Magnetic Brush Patents (Class 399/267)
  • 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
  • Publication number: 20130183067
    Abstract: The invention relates to a device, system and method for producing magnetically induced visual effects in coatings, particularly security or decorative features, containing orientable magnetic particles. The device comprises a printing unit, an orientation means, a substrate-guiding system and a photocuring unit. The printing unit is arranged to print with the coating composition an image on a first side of a substrate. The orientation means comprises a magnetic field generating element for orienting the magnetic particles in the coating composition of the printed image. The substrate-guiding system is arranged to bring and hold the substrate in contact with the orientation means. The photocuring unit irradiates the image printed on the substrate to at least partially cure the coating composition of the image while the substrate is still in contact with the orientation means.
    Type: Application
    Filed: September 23, 2011
    Publication date: July 18, 2013
    Applicant: SICPA HOLDING SA
    Inventors: Pierre Degott, Claude-Alain Despland, Mathieu Schmid
  • Publication number: 20130071145
    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: Application
    Filed: September 11, 2012
    Publication date: March 21, 2013
    Applicant: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventor: Tetsuya Toichi
  • Patent number: 8372570
    Abstract: The present invention provides a developer carrying member capable of maintaining excellent charge imparting property even under long-term use. The present invention relates to a developer carrying member including a substrate and a resin layer, wherein the resin layer includes an acrylic resin having three specific structural units and electroconductive particles.
    Type: Grant
    Filed: July 15, 2011
    Date of Patent: February 12, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takuma Matsuda, Masayoshi Shimamura, Yasutaka Akashi, Satoshi Otake, Minoru Ito, Yoshiyuki Takayama, Kazuhito Wakabayashi
  • Publication number: 20130034372
    Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a photoconductor is disclosed. A rotating speed of the rotating shell is adjusted, relative to a rotating speed of the rotating magnetic core such that from the point of view of a spot on a dielectric support member (DSM) in a nip region of the DSM, a similar point on the rotating shell is substantially in alignment with the DSM spot in the nip region when a pole flip occurs.
    Type: Application
    Filed: September 13, 2012
    Publication date: February 7, 2013
    Inventor: Eric C. Stelter
  • Patent number: 8335459
    Abstract: A method for selectively removing magnetically attractable toner particles from an image-forming device and an image-forming device for performing the same are provided. The image-forming device includes a cleaning magnet system, configured to provide an activatable second magnetic field. The method includes a step of switching the image-forming device into a cleaning mode, the cleaning mode including the steps of stopping the toner supply to the image-recording medium, rotating the rotatable sleeve in a second direction, opposite to the first direction, such that the magnetically attractable toner particles are transported out of the developing zone towards the cleaning magnet system, and activating the second magnetic field so as to remove the transported magnetically attractable toner particles from the rotating rotatable sleeve of the developing element.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: December 18, 2012
    Assignee: Oce-Technologies B.V.
