US3543720A - Apparatus for development of electrostatic images - Google Patents

Apparatus for development of electrostatic images Download PDF

Info

Publication number
US3543720A
US3543720A US709281A US3543720DA US3543720A US 3543720 A US3543720 A US 3543720A US 709281 A US709281 A US 709281A US 3543720D A US3543720D A US 3543720DA US 3543720 A US3543720 A US 3543720A
Authority
US
United States
Prior art keywords
developer
magnetic
cavity
insulating surface
brush
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US709281A
Other languages
English (en)
Inventor
Roger A Drexler
Conrad Altmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Application granted granted Critical
Publication of US3543720A publication Critical patent/US3543720A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/095—Removing excess solid developer, e.g. fog preventing

Definitions

  • two magnetic brushes are arranged to create [50] Field ofSearch 118/637, he accumulation in the f f a gemly tumbling rollback 637(MCH0; 1 7/175; gslunqmred); from the contacting of one of the brushes with the image-bear- 346/74(ES) ing surface.
  • the accumulation is accentuated by adjusttin the s acin between the brushes [56] References cued and the image-bearin g surf ce, adgustin g the peripheral speed UNITED STATES PATENTS of the brushes and controlling the direction of movement of 3,133,834 5/1964 Sowiak 118/637 the image-bearing surface relative to the movement of the 3,145,122 8/1964 Streich,Sr... 118/637 brushes. 3,219,014 1 1/1965 Mott et a1. 1.
  • Carrier carryout is reduced by directing a strong magnetic 3,256,855 6/1966 Oliphant 118/637 flux at the rollback area and by providing an auxiliary carrier 3,355,288 11/1967 Matkan 117/175 scavenging mechanism.
  • FIGJ A 3 9 5 H 2 I i f r ⁇ X I ROGER A.
  • DREXLER CONRAD ALTMANN INVENTORS ATTORNEYS APPARATUS FOR DEVELOPMENT OF ELECTROSTATIC IMAGES CROSS- REFERENCES TO RELATED APPLICATIONS Reference is made to commonly assigned cofiled U.S. application Ser. No. 709,280,now US. Pat. No. 3,457,900, entitled Single Magnetic Brush Apparatus for Development of Electrostatic Images filed even date herewith in the name of Roger A. Drexler.
  • This invention relates to electrostatic images (which term is meant to include all electrostatic charge patterns, regardless of the method of formation) and, more specifically, to methods and apparatus for developing electrostatic images carried on an insulating surface.
  • the toner In electr'ography, it is common to form an electrostatic image on an insulating surface and to develop that image by applying toner particles thereto. The resulting toner image is then utilized. In the most common commercial applications, the toner is either transferred in image configuration to another surface and then fixed or is fixed to the insulating surface itself. In processes in which the toner is transferred from the insulating surface prior to fixing, the insulating surface generally is reused.
  • Triboelectric developing systems have been adapted to the general development of electrostatic images.
  • finely divided toner particles are held to the surface of much larger carrier particles by electrostatic charges created by triboelectrification, forming a mixture (herein called a developer).
  • a developer electrostatic charges created by triboelectrification, forming a mixture (herein called a developer).
  • the developer is brought into contact with an electrostatic image, the attraction of the image for the triboelectrically charged toner overcomes the attraction of the carrier for the toner and the image is developed.
  • cascade systems In cascade systems, gravity is used to roll developer, across the image. Because cascade systems use gravity as their primary moving force, they are necessarily speed limited. In automatic machines, a cascade recirculation system generally requires substantial machinespace.
  • the carrier particles are ferromagnetic in nature. These ferromagnetic carrier particles are held to an applicator surface, for example, a nonmagnetic cylinder, in bristle formation by magnetic attraction. With the proper use of applicator, one or more magnets and developer, the bristles can be brushed across a surface carrying an electrostatic image. The electrostatic attraction of the toner for the image overcomes the triboelectrically created attraction between toner and ferromagnetic particles and the image is developed. Areas of the image exerting less attractive force on the toner than is exerted by the carrier are cleaned of toner as they are brushed. This is commonly aided by application of an electrical bias to the carrier through the applicating surface of the brush. Magnetic brushes also have been designed to give either fringe or solid area development by adjusting the conductivity of the carrier. They can also be made to tone areas of less charge and clean areas of greater charge giving what is known in the art as a reverse development.
