EP0513820A2 - Walze-Aufbereiter und Betriebsverfahren zur Verwendung für eine photoleitende Trommel in einem elektrofotografischen Farbdrucker - Google Patents

Walze-Aufbereiter und Betriebsverfahren zur Verwendung für eine photoleitende Trommel in einem elektrofotografischen Farbdrucker Download PDF

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Publication number
EP0513820A2
EP0513820A2 EP92108240A EP92108240A EP0513820A2 EP 0513820 A2 EP0513820 A2 EP 0513820A2 EP 92108240 A EP92108240 A EP 92108240A EP 92108240 A EP92108240 A EP 92108240A EP 0513820 A2 EP0513820 A2 EP 0513820A2
Authority
EP
European Patent Office
Prior art keywords
toner
photoconductive drum
drum
roller
conditioning
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Withdrawn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
EP92108240A
Other languages
English (en)
French (fr)
Other versions
EP0513820A3 (en
Inventor
Thomas Camis
James G. Bearss
James A. Hall
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.)
HP Inc
Original Assignee
Hewlett Packard 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
Priority claimed from US07/701,926 external-priority patent/US5136334A/en
Application filed by Hewlett Packard Co filed Critical Hewlett Packard Co
Publication of EP0513820A2 publication Critical patent/EP0513820A2/de
Publication of EP0513820A3 publication Critical patent/EP0513820A3/en
Withdrawn legal-status Critical Current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
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/169—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer with means for preconditioning the toner image before the transfer
    • 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
    • G03G15/0131—Details of unit for transferring a pattern to a second base
    • 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
    • G03G15/0157—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 with special treatment between monocolour image formation
    • 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

  • This invention relates generally to electrophotographic printing and more particularly to electrophotographic color printing using liquid toners for transferring developed color images directly from a photoconductor to an adjacent print medium.
  • the present invention described herein represents still further new and useful improvements in the art and technology of electrophotographic color printing, and particularly in the field of electrophotographic color printing using transparent liquid electrostatic color toners and conditioning rollers for preparing a developed color image for transfer to a print medium with good print quality and fidelity.
  • one conventional approach to developing a color image on an organic photoconductor and then transferring the developed color image to an adjacent print medium is to use a so-called intermediate transfer member (ITM) which is located between a surface of the organic photoconductive drum and the surface of the print medium.
  • ITM intermediate transfer member
  • liquid toners of cyan, yellow, magenta, and black are first transferred electrostatically in series from a conventional source of liquid toners to the surface of the organic photoconductor and then developed thereon such as by writing the desired color image with a controlled laser beam or other suitable light source.
  • Color liquid toners are generally well known in the art of electrophotographic printing and are described in some detail, for example, in U.S. Patent Nos. 4,925,766 and 4,946,753 issued to Elmasry et al and entitled "Liquid Electrophotographic Toners", both incorporated herein by reference.
  • the intermediate transfer member When each of the colors of cyan, yellow, magenta, and black are individually developed on the organic photoconductive drum, the intermediate transfer member is then brought into intimate contact with the surface of the drum and is rotated against the drum surface to thereby transfer the written color images from the surface of the photoconductive drum to the intermediate transfer member.
  • One example of a printing process using an intermediate transfer member in the transfer of the image from the photoconductive drum to the print media disclosed in U.S. Patent No. 4,286,039 issued to Landa et al and incorporated herein by reference.
  • the general purpose and principal object of the present invention is to provide a new and improved electrophotographic color printing apparatus which is operative to transfer the developed color toners and color images directly from the surface of a photoconductive drum to an adjacent print medium without going through an intermediate transfer step such as that described above using an intermediate transfer member positioned between the drum and the print medium.
  • Another object of this invention is to provide a new and improved electrophotographic color printing apparatus of the type described which is operative to eliminate the cost and complexity brought about by the prior art requirement for using this intermediate transfer member.
  • Another object of this invention is to provide a new and improved electrophotographic color printing apparatus of the type described which allows one to reduce the amount of liquid carrier which is transferred onto the photoconductive drum during the color image development process.
  • Another object of this invention is to provide a new and improved color printing apparatus of the type described which is operative in an alternative embodiment for the image conditioning roller to simultaneously reduce the amount of isopar fluid on the photoconductive drum, compress the toner images electrostatically to hold the color images in place and preserve their fidelity, and produce a desired net charge on the toner as it proceeds from the conditioning roller toward the print media.
