[go: up one dir, main page]

EP0753797B1 - Methode de formation d'images à élément de transfert intermédiaire - Google Patents

Methode de formation d'images à élément de transfert intermédiaire Download PDF

Info

Publication number
EP0753797B1
EP0753797B1 EP96202488A EP96202488A EP0753797B1 EP 0753797 B1 EP0753797 B1 EP 0753797B1 EP 96202488 A EP96202488 A EP 96202488A EP 96202488 A EP96202488 A EP 96202488A EP 0753797 B1 EP0753797 B1 EP 0753797B1
Authority
EP
European Patent Office
Prior art keywords
image
intermediate transfer
transfer member
images
transfer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP96202488A
Other languages
German (de)
English (en)
Other versions
EP0753797A2 (fr
EP0753797A3 (fr
Inventor
Ishaiau Lior
Benzion Landa
Amiran Lavon
Hanna Pinhas
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 Indigo BV
Original Assignee
Indigo BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Indigo BV filed Critical Indigo BV
Priority to DE1990633709 priority Critical patent/DE69033709T2/de
Priority to EP96202488A priority patent/EP0753797B1/fr
Priority claimed from EP94200966A external-priority patent/EP0609966B1/fr
Publication of EP0753797A2 publication Critical patent/EP0753797A2/fr
Publication of EP0753797A3 publication Critical patent/EP0753797A3/fr
Application granted granted Critical
Publication of EP0753797B1 publication Critical patent/EP0753797B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/23—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 specially adapted for copying both sides of an original or for copying on both sides of a recording or image-receiving material
    • G03G15/231—Arrangements for copying on both sides of a recording or image-receiving material
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/0167—Apparatus for electrophotographic processes for producing multicoloured copies single electrographic recording member
    • G03G2215/0174—Apparatus for electrophotographic processes for producing multicoloured copies single electrographic recording member plural rotations of recording member to produce multicoloured copy

Definitions

  • the present invention relates to image transfer techniques and apparatus for use in electrophotography.
  • U. S. Patent 3,838,919 to Takahashi describes a powder toner system in which color toner images are sequentially formed on an image forming member, individually transferred to an intermediate transfer member and transferred at one time to a recording member.
  • U. S. Patent 4,144,808 to Isawa et al. describes a method of printing on a metal plate utilizing powder toner and an intermediate transfer member where the plate is heated before transfer.
  • U. S. Patent 4,518,976 to Tarumi et al. describes a monochrome powder toner system in which a powder image is developed on a photoreceptor, and transferred electrostatically to an intermediate transfer member. Downstream this transfer, the intermediate transfer member and the image thereon are heated before transfer to a preheated substrate.
  • U. S. Patent 4,515,460 to Knechtel describes a powder toner apparatus wherein separate toner images are sequentially developed on a photoreceptor and electrostatically transferred to an intermediate transfer member. After all of the individual images have been transferred to the intermediate transfer member, they are transferred electrostatically to the final substrate. No heating of the images or substrate is disclosed.
  • U. S. Patent 4,585,319 to Okamoto et al. describes a powder developer type, single color system, utilizing a temperature controlled photoreceptor, a heated intermediate transfer member and a heated transfer fixing roller which is heated to a temperature slightly higher than that of the intermediate transfer member.
  • U. S. Patent 4,690,539 to Radulski et al. describes a liquid toner multi-color system in which a color image is developed on a photoreceptor and transferred to a belt type intermediate transfer member. The liquid carrier is removed from the toner image on the belt. There is no mention of heating the intermediate transfer member or of the problem of back transfer.
  • U. S. Patent 4,708,460 to Langdon describes a single color liquid toner system in which a developed image is transferred from a photoreceptor to an intermediate transfer member, heated on the transfer member and then transferred to a final substrate.
  • U. S. Patent 3,847,478 to Young describes a duplex printing system, wherein a developed image is transferred from a photoconductor to an intermediate transfer member, a second image is developed on the photoconductor and both images are transferred electrostatically to opposite sides of a piece of paper passed between the intermediate transfer member and the photoreceptor.
  • JP 61-117582 shows a duplex printer in which two images are formed on a photoreceptor and transferred directly from the photoreceptor to first and second intermediate transfer members.
  • the images on the two transfer members are transferred to opposite sides of a sheet of paper by forming a nip between the members and passing paper through the nip.
  • the present invention seeks to provide improved apparatus for image transfer.
  • FIG. 1 illustrates electrophotographic imaging apparatus constructed and operative in accordance with an embodiment shown for illustrative purposes.