    Inventor: Sandor H. G. Joppen
  • Patent number: 8331834
    Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, and a developer regulating member. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. A developer-releasing region releases the developer from the developer bearing member using a release force. The developer is disposed higher than a surface of the developer in the developer storing chamber. A component of a magnetic flux density of the magnetic field generated by the magnetic field generator in a direction normal to the developer-releasing region is directed to a same direction as the first and second magnetic poles across the developer-releasing region without forming a local maximum point.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: December 11, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Kyohta Koetsuka, Masayuki Ohsawa, Yoshiyuki Takano, Katsumi Masuda, Yoshio Hattori, Yuji Suzuki, Takamasa Ozeki, Hiroyuki Uenishi
  • Patent number: 8326189
    Abstract: There is provided a separation member for separating a first conveying path formed by a first conveying member from a second conveying path formed by a second conveying member. There is also provided an opposed member facing a magnetic pole H4 at an upstream side of two magnetic poles H4 and H6 that forms a developer-releasing magnetic pole H5.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: December 4, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Yoshiyuki Fukuda, Katsumi Masuda, Nobuyuki Taguchi, Yuuki Satoh, Yasufumi Takahashi, Keiichi Yoshida, Yoshio Hattori, Akira Azami, Takamasa Ozeki, Toshiki Hayashi
  • Patent number: 8311463
    Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a photoconductor is disclosed. A rotating speed of the rotating shell is adjusted relative to a photoconductor such that a banding reduction ratio is not a ratio of differing low whole numbers. Another method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is also disclosed. A rotating speed of the rotating shell is adjusted relative to a rotating speed of the rotating magnetic core such that from the point of view of a spot on a dielectric support member (DSM) in a nip region of the DSM, a similar point on the rotating shell is substantially in alignment with the DSM spot in the nip region when a pole flip occurs.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: November 13, 2012
    Assignee: Eastman Kodak Company
    Inventor: Eric C. Stelter
  • Patent number: 8290409
    Abstract: A developer station and method for an electrographic printer is provided that reduces developer agitation. The developer station includes a sump of magnetic developer, and a magnetic brush roller mounted above sump and having a rotatable magnetic core surrounded by a substantially cylindrical toning shell rotatably mounted with respect to the core. The toning shell defines a nip at its closest point to the photoconductor element. A tangent line tangent to the cylindrical toning shell at the nip is oriented substantially vertically, and the magnetic developer is applied to the toning shell at an angular distance of no more than about 120° from the nip. The toning shell may be eccentrically mounted with respect to the magnetic core and is substantially closest to the rotatable magnetic core within about +30° and ?30° from the nip. Such a configuration advantageously reduces the residence time of the developer on the toning shell.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: October 16, 2012
    Assignee: Eastman Kodak Company
    Inventors: Eric C. Stelter, James D. Shifley, Joseph E. Guth
  • Publication number: 20120230737
    Abstract: A developing device includes a developer container; a developer holding body including a magnet member and a substantially cylindrical member; a transport member including a rotating shaft and a substantially spiral transport blade; a layer-thickness regulating member; and an interrupting member that is arranged between the developer holding body and the transport member, that intersects with a first virtual plane passing through a facing position between the regulating member and the developer holding body and being adjacent to a rotation locus of a radial-direction outer edge of the transport blade at a position at which a speed in a circumferential direction of the transport blade has a speed component toward the regulating member, and a second virtual plane passing through rotation centers of the developer holding body and transport member, and that interrupts movement of the developer pushed and moving in the radial direction of the transport blade.
    Type: Application
    Filed: November 17, 2011
    Publication date: September 13, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yoshitaka Nakajima, Shigeru Inaba, Shota Oba, Takashi Ochi, Akihisa Maruyama, Toshihiro Kanematsu
  • Patent number: 8238801
    Abstract: A developing device, process cartridge method, and image forming apparatus for developing an electrostatic latent image on an image carrier, the developing device including a first carrying member that supplies a developer to a developer carrier at the position of a developer attracting fourth magnetic pole while longitudinally carrying the developer, and a second carrying member that carries the developer released from the developer carrier at the position of a developer releasing third magnetic pole. The developer carrier has two magnetic poles (second and fourth magnetic poles) of the same polarity sandwiching the developer releasing third magnetic pole. Moreover, the developer releasing third magnetic pole is formed by the two magnetic poles (second and fourth magnetic poles) so that the polarity of the developer releasing third magnetic pole differs from the polarity of the two magnetic poles (second and fourth magnetic poles).
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: August 7, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Yasuo Miyoshi, Yoshihiro Fujiwara, Takuya Seshita, Norio Kudo
  • Publication number: 20120195646
    Abstract: A toning apparatus for an electrophotographic marking engine using multi-component developer includes a magnet for producing a magnetic field through the surface of a toning member, so that the carrier particles in the developer in a receiving zone are attracted to the toning member. A rotatable ribbon blender includes an axle, a first inner ribbon and a first outer ribbon having opposite handednesses of twist and arranged to rotate with the axle, and a paddle connected to the first outer ribbon. The ribbon blender is disposed at least partially in the developer in the sump, so that when the ribbon blender rotates, the paddle transports developer from the sump to the receiving zone. No feed roller or supply roller is required; the ribbon blender mixes and transports developer.
