EP0488792A2 - Verfahren und Gerät zum Drucken von Farbbildern - Google Patents

Verfahren und Gerät zum Drucken von Farbbildern Download PDF

Info

Publication number
EP0488792A2
EP0488792A2 EP91311125A EP91311125A EP0488792A2 EP 0488792 A2 EP0488792 A2 EP 0488792A2 EP 91311125 A EP91311125 A EP 91311125A EP 91311125 A EP91311125 A EP 91311125A EP 0488792 A2 EP0488792 A2 EP 0488792A2
Authority
EP
European Patent Office
Prior art keywords
image
imaging means
charge level
image receiver
latent electrostatic
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.)
Withdrawn
Application number
EP91311125A
Other languages
English (en)
French (fr)
Other versions
EP0488792A3 (en
Inventor
John F. O'brien
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.)
Xerox Corp
Original Assignee
Xerox Corp
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 Xerox Corp filed Critical Xerox Corp
Publication of EP0488792A2 publication Critical patent/EP0488792A2/de
Publication of EP0488792A3 publication Critical patent/EP0488792A3/en
Withdrawn legal-status Critical Current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
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0142—Structure of complete machines
    • G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
    • G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
    • 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
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0105—Details of unit
    • G03G15/011—Details of unit for exposing
    • 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
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0142—Structure of complete machines
    • G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
    • G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
    • G03G15/0163—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member primary transfer to the final recording medium