  • a powder transfer process greatly increases image degradation caused by carrier carryout. More specifically, small carrier particles are commonly picked up by the insulating surface in the toning operation and have the effect at toner transfer of holding a large area of the transfer surface away from the photosensitive surface thereby inhibiting powder transfer. This problem is much reduced if no transfer of toner is included in'the process, as is the case when the powder is fixed to the toned surface.
  • scratching and scumming are reduced by a developer feed and discharge arrangement which provides a substantial developer accumulation in a cavity accessible to the image-carrying surface.
  • This accumulation gives a soft, less abrasive toning medium which, in turn, gives effective toning, including toning of solid areas.
  • the feed and discharge arrangement is so constructed to gently tumble the developer accumulated in the cavity, giving thorough mixing and triboelectric charging, and thereby providing effective toning at remarkably low on toner concentrations.
  • toner can be created and agitated with a number of forms of apparatus within the concept of this invention
  • One brush herein called the feed brush
  • the other brush herein called the discharge brush
  • the discharge brush is rotated at a slower speed in the same direction. It picks up developer from the feed brush and brushes it lightly across the insulating surface while carrying the developer out of the cavity.
  • this carrier or iron carryout by careful placement of a strong magnet in the feed brush so thatit creates a substantial ma'g- I netic attractive force directly in the rollback area.
  • FIG. 1 is a schematic cross-sectional view of a magnetic brush assembly constructed according to the invention.
  • FIG. 2 is a fragmentary top view showing the drivetrain of the magnetic'brushjassembly of FIG. 1.
  • a stationary magnetic pole piece 25 thatgmay be made of soft steel or other magnetic material.
  • Concentric with the arrangement of theseelements and on'the outside thereof are rotatable, preferably surface-roughened, nonmagnetic rollers 7 and 8.
  • Each brush is constructed so that, as the rollers 7 and'8 rotate, developer, particles are held on its surface and moved with the roller while in thefield of the magnetic strips.
  • the magnetic strips 6 are arranged so that a section of each roller is not in enough of the influence of the magnetic field to hold the developer on the roller.
  • Ferromagnetic carrier particles in the rollback area have a tendency to be occasionallycarried away by the insulating surface. This can be reduc'edby aiming"'a strong magnet I9 in the second brush at the rollback 9. The strength of this magnet is preferably worked out empirically for the softness desired in the rollback and the carryout permissible. Further, the feed brush, which lightly contacts the insulating surface after the surface passes the rollback area, is effective to remove some of those carrier particles actually picked up by the electrostatic image in toning.
  • a scavenging device 30 can also beused. It includes a stationary single strong magnet 31 placed in close proximity with theinsulating surface 2 and a rotatable nonmagnetic roller 32 between the magnet and surface 2 to carry out ferromagnetic particlesattracted toward the magnet.
  • FIG. 2 shows a single drive gear 29'connected to a source ofpower, not shown, drives a gear connected by a shaft 26 to roller 8 and drives a gear 27, which has a larger diameter than gear 28, and is connected through a shaft 24 to roller 7.
  • the difference in the diameters of the gears will cause roller 8 to be rotated at a faster speed than roller 7.
  • the gears can be made the same size and the rotations per minute .ofvthe rollers 7 and 8 be made equal, but the second roller 8 be made of larger diameter than the first roller 7, thereby provid ing a greater peripheral speed.
  • the size and speed of rotation of the rollers can be made equal, but the strength of the magnets and, hence, the size of the bristles in the feed brush made greater than in the discharge brush.
  • a toner dispenser 50 including a hopper 51 allows toner to fall at a regular rate onto a paddle wheel 52 which rotates and feeds toner into the trough 11. Fresh toner is circulated gradually toward the bottom of the feed brush 5 by paddle wheels 21'and 22, where it is picked up by the second brush'to begin use in the process.
