US3921580A - Liquid development of electrostatic images - Google Patents

Liquid development of electrostatic images Download PDF

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Publication number
US3921580A
US3921580A US478813A US47881374A US3921580A US 3921580 A US3921580 A US 3921580A US 478813 A US478813 A US 478813A US 47881374 A US47881374 A US 47881374A US 3921580 A US3921580 A US 3921580A
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United States
Prior art keywords
development electrode
development
developed
charge
rough surface
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
US478813A
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English (en)
Inventor
Heino Kase
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.)
Varian Medical Systems Inc
Original Assignee
Varian Associates 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 Varian Associates Inc filed Critical Varian Associates Inc
Priority to US478813A priority Critical patent/US3921580A/en
Priority to CA229,043A priority patent/CA1050829A/en
Priority to DE19752526097 priority patent/DE2526097A1/de
Priority to GB25232/75A priority patent/GB1512728A/en
Priority to JP50070250A priority patent/JPS609270B2/ja
Priority to FR7518441A priority patent/FR2274963A1/fr
Application granted granted Critical
Publication of US3921580A publication Critical patent/US3921580A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
    • G03G15/101—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material

Definitions

  • a cylindrical development electrode is mounted for rotation adjacent the charge retentive surface of a recording medium to be developed.
  • the cylindrical development electrode has a rough surface and is rotated with sufficient angular velocity such that the speed of the rough surface is faster than the speed of the moving charge image to be developed.
  • Liquid 'electrographic toner is supplied to the rough surface of the rotating development electrode so as to be carried by the rotating rough surface into contact with the charge image to be developed.
  • the present invention relates in general to liquid development of electrostatic charge images and more particularly to a method and apparatus employing a rotatable development electrode for carrying electrographic toner into contact with the charge images to be developed.
  • the development station included a rotating cylindrical drum-shaped development electrode.
  • the drum-shaped electrode was mounted adjacent the large image bearing surface of the recording medium.
  • the lower portion of the drum dipped into a bath of liquid toner so as to pick up toner on the smooth surface of the drum and carry it into contact with the charge images on the charge retentive surfaces to be developed.
  • the drum was rotated with sufficient angular velocity such that the peripheral speed of the drum exceeded the speed of the web being developed so as to establish a bead of liquid toner between the outer surface of the rotating drum and the charge retentive surface to be developed.
  • Such a development station is disclosed in U.S. Pat. No. 3,367,791 issued Feb. 6, 1968.
  • While such a development station is suitable for developing images moving at a relatively slow speed it is generally unsatisfactory for developing images on charge retentive surfaces of recording webs traveling at relatively high speeds, such as faster than two inches per second, because the angular andperipheral velocity of the development electrode must be relatively high to provide the necessary'amount-of toner to the images being developed, particularly when the images include relatively large dark areas which are to be developed with a uniform degree of darkness.
  • a porous or perforated drum-shaped development electrode with means inside the electrode for forcing electrographic liquid toner through the porous walls of the drum against the charge retentive surface of the recording web to be developed.
  • the drum was rotated at the same speed as the speed of the recording web being developed.
  • a perforated development electrode drum was rotated at a sufficient angular velocity such that the surface of the drum adjacent the charge retentive surface being developed was approximately up to ten times the speed of the image bearing web being developed.
  • This higher differential speed allowed the drum to disturb the boundary layer of liquid toner which would ordinarily form adjacent the surface of the moving recording web to be developed.
  • This boundary layer interferes with complete development because it soon becomes depleted of the electrographic toning particles.
  • This depleted layer is preferably removed so as to allow fresh electrographic toner to contact the charge image to be developed.
  • perforated or porous development electrode drums are capable of developing relatively large areas at relatively high speeds. such as tens of inches per second. they are cumbersome assemblies and are relatively difficult to fabricate and thus are more costly than imperforate drums.
  • the principal object of the present invention is the provision of an improved method and apparatus for liquid development of electrostatic charge images.