Definitions

  • the present invention relates to color printing and more particularly to direct writing imaging using ionographic printhead structures for color printing.
  • the primary configurations of interest for forming color images are a tandem xerographic engine system and a multiple cycle belt arrangement using four developer housings, one for each cycle.
  • the four cycle system minimizes the number of systems and parts and may result in maximum reliability at minimal cost. However, the four cycle system minimizes the page throughput for a given process speed. Moreover, placing all the developer housings in juxtaposition adjacent one belt maximizes subsystem interactions which can cause image quality defects due to materials interaction problems.
  • a less familiar form of electrostatic printing uses ions deposited on an electroreceptor.
  • ionographic devices such as that described in US Patent No. 4,524,371 granted to Sheridon et al. or US Patent No. 4,463,363 granted to Gundlach et al
  • an ion producing device generates ions to be directed past a plurality of modulation electrodes to an imaging surface.
  • ions are produced at a coronode supported within an ion chamber, and a moving fluid stream entrains and carries ions produced at the coronode out of the chamber.
  • a plurality of control electrodes or nibs are modulated with a control voltage to selectively control passage of ions through the chamber exit.
  • Ions directed through the chamber exit are deposited on a charge retentive surface in imagewise configuration to form an electrostatic latent image developable by electrostatographic techniques for subsequent transfer to a final substrate.
  • the arrangement produces a high resolution non-contact printing system.
  • Other ionographic devices exist which operate similarly, but do not rely on a moving fluid stream to carry ions to a surface.
  • US Patent No. 4,879,194 granted to Christopher Snelling discloses a method and apparatus using ion projection to form tri-level latent electrostatic images on a charge retentive surface.
  • the tri-level image described therein comprises two image areas and a background area. One of the images is developed with black toner while the other one is developed with a colored toner to thereby form a highlight color image.
  • US Patent No. 4,660,059 granted to John F. O'Brien discloses a highlight color printing apparatus in which a document is printed in at least two different colors. Ions are projected onto the surface of a receiving member to record at least two electrostatic latent images thereon. Each of the electrostatic latent images recorded on the receiving member is developed with different color marking particles. The different color marking particles are transferred substantially simultaneously from the receiving member to the document to print the desired information thereon.
  • US Patent No. 4,731,634 granted to Howard M. Stark discloses a method and apparatus for rendering latent electrostatic images visible using multiple colors of dry toner or developer for developing black and at least two highlight color images in a single pass of the imaging surface through the development stations of the apparatus. Two of the toners are attracted to only one charge level on the charge retentive surface to form the black and one highlight color image and two toners are attracted to a third image level to form the second highlight color.
  • US Patent No. 4,833,503 granted to Christopher Snelling on May 23, 1989 discloses a multi-color printer wherein the printing process is improved by using a charging unit prior to exposures subsequent to the first exposure to enhance uniformity of photoreceptor potential, i.e., neutralization of the previous image charge.
  • the '503 patent proposes the use of toner materials which are transparent to electromagnetic radiation.
  • a printing system which does not require multiple engines and which can create color images in a single pass is highly desirable.
  • the present invention provides a method of printing color images including subjecting a charged image receiver to ions to form thereon a latent electrostatic image and developing said latent electrostatic image using a toner, characterised by charging said image receiver to a uniform charge level, selectively subjecting a predetermined area of said uniformly charged image receiver to ions from imaging means to thereby form a first latent electrostatic image thereon which has a charge level different from said uniform charge level, developing said first latent electrostatic image using a toner of a first color, recharging said image receiver whereby said image receiver contains a uniform charge level, selectively subjecting said predetermined area of said uniformly charged image receiver to ions from a further imaging means to thereby form a second latent electrostatic image thereon which has a charge level different from said uniform charge level, and developing said second latent electrostatic image using a toner different in color from said first color.
  • an apparatus for printing color images including imaging means for subjecting a charged image receiver to ions to form thereon a latent electrostatic image and developer means for developing said latent electrostatic image using a toner, characterised by charging means for charging said image receiver to a uniform charge level, said imaging means serving for selectively subjecting a predetermined area of said uniformly charged image receiver to ions to thereby form a first latent electrostatic image thereon which has a charge level different from said uniform charge level, said developer means serving for developing said first latent electrostatic image with a toner of a first color, further charging means for recharging said image receiver whereby said image receiver contains a uniform charge level, and further imaging means for selectively subjecting said predetermined area of said uniformly charged image receiver to ions to thereby form a second latent electrostatic image thereon which has a charge level different from said uniform charge level, and further developing means for developing said second latent electrostatic image with a toner different in color from said first toner.
  • the present invention provides a printing system which does not require multiple image receptors and cleaning systems and which can produce color images in a single pass.
  • a uniformly charged image receiver is employed to form successive images using separate ion sources. Each image is developed using a different color toner. Subsequent to the development of each of the images except for the last one, the image receiver is recharged to the original charge level of the uniformly charged image receiver. The toners forming the image are then transferred to a substrate and passed through a fuser to effect adherence of the toners to the substrate.
  • the present invention is not limited to the use of toners which are transparent to electromagnetic radiation.
  • the ion images can be formed on top of previously developed images.
  • Figure 1 Disclosed in Figure 1 is one embodiment of a color printing device or apparatus generally indicated by reference character 10.
  • the printing apparatus 10 comprises a charge retentive image receiver in the form of a dielectric belt 12 having a dielectric constant of 3 about 2.5 to 6.
  • the belt 12 is supported for movement in an endless path by a pair of rollers 14 and 16, the latter of which is operatively coupled to a motor 18 for effecting such movement.
  • a corona discharge device 20 is provided for uniformly charging the belt 12 to a negative 1500 volts.
  • a plurality of ion generating devices 22, 24, 26 and 28-positioned in the path of movement of the belt 12 serve to form discharged area images on a predetermined area of the belt 12.
  • the image receiver In the process of forming each of the images the image receiver is discharged to approximately -800 volts in the image area.
  • the first ion generating device 22 is used to form a first image on the image receiver which is developed by a first scavengeless development system 30.
  • Any other suitable development system for example, magnetic brush development, could be used to develop the first image but it is preferred, in order to minimize developer interaction with an already formed image, to use a scavengeless system as disclosed in US-A 4,868,600 granted to Hays et al on September 19, 1989. Because a discharged area image is developed by the development system 30 it is referred to as a Discharged area Development or a DAD system. As disclosed, there are provided three other scavengeless development systems 32, 34 and 36.
  • the developer systems 30, 32, 34 and 36 are each negatively biased to a voltage level intermediate the uniform charge level of -1500 and the image voltage level of -800 volts (1500 -700).
  • a DC bias voltage of approximately -1400 volts is supplied by DC power sources 38, 40, 42 and 44 for biasing each of the development systems.
  • negatively charged toner is supplied by the donor roll structures of the development systems 30, 32, 34 and 36.
  • the negative toner particles are deposited on the less negatively charged areas (i.e. image areas) of the image receiver and repelled from the higher charged areas.
  • Recharging corona devices 46, 48 and 50 each positioned downstream of the development system with which it is associated are utilized to neutralize the toner images prior to the formation of the second, third and fourth images.
  • Neutralization of an image has the effect of raising the image charge level of -700 volts to -1500 volts, the voltage level to which the image receiver had been uniformly charged.
  • Recharging also tacks the toner image to the image receiver thereby helping to minimize image disturbance as the image passes subsequent developer systems.
  • the belt may be encoded adjacent one edge thereof as indicated by reference character 52 to provide timing marks for synchronizing the timely actuation of the ion generating devices as well as other components of the printing apparatus.
  • signals generated in a conventional manner by a sensor 54 positioned to sense the timing marks serve as inputs to an electronic subsystem, ESS 56.
  • the ESS is operatively connected by suitable circuity (not shown for sake of clarity) to the operative components of the printer including the ion printhead structures.
  • a pretransfer corona device 58 serves to condition the toner and image receiver for efficient transfer of the toner image to a substrate 60 such as plain paper.
  • a transfer corona structure 62 effects efficient toner image transfer to the substrate 60.
  • a cleaning system 64 is provided for removing residual toner from the image receiver.
  • a heat and pressure fuser comprising a fuser roll 66 and a pressure roll 68 permanently affixes toner powder images to the image receiver.
  • the fuser assembly includes a heated fuser roller adapted to be pressure engaged with a back-up roller with the toner powder images contacting the fuser roller. In this manner, the toner powder image is permanently affixed to an image receiver.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Color Electrophotography (AREA)
  • Color, Gradation (AREA)
  • Printers Characterized By Their Purpose (AREA)
  • Dot-Matrix Printers And Others (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
EP19910311125 1990-11-29 1991-11-29 A method and apparatus for printing color images Withdrawn EP0488792A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US61956190A 1990-11-29 1990-11-29
US619561 1990-11-29