    Type: Application
    Filed: January 27, 2011
    Publication date: August 2, 2012
    Inventors: EDWARD MICHAEL ECK, Wendy Buhay
  • Patent number: 8224209
    Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is disclosed. A rotating angular velocity of the rotating shell is adjusted relative to a angular velocity of a photoconductor such that a ratio of these angular velocities is not a ratio of whole numbers.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: July 17, 2012
    Assignee: Eastman Kodak Company
    Inventor: Eric C. Stelter
  • Patent number: 8219009
    Abstract: A developer station for an electrographic printer is provided that reduces developer agitation. The developer station includes a sump of magnetic developer, and a magnetic brush roller mounted above said sump and having a rotatable magnetic core surrounded by a substantially cylindrical toning shell rotatably mounted with respect to the core. The toning shell defines a nip at its closest point to the photoconductor element. A toning shell and magnetic core radius along with the eccentric offset of the toning shell from the rotating magnetic core are used in combination with the magnetic properties of the rotating magnetic core to determine the radius of the toning shell and magnetic core to improve the skiving and removal of developer from the toning shell after the developer has passed through the nip with the photoconductor element.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: July 10, 2012
    Assignee: Eastman Kodak Company
    Inventor: Eric C. Stelter
  • Patent number: 8204411
    Abstract: An electrostatic printing method in which the toning shell and the magnetic core each rotate in a co-current direction with the imaging member such that the portion of the toning shell adjacent to the image development area moves in a process direction, and the magnetic core rotates in the same direction as the toning shell such that a the average developer bulk velocity (ADBV) of the developer on the toning shell is in the same direction and proportional to the photoconductor velocity.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: June 19, 2012
    Assignee: Eastman Kodak Company
    Inventors: Eric C. Stelter, Joseph E. Guth
  • Patent number: 8204415
    Abstract: A developing unit includes a brush member that includes a base member and a plurality of raisings that are erected on a surface of the base. The brush member traps toner within the raisings and causes a flicker movement in the raisings of the brush so that the toner trapped within the raisings is shaken and flown due to the flicker movement to the surface of a toner carrying member.
    Type: Grant
    Filed: April 3, 2009
    Date of Patent: June 19, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Yoshinori Nakagawa, Yasuyuki Ishii, Hideki Kosugi, Tomoko Takahashi, Masaaki Yamada, Masanori Saitoh
  • Publication number: 20120107739
    Abstract: The present invention provides an electrostatic latent image developer used in an image forming apparatus including: an image holding member; a charging unit; a latent image forming unit; a developing unit which stores the electrostatic latent image developer and includes a developer holding member, wherein the developing unit develops the electrostatic latent image formed on the image holding member by bringing a magnetic brush, which is formed on a surface of the developer holding member by the electrostatic latent image developer, into contact with the image holding member, to form a toner image; a transfer unit; a cleaning unit; and a lubricant applying unit, wherein the electrostatic latent image developer contains a toner having a 50% integrated volume particle diameter of from 3.0 to 6.0 ?m, and a carrier having a mean magnetization of 5.0×10?16 to 4.0×10?15 AM2/particle in an applied magnetic field of 1 kilo-oersted.
    Type: Application
    Filed: April 26, 2011
    Publication date: May 3, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takayuki YAMASHITA, Kazuhiko ARAI, Kunihiko SATO, Haruhide ISHIDA, Michio TAKE, Sakon TAKAHASHI, Fusako KIYONO, Yoshifumi IIDA, Mona TASAKI
  • Publication number: 20120093543
    Abstract: An electrostatic latent image developer contains a toner having a volume-average particle diameter of about 2.0 ?m to about 6.5 ?m, and a carrier whose average magnetization per carrier particle at an applied magnetic field of 1 kilooersted is about 3.0×10?16 Am2/particle to about 3.0×10?15 Am2/particle, wherein the electrostatic latent image developer is used in an image forming apparatus including an image-carrying member having a top surface layer composed of a cured film containing fluorocarbon resin particles, a developing unit that develops an electrostatic latent image formed on the image-carrying member to form a toner image by bringing a magnetic brush formed of the electrostatic latent image developer and having a brush roughness of about 300 ?m to about 850 ?m into contact with the image-carrying member, and a cleaning unit that includes a cleaning blade.
