EP0486534B1 - Procede et appareil de formation d'images - Google Patents

Procede et appareil de formation d'images 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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German (de)
English (en)
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EP0486534A1 (fr
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/fr
Application filed by Indigo BV filed Critical Indigo BV
Priority claimed from CA002075948A external-priority patent/CA2075948C/fr
Publication of EP0486534A1 publication Critical patent/EP0486534A1/fr
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Publication of EP0486534B1 publication Critical patent/EP0486534B1/fr
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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 or 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 or 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.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)

Abstract

Procédé et appareil servant à transférer des images en toner liquide d'une surface (10) de formation d'image à un élément (40) de transfert intermédiaire afin de les transférer ultérieurement à un substrat final (42). Les images en toner liquide comprennent un liquide porteur et des particules de toner polymères et pigmentées qui sont essentiellement insolubles dans le liquide porteur à température ambiante et qui forment une seule phase à des températures élevées. Le procédé consiste: à concentrer l'image en toner liquide en rendant compacte la portion solide de l'image en toner liquide, et en enlevant le liquide porteur; à transférer l'image en toner liquide à l'élément (40) de transfert intermédiaire, et à chauffer l'image en toner liquide sur l'élément (40) de transfert intermédiaire jusqu'à une température à laquelle les particules de toner et le liquide porteur forment une seule phase; et à transférer l'image en toner liquide chauffé à un substrat final (42).

Claims (23)

  1. Procédé pour transférer une image de toner liquide qui comprend une partie liquide contenant un porteur liquide et une partie solide contenant des particules de toner polymère pigmenté, essentiellement insolubles dans le porteur liquide à température ambiante, ledit procédé de transfert servant à transférer une image de toner liquide d'une surface de formation d'image à un support final et comprenant les étapes consistant à:
    - concentrer l'image de toner liquide jusqu'à obtenir un pourcentage donné de solides non volatils grâce à une compression de sa partie solide et une élimination du porteur liquide, et
    - transférer l'image de toner liquide sur le support final, caractérisé en ce que:
    - l'image de toner liquide est transférée sur un élément de transfert intermédiaire avant le transfert de l'image de toner liquide sur le substrat final, et
    - l'image de toner liquide est chauffée sur l'élément de transfert intermédiaire jusqu'à une température donnée au moins aussi élevée que la température élevée à laquelle les particules de toner et le porteur liquide forment sensiblement une phase unique au pourcentage donné de solides.
  2. Procédé selon la revendication 1, dans lequel ladite phase unique est une phase liquide.
  3. Procédé selon la revendication 1, dans lequel ladite étape de concentration sert à augmenter ledit pourcentage de solides jusqu'à une valeur pour laquelle il ne peut pas se produire de séparation de phases.
  4. Procédé selon la revendication 1, dans lequel ledit pourcentage de solides est supérieur à environ 20 %.
  5. Procédé pour transférer une image de toner liquide comprenant une partie solide et une partie liquide d'une surface de formation d'image à un support final, qui comprend les étapes consistant à:
    - concentrer l'image de toner liquide grâce à une compression de sa partie solide et une élimination du porteur liquide, et
    - transférer l'image de toner liquide sur le support final, caractérisé en ce qu'il comprend l'étape consistant à:
    - transférer l'image de toner liquide sur un élément de transfert intermédiaire après l'étape de concentration et avant l'étape de transfert,
    et dans lequel l'étape de concentration concentre l'image de telle sorte que l'image ait un pourcentage de solides non volatils compris entre 20 et 35 %.
  6. Procédé selon l'une quelconque des précédentes revendications dans lequel ladite étape de concentration comprend l'application simultanée d'un champ électrique pour comprimer la partie solide de l'image et d'une pression mécanique pour éliminer le liquide de l'image.
  7. Procédé selon l'une quelconque des précédentes revendications dans lequel ledit pourcentage de solides est inférieur à environ 30 %.
  8. Procédé selon l'une quelconque des précédentes revendications dans lequel ledit pourcentage de solides est d'environ 25 %.
  9. Procédé selon l'une quelconque des précédentes revendications dans lequel ladite étape de concentration précède ladite étape de transfert de l'image liquide sur l'élément de transfert intermédiaire.
  10. Procédé selon l'une quelconque des précédentes revendications, comprenant également l'étape d'irradiation de l'image avec un rayonnement optique.
  11. Procédé selon la revendication 10, dans lequel ledit rayonnement optique contient un rayonnement provenant d'au moins deux sources de rayonnement qui émettent des lumières de couleur différente.
  12. Appareil de formation d'image utilisant un développeur liquide contenant un porteur liquide et des particules de toner polymère pigmenté qui sont essentiellement insolubles dans le porteur liquide à température ambiante, l'appareil comprenant:
    - une surface de formation d'image (16),
    - des moyens (20, 22) qui utilisent ledit développeur liquide pour former une image de toner liquide, comprenant une partie liquide contenant un porteur liquide et une partie solide contenant des particules de toner, sur ladite surface de formation d'image,
    - des moyens (28, 30) pour concentrer l'image de toner liquide par compression de la partie solide de l'image de toner liquide et élimination du porteur liquide pour former une image liquide ayant un pourcentage donné de solides non volatils, et
    - un moyen pour transférer l'image de toner liquide, après chauffage de celle-ci, sur un support final (42),
    caractérisé en ce que lesdites particules de toner forment sensiblement une phase unique avec le porteur liquide à une température élevée, et en ce qu'il comprend:
    - un moyen pour transférer l'image de toner liquide sur un élément de transfert intermédiaire (40) après la concentration de celle-ci, et
    - un moyen pour chauffer l'image de toner liquide sur l'élément de transfert intermédiaire jusqu'à une température donnée au moins aussi élevée que celle à laquelle les particules de toner et le porteur liquide forment sensiblement une phase unique au pourcentage de solides donné.
  13. Appareil selon la revendication 12, dans lequel ladite phase unique est une phase liquide.
  14. Appareil selon la revendication 12 ou 13, dans lequel ledit moyen de concentration sert à augmenter ledit pourcentage de solides jusqu'à une valeur pour laquelle il ne peut pas se produire de séparation de phases.
  15. Appareil selon l'une quelconque des revendications 12 à 14, dans lequel ledit pourcentage de solides est supérieur à environ 20 %.
  16. Appareil de formation d'image utilisant un développeur liquide, ledit appareil comprenant:
    - une surface de formation d'image (16),
    - des moyens (20, 22) qui utilisent ledit développeur liquide pour former une image de toner liquide, comprenant une partie liquide contenant un porteur liquide et une partie solide contenant des particules de toner, sur ladite surface de formation d'image,
    - des moyens (28, 30) pour concentrer l'image de toner liquide par compression de la partie liquide de celle-ci et élimination du porteur liquide, et
    - un moyen pour transférer l'image de toner liquide sur un support final (42),
    caractérisé en ce que :
    - le moyen de concentration comprend un moyen (30) pour augmenter le pourcentage de solides non volatils de ladite image de toner liquide jusqu'à entre 20 % et 35 %,
    - et en ce que ledit appareil comprend également un moyen pour transférer l'image de toner liquide sur un élément de transfert intermédiaire (40) avant son transfert sur le support final.
  17. Appareil selon l'une quelconque des revendications 12 à 16, dans lequel ledit moyen de concentration (30) comprend un moyen pour effectuer l'application simultanée d'un champ électrique afin de comprimer la partie solide de l'image et d'une pression mécanique afin d'éliminer le liquide de l'image.
  18. Appareil selon l'une quelconque des revendications 12 à 17, dans lequel ledit moyen de concentration comprend un rouleau en caoutchouc (30), électrifié, poussé contre ladite surface de formation d'image.
  19. Appareil selon l'une quelconque des revendications 12 à 18, dans lequel ledit pourcentage de solides est inférieur à environ 30 %.
  20. Appareil selon l'une quelconque des revendications 12 à 19, dans lequel ledit pourcentage de solides est d'environ 25 %.
  21. Appareil selon l'une quelconque des revendications 12 à 20, comprenant également un moyen (29) de rayonnement optique destiné à décharger à la fois l'image et les régions d'arrière-plan avant le transfert de l'image sur ledit élément de transfert intermédiaire.
  22. Appareil selon la revendication 21, dans lequel ledit moyen de rayonnement optique comprend au moins une diode émettrice de lumière.
  23. Appareil selon la revendication 21 ou la revendication 22, dans lequel ledit moyen de rayonnement optique comprend au moins deux sources de rayonnement qui émettent des lumières de couleur différente.
EP90911661A 1989-08-14 1990-07-23 Procede et appareil de formation d'images Expired - Lifetime EP0486534B1 (fr)

