US3638614A - Electrostatic latent image development apparatus - Google Patents

Electrostatic latent image development apparatus Download PDF

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Publication number
US3638614A
US3638614A US855002A US3638614DA US3638614A US 3638614 A US3638614 A US 3638614A US 855002 A US855002 A US 855002A US 3638614D A US3638614D A US 3638614DA US 3638614 A US3638614 A US 3638614A
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United States
Prior art keywords
support surface
magnetic field
developer material
emitting means
magnetizable
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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
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US855002A
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English (en)
Inventor
Eugene F Young
Ryland F Rogers
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Xerox Corp
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Xerox Corp
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Publication date
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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y15/00—Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors

Definitions

  • This invention relates to the development of electrostatic latent images and, in particular, to an apparatus for developing electrostatic latent images utilizing a magnetizable carrier material and an electroscopic toner powder.
  • this invention relates to a magnetic brush development apparatus having an extended development zone.
  • One attempt to increase the effective length of the development zone without adding to the size of the development unit has been by positioning two magnetic brush developing rollers adjacent each other and adjacent an electrostatic latent image-bearing surface such that the magnetic fields emitted from the development rollers intersect to convey developer material across the space between the rollers and in contact with the latent electrical charges on the imagebearing surface. While such a system provides an increased effective development zone and has proven to be very successful, it has been found in certain applications wherein the magnetizable carrier material is of a certain size, that the weight of the developer material is such that gravitational forces overcome the magnetic field emitted from the developing rollers and sufficient contact is not maintained between the developer material and the electrostatic latent image-bearing surface throughout the entire development zone as is desired.
  • Another object of this invention is to increase the effective development zone of developing apparatus.
  • a further object of this invention is to insure complete contact of developer material with an electrostatic latent imagebearing surface the development of which is effected by a plurality of magnetic brush development rollers positioned adjacent one another and the electrostatic latent image-bearing surface such that their magnetic fields intersect to convey developer material across the space therebetween in contact with the latent image-bearing surface.
  • FIG. 1 is a mechanical schematic of an automatic xerographic reproducing machine utilizing the invention of this application;
  • FIG. 2 is a front perspective view of the developing apparatus to better illustrate the developing units and the cylindrical roller which enhances development of the electrostatic latent image throughout the extended developing zone;
  • FIG. 3 is a schematic section of the apparatus shown in FIG. 2 taken along lines 3-3.
  • FIG. 1 there is illustrated a cross section mechanical schematic of an automatic xerographic reproducing machine utilizing this invention.
  • a light image of a document to be reproduced is projected 3 onto a photosensitive surface 1 to form an electrostatic latent image thereon.
  • the latent image is developed 4 to form an electroscopic toner powder image in the configuration of the latent image on the photoreceptor surface.
  • the powder image may then be transferred 5 to a support material to which it may be permanently fixed as by heat fusing, or the toner powder may be permanently affixed to the photoreceptive surface depending on the method of electrostatographic imaging employed as is well known in the art.
  • the developing apparatus 50 extends the width of the photoreceptor l and is substantially enclosed except for an opening adjacent the photoreceptor whereat development of the latent electrostatic image is effected, and an opening 11 upon which a toner powder dispenser 10 is positioned to replenish the toner depleted from the developer mixture during development of the electrostatic images.
  • a sump 51 at the lowermost portion of the housing containing developer material comprising magnetizable carrier material and colored electroscopic toner particles.
  • the toner particles are many times smaller than the carrier material and, due to a triboelectric relationship therebetween, substantially uniformly coat the carrier material.
  • the developing apparatus 50 is positioned within the automatic xerographic reproducing machine adjacent to the photoreceptor l by suitable brackets and braces appropriately secured to the developing apparatus and the frames of the machine.
  • a suitable mounting 12 is provided on the top of the developing apparatus between cover plates 52 and 53 to position and retain the toner powder dispenser 10.
  • Development of the electrostatic latent image is effected by a blanket of developing material formed between a pair of adjacent magnetic rollers 70 and positioned such that their magnetic force fields intersect to effect formation of a blanket of developing material upon the rollers 70 and 80, and in the space therebetween adjacent the photoreceptor l.
  • the magnetic rollers 70 and 80 comprise outer cylinders '71 and 81, respectively, of a nonmagnetic material, such as aluminum, extending the width of the developer housing with elongated bar magnets 72 and 82, respectively, extending nearly the full length of each cylinder.