  • the feed brush 5 feeds developer to the t discharge brush 4. If a close doctor blade is not used with the discharge brush to define a short'bristle size, a rollback 9 of developer will occur at a point just prior to contact of the discharge brush with the insulating surface. This rollback can be enhanced by several features shown in the drawing. First, the brushes are rotated so that they move in adirection opposite to the movement of the insulating surface 2 at the points of contact therewith. Second, the feed brush 5 is rotated at afaster rate than the discharge brush 4. Third, the feed brushis spaced farther from the insulating surface 2 than the discharge brush.
  • the rollback action provides a continuous soft mixing of toner and carrier helping to maintain theproper polarity of charge on the toner at the development area. This continuous mixing combined with the effectiveness of the toning allows for substantial variations in overall toning concentrations with toning results that are very close in quality. If the brushes are used as development electrodes, the apparatus will give especially uniform blacks in solid image areas.
  • two brushes are constructed as shown in FIG. 1.
  • the rotating cylinders 7 and 8 are made 3 inches in diameter and one-fourth inch apart at their closest outside points.
  • the strip magnets 6 have enough magnetic attraction for iron particles of +80- 120 mesh to produce bristles approximately one-fourth inches long.
  • the axes of cylinders 7 and 8 are offset with respect to the insulating surface 2 by one-sixteenth inch with the periphery of feed cylinder 8 approximately three-sixteenths inch and "discharge cylinder 7-approximately one-eighth inch from insulating surface 2, respectively, at their closest points. With surface 2 moving at 20 inches a second, feed cylinder 8 is rotated at 65 r.p.m.
  • developer feed means for feeding developer into said cavity at a first rate
  • developer discharge means for discharging developer from said cavity at a second rate which is less than said first rate
  • Developing apparatus for use in applying toner to an electrostatic image carried on a moving insulating surface, said apparatus comprising:
  • developer feed means for feeding developer into said cavity at a first quantity per unit of time
  • developer discharge means for discharging developer from said cavity at a second quantity per unit of time
  • said first quantity per unit of time being greater than said second quantity per unit of time thereby causing a substantial accumulation of freely tumbling developer in said cavity in contact with said insulating surface.
  • first magnetic brush feed means for feeding developer into said cavity at a first rate
  • second magnetic brush means for discharging developer from said cavity at a second rate less than said first rate so as to create an accumulation of developer in said cavity and tumble developer accumulated in said cavity through a path touching said moving insulating surface.
  • Developing apparatus for use in applying toner to an electrostatic image carried on an-insulating surface, said apparatus comprising:
  • a developer comprising a mixture of toner powder and carrier powder
  • developer feed means and developer discharge means portions of which combine with a portion of said insulating surface to define a rollback-cavity
  • said feed means including means to feed developer into said rollback cavity in a direction generally opposite said first direction and at a first rate
  • said discharge means including means to discharge developer from said rollback cavity at a second rate less than said first rate
  • said feed means and discharge means including means cooperating with said insulating surface to tumble developer accumulated in said cavity through a path a portion of which contacts said insulating surface.
  • Developing apparatus for use in applying toner to an electrostatic image carried on a moving insulating surface, said apparatus comprising:
  • magnetic brush means for feeding developer into said cavity at a first quantity per unit of time
  • magnetic brush means for discharging developer from said cavity at a second lesser, quantity per unit of time, whereby a substantial accumulation of freely tumbling developer is provided in said cavity in contact with said insulating surface.
  • a developing apparatus for use in applying toner to an electrostatic image carried on an insulating surface moving in a first direction, said apparatus comprising:
  • first magnetic brush means for feeding developer into said cavity at a first rate
  • second magnetic brush means for discharging developer from said cavity at a second rate which is less than the rate at which developer is fed into said cavity by said first magnetic brush means
  • said first and second magnetic brush being adapted to feed developer through said cavity in a second direction opposite to said first direction and being located with respect to said moving insulating surface so as to provide a gently tumbling accumulation of developer in said cavity.
  • a developing apparatus for use in applying toner to an electrostatic image carried on a moving insulating surface comprising:
  • a developer comprised of a mixture of toner powder and magnetically attractable carrier powder
  • reservoir means for holding said developer
  • magnetic means for feeding developer from said reservoir means to a rollback cavity, cavity, and by a portion of said magnetic means and a portion of said insulating surface
  • said magnetic means includeda. feed magnetic brush means for moving developer from said reservoir into said rollback cavity;
  • Apparatus according to claim 7 wherein said means for operating said feed and discharge magnetic brush means is adapted to move the developer being moved by said feed brush faster than the developer being moved by said discharge brush, thereby contributing to said accumulation of developer.
  • Apparatus according to claim 7 wherein a portion of said feed magnetic brush means is positioned close enough to said insulating surface to remove ferromagnetic particles deposited on said surface by said discharge brush means and by said developer accumulated in said cavity.
  • feed magnetic brush means includes a strong magnetic flux producing means whose lines of force extend substantially into said rollback of developer.
  • Apparatus according to claim 7 including an auxiliary magnetic means positioned subsequent to said magnetic means in thepath of said insulating surface for removing ter- 4 rornagnetic particles deposited on said insulating surface by said magnetic means and by said developer accumulated in said cavity.
  • Electrographic developing apparatus for use in applying toner to an electrostatic charge pattern carried on a'moving insulating surface to form a toner pattern defined by said charge pattern, said apparatus comprising:
  • said means including:
  • feed magnetic brush means for moving developer from said reservoir into close proximity with said moving insulating surface and then into said rollback cavity
  • magnetic flux producing means and v 2. a rotatable nonmagnetic cylinder, a portion of which cylinder is positioned within the influence of said magnetic flux producing means, said flux producing means being positioned to attract developer to the outer surface of said cylinder portion, said magnetic flux producing means being arranged in said feed magnetic brush means and said discharge magnetic brush means so that developer in said reservoir is attracted by the magnetic flux producing means of said feed magnetic brush means and held on its corresponding cylinder when rotated until said developer comes under the attraction of the magnetic flux producing means of said discharge magnetic brush means, said magnetic flux producing means of said discharge magnetic brush means being positioned to attract developer'from said feed magnetic brush means to the cylinder of said discharge magnetic brush means and hold said developer on said cylinder as it rotates said developer into contact with said insulating surface and then returns it to said reservoir, means for rotating the cylinders of said magnetic brush means at predetermined peripheral rates said predetermined rates being so chosen relative to the movement of said insulating surface to create a substantial accumulation of tumbling developer in said cavity.
  • Apparatus according to claim 24 wherein the cylinders of said magnetic brush means are positioned so that at their closest points the outer surface of the cylinder of said feed magnetic brush means is farther from the insulating surface than the outer surface of the cylinder of the discharge magnetic brush-means.
  • Apparatus according to claim 14 wherein said means for rotating the cylinders includes means to rotate the cylinder of said feed brush means at a faster peripheral speed than the peripheral speed of the cylinder of said discharge brush means.
  • Apparatus for developing an electrostatic image carried on a moving insulating surface comprising:
  • each brush having a rotatable nonmagnetic cylinder