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
US393649 1982-06-30
US07/393,649 US5047808A (en) 1989-02-06 1989-08-14 Image transfer apparatus including a compliant transfer member
US07/400,717 US5555185A (en) 1988-09-08 1989-08-30 Method and apparatus for imaging using an intermediate transfer member
US400717 1989-08-30
US44687789A 1989-12-06 1989-12-06
US446877 1989-12-06
US50828790A 1990-04-13 1990-04-13
US508287 1990-04-13
WOPCT/NL90/00048 1990-04-17
PCT/NL1990/000049 WO1991003006A1 (fr) 1989-08-14 1990-04-17 Appareil et procede pour transfert d'images
PCT/NL1990/000099 WO1991003007A1 (fr) 1989-08-14 1990-07-23 Procede et appareil de formation d'images
CA002075948A CA2075948C (fr) 1989-01-04 1990-12-13 Systeme d'imagerie a element de transfert intermediaire

Publications (2)

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

Family

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Application Number Title Priority Date Filing Date
EP90911661A Expired - Lifetime EP0486534B1 (fr) 1989-08-14 1990-07-23 Procede et appareil de formation d'images

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EP (1) EP0486534B1 (fr)
JP (1) JP3263069B2 (fr)
CA (1) CA2064848C (fr)
DE (1) DE69013000T2 (fr)
HK (1) HK137595A (fr)
WO (1) WO1991003007A1 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5592269A (en) * 1993-03-26 1997-01-07 Indigo N.V. Imaging system having an intermediate transfer member
WO1993011472A1 (fr) * 1991-11-29 1993-06-10 Spectrum Sciences B.V. Appareil d'imagerie electrographique serielle
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
US6551716B1 (en) 1997-06-03 2003-04-22 Indigo N.V. Intermediate transfer blanket and method of producing the same
EP1420306A4 (fr) * 2001-08-21 2009-11-25 Pfu Ltd Dispositif electrophotographique a revelateur liquide

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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

Also Published As

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

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