  • a unique and novel feature of this invention is the provision of a new and improved electrophotographic color printing apparatus of the type described which operates to form a compressed cohesive polymeric thin film structure of the developed color image. This thin film structure can then be transferred directly to the print medium with a high degree of resulting print quality heretofore unavailable with known direct transfer electrophotographic color liquid toner printing techniques.
  • Another feature of this invention is the provision of a new and improved electrophotographic color printing apparatus of the type described which operates to utilize a combination of mechanical, electrical and thermal energy to help prepare the developed color images for direct transfer to an adjacent media.
  • This is accomplished by the use of a compliant toner conditioning roller which is electrically biased and heated and includes a soft smooth elastomeric outer surface which operates in intimate contact with an adjacent photoconductor surface.
  • Another feature of this invention is a provision of a new and improved electrophotographic color printing apparatus of the type described which employs a novel electrical and thermal conditioning roller scheme useful to stabilize the color image on the surface of the photoconductive drum, thereby preserving its fidelity and preventing it from adhering to the roller while the amount of liquid fluid surrounding the image, such as an isopar hydrocarbon, is reduced.
  • the use of low level heating applied to the conditioning roller serves to initiate the transformation from discrete toner particles into a polymeric film structure on the surface of the photoconductive drum.
  • electrical and mechanical forces applied to this soft conditioning roller operate to preserve the fidelity of the toner-on-toner images developed on the adjacent photoconductive drum.
  • Another feature of this invention is the provision of a liquid toner conditioning apparatus of the type described wherein either AC bias or DC bias or both can be adjusted to charge the toner to the proper sign and optimum charge level before being applied to the print medium.
  • a new and improved conditioning roller which is multifunctional in purpose and includes a deformable roller consisting of a soft open cell conductive foam, such as a wettable polyurethane foam, disposed on a biased slip ring which, in turn, has been formed on an inner motor-driven metal roller core member.
  • a suitable DC bias is applied to the slip ring with the opposite polarity as the charge on the counter ions within the isopar carrier fluid for the color toner on the photoconductive drum.
  • the conductive deformable conditioning roller when it is rotatably driven against the surface of the photoconductive drum, it not only absorbs excess isopar carrier fluid from the surface of the drum, but it also compresses the toner image electrostatically on the drum to preserve its fidelity and it also pulls counter ions in the isopar fluid from the surface of the drum to thereby leave a net charge on the toner as is desired as the toner proceeds toward the print media.
  • Another feature of this invention is the provision of a new and improved method of operating a conditioning roller of the type used with a photoconductive drum within an electrophotographic color printer.
  • This method includes the steps of; dispensing liquid color toner within an isopar carrier fluid on the surface of the photoconductive drum, absorbing isopar fluid from the surface of the photoconductive drum, while simultaneously electrostatically compressing a toner image on the surface of the drum to preserve the fidelity of an image being developed, while simultaneously removing counter ions from the isopar fluid to leave a net charge on the liquid toner as it proceeds to the print medium.
  • the above described method of operation is carried out by rolling a soft wettable conductive foam, such as a polyurethane foam, against the surface of the photoconductive drum upon which color images are being developed in the liquid toner.
  • a soft wettable conductive foam such as a polyurethane foam
  • an electrophotographic color printing apparatus which includes, in combination, a photoconductive drum adjacent to which is positioned a source of liquid toner and electrostatic toner transferring means associated with the source of liquid toner for transferring the liquid color toners to the surface of the photoconductive drum.
  • Image writing means are also positioned adjacent to the surface of the photoconductive drum for developing the color toners
  • liquid toner conditioning means are positioned in intimate contact with the surface of the photoconductive drum for preparing and conditioning tile developed color liquid toner layers for direct transfer front the surface of the photoconductive drum to an adjacent print medium.
  • the liquid toner conditioning means includes means for compressing the toner image on the surface of the photoconductive drum using a combination of electrostatic and mechanical forces and thermal energy, thereby stabilizing the image on the surface of the drum and preserving its fidelity and preventing it from adhering to the toner conditioning apparatus.
