US3855969A - Quality control of electrostatic image developer mix - Google Patents

Quality control of electrostatic image developer mix Download PDF

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Publication number
US3855969A
US3855969A US00337340A US33734073A US3855969A US 3855969 A US3855969 A US 3855969A US 00337340 A US00337340 A US 00337340A US 33734073 A US33734073 A US 33734073A US 3855969 A US3855969 A US 3855969A
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US
United States
Prior art keywords
magnetic
roller
rollers
array
developing
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
US00337340A
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English (en)
Inventor
T Andrako
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.)
AB Dick Co
Original Assignee
Multigraphics Inc
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 Multigraphics Inc filed Critical Multigraphics Inc
Priority to US00337340A priority Critical patent/US3855969A/en
Priority to CA181,958A priority patent/CA989161A/en
Priority to ZA737664*A priority patent/ZA737664B/xx
Priority to AU60844/73A priority patent/AU6084473A/en
Priority to NL7314354A priority patent/NL7314354A/xx
Priority to DE19732353847 priority patent/DE2353847A1/de
Priority to FR7340313A priority patent/FR2220071B1/fr
Priority to BE137676A priority patent/BE807239A/xx
Priority to GB900974A priority patent/GB1467175A/en
Priority to JP2293274A priority patent/JPS543375B2/ja
Priority to IT20735/74A priority patent/IT1009676B/it
Application granted granted Critical
Publication of US3855969A publication Critical patent/US3855969A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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

