EP0486534B1 - Verfahren und gerät zur bildherstellung - Google Patents

Verfahren und gerät zur bildherstellung Download PDF

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Publication number
EP0486534B1
EP0486534B1 EP90911661A EP90911661A EP0486534B1 EP 0486534 B1 EP0486534 B1 EP 0486534B1 EP 90911661 A EP90911661 A EP 90911661A EP 90911661 A EP90911661 A EP 90911661A EP 0486534 B1 EP0486534 B1 EP 0486534B1
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EP
European Patent Office
Prior art keywords
liquid
image
toner image
solids
concentrating
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
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EP90911661A
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English (en)
French (fr)
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EP0486534A1 (de
Inventor
Benzion Landa
Yehuda Niv
Amiran Lavon
Hanna Pinhas
Yossi Adam
Yakov Krumberg
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HP Indigo BV
Original Assignee
Indigo BV
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Publication date
Priority claimed from US07/393,649 external-priority patent/US5047808A/en
Priority claimed from US07/400,717 external-priority patent/US5555185A/en
Priority claimed from PCT/NL1990/000049 external-priority patent/WO1991003006A1/en
Application filed by Indigo BV filed Critical Indigo BV
Priority claimed from CA002075948A external-priority patent/CA2075948C/en
Publication of EP0486534A1 publication Critical patent/EP0486534A1/de
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Publication of EP0486534B1 publication Critical patent/EP0486534B1/de
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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
    • G03G15/11—Removing excess liquid developer, e.g. by heat
    • 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
    • G03G15/1605—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 using at least one intermediate support
    • G03G15/161—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 using at least one intermediate support with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G03G5/142—Inert intermediate layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof

Definitions

  • the present invention relates to image transfer techniques and apparatus for use in electrophotography.
  • Liquid toner images are developed by varying the density of pigmented solids in a developer material on a latent image bearing surface in accordance with an imaged pattern.
  • the variations in density are produced by the corresponding pattern of electric fields extending outward from the latent image bearing surface.
  • the fields are produced by the different latent image and background voltages on the latent image bearing surface and a voltage on a developer plate or roller.
  • developed liquid toner images comprise carrier liquid and toner particles and are not homogeneous.
  • a liquid toner developer contains about 1.5% to 2% solids and a developed image contains about 15% solids.
  • the developed image has a higher density region closer to the latent image bearing surface and a "fluffy", i.e. loosely bound, region further away from the latent image bearing surface.
  • the technique of removing carrier liquid is known generally as metering.
  • An alternative metering technique described in U.S. Patents 3,767,300 and 3,741,643, employs an air knife, but has not been particularly successful due to sullying of the background as a result of turbulence. Corona discharge has also been used to compress and remove liquid from a developed liquid image.
  • liquid toner images are generally transferred to substrates by electrophoresis, whereby the charged image moves from the latent image bearing surface to the substrate through the carrier liquid under the influence of an electric field produced by a high voltage, associated with the substrate, which is of opposite polarity to the charge on the image particles.
  • the voltage and thus the field strength available for electrophoretic transfer are limited by the danger of electrical breakdown which can occur at both the input and output edges of the nip, due to the minimum of the Paschen curve being at about 8 microns.
  • the voltage difference at the nip preferably should not exceed about 360 volts, in order to avoid electrical breakdown and possible damage to the image and latent image bearing surface.
  • U. S. Patents 4,690,539 and 4,708,460 describe apparatus for removing substantially all of the carrier liquid from a liquid image on an image transfer member, prior to transfer to the final substrate.
  • U. S. Patent 4,684,238 describes the use of an electrified roller spaced away from a liquid image on an intermediate transfer member.
  • the stated object of this mechanism is the compacting of the image and the removal of liquid therefrom.
  • U. S. Patent 4,796,048 describes a system for transferring a liquid toner image from a photoconductor to an image transfer member.
  • the image transfer member is urged against the photoconductor during transfer to squeegee carrier liquid away from the non-image areas.