    Type: Application
    Filed: August 5, 2011
    Publication date: April 19, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Miho IKEDA, Sakon TAKAHASHI, Kazuhiko ARAI, Haruhide ISHIDA, Michio TAKE, Kunihiko SATO, Yoshinori KUBO, Fusako KIYONO
  • Publication number: 20120070197
    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: Application
    Filed: September 19, 2011
    Publication date: March 22, 2012
    Applicant: KYOCERA MITA CORPORATION
    Inventor: Takeshi Arakawa
  • Patent number: 8139245
    Abstract: An approach is provided for managing the processing of print data at a printing device based upon available consumable resources. A printing device includes a print process configured to determine consumable resources that are currently available at the printing device. The print process is further configured to determine which print data is to be processed based upon the consumable resources currently available at the printing device and the consumable resources required to completely process each of the print data. Print data that can be completely processed using the currently available consumable resources are selected for processing. The print process may also be configured to cause a notification to be provided to a client device to indicate the consumable resources currently available at a printing device and/or that insufficient consumable resources were available to process particular print data and to recommend other consumable resources to process the particular print data.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: March 20, 2012
    Assignee: Ricoh Company, Ltd.
    Inventor: Lifen Tian
  • Patent number: 8135312
    Abstract: There is provided a development apparatus including: a first developer storage container and a second developer storage container that store developer, having a first a and second openings, respectively; a first transport member provided within the first developer storage container, and that causes the developer to move to the second developer storage container via the first opening; a second transport member provided within the second developer storage container, and that causes the developer to move to the first developer storage container via the second opening; a developer holding member that performs development by causing the developer to move to a position facing an image holding body on which a latent image is formed; and a moving member provided so as to fit between an inner wall face of the second developer storage container and an outer edge of the second transport member.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: March 13, 2012
    Assignee: Fuji Xerox Co., Ltd
    Inventors: Hirohisa Kohno, Kazunori Koshimori, Kei Hirata, Akihide Kawamura, Naoya Iwata, Keisuke Kubo, Takashi Sakamoto, Taiyou Uehara, Toshikazu Tsumita, Takeshi Okoshi, Tomio Onuki
  • Patent number: 8135314
    Abstract: A developing device includes a first screw that supplies a developer to a developing roller while agitating/conveying the developer in a first direction, and a screw that collects residual developer from the developing roller, agitates/conveys the residual developer in a second direction opposite to the first direction, and delivers the residual developer to the first screw. Between two points that a magnetic flux density in a normal direction of a magnetic field formed in a developer separating magnetic pole in the developing roller become substantially zero, a point at a downstream side in a rotating direction of the developing roller is formed at an upstream side to a developing roller rotating direction, than a line joining the center of the developing roller and the center of the second screw.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: March 13, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Yasuo Miyoshi, Hisashi Kikuchi, Norio Kudo, Nobuo Iwata, Tsukuru Kai
  • Publication number: 20120058423
    Abstract: A contact developing method including supplying a two-component developer to an electrostatic latent image on a rotating image bearing member by rotating a developing sleeve and a rotatable magnet having multiple magnetic poles provided inside the developing sleeve, to develop the electrostatic latent image into a toner image. The developing sleeve and the image bearing member rotate in the same direction while facing each other. The two-component developer comprises a non-magnetic toner and a carrier. The carrier comprises a magnetic core particle and a resin layer covering the magnetic core particle. The resin layer comprises a conductive particle and a resin. The conductive particle comprises an alumina-based material and a conductive layer covering the alumina-based material. The resin is obtained by heating a copolymer comprising a monomer A unit and a monomer B unit.