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US709281A 1968-02-29 1968-02-29 Apparatus for development of electrostatic images Expired - Lifetime US3543720A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US70928168A 1968-02-29 1968-02-29

Publications (1)

Publication Number Publication Date
US3543720A true US3543720A (en) 1970-12-01

Family

ID=24849198

Family Applications (1)

Application Number Title Priority Date Filing Date
US709281A Expired - Lifetime US3543720A (en) 1968-02-29 1968-02-29 Apparatus for development of electrostatic images

Country Status (5)

Country Link
US (1) US3543720A (US20100223739A1-20100909-C00025.png)
JP (1) JPS5332260B1 (US20100223739A1-20100909-C00025.png)
BE (1) BE729079A (US20100223739A1-20100909-C00025.png)
FR (1) FR2002905A1 (US20100223739A1-20100909-C00025.png)
GB (1) GB1265901A (US20100223739A1-20100909-C00025.png)

Cited By (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3640248A (en) * 1969-06-04 1972-02-08 Xerox Corp Electrostatic magnetic developing apparatus
US3654902A (en) * 1969-11-28 1972-04-11 Plastic Coating Corp Toner unit for photoelectrostatic reproduction
DE2161852A1 (de) * 1970-12-14 1972-06-29 Xerox Corp Vorrichtung zur Magnetbürstenentwicklung elektrostatischer latenter Bilder
JPS4953836A (US20100223739A1-20100909-C00025.png) * 1972-09-25 1974-05-25
JPS4962432U (US20100223739A1-20100909-C00025.png) * 1972-09-12 1974-05-31
US3863603A (en) * 1974-01-07 1975-02-04 Ibm Magnetic brush roll having resilient polymeric surface
JPS5036133A (US20100223739A1-20100909-C00025.png) * 1973-07-24 1975-04-05
US3881446A (en) * 1973-01-25 1975-05-06 Minolta Camera Kk Magnetic brush developing apparatus
US3882823A (en) * 1973-08-15 1975-05-13 Minolta Camera Kk Stirring and scraping device for developing material
US3884571A (en) * 1972-05-05 1975-05-20 Adalbert A Lux Leakage developer recirculation assembly
US3897749A (en) * 1973-02-05 1975-08-05 Identicator Corp Dry powder fingerprinting apparatus
US3908595A (en) * 1973-04-05 1975-09-30 Fuji Xerox Co Ltd Magnetic brush development apparatus utilizing magnetic means
JPS50149350A (US20100223739A1-20100909-C00025.png) * 1974-05-21 1975-11-29
DE2521275A1 (de) * 1974-05-13 1975-12-04 Fuji Xerox Co Ltd Entwicklereinrichtung
US3937181A (en) * 1973-05-23 1976-02-10 Fuji Xerox Co., Ltd. Magnetic brush type developing mechanism in electrophotographic copying machine
JPS5160252U (US20100223739A1-20100909-C00025.png) * 1974-11-05 1976-05-12
US3977361A (en) * 1975-05-13 1976-08-31 Fuji Xerox Co., Ltd. Magnetic brush developing device
US3985099A (en) * 1974-05-13 1976-10-12 Fuji Xerox Co., Ltd. Magnetic brush developing device
US4013041A (en) * 1975-10-24 1977-03-22 Eastman Kodak Company Self-compensating photoconductor web
US4041903A (en) * 1974-05-21 1977-08-16 Konishiroku Photo Industry Co., Ltd. Developing device for use in electrophotography
JPS53102754A (en) * 1977-02-21 1978-09-07 Ricoh Co Ltd Electrophotographic developing device
US4116555A (en) * 1975-10-29 1978-09-26 Xerox Corporation Background removal apparatus
US4185130A (en) * 1977-04-18 1980-01-22 E. I. Du Pont De Nemours And Company Magnetic image decorator
US4190351A (en) * 1978-11-13 1980-02-26 Pitney-Bowes, Inc. Copying machine with electromechanical scavenger assembly and process
US4213617A (en) * 1978-04-17 1980-07-22 Lumoprint Zindler Kg (Gmbh & Co.) Assembly for sealing lead-in areas in a developer station
EP0028537A1 (en) * 1979-11-05 1981-05-13 Xerox Corporation Apparatus for developing a latent image and electrostatographic printing machine incorporating same
US4267797A (en) * 1979-04-27 1981-05-19 Xerox Corporation Development system
US4299901A (en) * 1979-04-27 1981-11-10 Xerox Corporation Method of development
US4350440A (en) * 1979-07-16 1982-09-21 Canon Kabushiki Kaisha Developing apparatus
US4354763A (en) * 1979-11-26 1982-10-19 Konishiroku Photo Industry Co., Ltd. Dry-type developing device
US4442790A (en) * 1982-09-29 1984-04-17 Eastman Kodak Company Magnetic brush development apparatus
US4496644A (en) * 1983-02-28 1985-01-29 Eastman Kodak Company Electric field adjustment for magnetic brushes
US4797708A (en) * 1987-05-04 1989-01-10 Eastman Kodak Company Apparatus for scavenging unwanted particles from a photoconductor of an electrographic apparatus
US4918488A (en) * 1989-06-26 1990-04-17 Eastman Kodak Company Scavenging apparatus
US4994863A (en) * 1989-12-18 1991-02-19 Eastman Kodak Company Electrostatic scavenger having magnetic drive disk
US5023664A (en) * 1986-09-24 1991-06-11 Siemens Aktiengesellschaft Non-mechanical printer or copier means comprising an exposure means arranged in the development region
US5047807A (en) * 1990-10-15 1991-09-10 Eastman Kodak Company Development apparatus having a plate scavenging device
US5140936A (en) * 1990-12-20 1992-08-25 Eastman Kodak Company Development apparatus having means for partially skiving magnetic developer
US5363183A (en) * 1991-09-06 1994-11-08 Xerox Corporation Copying machine with device for removing carrier beads from the photoconductive surface
US5483322A (en) * 1993-06-30 1996-01-09 Hitachi Koki Co., Ltd. Developing unit for an electrophotographic apparatus
US20040105705A1 (en) * 2002-11-14 2004-06-03 Canon Kabushiki Kaisha Developing apparatus
US20160054675A1 (en) * 2014-08-21 2016-02-25 Canon Kabushiki Kaisha Image forming apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53129639A (en) * 1977-04-19 1978-11-11 Mita Industrial Co Ltd Method of and device for electrostatic copying
JPS62126664U (US20100223739A1-20100909-C00025.png) * 1986-01-31 1987-08-11
JPH0673543U (ja) * 1993-03-31 1994-10-18 株式会社荒井製作所 オイルシール