  • This and other embodiments of the invention are described in the context of liquid developer systems with negatively charged toner particles and positively charged photoreceptors. Such systems operate in a "write-white" mode, for which areas which are not to be toned are exposed to light.
  • the invention may be useful for other combinations of toner charge, photoreceptor charge as well as for other writing systems, such as "write-black" systems.
  • liquid developer system The apparatus of the invention is described using a liquid developer system.
  • the liquid developer of Example 1 of U. S. Patent 4,794,651 can be used, but other suitable developers may be used in the practice of the invention.
  • liquid developers comprising toner particles which solvate the carrier liquid of the developer at elevated temperatures, above room temperature.
  • the apparatus of Fig. 1 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 photoreceptor surface 16.
  • a corona discharge device 18 is operative to generally uniformly charge photoreceptor surface 16 with a positive charge.
  • An exposure unit including a lens 20.
  • Lens 20 focuses a desired image, which may be laser generated, onto charged photoreceptor surface 16, selectively discharging the photoreceptor surface, thus producing an electrostatic latent image thereon.
  • the development unit 22 can, for example, comprise a plurality of developers, one for each color, which are selectively engaged with the photoreceptor, as described, for example, in U.S. Patent 4,690,539, which is incorporated herein by reference, or a single development station where the liquid toner is changed between colors, or any other suitable development system.
  • this development process takes place at a relatively low temperature, namely approximately the temperature of the environment of the system.
  • photoreceptor surface 16 passes a typically positively charged rotating roller 26, preferably rotating in a direction indicated by an arrow 28.
  • Roller 26 functions as a metering roller and reduces the thickness of liquid on photoreceptor surface 16.
  • the spatial separation of roller 26 from photoreceptor surface 16 is about 50 microns.
  • roller 26 is intermediate the voltages of the latent image areas and of the background areas on the photoreceptor surface.
  • Typical voltages are: roller 26: +200V, background area: +50V and latent image areas: up to about +1000V.
  • Liquid 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 a resilient polymeric material, for example a slightly conductive resilient polymeric material as described in either or both of U.S. Patents 3,959,574 and 3,863,603 the disclosures of which are incorporated herein by reference. Roller 30 is preferably resiliently urged against photoconductive surface 16.
  • roller 30 An electrically biased squeegee roller is used as roller 30.
  • Roller 30 is negatively charged to a potential of at least several hundred and up to 2000 volts with the same sign as the charge on the pigmented toner particles, so that it repels similarly charged pigmented particles and causes them to more closely approach the image areas of the photoreceptor surface 16, thus compressing and rigidizing the image.
  • intermediate transfer member 40 Downstream of rigidizing roller 30 there is provided an intermediate transfer member 40, which rotates in a direction opposite to that of photoreceptor surface 16, as shown by arrow 41, providing zero relative motion between their respective surfaces at the point of propinquity. Intermediate transfer member 40 is operative for receiving the toner image from photoreceptor surface 16 and for transferring the toner image to a receiving substrate 42, such as paper. Disposed internally of intermediate transfer member 40 there may be provided a heater 46, to heat intermediate transfer member 40.
  • cleaning station 49 Following the transfer of the toner image to intermediate transfer member 40, photoreceptor surface 16 engages a cleaning station 49.
  • This station may be any conventional cleaning station, comprising a cleaning roller 50 which may comprise a suitable resilient material such as foam polyethylene or neoprene.
  • Cleaning roller 50 may be wetted by clean lubricating cleaning liquid, which preferably comprises liquid developer from which all or nearly all of the toner particles have been removed.
  • Cleaning roller 50 is driven so that its surface moves opposite to surface 16 at their nip, to provide scrubbing action for removal of residual particles and carrier liquid from photoreceptor surface 16.
  • a scraper 56 completes the removal of any residual toner which may not have been removed by cleaning station 49.
  • a lamp 58 completes the cycle by removing any residual charge, characteristic of the previous image, from semiconductor surface 16.
  • Transfer of the image to intermediate transfer member 40 is preferably aided by providing electrification of intermediate transfer member 40 to a voltage opposite that of the charged particles, thereby causing transfer by electrophoresis. It has been found by the inventors, that, at least for the preferred developer, raising the temperature of the developed toner image to a temperature higher than the development temperature and room temperature aids this first transfer, even when the transfer is by electrophoresis.
  • Subsequent final transfer of the image from intermediate transfer member 40 to substrate 42 is preferably aided by heat and pressure.
  • a higher temperature than that used for first transfer is preferably utilized for this subsequent final transfer.
  • the preferred first transfer step i.e., the transfer of the liquid toner image to the intermediate transfer member includes the heating of the image either before or during first transfer.
  • the preferred final transfer step i.e., the transfer of the liquid toner image to the final substrate, includes the further heating of the image before and/or during second transfer.