  • the development station includes a cylindrical development electrode having a rough outer surface to be rotated adjacent the charge retentive surface of the recording medium being developed. This rough surface serves to facilitate the carrying of liquid toner to the charge images being developed and to disrupt the boundary layer of liquid toner otherwise tending to form adjacent the charge images to be developed, whereby improved liquid electrographic development is obtained.
  • liquid electrographic toner is applied to the rough surface of a cylindrical development electrode by directing a stream of liquid development toner against the outer rough surface of the development electrode.
  • the toner is preferably applied to a region of the rotatable development electrode which is moving toward the charge bearing surface to be developed.
  • the outer surface of a cylindrical development electrode includes an array of lands and grooves such lands and grooves being elongated and running transverse to the direction of rotation of the development electrode.
  • FIG. 1 is a transverse sectional view of a liquid electrographic development station incorporating features of the present invention.
  • FIG. 2 is an enlarged detail view of a portion of the structure of FIG. 1 delineated by line 22.
  • FIG. 1 there is shown a liquid electrographic development station 1 incorporating'features of the present invention.
  • Electrographic recording paper 2 is pulled through the development station 1 by passing through the nip of a pair of rollers 3 and 4.
  • Roller 4 is a squeegee roller having a compressible layer 5 on the outer surface thereof and such layer 3 being compressedagainst the other roller 3, as of stainlesssteel, to provide a frictional drive for the paper web 2 sandwiched between the two rollers 3 and 4.
  • the squeegee roller 4 is driven in the clockwise direction via'any one of a number of conventional drive means, such as a gear train or V-belt, not shown.
  • the electrographic recording paper 2 is threaded betweenan idler roller 5, as of stainless steel, and a development electrode roller 6, as of aluminum. Rollers 3 and 5 are positioned relative to the development roller 6' so as to cause the electrographic recording web 2 to be pressed into nominal engagement with a portion of the surface of the development electrode 6,.
  • a V-belt power take off ofthe squeegee roller 4 is passed over an idler pulley 8 which in-turn drives the development roller 6 via a second V-belt drive 9.
  • the pulley ratios are-chosen so that the peripheral speed of the development electrode 6 is within the range of 2 to 5 times the speed of the electrographic recording web 2 which is to be developed. Any one of a number of drive means. such as ge'ar trains, etc., may be employed as an alternative to they-belt drives 7 and 9.
  • Liquid electrographic toner isapplied to the develop ment drum via a spray pipe 11 which directs a stream 12 of liquid toner against the outer cylindrical surface l3.of the development electrode 6 in a region where the direction of movement of the development electrode 6 is toward the electrographic web 2 to be developed;
  • the liquid electrographic toner comprises a dielectric liquid vehicle having a suspension of charged pigmentedtoner particles therein.
  • the toner is drawn from'a reservoir 14 andsupplied to the spray pipe 11 via a pump 15 and conduit 16.
  • a spray shield 17 is interposed betweenthe spray vpipe 11 and the electrographic web 2;-to prevent unwantedspraying of the electrographic toner directly ontothe web 2.
  • the electrographic recording web 2 includes a conductive paper backing having a dielectric insulative layerzcoated thereon to form a charge retentive surface.
  • Charge images to be developed are deposited uponthe'charge retentive surface and carried by the web 2 into the development station 1.
  • the charge retentive. layer is disposed facing the development drum 6.;Rollers 3 and 5 make electrical contact to the conductive side of the web and the development electrode drum 6 may be operated at-a floating potential relative to the potentials applied to rollers 3 and 5 or the development drum 6 may be operated at a suitable development potential relative to the potentials applied to rollers 3and- 5.
  • the outer surface 13 of the drum 6 is rough, and in a preferred embodiment comprises an array of relatively thin longitudinally directed lands 21 separated by wider groove portions 22.
  • the lands 21 have a height of approximately 0.050 inch relative to the bottom of the groove portions 22.
  • the land portions 21 serve as wipers for wiping the depleted boundary layer of toner from the charge retentive surface of the recording web 2.
  • the groove regions 22 between adjacent lands 2l serve to carry fresh toner into contact with the charge images to be developed on the recording web 2.
  • the bottom surface of the grooves 22 serves the function of the development electrode, namely, to provide a conductive surface operating at a different potentiaithan that of the charge images to be developed so that the field lines will extend between the charge images and the adjacent surface'of the development electrode 6.
  • the electric fields in the electrographic toner region between the development electrode 6 and the charge retentive surface are relatively high to expedite transfer of toner particles from the electrographic toner liquid to the charge images to be developed.
  • the groove portions 22 are within 0.100 inch or less of the charge image being developed.