Cited By (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3640248A (en) * 1969-06-04 1972-02-08 Xerox Corp Electrostatic magnetic developing apparatus
US3654902A (en) * 1969-11-28 1972-04-11 Plastic Coating Corp Toner unit for photoelectrostatic reproduction
DE2161852A1 (de) * 1970-12-14 1972-06-29 Xerox Corp Vorrichtung zur Magnetbürstenentwicklung elektrostatischer latenter Bilder
US3724422A (en) * 1970-12-14 1973-04-03 Xerox Corp Magnetic brush developing apparatus
US3884571A (en) * 1972-05-05 1975-05-20 Adalbert A Lux Leakage developer recirculation assembly
JPS4962432U (US20100223739A1-20100909-C00025.png) * 1972-09-12 1974-05-31
JPS5138363Y2 (US20100223739A1-20100909-C00025.png) * 1972-09-12 1976-09-20
JPS4953836A (US20100223739A1-20100909-C00025.png) * 1972-09-25 1974-05-25
JPS5330329B2 (US20100223739A1-20100909-C00025.png) * 1972-09-25 1978-08-26
US3918402A (en) * 1972-09-25 1975-11-11 Ricoh Kk Apparatus for developing an electrostatic latent image in electrophotography with a dry developing agent
US3881446A (en) * 1973-01-25 1975-05-06 Minolta Camera Kk Magnetic brush developing apparatus
US3897749A (en) * 1973-02-05 1975-08-05 Identicator Corp Dry powder fingerprinting apparatus
US3908595A (en) * 1973-04-05 1975-09-30 Fuji Xerox Co Ltd Magnetic brush development apparatus utilizing magnetic means
US3937181A (en) * 1973-05-23 1976-02-10 Fuji Xerox Co., Ltd. Magnetic brush type developing mechanism in electrophotographic copying machine
JPS5547743B2 (US20100223739A1-20100909-C00025.png) * 1973-07-24 1980-12-02
JPS5036133A (US20100223739A1-20100909-C00025.png) * 1973-07-24 1975-04-05
US3882823A (en) * 1973-08-15 1975-05-13 Minolta Camera Kk Stirring and scraping device for developing material
US3863603A (en) * 1974-01-07 1975-02-04 Ibm Magnetic brush roll having resilient polymeric surface
US3985099A (en) * 1974-05-13 1976-10-12 Fuji Xerox Co., Ltd. Magnetic brush developing device
DE2521275A1 (de) * 1974-05-13 1975-12-04 Fuji Xerox Co Ltd Entwicklereinrichtung
US4008686A (en) * 1974-05-21 1977-02-22 Konishiroku Photo Industry Co., Ltd. Developing device for use in electrophotography
US4041903A (en) * 1974-05-21 1977-08-16 Konishiroku Photo Industry Co., Ltd. Developing device for use in electrophotography
JPS50149350A (US20100223739A1-20100909-C00025.png) * 1974-05-21 1975-11-29
JPS5160252U (US20100223739A1-20100909-C00025.png) * 1974-11-05 1976-05-12
JPS5354248Y2 (US20100223739A1-20100909-C00025.png) * 1974-11-05 1978-12-26
US3977361A (en) * 1975-05-13 1976-08-31 Fuji Xerox Co., Ltd. Magnetic brush developing device
US4013041A (en) * 1975-10-24 1977-03-22 Eastman Kodak Company Self-compensating photoconductor web
US4116555A (en) * 1975-10-29 1978-09-26 Xerox Corporation Background removal apparatus
JPS53102754A (en) * 1977-02-21 1978-09-07 Ricoh Co Ltd Electrophotographic developing device
JPS579062B2 (US20100223739A1-20100909-C00025.png) * 1977-02-21 1982-02-19