    Type: Application
    Filed: July 13, 2011
    Publication date: March 8, 2012
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Mariko Takii, Toyoshi Sawada, Toyoaki Tano, Hiroshi Tohmatsu, Koichi Sakata, Hiroyuki Kishida, Saori Yamada
  • Patent number: 8126379
    Abstract: The present invention provides a developing device which is capable of suppressing the generation of a fogging phenomenon and deposition of carrier particles to an electrostatic latent image carrier and developing the electrostatic latent image efficiently, the device includes a development sleeve and a magnet body onto which the sleeve is fitted, and using a two-component developer. An angular position which indicates the peak value of the magnetic flux density in the normal direction produced by a development pole of the magnet body is shifted downstream from the center position of the development pole in the direction of movement of the surface of a photosensitive member in a development region. The present invention also provides an image forming apparatus which can form high-quality images with reduced noise such as fogging by mounting the developing device.
    Type: Grant
    Filed: June 8, 2009
    Date of Patent: February 28, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Toru Hayase, Yuusuke Okuno, Shigeki Yamamoto, Kuniya Matsuura, Hiroshi Murasaki
  • Patent number: 8086118
    Abstract: In accordance with an embodiment of the embodiment of the invention, an image forming apparatus includes: an electrostatic image-bearing member; and a developing device. The developing device includes a developer-carrying member disposed to face the electrostatic image-bearing member, and a developer carried on the developer-carrying member. The developer includes a carrier having a volume-average particle size dc (?m) and a toner having a volume-average particle size dt (?m) of at most 5 ?m and contained at a weight ratio C with respect to the carrier of from 5 to 10% and is controlled so as to provide a surface coverage F of the carrier with the toner of from 30 to 80% as calculated according to Formula (I): F=(¼)×(dc/dt)×(pc/pt)×C, wherein pc denotes a true specific gravity (?) of the carrier, pt denotes a toner absolute specific gravity (?), and C denotes a weight ratio (?) of the toner to the carrier.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: December 27, 2011
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Mitsutoshi Watanabe
  • Patent number: 8068771
    Abstract: A developing unit includes a developing hopper for storing a dual-component developer. In the developing hopper, an opening portion is formed at the position opposing the outer peripheral surface of a photoreceptor drum. A developing roller for supplying the developer to the photoreceptor drum to develop an electrostatic latent image is provided inside the developing hopper. The developing roller has a multi-pole magnetic member having a multiple magnetic poles and a non-magnetic sleeve. The multi-pole magnetic member has a multiple number of magnetic poles radially arranged apart from each other. The photoreceptor drum incorporates an opposing magnetic pole formed of a bar magnet having a rectangular section, disposed at a position opposing the magnetic pole across a photosensitive layer. The opposing magnetic pole has a polarity dissimilar to that of the main magnetic pole.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: November 29, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yuhsuke Yoshimoto
  • Patent number: 8059995
    Abstract: An image forming apparatus including: an image bearing member; and a developer bearing member bearing a developer including a toner and a carrier, the developer bearing member developing an electrostatic image formed on the image bearing member with the developer, and the developer bearing member being applied with an alternate voltage in order to form an alternate electric field between the developer bearing member and the image bearing member, wherein assuming that electric field intensities Eb and Ed be Eb=|(Vp1?VL)/D| and Ed=|(Vp2?VL)/D|, a relationship, 0?K1>K2, is satisfied, where K1: a gradient at Ed, and K2: a gradient at Eb, and wherein a resistivity ?b of the carrier at the electric field intensity Eb satisfies 1.1×106×en<?b<6.0×107 [?·m] (where: e is the base of natural logarithms; and n=4×Eb×10?7).