  • the image areas are kept in a spaced relationship from the intermediate transfer member by spacer particles in the toner material as described in U. S. Patent Number 4,582,774.
  • This toner material is the only toner described in U. S. Patent 4,796,048 as being a suitable toner.
  • the present invention seeks to provide improved apparatus for enhancement of image transfer.
  • a liquid toner image is transferred from an image forming surface to an intermediate transfer member for subsequent transfer to a final substrate.
  • the liquid toner image includes a liquid portion including carrier liquid and a solids portion including pigmented polymeric toner particles which are essentially non-soluble in the carrier liquid at room temperature, and the polymer portion of which forms substantially a single phase with carrier liquid at elevated temperatures.
  • An imaging method includes the steps of concentrating the liquid toner image to a given non-volatile solids percentage by compacting the solids portion thereof and removing carrier liquid therefrom; transferring the liquid toner image to an intermediate transfer member; heating the liquid toner image on the intermediate transfer member to a temperature at least as high as that at which the polymer portion of the toner particles and the carrier liquid form substantially a single phase at the given solids percentage; and transferring the heated liquid toner image to a final substrate.
  • a liquid toner image is transferred from an image forming surface to an intermediate transfer member for subsequent transfer to a final substrate.
  • the liquid toner image includes a liquid portion including carrier liquid and a solids portion including toner particles.
  • An imaging method is provided which includes the steps of concentrating the liquid toner image by compacting the solids portion thereof and removing carrier liquid therefrom such that the image has a non-volatile solids percentage of between 20% and 35%; transferring the liquid toner image to an intermediate transfer member; and transferring the liquid toner image to a final substrate.
  • the step of concentrating includes the simultaneous application of an electric field to compact the solids portion of the image and of pressure to remove liquid from the image.
  • the non-volatile solids percentage can be about 20, 25%, 30% or 35% or greater after the step of concentration.
  • the single phase is a liquid phase.
  • the step of concentrating is operative to increase the solids percentage to a value at which phase separation cannot occur.
  • imaging apparatus utilizing a liquid developer comprising carrier liquid and pigmented polymeric toner particles which are essentially non-soluble in the carrier liquid at room temperature, and the polymer portion of which form substantially a single phase with carrier liquid at elevated temperatures
  • the apparatus including: an image forming surface, apparatus, utilizing the liquid developer, for forming a liquid toner image having a liquid portion including carrier liquid and a solids portion including toner particles, on the image forming surface, apparatus for concentrating the liquid toner image to a given non-volatile solids percentage by compacting the solids portion of the liquid toner image and removing carrier liquid therefrom; apparatus for transferring the liquid toner image to an intermediate transfer member after concentration thereof, apparatus for heating the liquid toner image on the intermediate transfer member to a temperature at least as high as that at which the polymer portion of the toner particles and the carrier liquid form substantially a single phase at the given concentration and apparatus for transferring the liquid toner image, after heating thereof, to a final substrate.
  • imaging apparatus utilizing a liquid developer
  • the apparatus including: an image forming surface, apparatus utilizing the liquid developer, for forming a liquid toner image having a liquid portion including carrier liquid and a solids portion including toner particles, on the image forming surface, apparatus for concentrating the liquid toner image by compacting the solids portion thereof and removing carrier liquid therefrom, including apparatus for increasing the non-volatile solids percentage of the liquid toner image to between 20% and 35%, apparatus for transferring the liquid toner image to an intermediate transfer member and apparatus for transferring the liquid toner image from the intermediate transfer member to a final substrate.
  • the apparatus for concentrating includes apparatus for the simultaneous application of an electric field to compact the solids portion of the image and of mechanical pressure to remove liquid from the image.
  • the apparatus for concentrating includes an electrified squeegee roller urged against the image forming surface.
  • the single phase is a liquid phase.
  • the apparatus for concentrating is operative to increase the solids percentage to a value at which phase separation cannot occur.
  • the imaging apparatus also includes optical radiation apparatus for discharging both image and background areas prior to image transfer to the image transfer member.