US4185130A (en) * 1977-04-18 1980-01-22 E. I. Du Pont De Nemours And Company Magnetic image decorator
US4213617A (en) * 1978-04-17 1980-07-22 Lumoprint Zindler Kg (Gmbh & Co.) Assembly for sealing lead-in areas in a developer station
US4190351A (en) * 1978-11-13 1980-02-26 Pitney-Bowes, Inc. Copying machine with electromechanical scavenger assembly and process
US4267797A (en) * 1979-04-27 1981-05-19 Xerox Corporation Development system
US4299901A (en) * 1979-04-27 1981-11-10 Xerox Corporation Method of development
US4350440A (en) * 1979-07-16 1982-09-21 Canon Kabushiki Kaisha Developing apparatus
EP0028537A1 (en) * 1979-11-05 1981-05-13 Xerox Corporation Apparatus for developing a latent image and electrostatographic printing machine incorporating same
US4297972A (en) * 1979-11-05 1981-11-03 Xerox Corporation Development system
US4354763A (en) * 1979-11-26 1982-10-19 Konishiroku Photo Industry Co., Ltd. Dry-type developing device
US4442790A (en) * 1982-09-29 1984-04-17 Eastman Kodak Company Magnetic brush development apparatus
US4496644A (en) * 1983-02-28 1985-01-29 Eastman Kodak Company Electric field adjustment for magnetic brushes
US5023664A (en) * 1986-09-24 1991-06-11 Siemens Aktiengesellschaft Non-mechanical printer or copier means comprising an exposure means arranged in the development region
US4797708A (en) * 1987-05-04 1989-01-10 Eastman Kodak Company Apparatus for scavenging unwanted particles from a photoconductor of an electrographic apparatus
US4918488A (en) * 1989-06-26 1990-04-17 Eastman Kodak Company Scavenging apparatus
US4994863A (en) * 1989-12-18 1991-02-19 Eastman Kodak Company Electrostatic scavenger having magnetic drive disk
US5047807A (en) * 1990-10-15 1991-09-10 Eastman Kodak Company Development apparatus having a plate scavenging device
US5140936A (en) * 1990-12-20 1992-08-25 Eastman Kodak Company Development apparatus having means for partially skiving magnetic developer
US5363183A (en) * 1991-09-06 1994-11-08 Xerox Corporation Copying machine with device for removing carrier beads from the photoconductive surface
US5483322A (en) * 1993-06-30 1996-01-09 Hitachi Koki Co., Ltd. Developing unit for an electrophotographic apparatus
US20040105705A1 (en) * 2002-11-14 2004-06-03 Canon Kabushiki Kaisha Developing apparatus
US6993274B2 (en) * 2002-11-14 2006-01-31 Canon Kabushiki Kaisha Developing apparatus with plural developer bearing members for each image bearing member
US7054584B2 (en) 2002-11-14 2006-05-30 Canon Kabushiki Kaisha Developing apparatus with first and second developing bearing members each including a magnetic field generator wherein a peak position magnetic force of the second developing members is a defined value
US20160054675A1 (en) * 2014-08-21 2016-02-25 Canon Kabushiki Kaisha Image forming apparatus
US9568854B2 (en) * 2014-08-21 2017-02-14 Canon Kabushiki Kaisha Image forming apparatus configured to execute removal control