Definitions

  • ABSTRACT Apparatus for effecting development of an electrostatic latent image comprising a plurality of magnetic developing rollers positioned with intersecting magnetic force fields for effecting a blanket of developing material extending about and between the developing rollers adjacent an electrostatic latent image bearing surface.
  • the apparatus differs from prior practice in that the mix is not removed from the back side of the rolls, but rather is deliberately established in that area,
  • 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 materialand an electroscopic toner powder.
  • this invention relates to a magnetic brush development apparatus having an extended development zone.
  • magnetic brush development In the method of development of electrostatic latent .images by the application of electroscopic toner powder through the use of magnetizable carrier material, referred to in the art as magnetic brush development, there is generally employed a single magnetic brush closely spaced adjacent a surface carrying latent electricalcharges in image configuration. For example, see Fisher U.S. Pat. No. 2,904,000.
  • the Hojo developer employs two entirely separate development brushes in order to have the image brushed twice at two separate stations.
  • a later effort to decrease the size of the equipment is shown in Young et al U.S. Pat. No. 3,638,614.
  • Ostensibly, according to Young et al the mere placement of two magnetic brushes adjacent one another is only conditionally satisfactory, and they taught the use of a small intermediate roller between the two rollers to thus provide a means positioned between the plurality of spaced cylinders and adjacent the support surface,
  • the support surface is the drum or paper surface to be toned.
  • the intermediate roller will thereby support the magnetizable developer material in brush-like tuffs in response to the magnetic field emitted through the cylinders.
  • the purpose of this invention is to create a magnetic blanket completely encompassing a plural roll magnetic brush assembly beginning along the face of one roller brush, bridging to the next and any subsequent roller brushes, and carrying overto the back of the final roller and then proceeding down the back of the entire set to the beginning point.
  • the mix turns and mixes between each roll by reason of the closely spaced rollers and strength of magnets. Then, by cascading an abundance of fresh toner mix on the back side in greater quantity that the brush roller magnets are capable of holding, new material is intermixed with the old as the turning and mixing takes place.
  • FIG. 1 is a mechanical schematic of an automatic xerographic reproducing machine utilizing the present invention
  • FIG. 2 is a view taken along the line 2-2 of FIG. 1 illustrating the static mixing device of this invention
  • FIG. 3 is a schematic illustration of the magnetic brush array with the toner mix accurately illustrated on the surface thereof;
  • FIG. 4 is a view of the end of a roller brush showing the adjustable magnet support
  • FIG. 5 is a top view of the roller and magnet support.
  • the latent image is developed with an oppositely charged developing material comprising carrier beads and smaller toner particles triboelectrically adhering thereto to form a powder image, corresponding to the latent image on the plate surface.
  • the powder image is then electrostatically fused either directly upon the surface where created, or
  • the carrier is magnetizable and also provides mechanical control for the formation of the brush bristles by virtue of magnetic fields so that the toner can be readily handled and brought into contact with the exposed surface.
  • the toner is then attracted to the electrostatic latent image from the carrier bristles to produce a visible powder image on an insulating surface.
  • FIG. ll illustrates a substantially familiar arrangement of an electrostatic toning apparatus wherein there is a drum which represents a photoconductive metal drum or the carriage for a sheet of photoconductive paper, for example.
  • the illustrated apparatus includes a four cylinder development station 12 which is the principal subject of the present invention.
  • the individual rollers of the station are substantially conventional in form and comprise nonmagnetic rollers 14 which are driven in the same clockwise direction in the FIG. 1 by a drive mechanism consisting of gears or chain driven sprockets, for example but which are not illustrated in this drawing.
  • Each of the rollers 114$ is provided internally with a magnet system 16 of essentially conventional general arrangement but specifically designed for this invention in the dimension and arrangement of the parts.
  • the magnet system 16 is comprised of a carrier 17 with a one-half inch square iron magnet 18 facing the drum 10. This side will hereinafter be referred to as the face side or the front side of the roller.
  • the opposite or back side of the roller is under the influence of a V2 by 1 inch ferritic iron magnet.
  • the magnets are arranged in opposite polarity from adjoining rollers in order to establish a flux field which bridges from one magnet to the other.
  • the magnetic carrier particles are coated with smaller triboelectric toner particles which are wiped away from the magnetic carrier particle upon contact with the oppositely charged image on the drum 10.
  • the magnetic field causes the brush to stand up in the normal soft tufts 21, but as that tufts is carried along the surface of a roller 14 and the brush structure meets the bridge flux going to the subsequent adjacent roller, the brush structure will lie down and proceed in a substantially horizontal path as opposed to the vertical path previously assumed in the tufts 21.
  • Such a bridge is indicated by the reference character 22 in FIG. 3.
  • the brush structure assumes an upright position reversed from that in the previous brush.
  • the magnetic toner mix progresses from face to face or from back to back surface of the rollers it is constantly churned and mixed by lying down and standing up and thus assures as complete a wiping of the triboelectric toner particles from the brush structure as possible.
  • the carrier 17 is mounted on an adjustable attitude control lever 23 as shown in FIGS. 4 and 5.
  • Prior art devices have shown paddle wheel impellers or augers to stir and mix magnetic toner mix in a sump 26. It has been found that the toner mix is sometimes subject to excessive wear when mechanically agitated to any degree and therefore an old and well known bucket system is employed with this invention, but in a somewhat novel manner.
  • FIG. 1 A bucket conveyor 24 is shown with buckets 25 to lift material from a sump area 26 and cascade the material down over the backside of the rolls in the development station 12. Note, however, that the location of the conveyor is such that the buckets tend first to lose their mix at the top of the uppermost chain sprocket.
  • a cross mixing baffle 27 is placed directly over the shaft of the upper drive sprocket in order to cause the spilled toner mix to mix and cross mix and to thus assure a more even distribution of the toner particles. That which does not fall on the cross mixing baffle will spill and fall generally in the area of the back face of the development station and be picked up by the magnetic field along with that material which is carried around the end of the last roller in the series and is returning down the back of the brush array.
  • the strength of the magnets within the brush array are designed to create a strong arch bridge 22 in order to prevent sagging without the need of auxiliary rollers, but the strength of the magnet is limited.
  • the material cascades down over the back of the develop ment station there will be some physical dislodgement of the mix being carried by the rollers 14 and new material taking its place.
  • another aspect of this invention is involved in the fact that the moving blanket of material, turning and churning down the backside of the roller array not only further mixes the exhausted brush structure elements with toner available from neighboring elements, but actually picks up fresh material and/or is dislodged and replaced by fresh material cascading along the backside of the array in the developer station.
  • a doctor blade 30 establishes the proper height brush structure to control the amount of toner mix which enters the developer station 12.
  • a magnetic brush apparatus for applying developing material to electrostatic latent images in a electrostatic printing machine of the type utilizing a moving photoreceptor surface comprising;
  • a plurality of magnetic developing brushes each having a roller with a periphery upon which bristles of magnetic developing material are adapted to be formed.
  • rollers each having an axis of rotation, said axis being substantially parallel to the path of the photoreceptor surface and aligned in a vertical array;
  • rollers having a clear space therebetween and internal magnets within the rollers oriented in opposite polarities in one roller from that in the other and establishing a merging magnetic field bridging between the roller brushes to establish a continuous migrating magnetic blanket which accepts magnetic powder material at the first roller and transports the magnetic material between the rollers and the photoreceptor surface along the front face of the rollers in brush form and bridges between rollers in reclining array;
  • each of the rotor brushes has a composite inner magnetic system composed of a one-half inch square cross section iron magnet extending the length of the roller facing the photoreceptor, and a V2 by l inch cross section iron magnet facing the opposite or back side of the roller, and the magnetic system mounted on an adjustable attitude control lever for tuning the bridging magnetic systems with respect to one another.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US00337340A 1973-03-02 1973-03-02 Quality control of electrostatic image developer mix Expired - Lifetime US3855969A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US00337340A US3855969A (en) 1973-03-02 1973-03-02 Quality control of electrostatic image developer mix
CA181,958A CA989161A (en) 1973-03-02 1973-09-26 Quality control of electrostatic image developer mix
ZA737664*A ZA737664B (en) 1973-03-02 1973-09-28 Quality control of electrostatic image developer mix
AU60844/73A AU6084473A (en) 1973-03-02 1973-09-28 Electrostatic developing
NL7314354A NL7314354A (it) 1973-03-02 1973-10-18
DE19732353847 DE2353847A1 (de) 1973-03-02 1973-10-26 Entwicklungsvorrichtung zur entwicklung eines latenten elektrostatischen ladungsbildes
FR7340313A FR2220071B1 (it) 1973-03-02 1973-11-13
BE137676A BE807239A (fr) 1973-03-02 1973-11-13 Dispositif de melange de developpement des images electrostatiques
GB900974A GB1467175A (en) 1973-03-02 1974-02-27 Electrostatic developing
JP2293274A JPS543375B2 (it) 1973-03-02 1974-02-28
IT20735/74A IT1009676B (it) 1973-03-02 1974-04-08 Sviluppatore a spazzole magnetiche