  • the toner conditioning means used for treating the liquid toner includes a deformable stabilizing roller which is rotatably mounted adjacent to the surface of the photoconductive drum, and this roller has an inner core member and a soft and smooth outer core member.
  • the inner core member may advantageously be provided with a source of heat and is further connected to a source of either DC bias or AC bias or both.
  • the stabilizing roller is operative to utilize a combination of mechanical, electrical and thermal energy to condition the developed color images for direct transfer from the photoconductive drum to the adjacent print media.
  • the developed color image which has been conditioned by the toner conditioning roller is transferred to the print media using a heated transfer roller which may, if desired, be also connected to a source of DC bias voltage to electrostatically assist in the direct transfer of the color image to the print media in accordance with the novel teachings in the above identified European Patent application.
  • Figure 1 is an abbreviated schematic cross sectional view of an electrophotographic color printer constructed in accordance with the present invention.
  • Figure 2 is an enlarged view of the toner conditioning apparatus portion of the printer combination shown in Figure 1 and according to one embodiment of the invention.
  • Figure 3 is an enlarged view of the toner conditioning apparatus portion of printer combination shown in Figure 1 and according to another, alternative embodiment of the invention.
  • an organic photoconductive drum 10 which is positioned adjacent to a source 12 of monochromatic (e.g. laser) light 14 used for developing color images on the surface of the drum 10.
  • the apparatus in Figure 1 further includes a conventional corona charge mechanism 16 for the drum 10 and a conventional drum surface cleaning apparatus 18 mounted as shown adjacent to the surface of the photoconductive drum 10.
  • Cyan, yellow, magenta, and black color liquid toner sources 20, 22, 24, and 26 are located as shown adjacent to the lower surface of the photoconductive drum 10, and these color and black sources of transparent liquid toner are constructed and operated in a well known manner understood by those skilled in the electrophotographic color printing arts and are therefor not described in any significant detail herein.
  • Cyan, yellow, magenta, and black color liquid toner sources 20, 22, 24, and 26 are located as shown adjacent to the lower surface of the photoconductive drum 10, and these color and black sources of transparent liquid toner are constructed and operated in a well known manner understood by those skilled in the electrophotographic color printing arts and are therefor not described in any significant detail herein.
  • a heated and electrically biased transfer roller is designated generally as 28 and is rotatably mounted as shown above the upper surface of the photoconductive drum 10.
  • the transfer roller 28 is operative to be driven against the upper surface of a print medium 30, such as paper, which passes between the outer surface of the transfer roller 28 and the outer surface of the organic photoconductive drum 10.
  • the transfer roller 28 is constructed and operated in accordance with the principles and teachings in the above identified European patent application, and will include a conductive inner core member 32 within which a heater element 34 is located.
  • the conductive inner cOre or metal sleeve member 32 is surrounded at its outer surface by a first cylindrically formed elastomer layer 36 which in turn is coated by a thin outer protective coating 38.
  • the metal inner core member 32 is connected by way of a conductor 40 to a source 42 of electrical bias, the other side of which is grounded at node 45.
  • This heater tube will typically be heated during an image transfer operation to a controlled elevated temperature on the order of 80 - 90°C or greater to provide the thermal energy in combination with electrical and mechanical forces in the nip zone of the transfer roller 28 which makes direct contact with the media 30.
  • the inner metal sleeve 32 will be DC biased to a voltage in excess of minus 900 volts DC, and a mechanical pressure will also be applied to the nip zone at a level on the order of five (5) psi or greater.
  • a liquid toner conditioning and stabilizing apparatus is indicated generally as 46 and is located as shown on the right hand side of the photoconductive drum 10.
  • This toner conditioning apparatus 46 is operatively driven by a drive motor 48 and drive belt 50 and is in intimate contact with the outer surface of the photoconductive drum 10.
  • the toner conditioning and stabilizing apparatus 46 also includes a centrally disposed heating element 52 which is surrounded first by a cylindrical air gap 54 and then by an inner metal roller core 56 of a suitable metal such as aluminum.
  • the heating element 52 may also be an elongated quartz tube positioned at the rotational axis of the conditioning roller 46.
  • the roller core member 56 is surrounded by a metal slip ring 58 which is in turn connected through a bias electrode 60 and an interconnect pin 62 within the adjacent housing 64 to source 66 of DC bias, the other side of which is grounded at node 68.