  • the land regions 21 should be relatively narrow relative to the groove region 22 so that nominal contact is established between the upper surfaces of the lands 22 and the charge retentive surface so as to efficiently disrupt the boundary layer of depleted toner adjacent the web 2.
  • the lands 2] should have a slight pitch relative to the axis of revolution of the development electrode 6 so that the paper web 2, particularly in the case of a fan-fold electrographic web, does not get caught and torn by the more rapidly moving peripheral surface of the development electrode 6.
  • the spiral pitch of the lands is sufficient if the pitch has advanced by one angular land period over the length of the development electrode 6.
  • the surface 13 of the development electrode should be free of surface detail which is invariant in thedirection of rotation of the development electrode to prevent streaking and patterning of the developed image. 7
  • the surface of the development electrode may be roughened by sand blasting, photoetching, or knurling.
  • the rough surface 13 should have surface detail thereon having mean peak-to-peak amplitude variations of between 0.005 and 0.100 inch.
  • the rough surface can be conceived of as comprising a plurality of discrete projecting surface portions (i.e.. high points) mutually separated from one another by a plurality of recessive surface portions (i.e. low points).
  • the development electrode drive can be arranged for driving the development electrode in a direction counter to the direction of movement of the electrographic web 2.
  • the V-belt take off drive 7 is moved to the back up roller 3 so as to drive the development electrode 6 in the counterclockwise direction.
  • the spray pipe 12 is preferably moved to a region adjacent the first quadrant of the development electrode so that the electrographic toner is sprayed onto the roughened surface of the surface 13 of the drum in a region moving toward the charge retentive surface to be developed.
  • the surface roughening feature of the development electrode is, in a preferred embodiment, ap-
  • the lands function in the same manner as previously described with regard to the embodiment of FIG. 1 wherein the lands 2] serve to disrupt the boundary layer of depleted toner adjacent the charge retentive surface of the recording web 2.
  • the differential speed between the speed of the recording web 2 and that of the periphery of the development electrode 6 is preferably at least twice the speed of the web 2.
  • development electrode means having a rough cylindrical surface comprising a plurality of discrete projecting surface portions, separated from one another by a plurality of recessive surface portions; means for mounting said development electrode means for rotation about its axis of revolution; means for passing the charge retentive surface of a recording medium, for bearing latent charge images thereon to be developed, adjacent said rough surface of said development electrode and contiguous with said projecting surface portions thereof;
  • liquid electrographic development toner having electroscopic toner particles suspended in a dielectric liquid.
  • said toner liquid being carried into contact with the charge images on the charge retentive surface to be developed for developing same, said liquid toner being carried within said recessive surface portions.
  • said projecting surface portions serving to wipe liquid toner from said charge retentive surface, whereby said charge-retentive surface undergoes a plurality of successive development operations, each of said operations being followed by a wiping operation.
  • said means for supplying liquid toner to said rough surface of said de- 6 velopment electrode comprises. means for directing a stream of liquid toner onto the outer rotating rough surface of said development electrode.
  • said rough surface of said development electrode is made of an electrically conductive material. and wherein said means for passing the charge retentive surface to be developed adjacent said rough surface of said development electrode includes means for passing said charge retentive surface within 0.100 inch of the recessive surface portions of said development electrode.
  • said rough surface of said development electrode comprises an array of elongated land regions separated by elongated groove regions, said land and groove regions being elongated in a direction transverse to the direction of rotation of said development electrode.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
US478813A 1974-06-12 1974-06-12 Liquid development of electrostatic images Expired - Lifetime US3921580A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US478813A US3921580A (en) 1974-06-12 1974-06-12 Liquid development of electrostatic images
CA229,043A CA1050829A (en) 1974-06-12 1975-06-11 Electrostatic image development using development electrode with rough surface
DE19752526097 DE2526097A1 (de) 1974-06-12 1975-06-11 Verfahren und vorrichtung zur entwicklung latenter elektrostatischer bilder
GB25232/75A GB1512728A (en) 1974-06-12 1975-06-12 Liquid development of electrostatic images
JP50070250A JPS609270B2 (ja) 1974-06-12 1975-06-12 静電潜像の液体現像装置
FR7518441A FR2274963A1 (fr) 1974-06-12 1975-06-12 Procede et appareil de developpement par voie humide d'images latentes electrostatiques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US478813A US3921580A (en) 1974-06-12 1974-06-12 Liquid development of electrostatic images