  • the optical radiation apparatus includes at least one light emitting diode.
  • the optical radiation apparatus includes at least two radiation sources radiating different color light.
  • FIG. 1 illustrates electrophotographic imaging apparatus constructed and operative in accordance with a preferred embodiment of the present invention.
  • the invention is described for liquid developer systems with negatively charged toner particles, and negatively charged photoconductors, i.e., systems operating in the reversal mode.
  • toner particle and photoconductor polarity the values and polarities of the voltages are changed, in accordance with the principles of the invention as claimed.
  • the invention can be practiced using a variety of liquid developer types but is especially useful for liquid developers comprising carrier liquid and pigmented polymeric toner particles which are essentially non-soluble in the carrier liquid at room temperature, and which solvate carrier liquid at elevated temperatures.
  • This is a characteristic of the liquid developer of Example 1 of U. S. Patent 4,794,651, the disclosure of which is included herein by reference.
  • Part of a simplified phase diagram of a typical toner of this type is shown in Fig. 2. This diagram represents the states of the polymer portion of the toner particles and the carrier liquid.
  • the pigment in the particles generally takes little part in the process, and references herein to "single phase” and to “solvation” refer to the state of the polymer part of the toner particles together with the carrier liquid.
  • a liquid developer is prepared by mixing 10 parts of Elvax II 5950 (E. I. du Pont) and 5 parts by weight of Isopar L (Exxon) at low speed in a jacketed double planetary mixer connected to an oil heating unit for one hour, the heating unit being set at 130°C.
  • a mixture of 2.5 parts by weight of Mogul L carbon black (Cabot) and 5 parts by weight of Isopar L is then added to the mix in the double planetary mixer and the resultant mixture is further mixed for one hour at high speed.
  • 20 parts by weight of Isopar L pre-heated to 110°C are added to the mixer and mixing is continued at high speed for one hour.
  • the heating unit is disconnected and mixing is continued until the temperature of the mixture drops to 40°C.
  • the resulting material 100 g of the resulting material is mixed with 120 g of Isopar L and the mixture is milled for 19 hours in an attritor to obtain a dispersion of particles.
  • the material is dispersed in Isopar L to a solids content of 1.5% by weight.
  • the preferred liquid developer prepared comprises toner particles which are formed with a plurality of fibrous extensions or tendrils as described in U.S. Patent 4,794,651, the disclosure of which is incorporated herein by reference.
  • the preferred liquid developer is characterized in that when the concentration of toner particles is increased above 20%, the viscosity of the material increases greatly, apparently in approximately an exponential manner.
  • a charge director prepared in accordance with Example 1 of assignee's co-pending U.S. Patent Application Serial Number 354,121 filed April 22, 1989 and entitled HUMIDITY TOLERANT CHARGE DIRECTOR MATERIALS, the disclosure of which is incorporated herein by reference, is added to the dispersion in an amount equal to about 3% of the weight of the solids in the developer.
  • the apparatus of Fig. 1 typically comprises a drum 10 arranged for rotation about an axle 12 in a direction generally indicated by arrow 14.
  • Drum 10 is formed with a cylindrical photoconductor surface 16.
  • a corona discharge device 18 is operative to generally uniformly charge photoconductor surface 16 with a negative charge.
  • the latent image comprises image areas at a given range of potentials and background areas at a different potential.
  • the image may be laser generated as in printing from a computer or it may be the image of an original as in a copier.
  • Development unit 22 may be a single color developer of any conventional type, or may be a plurality of single color developers for the production of full color images as is known in the art. Alternatively, full color images may be produced by changing the liquid toner in the development unit when the color to be printed is changed. Alternatively, highlight color development may be employed, as is known in the art.
  • photoconductor surface 16 passes a typically charged rotating roller 26, preferably rotating in a direction indicated by an arrow 28.
  • roller 26 typically acts as a metering roller as is known in the art, reducing the amount of carrier liquid on the background areas and reducing the amount of liquid overlaying the image.