  • the outer surface of the metal slip ring 58 is surrounded by a soft core elastomer material 70 having a very smooth outer surface 72 which material is described in greater detail below.
  • the outer core member 70 may for example be a conductive silicone or a conductive polyurethane material.
  • the reason that the soft core material 70 appears discontinuous in the figures is that the elements 60, 62, and 64 of the biasing arrangement for the slip ring 58 are located in front of the soft core roller 70 in Figure 2.
  • the heated and biased transfer roller 28 and media 30 are initially moved away from the surface of the organic photoconductive drum 10 during the exposure and development process used for developing layers of cyan, yellow, magenta, and black transparent color toners, one on top of another, on the surface of the photoconductive drum 10.
  • the toner conditioning apparatus 46 on the right hand side of the drum 10 and then subsequently exposed by light 14 from the monochromatic light source 12 on the left hand side of the photoconductive drum 10.
  • the heated and biased transfer roller 28 and print medium 30 are then brought into intimate contact in the position shown in Figure 1 with the surface of the photoconductive drum 10.
  • the composite developed color image is transferred to the lower surface of the print medium 30 as a unitary and cohesive polymeric film which holds tightly together all of the developed color toners.
  • these color toners would be transferred in discrete particle form from the surface of the photoconductive drum 10 to the underside of the print medium 30.
  • Each of the sources of color liquid transparent toners 20, 22, 24, and may include a combination of negatively charged toner particles which are immersed in a charged isopar toner carrier liquid.
  • the positively charged surface of the photoconductive drum 10 rotates past these liquid toner sources 20, 22, 24, and 26, the negatively charged toner particles are electrostatically pulled onto the surface of the photoconductive drum 10, while simultaneously the positively charged counter ions are stripped away from their negatively charged nuclei and onto an adjacent negatively charged substrate (not shown).
  • some of the carrier liquid is pulled onto the surface of the photoconductive drum 10 along with the negatively charged toner particles which it surrounds and therefore needs to be conditioned and stabilized in order to develop the color-on-color layers of toner into a cohesive and unitary polymeric film. This is accomplished by operation of the toner conditioning and stabilizing apparatus 46 as shown on the right hand side of Figure 1 and in the enlarged cross section view in Figure 2.
  • the toner conditioning apparatus 46 is operative to provide a combination of mechanical pressure, electrostatic forces, and a low level of thermal energy to the successive layers of liquid toner as they pass, in succession counter-clockwise against the smooth surface 72 of the outer conditioning soft core roller member 70.
  • the outer roller member 70 is preferably a soft elastomeric material such as a polyurethane or conductive silicone material having a volume resistivity less than about 108 ohm ⁇ centimeters and a Shore A Hardness less than 30.
  • the soft elastomeric roller 70 outer cover layer must be designed to have a smooth surface finish which is useful to preserve the fidelity of images and must also be blade cleaned to remove excess carrier fluid therefrom, using, for example, wiper blade 74.
  • the inner core 56 of the toner conditioning apparatus 46 is a cylindrical metal sleeve such as aluminum and biased to a maximum allowable DC potential of the same polarity as that of the liquid toner particles. This feature is useful in order to provide a recharging of any electrically discharged toner particles which will naturally take place during the operation of the above color toner development process. Both DC and AC bias may be used on conductor 62 to provide the proper sign and level of toner charge for the efficient transfer of the developed polymeric film on the outer surface of the photoconductive drum 10 directly onto the undersurface of the print medium 30.
  • a novel electrophotographic color printing and toner conditioning apparatus 46 which is operative in an efficient manner to properly prepare developed transparent color liquid toners for direct transfer to a receiving sheet of paper.
  • the electrically biased and heated conditioning roller 46 which is in intimate contact with the surface of the photoconductive drum 10 compresses the charged toner particles thereon which are received by the conditioning apparatus 46 in discrete particle form.
  • This electrostatic and mechanical compression by the toner conditioning apparatus 46 of the multiple and serially deposited discrete particle films operates to preserve the fidelity of the images superimposed one upon another, and it also helps prevent degradation of these images. Such degradation may otherwise take the form of poor edge acuity around printed characters, streaks, and general toner scattering.
  • the biased and heated roller conditioning apparatus 46 will also serve to apply the proper toner charge level and polarity in the case where toners become charge deficient as indicated above.