Publications (1)

Publication Number Publication Date
US3921580A true US3921580A (en) 1975-11-25

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US478813A Expired - Lifetime US3921580A (en) 1974-06-12 1974-06-12 Liquid development of electrostatic images

Country Status (6)

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US (1) US3921580A (ja)
JP (1) JPS609270B2 (ja)
CA (1) CA1050829A (ja)
DE (1) DE2526097A1 (ja)
FR (1) FR2274963A1 (ja)
GB (1) GB1512728A (ja)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4127082A (en) * 1975-09-26 1978-11-28 Sharp Kabushiki Kaisha Wiper roller for drying a wet sheet in a copying machine
US4357096A (en) * 1981-03-06 1982-11-02 Eastman Kodak Company Dispersion supply apparatus for photoelectrophoretic migration imaging
US4410260A (en) * 1981-12-09 1983-10-18 Coulter Systems Corporation Toning apparatus and method
EP0223693A2 (en) * 1985-11-04 1987-05-27 Benson, Inc. Plotter toner station
EP0369805A2 (en) * 1988-11-16 1990-05-23 Xerox Corporation Apparatus for cleaning and moving a photoreceptor
WO1990014619A1 (en) * 1989-05-15 1990-11-29 Spectrum Sciences B.V. Color imaging system
WO1992003764A1 (en) * 1990-08-22 1992-03-05 Spectrum Sciences B.V. Liquid developer system
WO1992013297A1 (en) * 1991-01-22 1992-08-06 Spectrum Sciences B.V. Liquid toner developer
US5400124A (en) * 1992-11-16 1995-03-21 Eastman Kodak Company Development station having a roughened toning shell
US5557376A (en) * 1989-05-15 1996-09-17 Indigo N.V. Color imaging system
US5701561A (en) * 1995-09-26 1997-12-23 Minnesota Mining And Manufacturing Company Method and apparatus for applying liquid toner to a print medium using multiple toner applicators for each liquid toner
US5999779A (en) * 1997-12-05 1999-12-07 Ricoh Company, Ltd. Developing device for an image forming apparatus

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54345U (ja) * 1977-06-03 1979-01-05
FR2432660A1 (fr) * 1978-08-01 1980-02-29 Kelsey Hayes Co Dispositif d'etancheite aux fluides d'un ensemble de piston et de cylindre pour l'actionnement d'un frein a disque
JPS5717043A (en) * 1980-07-04 1982-01-28 Hitachi Ltd Power-on resetting circuit
JPS5848555A (ja) * 1981-09-18 1983-03-22 Fujitsu Ltd Ｐｃｍ再生中継回路
JPS5957522A (ja) * 1982-09-27 1984-04-03 Fujitsu Ltd 自動初期リセツト回路

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3245381A (en) * 1961-04-19 1966-04-12 Agfa Ag Developing apparatus
US3356072A (en) * 1966-10-12 1967-12-05 Dennison Mfg Co Apparatus for developing electrostatic images
US3367791A (en) * 1966-07-11 1968-02-06 Addressograph Multigraph Liquid development of electrostatic images
US3405683A (en) * 1963-06-22 1968-10-15 Azoplate Corp Apparatus for the development of latent electrostatic images
US3667428A (en) * 1969-07-01 1972-06-06 Xerox Corp Developing systems
US3712728A (en) * 1971-01-06 1973-01-23 Xerox Corp Reversal development
US3744897A (en) * 1969-05-02 1973-07-10 Xerox Corp Transparent electrode for electrophoretic imaging
US3783827A (en) * 1970-12-30 1974-01-08 Fuji Photo Film Co Ltd Liquid development apparatus for electrophotography
US3801315A (en) * 1971-12-27 1974-04-02 Xerox Corp Gravure imaging system
US3816114A (en) * 1972-03-03 1974-06-11 Xerox Corp Electro-photographic method
US3817748A (en) * 1972-01-28 1974-06-18 Xerox Corp Contrast control in electrostatic copying utilizing liquid development
US3830199A (en) * 1971-03-24 1974-08-20 Ricoh Kk Device for developing an electrostatic image with a developing fluid