Also Published As

Publication number Publication date
GB1265901A (US20100223739A1-20100909-C00025.png) 1972-03-08
DE1910068A1 (de) 1969-09-25
BE729079A (US20100223739A1-20100909-C00025.png) 1969-08-01
FR2002905A1 (US20100223739A1-20100909-C00025.png) 1969-10-31
DE1910068B2 (de) 1972-07-27
JPS5332260B1 (US20100223739A1-20100909-C00025.png) 1978-09-07

Similar Documents

Publication Publication Date Title
US3543720A (en) Apparatus for development of electrostatic images
US3703395A (en) Method for development of electrostatic images
US3457900A (en) Single magnetic brush apparatus for development of electrostatic images
US4458627A (en) Developing apparatus for electrostatic image
US4034709A (en) Developer roll
US3176652A (en) Xerographic developing apparatus
US2911330A (en) Magnetic brush cleaning
JPS5843739B2 (ja) 現像装置
US4006987A (en) Apparatus for cleaning a residual toner on an electrostatic recording medium
US3941469A (en) Dry type developing device for a copying apparatus or like apparatus
IL31757A (en) Electrostatic copying method and apparatus
US3982498A (en) Development apparatus
US4041903A (en) Developing device for use in electrophotography
US3572289A (en) Magnetic brush development apparatus
JPH02125282A (ja) ２ロール式清掃装置を備えた電子写真式プリンタ
JPS59116769A (ja) 現像装置
JPH0251168A (ja) クリーニングレス電子写真プリンティング方法
JPH0740167B2 (ja) 電子写真装置用のバイアスした掃去グリッド
US4008686A (en) Developing device for use in electrophotography
US3915121A (en) Development apparatus
US3645618A (en) Vacuum nozzle to remove agglomerates on a toner applicator
US3592166A (en) Apparatus for developing electrostatic images
JPS607790B2 (ja) 静電潜像現像装置
US4292924A (en) Magnetic brush apparatus
US5376997A (en) Rotating sleeve-type magnetic brush cleaning device