  • roller 26 is intermediate that of the latent image areas and of the background areas on the photoconductor surface.
  • Typical approximate voltages are: roller 26: -500 V, background area: -1000 V and latent image areas: -150 V.
  • the liquid toner image which passes roller 26 should be relatively free of pigmented particles except in the region of the latent image.
  • Rigidizing roller 30 is preferably formed of resilient polymeric material, such as polyurethane which may have only its natural conductivity or which may be filled with carbon black to increase its conductivity.
  • roller 30 is urged against photoconductor surface 16 as by a spring mounting (not shown).
  • the surface of roller 30 typically moves in the same direction and with the same velocity as the photoconductor surface to remove liquid from the image.
  • roller 30 is biased to a potential of at least several hundred and up the several thousand Volts with respect to the potential of the developed image on photoconductor surface causes that it repels the charged pigmented particles and causes them to more closely approach the image areas of photoconductor surface 16, thus compacting and rigidizing the image.
  • rigidizing roller 30 comprises an aluminum core having a 20 mm diameter, coated with a 4 mm thick carbon-filled polyurethane coating having a Shore A hardness of about 30-35, and a volume resistivity of about 108 ohm-cm.
  • roller 30 is urged against photoconductor surface 16 with a pressure of about 40-70 grams per linear cm of contact, which extends along the length of the drum.
  • the core of rigidizing roller 30 is energized to between about -1800 and -2800 volts, to provide a voltage difference of preferably between about 1600 and 2700 volts between the core and the photoconductor surface in the image areas. Voltage differences of as low as 600 volts are also useful.
  • the solids percentage in the image portion is believed to be as high as 35% or more, when carrier liquid absorbed as plasticizer is considered as part of the solids portion. It is preferable to have an image with at least 25-30% solids, after rigidizing.
  • the solids percentage is preferably above 20% and is usually less than 30%. Values of 25% have been found to be especially useful. At these concentrations the material has a paste like consistency.
  • the carbon filled polyurethane can be replaced by unfilled polyurethane with a volume resistivity of about 3 x 1010, and the voltage is adjusted to give proper rigidizing.
  • LEDs 29 Downstream of rigidizing roller 30 there is preferably provided a plurality of light emitting diodes (LEDs) 29 to discharge the photoconductor surface, and equalize the potential between image and background areas.
  • LEDs light emitting diodes
  • both red and green LEDs are provided to discharge the areas of the photoconductor behind the developed image as well as the background areas.
  • an intermediate transfer member 40 Downstream of LEDs 29 there is provided an intermediate transfer member 40, which rotates in a direction opposite to that of photoconductor surface 16, as shown by arrow 41.
  • the intermediate transfer member is operative for receiving the toner image from the photoconductor surface and for subsequently transferring the toner image to a receiving substrate 42, such as paper.
  • intermediate transfer member 40 is urged against photoconductor surface 16.
  • One of the effects of the rigidization described above is to prevent substantial squash or other distortion of the image caused by the pressure resulting from the urging.
  • the rigidization effect is especially pronounced due to the sharp increase of viscosity with concentration for the preferred toner.
  • Transfer of the image to intermediate transfer member 40 is preferably aided by providing electrical bias to the intermediate transfer member 40 to attract the charged toner thereto, although other methods known in the art may be employed.
  • Subsequent transfer of the image to substrate 42 is preferably aided by heat and pressure, with pressure applied by a backing roller 43, although other methods known in the art may be employed.
  • the intermediate transfer member voltage is between -300 V and 0 V where no pre-transfer LEDs are used and between +200 V and +500 V where they are used.
  • photoconductor surface 16 is engaged by a cleaning roller 50, which typically rotates in a direction indicated by an arrow 52, such that its surface moves in a direction opposite to the movement of adjacent photoconductor surface 16 which it operatively engages.
  • Cleaning roller 50 is operative to scrub and clean surface 16.
  • a cleaning material such as toner, may be supplied to the cleaning roller 50, via a conduit 54.