  • This toner conditioning apparatus 46 is also used to reduce and limit undesirable amounts of liquid carrier (e.g. isopar) that is normally carried out onto the print medium due to its presence on the photoconductor in both image and background regions.
  • This isopar fluid is significantly removed by the conditioning apparatus 46 whose smooth outer surface 72 is continuously cleaned by the wiping action of the cleaning blade 74 as previously described to scrape away residual isopar from the surface 72 of the conditioning roller 46.
  • Optimum cleaning is achieved by the use of a sharp cleaning blade 74 which brushes in intimate contact with the smooth surface 72 of the roller member 46 thereby enabling the isopar excess liquid to be collected in an adjacent container (not shown).
  • This conditioning roller is designated generally as 76 and includes an outer soft open cell conductive foam member 78 which is preferably an open cell polyurethane foam.
  • the soft open cell conductive wettable foam deformable roller member 78 is disposed on an inner cylindrical slip ring 80 which, in turn, has been formed on the outer surface of a central metal roller core member 82.
  • the slip ring member 80 is electrically biased by means of a metal brush 84 which is connected by way of conductor 86 to a source 88 of DC bias voltage.
  • a brush holder member 90 is positioned as shown to hold the brush 84 against the slip ring 80 and it includes an opening therein through which the conductor 86 passes between the brush 84 and the source 88 of DC bias voltage.
  • An excess fluid carrier accumulation member 92 is positioned as shown to receive the excess isopar carrier fluid as the deformable foam roller member 78 rotates against the outer surface of the photoconductive drum member 10.
  • the conditioning apparatus 76 is rotatably driven in a clockwise direction as shown by use of a drive motor 48 and belt 50 which is wound around the outer surface of the metal roller core member 82 on the reverse side of the roller conditioning apparatus 76 as viewed in Figure 3.
  • the electrical bias 88 applied to the slip ring 80 of the conditioning roller apparatus 76 will always be of the opposite polarity as the polarity of the counter ions within the isopar carrier fluid for the liquid toner on the surface of the photoconductive drum 10. In this manner, not only does the conductive soft open cell foam roller member 78 absorb the excess isopar liquid as it rotates against the surface of the photoconductive drum 10, but a voltage of appropriate polarity applied at bias node 88 to the slip ring 80 and to the conductive roller member 78 will cause charged counter ions to be pulled out of the isopar liquid and into the foam member 78.
  • a positive voltage is applied at node 88 and the conditioning roller apparatus 76 will leave a net positive charge on the toner.
  • the positive DC voltage applied as electrical bias to the slip ring 80 will thus repel the net positive charge on the toner and thereby cause the toner images on the photoconductive drum 10 to be electrostatically compressed on the surface thereof, thereby holding the toner images firmly in place on the drum surface to thereby preserve image fidelity.
  • the present invention is not limited by the particular materials or geometric configuration of the conditioning roller described herein, and this toner stabilizing roller 46, 76 may be used in combination with many different types of electrophotographic writing schemes, with alternatively charged toner systems, with color toner transferring techniques for applying toner to the photoconductive drum and with various different additional schemes for aiding in the direct transfer of the developed color toners from the surface of the photoconductive drum to an adjacent print media.