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1183531A (en) * 1966-04-25 1970-03-11 Rank Xerox Ltd Developing electrostatic images
JPS4965226A (ja) * 1972-10-21 1974-06-25

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3245381A (en) * 1961-04-19 1966-04-12 Agfa Ag Developing apparatus
US3405683A (en) * 1963-06-22 1968-10-15 Azoplate Corp Apparatus for the development of latent electrostatic images
US3367791A (en) * 1966-07-11 1968-02-06 Addressograph Multigraph Liquid development of electrostatic images
US3356072A (en) * 1966-10-12 1967-12-05 Dennison Mfg Co Apparatus for developing electrostatic images
US3744897A (en) * 1969-05-02 1973-07-10 Xerox Corp Transparent electrode for electrophoretic imaging
US3667428A (en) * 1969-07-01 1972-06-06 Xerox Corp Developing systems
US3783827A (en) * 1970-12-30 1974-01-08 Fuji Photo Film Co Ltd Liquid development apparatus for electrophotography
US3712728A (en) * 1971-01-06 1973-01-23 Xerox Corp Reversal development
US3830199A (en) * 1971-03-24 1974-08-20 Ricoh Kk Device for developing an electrostatic image with a developing fluid
US3801315A (en) * 1971-12-27 1974-04-02 Xerox Corp Gravure imaging system
US3817748A (en) * 1972-01-28 1974-06-18 Xerox Corp Contrast control in electrostatic copying utilizing liquid development
US3816114A (en) * 1972-03-03 1974-06-11 Xerox Corp Electro-photographic method

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4127082A (en) * 1975-09-26 1978-11-28 Sharp Kabushiki Kaisha Wiper roller for drying a wet sheet in a copying machine
US4357096A (en) * 1981-03-06 1982-11-02 Eastman Kodak Company Dispersion supply apparatus for photoelectrophoretic migration imaging
US4410260A (en) * 1981-12-09 1983-10-18 Coulter Systems Corporation Toning apparatus and method
EP0223693A2 (en) * 1985-11-04 1987-05-27 Benson, Inc. Plotter toner station
EP0223693A3 (en) * 1985-11-04 1989-12-13 Benson, Inc. Plotter toner station
EP0369805A3 (en) * 1988-11-16 1991-04-10 Xerox Corporation Apparatus for cleaning and moving a photoreceptor
US4949133A (en) * 1988-11-16 1990-08-14 Xerox Corporation Apparatus for cleaning and moving a photoreceptor
EP0369805A2 (en) * 1988-11-16 1990-05-23 Xerox Corporation Apparatus for cleaning and moving a photoreceptor
WO1990014619A1 (en) * 1989-05-15 1990-11-29 Spectrum Sciences B.V. Color imaging system
US5557376A (en) * 1989-05-15 1996-09-17 Indigo N.V. Color imaging system
US5585900A (en) * 1989-05-15 1996-12-17 Indigo N.V. Developer for liquid toner imager
US5749032A (en) * 1989-05-15 1998-05-05 Indigo N.V. Color imaging system
WO1992003764A1 (en) * 1990-08-22 1992-03-05 Spectrum Sciences B.V. Liquid developer system
US5148222A (en) * 1990-08-22 1992-09-15 Spectrum Sciences B.V. Liquid developer system
WO1992013297A1 (en) * 1991-01-22 1992-08-06 Spectrum Sciences B.V. Liquid toner developer
US5400124A (en) * 1992-11-16 1995-03-21 Eastman Kodak Company Development station having a roughened toning shell
US5701561A (en) * 1995-09-26 1997-12-23 Minnesota Mining And Manufacturing Company Method and apparatus for applying liquid toner to a print medium using multiple toner applicators for each liquid toner
US5999779A (en) * 1997-12-05 1999-12-07 Ricoh Company, Ltd. Developing device for an image forming apparatus

Also Published As

Publication number Publication date
CA1050829A (en) 1979-03-20
FR2274963B1 (ja) 1982-04-16
JPS609270B2 (ja) 1985-03-08
JPS5111448A (ja) 1976-01-29
DE2526097A1 (de) 1976-01-02
GB1512728A (en) 1978-06-01
FR2274963A1 (fr) 1976-01-09

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