  • a wiper blade 56 completes the cleaning of the photoconductor surface. Any residual charge left on photoconductor surface 16 is removed by flooding the photoconductor surface with light from a lamp 58.
  • the cycle is sequentially repeated for other colors which are sequentially transferred from photoconductor surface 16 to intermediate transfer member 40.
  • the single color images may be sequentially transferred to the paper, in alignment, or may alternatively be overlaid on the intermediate transfer member and transferred as a group to substrate 42.
  • the image is heated on intermediate transfer member 40 in order to facilitate its transfer to substrate 42.
  • This heating is preferably to a temperature above a threshold temperature of substantial solvation of the carrier liquid in the toner particles.
  • the state of the image i.e. of the polymer portion of the toner particles and the carrier liquid, depends on several factors, mainly on the temperature of the intermediate transfer member and on the concentration of toner particles.
  • the percentage of toner particles is "A” and the intermediate transfer member temperature is "Y” the liquid image separates into two phases, one phase being substantially a liquid polymer/carrier-liquid phase and the other phase consisting mainly of carrier liquid.
  • the percentage of toner particles is "B" at the same temperature, then substantially only one phase, a liquid polymer/carrier-liquid phase will be present. It is believed to be preferable that separate liquid polymer/carrier-liquid and liquid phases do not form to any substantial degree, as will be the case for example if the concentration is "C".
  • phase separation is believed to be undesirable on the intermediate transfer member. It is believed that an absence of substantial phase separation of this type in the image on the intermediate transfer member results in improved image quality, including an improvement in line uniformity.
  • heating the image on the intermediate transfer member is not meant to completely dry the image, although some evaporation of carrier liquid may result. Rather, the image on the intermediate transfer member remains a viscous liquid until its transfer to the final substrate.
  • the invention has been described by a specific embodiment utilizing an electrified squeegee roller for concentrating the liquid toner image on the photoconductor surface.
  • other methods of concentrating the image i.e., compacting the solids portion thereof and removing liquid therefrom, can be utilized provided they concentrate the image to the extent required.
  • These methods include the use of separate solids portion compactors and liquid removal means, such as those described in U. S. Patent Application Serial Number 306,076, previously incorporated herein by reference.
  • the apparatus may utilize a solids portion compactor followed by an intermediate transfer member urged against the photoconductor to remove liquid from the image.
  • the commutated intermediate transfer member described in U.S. Patent Application Serial Number 306,076 may be used to provide both solids portion compacting and liquid removal, just prior to transfer to the intermediate transfer member.
  • the concentrating step may take place on the intermediate transfer member after transfer of the liquid toner image thereto and before heating the image.

Claims (23)

  1. Verfahren zur Übertragung eines Flüssigtoner-Bildes, welches einen Flüssigabschnitt mit einer Trägerflüssigkeit und einen festen Abschnitt enthält, welcher pigmentierte polymerische Tonerteilchen enthält, die in der Trägerflüssigkeit bei Raumtemperatur im wesentlichen nicht löslich sind, wobei das Übertragungsverfahren dazu dient, ein Flüssigtonerbild von einer bildformenden Fläche auf ein endgültiges Substrat zu übertragen, mit den folgenden Schritten:
       Konzentrieren des Flüssigtonerbildes auf einen gegebenen nichtflüchtigen Feststoff-Prozentsatz durch Verdichten des festen Abschnitts desselben und durch Entfernen der Trägerflüssigkeit aus diesem, und
       Übertragen des Flüssigtonerbildes auf das endgültige Substrat,
    dadurch gekennzeichnet, daß
       das Flüssigtonerbild auf ein Zwischenübertragungsteil übertragen wird, und zwar vor der Übertragung des Flüssigbildes auf das endgültige Substrat, und daß
       das Flüssigtonerbild auf dem Zwischenübertragungsteil auf eine gegebene Temperatur erhitzt wird, die wenigstens so hoch ist wie eine erhöhte Temperatur, bei der die Tonerteilchen und die Trägerflüssigkeit bei dem gegebenen Feststoff-Prozentsatz im wesentlichen eine einzelne Phase bilden.