  • the bar magnets 72 and 82 are each supported, for example, on a ferromagnetic bar 73 having rod 74 secured to each end, as by welding, and securely fastened in mounting blocks 75 appropriately secured to side frame plates 54 of the developer apparatus.
  • the outer cylinders 71 and 81 of nonmagnetic material are each mounted for rotation within the developer housing by means of suitable bearing sur faces 76 carried by the side frame plates 54 of the developer housing (FIG. 2).
  • One end of the cylinder is enclosed by a cap 77 having a central opening therein, through which the rod portion 74 passes, and is rotatably supported thereabout in the frame plate 54 by the bearing 76.
  • the driven end is enclosed by an end cap 78 rotatably supported in suitable bearings in the side frame plate 54 and having a drive gear 89 secured thereto to effect rotation of each cylinder.
  • the rotational drive for all other rotary components of the developing apparatus 50 is derived from drive gear 89 by means of a suitable timing belt (not shown) engaging suitable drive connections on each component.
  • the outer cylinders may be rotatably driven about the stationary elongated bar magnets 72 and 82.
  • the polar orientation of the elongated bar magnets is arranged such that the magnetic force fields project through the walls of the nonmagnetic cylinders 71 and 111 to form the magnetizable carrier material into a brushlike configuration in a manner well known in the art.
  • the peripheral walls of the cylinders 71 and 81 are positioned in closely spaced relationship adjacent to one another.
  • the brush bristles produced by action of the magnetic field emanating from the magnets acting upon the magnetizable carrier material will form on the upper region of the cylinder 71 within the magnetic field emanating from magnets 72 and the under surface of the electrostatic image-bearing photoreceptor 1. These bristles are formed during the developing cycle, and are produced by the magnetic field from the bar magnets 72.
  • the bristles When the bristles are moved by the cylinder 71 out of the influence of magnet 72 beyond the closest distance between the photoreceptor ll and the cylinder 71, they are attracted by the greater magnetic field of the magnet 82 which is stronger at this point than the diminished strength of the magnetic field attributed to the magnet 72.
  • the developer material is carried therealong during rotation of the cylinder 81 until the material reaches a point beyond the development zone whereat the magnet field is diminished and the carrier material and toner particles drop off the cylinder 81 and back into the sump portion 51 of the developer apparatus.
  • a suitable stripping mechanism such as a nonmagnetizable doctor blade 96 may be utilized to insure that the magnetizable developer material is removed from the cylinder 81.
  • the magnetizable developer material is in the form of a blanket extending the entire distance (P16. 3) between the two cylinders and in contact with the photoreceptor 1. Therefore, the width of the development zone is larger than the sum of the individual development zones for either of the magnetic rollers 71 or 81.
  • a rotatable wire brush or other cylinder 60 is positioned between the magnetic developing rollers 70 and 80, adjacent the latent image-bearing surface 1.
  • the cylinder 60 is rotatably supported in suitable bearing surfaces carried by side frame plates 54 and may be positively driven, or act as an idler, and functions to support the developer material as it passes from cylinder 71 to cylinder 81.
  • the cylinder 60 prevents the developer tufts from collapsing under their own weight as they pass from the magnetic field emanating from roller 70 into the magnetic field emanating from roller 80.
  • a suitable electrical bias such as 250 volts
  • a developer conveyor 20 is rotatably mounted within the side frame plates 541 of the developer apparatus by suitable bearings and carries the developer material from the sump portion to be introduced to the magnetic developing rollers 70 and 80.
  • the developer conveyor comprises a plurality of spaced buckets 21 carried by a belt 22 appropriately driven by a shaft 23 rotatably mounted in suitable bearing surfaces in the side frame plates d and driven by means ofa gear (not shown) suitably secured to one end of the shaft 23 and engaging a suitable drive system.
  • Apparatus for developing a support surface carrying latent electrical charges selectively retained in image configa ration including a first magnetic field emitting means to convey a quantity of magnetizable developer material in contact with a sup port surface to be developed,
  • a second magnetic field emitting means spaced therefrom with the respective magnetic fields intersecting to convey developer material across the space therebetween in con tact with the latent electrical charges to effect the development thereof
  • Apparatus for developing a support surface having latent electrical charges selectively retained in image configuration including a first magnetic field emitting means to move a quantity of magnetizable developer material in contact with a support surface having latent electrical charges selectively retained in image configuration,
  • a second magnetic field emitting means spaced therefrom with the respective emitted magnetic fields intersecting to move magnetizable developer material in contact with the support surface through the space between said first and second magnetic field emitting means to effect the development of the latent electrical charges selectively retained in image configuration
  • Apparatus for developing a support surface having latent electrical charges selectively retained in image configuration including a plurality of spaced cylinders rotatably supported adjacent a support surface having latent electrical charges tively retained in image configuration to convey a quantity of magnetizable developer material thereto for ing the development thereof,