  • the present invention is not limited to use with the particular transfer roller apparatus 28 described herein. Accordingly, these and other design modifications are clearly within the scope of the following appended claims.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Wet Developing In Electrophotography (AREA)
EP19920108240 1991-05-17 1992-05-15 Conditioning roller and method of operation for use with a photoconductive drum in an electrophotographic color printer Withdrawn EP0513820A3 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US701926 1991-05-17
US07/701,926 US5136334A (en) 1991-05-17 1991-05-17 Method and apparatus for preparing liquid tone for direct transfer to the media during electrophotographic printing
US74812091A 1991-08-21 1991-08-21
US748120 1991-08-21

Publications (2)

Publication Number Publication Date
EP0513820A2 true EP0513820A2 (de) 1992-11-19
EP0513820A3 EP0513820A3 (en) 1993-05-19

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EP19920108240 Withdrawn EP0513820A3 (en) 1991-05-17 1992-05-15 Conditioning roller and method of operation for use with a photoconductive drum in an electrophotographic color printer

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0513819A2 (de) * 1991-05-17 1992-11-19 Hewlett-Packard Company Walze und Verfahren zur elektrostatischen Unterstützten direkter Übertragen von Flüssigtoner auf ein Druckmedium
EP0602339A1 (de) * 1992-12-17 1994-06-22 Hewlett-Packard Company Bildentwicklungsverfahren und Bildübertragungsverfahren sowie Vorrichtung dazu für einen elektrophotographischen Farbdrucker
EP0636948A2 (de) * 1993-07-26 1995-02-01 Hewlett-Packard Company Verfahren und Vorrichtung zum Auftragen einer Klebschicht zur verbesserten Bildübertragung in der Elektrophotographie
EP0684530A1 (de) * 1994-05-23 1995-11-29 Xerox Corporation Gerät und Verfahren zum Aufbereiten eines mit Flüssigentwickler erzeugten Bildes
US5493369A (en) * 1994-08-29 1996-02-20 Xerox Corporation Apparatus and method for improved liquid developer image conditioning
US5650253A (en) * 1995-09-29 1997-07-22 Minnesota Mining And Manufacturing Company Method and apparatus having improved image transfer characteristics for producing an image on a receptor medium such as a plain paper
US5916718A (en) * 1995-09-29 1999-06-29 Imation Corp. Method and apparatus for producing a multi-colored image in an electrophotographic system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1142315A (en) * 1965-05-26 1969-02-05 Ritzerfeld Gerhard Electrostatic printing machines
WO1990004216A1 (en) * 1988-10-04 1990-04-19 Spectrum Sciences B.V. Method and apparatus for imaging using an intermediate transfer member
WO1990008984A1 (en) * 1989-02-06 1990-08-09 Spectrum Sciences B.V. Imaging system
US4985733A (en) * 1988-04-02 1991-01-15 Ricoh Company, Ltd. Image fixing unit for use in wet-type electrophotographic copying machine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1142315A (en) * 1965-05-26 1969-02-05 Ritzerfeld Gerhard Electrostatic printing machines
US4985733A (en) * 1988-04-02 1991-01-15 Ricoh Company, Ltd. Image fixing unit for use in wet-type electrophotographic copying machine
WO1990004216A1 (en) * 1988-10-04 1990-04-19 Spectrum Sciences B.V. Method and apparatus for imaging using an intermediate transfer member
WO1990008984A1 (en) * 1989-02-06 1990-08-09 Spectrum Sciences B.V. Imaging system

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0513819A2 (de) * 1991-05-17 1992-11-19 Hewlett-Packard Company Walze und Verfahren zur elektrostatischen Unterstützten direkter Übertragen von Flüssigtoner auf ein Druckmedium
EP0513819A3 (en) * 1991-05-17 1993-05-12 Hewlett-Packard Company Electrostatically assisted transfer roller and method for directly transferring liquid toner to a print medium
EP0602339A1 (de) * 1992-12-17 1994-06-22 Hewlett-Packard Company Bildentwicklungsverfahren und Bildübertragungsverfahren sowie Vorrichtung dazu für einen elektrophotographischen Farbdrucker
EP0636948A2 (de) * 1993-07-26 1995-02-01 Hewlett-Packard Company Verfahren und Vorrichtung zum Auftragen einer Klebschicht zur verbesserten Bildübertragung in der Elektrophotographie
EP0636948A3 (de) * 1993-07-26 1996-02-07 Hewlett Packard Co Verfahren und Vorrichtung zum Auftragen einer Klebschicht zur verbesserten Bildübertragung in der Elektrophotographie.
EP0684530A1 (de) * 1994-05-23 1995-11-29 Xerox Corporation Gerät und Verfahren zum Aufbereiten eines mit Flüssigentwickler erzeugten Bildes
US5493369A (en) * 1994-08-29 1996-02-20 Xerox Corporation Apparatus and method for improved liquid developer image conditioning
US5650253A (en) * 1995-09-29 1997-07-22 Minnesota Mining And Manufacturing Company Method and apparatus having improved image transfer characteristics for producing an image on a receptor medium such as a plain paper
US5916718A (en) * 1995-09-29 1999-06-29 Imation Corp. Method and apparatus for producing a multi-colored image in an electrophotographic system

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