  2. Verfahren nach Anspruch 1, bei dem die einzelne Phase eine Flüssigphase ist.
  3. Verfahren nach Anspruch 1, bei dem der Schritt der Konzentration dazu dient, den Feststoff-Prozentsatz auf einen Wert zu erhöhen, bei dem eine Phasentrennung nicht stattfinden kann.
  4. Verfahren nach Anspruch 1, bei dem der Feststoff-Prozentsatz über ca. 20% liegt.
  5. Verfahren zum Übertragen eines Flüssigtonerbildes mit einem Feststoff- oder Festkörper-Abschnitt und einem flüssigen Abschnitt von einer bildformenden Fläche auf ein endgültiges Substrat mit den folgenden Schritten:
       Konzentrieren eines Flüssigtonerbildes durch Verdichten des Feststoffabschnitts desselben und Entfernen der Trägerflüssigkeit aus demselben, und
       Übertragen des Flüssigtonerbildes auf das endgültige Substrat,
    dadurch gekennzeichnet, daß die folgenden Schritt durchgeführt werden:
       Übertragen des Flüssigtonerbildes auf ein Zwischenübertragungsteil nach dem Schritt der Konzentrierung und vor dem Schritt der Übertragung, und
       daß der Schritt der Konzentrierung das Bild derart konzentriert, daß das Bild einen nichtflüchtigen Feststoff-Prozentsatz zwischen 20 und 35% aufweist.
  6. Verfahren nach irgendeinem der vorhergehenden Ansprüche, bei dem der Schritt der Konzentrierung das gleichzeitige Anlegen eines elektrischen Feldes umfaßt, um den Feststoffabschnitt des Bildes zu kompaktieren, und das Ausüben eines mechanischen Druckes umfaßt, um die Flüssigkeit aus dem Bild zu entfernen.
  7. Verfahren nach irgendeinem der vorhergehenden Ansprüche, bei dem der Feststoff-Prozentsatz unter ca. 30% liegt.
  8. Verfahren nach irgendeinem der vorhergehenden Ansprüche, bei dem der Feststoff-Prozentsatz bei ca. 25% liegt.
  9. Verfahren nach irgendeinem der vorhergehenden Ansprüche, bei dem der Schritt der Konzentrierung dem Schritt der Übertragung des Flüssigbildes auf das Zwischenübertragungsteil vorangeht.
  10. Verfahren nach irgendeinem der vorhergehenden Ansprüche mit dem weiteren Schritt der Bestrahlung des Bildes mit einer optischen Strahlung.
  11. Verfahren nach Anspruch 10, bei dem die optische Strahlung eine Strahlung aus wenigstens zwei Strahlungsquellen enthält, die unterschiedliches farbiges Licht ausstrahlen.
  12. Bildherstellungsvorrichtung, bei der ein Flüssigentwickler mit einer Trägerflüssigkeit und mit pigmentierten polymerischen Tonerteilchen verwendet wird, die in der Trägerflüssigkeit bei Raumtemperatur im wesentlichen nicht lösbar sind, wobei die Vorrichtung aufweist:
       eine bildformende Fläche (16);
       eine den Flüssigentwickler verwendende Einrichtung (20, 22) zum Bilden eines Flüssigtonerbildes mit einem Flüssigabschnitt, der die Trägerflüssigkeit enthält, und mit einem Feststoffabschnitt, der Tonerteilchen enthält, und zwar auf der bildformenden Fläche;
       eine Einrichtung (28, 30) zum Konzentrieren des Flüssigtonerbildes durch Kompaktieren des Feststoff-Abschnitts des Flüssigtonerbildes und durch Entfernen der Trägerflüssigkeit aus demselben, um ein Flüssigbild zu formen, welches einen gegebenen nichtflüchtigen Feststoff-Prozentsatz enthält, und
       mit einer Einrichtung zum Übertragen des Flüssigtonerbildes auf ein endgültiges Substrat (42) nach Erwärmen desselben,
    dadurch gekennzeichnet, daß die Tonerteilchen mit der Trägerflüssigkeit bei einer erhöhten Temperatur im wesentlichen eine Einzelphase bilden, und daß die Vorrichtung folgendes enthält:
       eine Einrichtung zum Übertragen des Flüssigtonerbildes auf ein Zwischenübertragungsteil (40) nach der Konzentrierung desselben, und
       eine Einrichtung zum Erhitzen des Flüssigtonerbildes auf dem Zwischenübertragungsteil auf eine gegebene Temperatur, die wenigstens so hoch ist wie diejenige, bei der die Tonerteilchen und die Trägerflüssigkeit im wesentlichen eine einzelne Phase bei dem gegebenen Feststoff-Prozentsatz bilden.