    Type: Grant
    Filed: June 17, 2010
    Date of Patent: November 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Yamamoto, Yoshinobu Baba, Manami Haraguchi, Kenta Kubo
  • Patent number: 8055167
    Abstract: An image forming apparatus is disclosed. The image forming apparatus includes a photosensitive body, a magnetic roller disposed at a predetermined distance from the photosensitive body, and a donor roller disposed between the photosensitive body and the magnetic roller. The donor roller has a diameter larger than the closest distance between the photosensitive body and the magnetic roller. The image forming apparatus includes gap rings and pressing device to maintain desired gaps between the magnetic roller and the donor roller and between the donor roller and the photosensitive body.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: November 8, 2011
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventors: Gyeong Ho Park, Won Choe
  • Patent number: 8055168
    Abstract: A magnet knife assembly for a toner developing device including a ferromagnetic strip held between like poles (N) of two permanent magnets such that a knife edge portion of the strip projects outwardly beyond the two magnets and is subject to a magnet force that tends to urge the strip in a direction in which the knife edge projects further out of the magnets, wherein the length of the strip is selected such that a portion of the strip opposite to the knife edge is subject to a magnetic force that at least counterbalances said magnetic force on the knife edge portion.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: November 8, 2011
    Assignee: Oce-Technologies B.V.
    Inventors: Paulus A. C. Groenen, Henricus A. M. Janssen
  • Patent number: 8054476
    Abstract: What is disclosed is a system and method for minimizing the Inter-Document Zone (IDZ) in printing system architectures with print engines running at constant speed. The asymmetric IDZ precession disclosed herein is intended for those multi-pass systems where there is a difference in required start and stop durations of various transition subsystems such as transfer engagement and disengagement processes. This mode reduces the required inter-document zone region by shifting the zone in accordance with asymmetric timing of start and stop times of processes that must occur during this time. Advantageously, productivity gains are effectuated without altering process speeds.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: November 8, 2011
    Assignee: Xerox Corporation
    Inventor: Jeffrey J. Folkins
  • Patent number: 8023867
    Abstract: A magnet roller includes a cylindrical roller body including a side surface in which a groove is formed, a magnet body which is disposed in the groove, and a magnetic metal member which is attached to a surface of the magnet body, which is remote from an opening of the groove.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: September 20, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiyuki Takano, Tsuyoshi Imamura, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Hiroya Abe, Takashi Innami, Tadaaki Hattori, Mieko Terashima
  • Publication number: 20110217085
    Abstract: A developing apparatus contains a developer for developing a latent image formed on an image carrier. The developing apparatus includes a developer carrier disposed opposite to the image carrier; a developer regulating member regulating an amount of the developer carried by the developer carrier; and a developer circulating unit transporting the developer in a circulating path. The developer circulating unit includes a rotatable first transport member supplying the developer to the developer carrier while transporting the developer in a horizontal direction, a shielding member preventing the developer separated from the developer carrier from flowing back toward the first transport member, and a rotatable second transport member collecting the developer separated from the developer carrier while transporting the developer in the horizontal direction. A distance between the second transport member and the developer carrier is greater than a distance between the first transport member and the developer carrier.
    Type: Application
    Filed: February 15, 2011
    Publication date: September 8, 2011
    Inventors: Yoshio HATTORI, Yoshiyuki Fukuda, Atsushi Nakamoto
  • Patent number: 7983604
    Abstract: An apparatus and method for managing magnetic carrier in an electrostatographic printer including an apparatus for directing magnetic carrier from a photoconductor, back toward a feed apparatus wherein the apparatus includes a magnetic carrier scavenger such that there is more magnetic carrier volume in the direction of the feed apparatus as well as a well to collect any magnetic carrier that does not move toward the feed apparatus.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: July 19, 2011
    Assignee: Eastman Kodak Company
    Inventors: Kenneth J. Brown, Eric C. Stelter
  • Publication number: 20110170914
    Abstract: An apparatus and method for arranging the spacing of magnets in an electrostatogaphic printer to eliminate steaks due to the magnetic carrier that does not move uniformly across the photoconductor surface.