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00337340A US3855969A (en) 1973-03-02 1973-03-02 Quality control of electrostatic image developer mix

Publications (1)

Publication Number Publication Date
US3855969A true US3855969A (en) 1974-12-24

Family

ID=23320157

Family Applications (1)

Application Number Title Priority Date Filing Date
US00337340A Expired - Lifetime US3855969A (en) 1973-03-02 1973-03-02 Quality control of electrostatic image developer mix

Country Status (11)

Country Link
US (1) US3855969A (it)
JP (1) JPS543375B2 (it)
AU (1) AU6084473A (it)
BE (1) BE807239A (it)
CA (1) CA989161A (it)
DE (1) DE2353847A1 (it)
FR (1) FR2220071B1 (it)
GB (1) GB1467175A (it)
IT (1) IT1009676B (it)
NL (1) NL7314354A (it)
ZA (1) ZA737664B (it)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3985099A (en) * 1974-05-13 1976-10-12 Fuji Xerox Co., Ltd. Magnetic brush developing device
US4022157A (en) * 1975-08-04 1977-05-10 Addressograph Multigraph Corporation Magnetic brush developer equipped with self-metering controls
US4279942A (en) * 1980-03-03 1981-07-21 Eastman Kodak Company Magnetic field adjustment for magnetic brushes
US4912511A (en) * 1988-06-17 1990-03-27 Minolta Camera Kabushiki Kaisha Developing device capable of preventing a developer from passing through the space between adjacent developing sleeves

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51152289U (it) * 1975-05-29 1976-12-04
JPS51152287U (it) * 1975-05-29 1976-12-04
JPS57157962U (it) * 1981-03-30 1982-10-04
JPS5888251U (ja) * 1981-12-02 1983-06-15 日立金属株式会社 磁気ブラシ現像装置
JPS58185862U (ja) * 1982-06-04 1983-12-10 株式会社東芝 マグネツトロ−ラ−

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357402A (en) * 1966-12-27 1967-12-12 Xerox Corp Rotary brush development
US3537427A (en) * 1967-10-17 1970-11-03 Fuji Photo Film Co Ltd Electrostatic latent image developing device
US3575139A (en) * 1969-06-04 1971-04-20 Xerox Corp Electrostatic magnetic developer unit gating apparatus
US3638614A (en) * 1969-09-03 1972-02-01 Xerox Corp Electrostatic latent image development apparatus
US3641980A (en) * 1969-10-20 1972-02-15 Xerox Corp Development apparatus
US3707947A (en) * 1970-12-29 1973-01-02 Xerox Corp Cross-channel mixer
US3724422A (en) * 1970-12-14 1973-04-03 Xerox Corp Magnetic brush developing apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357402A (en) * 1966-12-27 1967-12-12 Xerox Corp Rotary brush development
US3537427A (en) * 1967-10-17 1970-11-03 Fuji Photo Film Co Ltd Electrostatic latent image developing device
US3575139A (en) * 1969-06-04 1971-04-20 Xerox Corp Electrostatic magnetic developer unit gating apparatus
US3638614A (en) * 1969-09-03 1972-02-01 Xerox Corp Electrostatic latent image development apparatus
US3641980A (en) * 1969-10-20 1972-02-15 Xerox Corp Development apparatus
US3724422A (en) * 1970-12-14 1973-04-03 Xerox Corp Magnetic brush developing apparatus
US3707947A (en) * 1970-12-29 1973-01-02 Xerox Corp Cross-channel mixer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3985099A (en) * 1974-05-13 1976-10-12 Fuji Xerox Co., Ltd. Magnetic brush developing device
US4022157A (en) * 1975-08-04 1977-05-10 Addressograph Multigraph Corporation Magnetic brush developer equipped with self-metering controls
US4279942A (en) * 1980-03-03 1981-07-21 Eastman Kodak Company Magnetic field adjustment for magnetic brushes
US4912511A (en) * 1988-06-17 1990-03-27 Minolta Camera Kabushiki Kaisha Developing device capable of preventing a developer from passing through the space between adjacent developing sleeves

Also Published As

Publication number Publication date
GB1467175A (en) 1977-03-16
CA989161A (en) 1976-05-18
FR2220071A1 (it) 1974-09-27
NL7314354A (it) 1974-09-04
ZA737664B (en) 1974-08-28
BE807239A (fr) 1974-03-01
IT1009676B (it) 1976-12-20
DE2353847A1 (de) 1974-09-26
FR2220071B1 (it) 1980-01-04
JPS502550A (it) 1975-01-11
JPS543375B2 (it) 1979-02-22
AU6084473A (en) 1975-04-10

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