  • This further heating can be achieved by heating the image on intermediate transfer member 40, for example by heat transfer from intermediate transfer member 40 during the interval between first and final transfer and/or by external heating of the image.
  • the image is heated to a temperature at which it solvates liquid to form a single phase, without evaporating substantial amounts of liquid carrier.
  • the further heating can be achieved by conduction heating of the image from the final substrate during final transfer.
  • the embodiments of the invention described herein provide improved first and final transfer and for multicolor systems can solve the back transfer problem.
  • photoreceptor 16 is at a first, relatively low temperature
  • intermediate transfer member 40 is at a second, somewhat higher temperature, to provide for improved first transfer
  • final substrate 42 is at a third, even higher temperature to provide for good transfer from intermediate transfer member 40 to substrate 42.
  • some of the embodiments can be characterized in that, when a toner image is transferred from photoreceptor surface 16 to intermediate transfer member 40, and then to final substrate 42, the toner image is hotter during transfer to the intermediate transfer member than it was on the photoreceptor surface and the image is hotter when it is transferred to the final substrate, than during the earlier transfer.
  • some of the embodiments can be characterized in that, when multiple toner images are transferred sequentially from photoreceptor surface 16 to intermediate transfer member 40, and then to final substrate 42 as a group, the composite, multicolor toner image is hotter when it is transferred to the final substrate than during any contact of earlier transferred images with the photoreceptor.
  • One embodiment of the invention can be characterized in that the image is transferred from a photoreceptor surface, at a first relatively low temperature to a first intermediate transfer member at a second intermediate temperature. The image is then transferred to a second intermediate transfer member. Final transfer takes place from the second intermediate transfer member to the final substrate at a third, higher temperature.
  • the image temperature during first transfer is higher than that of that portion of the photoreceptor surface not in contact with the intermediate transfer member.
  • intermediate transfer member 40 is heated to a temperature sufficient to enhance the electrophoretic transfer of toner particles from photoreceptor surface 16 to intermediate transfer member 40.
  • the image is heated during transfer to intermediate transfer member 40, and the heating continues while the image is on intermediate transfer member 40 until the image is at the temperature of intermediate transfer member 40.
  • Rotation of intermediate transfer member 40 brings the heated intermediate transfer member 40 into image transfer relationship with a final substrate 42, which is pressed against the intermediate transfer member by a heated backing roller 43. Heated backing roller 43 heats the paper and thereby heats the image in contact therewith by conduction from the paper, to a sufficient degree to ensure that complete or nearly complete final transfer of the image to the substrate, by heat and pressure, takes place.
  • the invention is generally described herein, in a monochromatic version, where it gives improved transfer from the photoreceptor to the intermediate transfer member and from the intermediate transfer member to the final substrate, the invention is particularly useful in a multicolor system, wherein images of different colors are sequentially formed on photoreceptor surface 16, and transferred one by one in mutual alignment to image transfer member 40 prior to a single transfer of all of the images, which form a multicolor image, to final substrate 42.
  • Final substrate 42 is brought into transfer engagement with intermediate transfer member 40 only when all of the colors have been transferred to intermediate transfer member 40, for final transfer of the multicolor image to substrate 42.
  • the intermediate transfer member is heated to a temperature which is useful for good final transfer, then there is a tendency for the image to back transfer to the photoreceptor.
  • Fig. 2 shows a second embodiment in which all of the parts and operation are generally the same as those of the apparatus of Fig. 1, except that heated backing roller 43 is replaced by an unheated backing roller 44, and final substrate 42 is preheated by a heating lamp 45.
  • a combination of the embodiments of Figs. 1 and 2 is also useful, whereby paper 42 is pre-heated by lamp 45, and heated roller 43 is used.
  • FIG. 3 A third embodiment is shown in Fig. 3.
  • intermediate transfer member 40 is heated to a first, moderate, temperature which is high enough to enhance first transfer, but not so high as to cause substantial back transfer of previously transferred images from intermediate transfer member 40 to photoreceptor surface 16.
  • the images are transferred to a second intermediate transfer member 47 which is heated by an internal heater 48 to a higher temperature, sufficient to assure good final transfer to final substrate 42.
  • intermediate transfer member 40 is maintained at a first voltage (different from the voltage of the photoreceptor surface 16) to enhance transfer of the image thereto from photoreceptor surface 16, and second intermediate transfer member 47 is electrified to a second voltage, different from the first voltage, to enhance transfer of the image thereto from intermediate transfer member 40.
  • first voltage different from the voltage of the photoreceptor surface 16
  • second intermediate transfer member 47 is electrified to a second voltage, different from the first voltage, to enhance transfer of the image thereto from intermediate transfer member 40.