    Type: Application
    Filed: January 14, 2010
    Publication date: July 14, 2011
    Inventors: Dennis J. Grabb, Kenneth J. Brown, Robert E. Zeman
  • Patent number: 7965964
    Abstract: A developing roller according to the invention includes a columnar magnet roller, and a cylindrical sleeve that houses the magnet roller. A plurality of fragmented micro recesses is formed on the surface of the sleeve. The micro recesses are arranged dispersively both in an axial direction and in a circumferential direction of the sleeve.
    Type: Grant
    Filed: April 3, 2008
    Date of Patent: June 21, 2011
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Norikazu Ochiai, Mitsuhisa Kato
  • Patent number: 7939234
    Abstract: An image forming apparatus, including a latent image-holding member, a developing unit, a transfer unit, a cleaning unit, and a recycling unit, wherein the developer includes a toner having an external-additive adhesiveness index SA in the range of approximately 50% to approximately 95% and: a carrier containing magnetic particles and a coating layer coating the surface of the magnetic particles and having a total energy of approximately 1,420 to approximately 2,920 mJ; or a carrier containing magnetic powder-dispersed particles and a coating layer coating the surface of the magnetic powder-dispersed particles and having a total energy of, approximately 890 to approximately 1,390 mJ.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: May 10, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Matsumoto, Akihiro Iizuka, Fusako Kiyono
  • Patent number: 7937008
    Abstract: An image forming apparatus having a touchdown-development type developing apparatus, in which a toner collecting roller that collects scattered toner suspended in the vicinity of a toner holding body and a two-component developer holding body is arranged on the downstream side in a rotational direction of the two-component developer holding body from a closest position of the two-component developer holding body and the toner holding body, and between the two-component developer holding body and the housing wall, and further, bias means that applies a bias voltage for collecting the scattered toner to the toner collecting roller, and image density sensing means for sensing a density of a toner image developed on the electrostatic latent image holding body surface or a toner image on a transfer body onto which the toner image developed on the electrostatic latent image holding body surface is transferred to control the bias voltage are provided.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: May 3, 2011
    Assignee: Kyocera Mita Corporation
    Inventors: Masashi Fujishima, Akihiro Watanabe, Sayo Uemura, Yukihiro Mori
  • Patent number: 7917067
    Abstract: A magnetic field generating member with high stiffness and small size, an image development device, a process cartridge and an image forming apparatus including the magnetic field generating member as well as a manufacturing method of the magnetic field generating member are provided where the magnetic field generating member includes a main body, a groove provided in the main body, an interposition member configured to be fitted in the groove of the main body and including a concave portion and a magnetic member as a long magnetic compact fixed into the concave portion of the interposition member.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: March 29, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiyuki Takano, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Mieko Terashima, Rei Suzuki, Hiroya Abe, Takashi Innami, Tadaaki Hattori
  • Publication number: 20110064927
    Abstract: A toner comprising toner particles having at least one type of surface additive, the toner particles having an FPIA average circularity of at least 0.95, whereby at least 80% wt of the total amount of surface additives stays onto the surface of the toner particles when an ultrasonic treatment of 4500 to 4700 J/gram of toner is applied; a substrate printed or marked with the above-described toner; and a method for manufacturing a toner, said method including the steps of: mixing a binder resin, a colorant and optionally other additives, thereby forming a mixture, melting, kneading and milling said mixture, thereby obtaining a melted kneaded product, pulverizing said melted kneaded product, adding at least one surface additive before or while bringing the FPIA average circularity of said toner particles to 0.