  • magnetic field producing means supported within each of said cylinders to emit a magnetic field passing therethrough and intersecting with the magnetic field emitted from within another of said spaced cylinders
  • said means to support the magnetizable developer material in brushlike tufts in response to the magnetic field emitted through said cylinders includes a rotatable cylinder supported adjacent the latent image bearing support surface with the magnetizable developer material passing therebetween.
  • Apparatus for developing a support surface having latent electrical charges selectively retained in image configuration including,
  • magnetic field producing means supported within each of said cylinders to emit a magnetic field passing therethrough and intersecting with the magnetic field emitted from within another of said spaced cylinders
  • an electrically conductive rotatable cylinder supported adjacent the latent image-bearing support surface between adjacent pairs of said spaced cylinders to support the magnetizable developer material in brushlike tufts in response to the magnetic fields emitted through said cylinders.
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • a first magnetic field emitting means for conveying a quantity of magnetizable developer material over the support surface to be developed
  • a second magnetic field emitting means for conveying a quantity of magnetizable developer material from said first magnetic field emitting means over the support surface to be developed, said second magnetic field emitting means being spaced from said first magnetic field emitting means such that the respective magnetic fields are in overlapping relationship with each other, and
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • a first magnetic field emitting means for moving a quantity of magnetizable developer material over the support surface to be developed
  • a second magnetic field emitting means for moving a quantity of magnetizable developer material over the support surface to be developed, said second magnetic field emitting means being spaced from said first magnetic field emitting means with the respectively emitted magnetic fields intersecting therebetween to support magnetizable developer material across the space between said first and said second magnetic field emitting means, and
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • a first magnetic field producing means supported within said first cylindrical member for attracting a quantity of magnetizable developer material to the surface of said cylindrical member for movement of said cylindrical member over said support surface
  • a second magnetic field producing means supported within said second cylindrical member, the field from said second magnetic field producing means extending across the space between said first and said second cylindrical members into the field of said first magnetic field producing means to attract a quantity of magnetizable developer material from the surface of said first cylindrical member to the surface of said second cylindrical member for movement by said second cylindrical member over said support surface, and
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • a first magnetic field producing means supported within said first cylindrical member for attracting a quantity of magnetizable developer material to the surface of said cylindrical member for movement by said cylindrical member over said support surface
  • a second magnetic field producing means supported within said second cylindrical member, the field from said second magnetic field producing means extending across the space between said first and said second cylindrical members into the field of said first magnetic field producing means to attract a quantity of magnetizable developer material from the surface of said first cylindrical member to the surface of said second cylindrical member for movement by said second cylindrical member over said support surface, and
  • a support member of generally cylindrical configuration positioned intermediate said first and said second cylindrical members and adapted for rotation to support the magnetizable developer material proximate to the support surface as the developer material is moved across the space between said first and said second cylindrical members.
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • magnetic field producing means supported within said cylindrical members, the respective fields from said magnetic field producing means extending across the spaces between adjacent ones of said cylindrical members in overlapping relationship to attract magnetizable developer material from the surfaces of precedingly adjacent cylindrical members to the surfaces of succeedingly adjacent cylindrical members as the developer material is moved by said cylindrical members over said support surface, and
  • Apparatus for developing latent electrostatic charge patterns on a support surface comprising,
  • magnetic field producing means supported within said cylindrical members, the respective fields from said magnetic field producing means extending across the spaces between adjacent ones of said cylindrical members in over said support surface, and means positioned between adjacent pairs of said cylindrical members for supporting the magnetizable developer material proximate to the support surface as the: developer material is moved across the spaces between said cylindrical members.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Molecular Biology (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US855002A 1969-09-03 1969-09-03 Electrostatic latent image development apparatus Expired - Lifetime US3638614A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85500269A 1969-09-03 1969-09-03