  13. Vorrichtung nach Anspruch 12, bei der die Einzelphase eine Flüssigphase ist.
  14. Vorrichtung nach Anspruch 12 oder 13, bei der die Einrichtung zum Konzentrieren dafür ausgebildet ist, den Feststoff-Prozentsatz auf einen Wert zu erhöhen, bei dem eine Phasentrennung nicht auftreten kann.
  15. Vorrichtung nach irgendeinem der Ansprüche 12 bis 14, bei der der Feststoff-Prozentsatz oberhalb ca. 20% liegt.
  16. Bildherstellende Vorrichtung, bei der ein Flüssigentwickler verwendet wird, wobei die Vorrichtung enthält:
       eine bildformende Fläche (16);
       eine den Flüssigentwickler verwendende Einrichtung (20, 22) zum Bilden eine Flüssigtonerbildes mit einem Flüssigabschnitt, der die Trägerflüssigkeit enthält, und mit einem Feststoffabschnitt, der Tonerteilchen enthält, und zwar auf der bildformenden Fläche;
       eine Einrichtung (28, 30) zum Konzentrieren des Flüssigtonerbildes durch Kompaktieren des Feststoff-Abschnitts des Flüssigtonerbildes und durch Entfernen der Trägerflüssigkeit aus demselben, und
       eine Einrichtung zum Übertragen des Flüssigtonerbildes auf ein endgültiges Substrat,
    dadurch gekennzeichnet, daß
       die Einrichtung zum Konzentrieren eine Vorrichtung (30) zum Erhöhen des nichtflüchtigen Feststoff-Prozentsatzes des genannte Flüssigtonerbildes auf den Bereich zwischen ca. 20 und 35% enthält, und
       die Vorrichtung eine Einrichtung zum Übertragen des Flüssigtonerbildes auf ein Zwischenübertragungsteil (40) vor dem Übertragen auf das endgültige Substrat enthält.
  17. Vorrichtung nach irgendeinem der Ansprüche 12 bis 16, bei der die genannte Einrichtung (30) zum Konzentrieren eine Vorrichtung enthält, um das gleichzeitige Anlegen eines elektrischen Feldes zum Kompaktieren des Feststoffanteils des Bildes und zum Ausüben eines mechanischen Druckes zum Entfernen der Flüssigkeit aus dem Bild zu bewirken.
  18. Vorrichtung nach irgendeinem der Ansprüche 12 bis 17, bei der die Einrichtung zum Konzentrieren eine elektrisch angetriebene Quetsch- oder Gummiwalze (30) aufweist, welche gegen die bildformende Fläche gedrückt wird.
  19. Vorrichtung nach irgendeinem der Ansprüche 12 bis 18, bei der der genannte Feststoff-Prozentsatz unter ca. 30% liegt.
  20. Vorrichtung nach irgendeinem der Ansprüche 12 bis 19, bei der der genannte Feststoff-Prozentsatz bei ca. 25% liegt.
  21. Vorrichtung nach irgendeinem der Ansprüche 12 bis 20 mit einer optischen Strahlungseinrichtung (29), um sowohl Bild- als auch Hintergrundbereiche vor der Übertragung des Bildes auf das Zwischenübertragungsteil zu entladen.
