toner and carriers, wherein when the first distance is longer than the second distance, an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending upstream from the closest point with respect to the specified direction is smaller than an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending downstream from the closest point with respect to the specified direction.
    Type: Grant
    Filed: January 4, 2012
    Date of Patent: April 8, 2014
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Tomohisa Yoshida, Masayasu Haga, Kanji Nakayama, Wataru Onoda, Narutaka Yoshida, Noboru Ito
  • Publication number: 20140086641
    Abstract: A two-component developer includes toner and a magnetic carrier. The two-component developer is used in a developing device including a circular cylindrical developer transporting member that is disposed so as to be separated by 125 ?m to 250 ?m from a latent image carrier that rotates. The two-component developer is used so as to satisfy a condition in which a width of a region where a magnetic brush contacts a surface of the latent image carrier is in a range of from 1.0 mm to 2.25 mm, and a condition in which a developer density of the region where the magnetic brush contacts the surface of the latent image carrier is in a range of from 0.75×10?6 to 1.50×10?6 g/m3.
    Type: Application
    Filed: May 7, 2013
    Publication date: March 27, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takashi OCHI, Yasuaki WATANABE, Tomoyuki YOSHII, Jun ABE, Takayuki YAMASHITA, Toji TOKUTSU
  • Publication number: 20140072349
    Abstract: A developing device, including: a developer bearing member, which is disposed opposite to an electrostatic latent image bearing member and which bears thereon a developer for developing an electrostatic latent image formed on the electrostatic latent image bearing member and conveys the developer to a developing region, wherein the developer includes a toner and a carrier, the toner containing: a toner base containing a binder resin and a colorant; and an external additive, wherein the external additive contains coalescent particles each made up of a plurality of coalescing primary particles, and wherein a work function Wc of the carrier and a work function Ws of the developer bearing member satisfy a relationship of the following formula (1): Ws?Wc?0.
    Type: Application
    Filed: September 10, 2013
    Publication date: March 13, 2014
    Inventors: Shingo SAKASHITA, Junichi AWAMURA, Tsuneyasu NAGATOMO, Satoshi KOJIMA, Tomoki MURAYAMA
  • Patent number: 8577262
    Abstract: A charging device includes: a first electrode; a second electrode; an insulating body that is provided between the first electrode and the second electrode; wherein either the first electrode or the second electrode includes an opening portion that is formed so as to open toward a first direction in which the first electrode, the insulating body, and the second electrode are laminated, and the insulating body includes a region limiting portion which is a space that communicates with the opening portion, and opens toward a direction in which the region limiting portion communicates with the opening portion, and is limited in a second direction vertical to the first direction.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: November 5, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masao Ohmori, Hidehiko Yamaguchi, Takanori Morino
  • Patent number: 8543041
    Abstract: The specification discloses a developing device comprises a first developer bearing member configured to bear a developer including a toner and a carrier, and to convey the developer to a first developing region facing an image bearing member, so as to develop an electrostatic latent image formed onto the image bearing member and a second developer bearing member configured to bear a developer transferred from the first developer bearing member, and to develop an electrostatic latent image formed on the image bearing member, by conveying a developer to a second developing region facing the image bearing member and a cover unit configured to shield a route toward the image bearing member from a mutual gap position between the first developer bearing member and the second developer bearing member.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: September 24, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuya Nose, Akihiro Noguchi, Kyosuke Takahashi
  • Publication number: 20130216263
    Abstract: An image forming apparatus includes: an image bearing member; an electrostatic image forming device; and a developer carrying member. The developer carrying member is provided so as to be rotated in a direction opposite to a rotational direction of the image bearing member at a peripheral speed higher than that of the image bearing member. When the peripheral speed of the image bearing member is Vp (m/sec), the peripheral speed of the developer carrying member is Vs (m/sec), and a time, of movement of the developer from the surface of the developer carrying member to the image bearing member, actually measured in a gap between the image bearing member and the developer carrying member is Tsd (sec), the peripheral speeds Vp and Vs and the time Tsd satisfy the following relationship: (Vs?Vp)×Tsd<3×105 (m).
    Type: Application
    Filed: February 13, 2013
    Publication date: August 22, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: CANON KABUSHIKI KAISHA