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US3638614A true US3638614A (en) 1972-02-01

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US (1) US3638614A (no)
JP (1) JPS491217B1 (no)
CA (1) CA929338A (no)
DE (1) DE2043814C3 (no)
GB (1) GB1304236A (no)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3754526A (en) * 1971-12-17 1973-08-28 Ibm Electrophotographic development apparatus
US3855969A (en) * 1973-03-02 1974-12-24 Addressograph Multigraph Quality control of electrostatic image developer mix
US3866564A (en) * 1973-04-25 1975-02-18 Xerox Corp Magnetic brush developing apparatus for copiers
US3879737A (en) * 1974-04-08 1975-04-22 Minnesota Mining & Mfg Integrated electrographic recording and developing stylus assembly
US3881446A (en) * 1973-01-25 1975-05-06 Minolta Camera Kk Magnetic brush developing apparatus
US3926516A (en) * 1974-02-20 1975-12-16 Xerox Corp Development apparatus for an electrostatographic printing machine
US3991713A (en) * 1974-02-20 1976-11-16 Xerox Corporation Development apparatus for an electrostatographic printing machine
US4026241A (en) * 1974-06-04 1977-05-31 Minolta Camera Kabushiki Kaisha Magnetic brush developing device for use in electrophotographic copying apparatus
US4050413A (en) * 1975-09-22 1977-09-27 Xerox Corporation Magnetic brush crossmixing system
US4063533A (en) * 1976-08-02 1977-12-20 International Business Machines Corporation Multiple brush developer applying apparatus with a toner diverter blade
US4266868A (en) * 1979-07-16 1981-05-12 Minnesota Mining And Manufacturing Company Multiple roll developing apparatus
EP0060534A1 (de) * 1981-03-13 1982-09-22 International Duplicator Ltd. GmbH. Magnetbürsten-Entwicklungsvorrichtung für elektrostatische Ladungsbilder auf Aufzeichnungsträgern
US4461562A (en) * 1982-02-17 1984-07-24 Better Methods, Inc. Magnetic toner applicator
US4553827A (en) * 1983-06-30 1985-11-19 Ricoh Company, Ltd. Electrophotographic copying apparatus including an enlarged image developing station
EP0180407A1 (en) * 1984-10-29 1986-05-07 Kabushiki Kaisha Toshiba Developing device
US5907755A (en) * 1997-05-09 1999-05-25 Hitachi Koki Co., Ltd. Developing device
US20070292166A1 (en) * 2006-06-15 2007-12-20 Xerox Corporation Electrostatographic developer unit having multiple magnetic brush rolls with a magnetic restrictor for carrier particle emission control
US20100086323A1 (en) * 2008-10-08 2010-04-08 Konica Minolta Business Technologies, Inc. Image forming apparatus
US20110069998A1 (en) * 2009-09-18 2011-03-24 Fuji Xerox Co., Ltd. Developing device and image forming apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3117891A (en) * 1960-09-26 1964-01-14 Xerox Corp Xerographic apparatus
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3113042A (en) * 1960-04-19 1963-12-03 Xerox Corp Xerographic apparatus with magnetic conveyor
US3358637A (en) * 1962-04-24 1967-12-19 Plastic Coating Corp Toner unit for photoelectrostatic reproduction equipment