  22. Vorrichtung nach Anspruch 21, bei der die optische Strahlungseinrichtung wenigstens eine lichtemittierende Diode aufweist.
  23. Vorrichtung nach Anspruch 21 oder Anspruch 22, bei der die optische Strahlungseinrichtung wenigstens zwei Strahlungsquellen enthält, die unterschiedliches farbiges Licht ausstrahlen.
EP90911661A 1989-08-14 1990-07-23 Verfahren und gerät zur bildherstellung Expired - Lifetime EP0486534B1 (de)

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
US393649 1989-08-14
US07/393,649 US5047808A (en) 1989-02-06 1989-08-14 Image transfer apparatus including a compliant transfer member
US400717 1989-08-30
US07/400,717 US5555185A (en) 1988-09-08 1989-08-30 Method and apparatus for imaging using an intermediate transfer member
US44687789A 1989-12-06 1989-12-06
US446877 1989-12-06
US50828790A 1990-04-13 1990-04-13
US508287 1990-04-13
PCT/NL1990/000049 WO1991003006A1 (en) 1989-08-14 1990-04-17 Image transfer apparatus and method
WOPCT/NL90/00048 1990-04-17
PCT/NL1990/000099 WO1991003007A1 (en) 1989-08-14 1990-07-23 Imaging method and apparatus
CA002075948A CA2075948C (en) 1989-01-04 1990-12-13 Imaging system with intermediate transfer member

Publications (2)

Publication Number Publication Date
EP0486534A1 EP0486534A1 (de) 1992-05-27
EP0486534B1 true EP0486534B1 (de) 1994-09-28

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WO (1) WO1991003007A1 (de)

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US5592269A (en) * 1993-03-26 1997-01-07 Indigo N.V. Imaging system having an intermediate transfer member
WO1993011472A1 (en) * 1991-11-29 1993-06-10 Spectrum Sciences B.V. Serial electrographic imaging apparatus
US5570173A (en) * 1994-10-31 1996-10-29 Xerox Corporation Color printer using liquid developer
IL112731A0 (en) * 1995-02-21 1995-05-26 Indigo Nv Imaging apparatus with temperature control
IL114992A0 (en) 1995-08-17 1995-12-08 Indigo Nv Intermediate transfer blanket and method of producing the same
JP2000508280A (ja) * 1995-09-08 2000-07-04 インディゴ ナムローゼ フェンノートシャップ 画像装置及びその改良された送出装置
US5655192A (en) * 1996-04-01 1997-08-05 Xerox Corporation Method and apparatus for compaction of a liquid ink developed image in a liquid ink type electrostatographic system
AU2975397A (en) 1997-06-03 1998-12-21 Indigo N.V. Intermediate transfer blanket and method of producing the same
US6898404B2 (en) * 2001-08-21 2005-05-24 Pfu Limited Liquid development electrophotographic device

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US4286039A (en) * 1979-05-15 1981-08-25 Savin Corporation Method and apparatus for removing excess developing liquid from photoconductive surfaces
US4794651A (en) * 1984-12-10 1988-12-27 Savin Corporation Toner for use in compositions for developing latent electrostatic images, method of making the same, and liquid composition using the improved toner
US4684238A (en) * 1986-06-09 1987-08-04 Xerox Corporation Intermediate transfer apparatus
US4708460A (en) * 1986-07-25 1987-11-24 Xerox Corporation Simultaneous transfer and fusing in electrophotography
US4796048A (en) * 1987-11-23 1989-01-03 Xerox Corporation Resilient intermediate transfer member and apparatus for liquid ink development

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WO1991003007A1 (en) 1991-03-07
JP3263069B2 (ja) 2002-03-04
CA2064848A1 (en) 1991-02-15
HK137595A (en) 1995-09-08
JPH04507303A (ja) 1992-12-17
EP0486534A1 (de) 1992-05-27
CA2064848C (en) 2001-05-29
DE69013000D1 (de) 1994-11-03
DE69013000T2 (de) 1995-05-04

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