    Type: Application
    Filed: November 19, 2010
    Publication date: March 17, 2011
    Inventors: Lode DEPREZ, Werner OP DE BEECK, Karlien TORFS
  • Patent number: 7904003
    Abstract: A developing device includes: a first screw provided in a first carrying path, the first screw rotating so as to simultaneously stir the developer and carry the developer in the first carrying path in a predetermined direction; a second screw provided in a second carrying path, the second screw rotating so as to simultaneously stir the developer and carry the developer in the second carrying path in an opposite direction from the predetermined direction; a first communicating path communicating the first carrying path with the second carrying path; a second communicating path communicating the first carrying path with the second carrying path, the second communicating path being formed downstream of the first communicating path in the opposite direction; and a developer bearing member for bearing the developer in the second carrying path so as to supply the toner included in the developer onto a photoreceptor, the toner being supplied through a supply opening to the first carrying path, wherein the developing
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: March 8, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hisashi Kunihiro
  • Publication number: 20110044729
    Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is disclosed. A rotating angular velocity of the rotating shell is adjusted relative to a angular velocity of a photoconductor such that a ratio of these angular velocities is not a ratio of whole numbers.
    Type: Application
    Filed: August 18, 2009
    Publication date: February 24, 2011
    Inventor: Eric C. Stelter
  • Publication number: 20110044728
    Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a photoconductor is disclosed. A rotating speed of the rotating shell is adjusted relative to a photoconductor such that a banding reduction ratio is not a ratio of differing low whole numbers. Another method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is also disclosed. A rotating speed of the rotating shell is adjusted relative to a rotating speed of the rotating magnetic core such that from the point of view of a spot on a dielectric support member (DSM) in a nip region of the DSM, a similar point on the rotating shell is substantially in alignment with the DSM spot in the nip region when a pole flip occurs.
    Type: Application
    Filed: August 18, 2009
    Publication date: February 24, 2011
    Inventor: Eric C. Stelter
  • Patent number: 7890028
    Abstract: A developing device and image forming apparatus that can satisfy stability over time in relation to amount of developer carried, and prevent developer retention, deterioration of developer and developing sleeve adhesion, wherein the amount of developer carried per unit area on the developer carrier in the developing region is 30 mg/cm2 to 60 mg/cm2; the weight mean particle diameter of the toner is 4.5 ?m to 8.0 ?m; the ratio Dw/Dn of the toner weight mean particle diameter (Dw) and the number mean particle diameter (Dn) is 1.20 or less; an irregular roughness pattern having the maximum height Rz of the surface roughness of 20 to 40 ?m and the mean space Sm of the roughness of 100 to 200 ?m is formed on the surface of the developer carrier; and the relationship between the developing gap PG and the gap DG between the developer restricting member and the developer carrier is 1.0?(DG/PG)?3.0.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: February 15, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoru Miyamoto, Koichi Sakata, Maiko Koeda, Kiyonori Tsuda
  • Publication number: 20110026976
    Abstract: A method for forming an electrographic image includes providing an imaging member having an electrostatic image and a toning shell adjacent to the imaging member to take into account the slippage as a result of toner particles that are approximately spherical.
    Type: Application
    Filed: July 31, 2009
    Publication date: February 3, 2011
    Inventors: Eric C. Stelter, Joseph E. Guth
  • Patent number: 7877047
    Abstract: A developing device, which can inhibit the increase of the rate of uncharged toner caused by long hours of operation and develop an excellent image, and a process cartridge and an image forming apparatus that use such a developing device. A developing sleeve is rotary driven, and has, as magnetic field generating means that is fixedly disposed within the developing sleeve, a magnet roll composed of a plurality of stationary magnets. The magnet roll has five magnetic poles, P1 (south pole), P2 (north pole), P3 (north pole), P4 (south pole) and P5 (north pole), which are arranged in the direction of rotation of the developing sleeve in this order starting from a developing position that is a region facing a photoreceptor.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: January 25, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasuo Miyoshi
  • Patent number: 7856199
    Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a rotatable developer carrying member, provided opposed to the image bearing member, for carrying a developer including toner and a carrier to a position where the developer carrying member is opposed to the image bearing member; a regulating member for regulating the amount of the developer to be carried on the developer carrying member; a driving device for rotating the developer carrying member; a controller for controlling the driving device to execute, at the time of end of image formation, a plurality of continuous operations each including acceleration of a rotational speed of the developer carrying member and deceleration thereof following the acceleration.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: December 21, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takeshi Tomizawa