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3117891A (en) * 1960-09-26 1964-01-14 Xerox Corp Xerographic apparatus
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Medley, H. C. Development of Electrostatic Images. IBM Technical Disclosure Bulletin, August 1959, Vol. 2, No. 2. *

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3754526A (en) * 1971-12-17 1973-08-28 Ibm Electrophotographic development apparatus
US3881446A (en) * 1973-01-25 1975-05-06 Minolta Camera Kk Magnetic brush developing apparatus
US3855969A (en) * 1973-03-02 1974-12-24 Addressograph Multigraph Quality control of electrostatic image developer mix
US3866564A (en) * 1973-04-25 1975-02-18 Xerox Corp Magnetic brush developing apparatus for copiers
US3926516A (en) * 1974-02-20 1975-12-16 Xerox Corp Development apparatus for an electrostatographic printing machine
US3991713A (en) * 1974-02-20 1976-11-16 Xerox Corporation Development apparatus for an electrostatographic printing machine
US3879737A (en) * 1974-04-08 1975-04-22 Minnesota Mining & Mfg Integrated electrographic recording and developing stylus assembly
US4026241A (en) * 1974-06-04 1977-05-31 Minolta Camera Kabushiki Kaisha Magnetic brush developing device for use in electrophotographic copying apparatus
US4050413A (en) * 1975-09-22 1977-09-27 Xerox Corporation Magnetic brush crossmixing system
US4063533A (en) * 1976-08-02 1977-12-20 International Business Machines Corporation Multiple brush developer applying apparatus with a toner diverter blade
FR2360920A1 (fr) * 1976-08-02 1978-03-03 Ibm Procede et dispositif a brosses magnetiques multiples pour appliquer un melange de developpement sur une surface photoconductrice portant une image latente
US4266868A (en) * 1979-07-16 1981-05-12 Minnesota Mining And Manufacturing Company Multiple roll developing apparatus
EP0060534A1 (de) * 1981-03-13 1982-09-22 International Duplicator Ltd. GmbH. Magnetbürsten-Entwicklungsvorrichtung für elektrostatische Ladungsbilder auf Aufzeichnungsträgern
WO1982003280A1 (en) * 1981-03-13 1982-09-30 Brueckel Dieter Magnetic brush developing device for electrostatic charge pictures on recording media
US4461562A (en) * 1982-02-17 1984-07-24 Better Methods, Inc. Magnetic toner applicator
US4553827A (en) * 1983-06-30 1985-11-19 Ricoh Company, Ltd. Electrophotographic copying apparatus including an enlarged image developing station
EP0180407A1 (en) * 1984-10-29 1986-05-07 Kabushiki Kaisha Toshiba Developing device
US4686934A (en) * 1984-10-29 1987-08-18 Kabushiki Kaisha Toshiba Developing device
US5907755A (en) * 1997-05-09 1999-05-25 Hitachi Koki Co., Ltd. Developing device
US20070292166A1 (en) * 2006-06-15 2007-12-20 Xerox Corporation Electrostatographic developer unit having multiple magnetic brush rolls with a magnetic restrictor for carrier particle emission control
US7356292B2 (en) * 2006-06-15 2008-04-08 Xerox Corporation Electrostatographic developer unit having multiple magnetic brush rolls with a magnetic restrictor for carrier particle emission control
US20100086323A1 (en) * 2008-10-08 2010-04-08 Konica Minolta Business Technologies, Inc. Image forming apparatus
US8244164B2 (en) * 2008-10-08 2012-08-14 Konica Minolta Business Technologies, Inc. Image forming apparatus with two developing rollers, and an electrode therebetween
US20110069998A1 (en) * 2009-09-18 2011-03-24 Fuji Xerox Co., Ltd. Developing device and image forming apparatus
US8611798B2 (en) * 2009-09-18 2013-12-17 Fuji Xerox Co., Ltd. Developing device and image forming apparatus

Also Published As

Publication number Publication date
DE2043814A1 (no) 1971-03-25
DE2043814C3 (de) 1982-10-28
DE2043814B2 (de) 1979-04-19
GB1304236A (no) 1973-01-24
CA929338A (en) 1973-07-03
JPS491217B1 (no) 1974-01-12

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