Publications (2)

Publication Number Publication Date
EP0488792A2 true EP0488792A2 (de) 1992-06-03
EP0488792A3 EP0488792A3 (en) 1993-08-25

Family

ID=24482407

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910311125 Withdrawn EP0488792A3 (en) 1990-11-29 1991-11-29 A method and apparatus for printing color images

Country Status (3)

Country Link
EP (1) EP0488792A3 (de)
JP (1) JPH04291368A (de)
CA (1) CA2050640A1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0589650A1 (de) * 1992-09-23 1994-03-30 Xerox Corporation Farbdrucker
EP0581563A3 (en) * 1992-07-29 1994-09-14 Xerox Corp Pre-recharge device for voltage uniformity in read color systems
DE10354345A1 (de) * 2003-11-20 2005-07-07 Schott Ag Mehrfarben-Druckvorrichtung

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4761669A (en) * 1987-05-21 1988-08-02 Xerox Corporation Highlight color printing

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0581563A3 (en) * 1992-07-29 1994-09-14 Xerox Corp Pre-recharge device for voltage uniformity in read color systems
EP0589650A1 (de) * 1992-09-23 1994-03-30 Xerox Corporation Farbdrucker
DE10354345A1 (de) * 2003-11-20 2005-07-07 Schott Ag Mehrfarben-Druckvorrichtung

Also Published As

Publication number Publication date
CA2050640A1 (en) 1992-05-30
EP0488792A3 (en) 1993-08-25
JPH04291368A (ja) 1992-10-15

Similar Documents

Publication Publication Date Title
US5204697A (en) Ionographic functional color printer based on Traveling Cloud Development
US4901114A (en) Tri level xerography using a MICR toner in combination with a non-MICR toner
US5258820A (en) Pre-recharge device for voltage uniformity in read color systems
US4810604A (en) Combination xerographic and direct electrostatic printing apparatus for highlight color imaging
US5241356A (en) Method and apparatus for minimizing the voltage difference between a developed electrostatic image area and a latent electrostaic non-developed image
EP0594368A2 (de) Im Tandembetrieb arbeitender Dreistufenprozessfarbdrucker
US7720401B2 (en) Inter-document zone gloss defect eliminator
US5576824A (en) Five cycle image on image printing architecture
US4778740A (en) Color electrophotographic method and apparatus
CA2044319C (en) Highlight printing apparatus
EP0340996B1 (de) Drei-Niveau, Spitzlicht-Farbbilderzeugung mittels Ionographie
US5583629A (en) Color electrophotographic printing machine
EP0549575B1 (de) Flüssigentwicklungssystem zur bilderzeugung auf durchsichtigen und undurchsichtigen bildträgern
US5080988A (en) Biasing scheme for improving latitudes in the tri-level xerographic process
EP0869402B1 (de) Steuerung der elektrischen Vorspannung zur Vermeidung der Überlagerung in einem elektrostatografischen Drucksystem
EP0488792A2 (de) Verfahren und Gerät zum Drucken von Farbbildern
US5030531A (en) Tri-level xerographic two-color forms printer with slide attachment
US4920024A (en) Photoreceptor edge erase system for tri-level xerography
US5890045A (en) Elastic intermediate belt and system particularly for use in electrostatographic printing systems
EP0735433B1 (de) Fünfstufige Xerografievorrichtung
US5480751A (en) Tri-level background suppression scheme using an AC scorotron with front erase
CN1424630B (zh) 非接触式成像系统及成像方法
US6292645B1 (en) Apparatus and method for minimizing the halo effect in an electrostatographic printing system
US4804603A (en) Electrophotographic method and apparatus
US5571645A (en) Printing with increased color density

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19940203

17Q First examination report despatched

Effective date: 19940927

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19950324