  • Transfer to second intermediate transfer member 41 can occur sequentially for each of the images, or preferably the images are collected on first intermediate transfer member 40 and then the multicolor image is transferred as a whole to second intermediate transfer member 47 for final transfer to the final substrate 42.
  • a duplex embodiment of the invention, for printing two sides of a substrate at the same time is shown in Fig. 4.
  • the separate color images which make up the multi-colored image to be printed on a first side of substrate 42 are first transferred sequentially to intermediate transfer member 40 and then are transferred, preferably as a group, to second intermediate transfer member 47.
  • Second image transfer member 47 is preferably heated to a higher temperature than intermediate transfer member 40.
  • the images to be printed on the other side of the page are subsequently transferred sequentially to intermediate transfer member 40, which is meanwhile kept out of transfer engagement with second intermediate transfer member 47.
  • Final substrate 42 is then passed between intermediate transfer member 40 and second intermediate transfer member 47, while pressing the two intermediate transfer members together to effect transfer of the images to both sides of the paper by heat and pressure.
  • second intermediate transfer member 47 heats substrate 42 and the image to a suitable temperature to assure good transfer of the image on intermediate transfer member 40 to substrate 42.
  • the paper may be heated before transfer as described above in connection with Fig. 2.
  • intermediate transfer member 40 acts to heat the image to a first temperature during first transfer from photoreceptor 16 to intermediate transfer member 40, and to heat the image to a second higher temperature before second and final transfer from intermediate transfer member 40 to final substrate 42.
  • Exemplary embodiments include the apparatus shown in Fig. 5.
  • This apparatus is generally the same as the apparatus of Fig. 1, except that a cooling station 60 is operatively associated with intermediate transfer member 40 just before it returns to make contact with photoreceptor surface 16.
  • Intermediate transfer member 40 is cooled at cooling station 60 to locally reduce the temperature of intermediate transfer member 40 before and during contact with the image on the photoreceptor. This local cooling allows the liquid toner image to be hotter at the point of final transfer from intermediate transfer member 40 to final substrate 42 than it is at first transfer from photoreceptor surface 16 to intermediate transfer member 40.
  • Cooling station 60 may comprise, for example, apparatus for providing a stream of cool air to the surface of the photoreceptor or a cooled roller in contact with the photoreceptor surface. Either or both cooling systems cool intermediate transfer member 40 to a temperature, higher than room temperature, but lower than the final transfer temperature.
  • a roller cooler In a multicolor system, if a roller cooler is used it is coated with a non-stick coating to avoid transfer of the image from intermediate transfer member 40 to the roller of cooling station 60.
  • FIG. 6 Another exemplary embodiment of this type is illustrated in Fig. 6, which is essentially the same as Fig. 8 of WO 90/04216 previously referenced.
  • an intermediate transfer member 140 is of low heat capacity, and is heated only after first transfer is completed.
  • Fig. 7 which is the same as Fig. 9 of the above referenced application, the temperature at the first transfer is above room temperature in order to improve first transfer, and the temperature at second transfer is even higher to assure complete or nearly complete second transfer.
  • the temperatures and heat capacities are selected so that the first transfer takes place at a temperature low enough to avoid back transfer.
  • intermediate transfer members 40 and 47 have been described as having heaters placed internal to the core to heat each of them to its required temperature. Other methods of heating intermediate transfer members known in the art can also be used in the practice of the invention.
  • Colored liquid developer is prepared in the following manner:
  • a mixture of 2.5 parts by weight of Mogul L carbon black (Cabot) and 5 parts by weight of Isopar L are 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 preheated to 110 degrees C are added to the mixer and mixing is continued at high speed for one hour.
  • the heating unit is then disconnected and mixing is continued until the temperature of the mixture drops to 40 degrees C.
  • the resulting mixture is transferred to an S-1 attritor device equipped with 3/16 inch carbon steel media, diluted with Isopar L to a 16% solids ratio and ground without cooling until the temperature rises to about 60 degrees C. Cooling, which reduces the temperature to about 30 degrees is then commenced and grinding is continued for a total of 24 hours.
  • the mixture is removed from the device and diluted with Isopar L to 1.5% by weight solids concentration.
  • the particles in the resultant toner concentrate have an average diameter of 2.5 microns.
  • Charge director as known in the art, is added to give the final liquid developer.
  • Pre-heated Isopar L is then added to reduce the solids concentration to preferably 35% and mixing is continued at high speed for one hour. The heating unit is then disconnected and mixing is continued until the temperature of the mixture drops to 40 degrees C.
  • the mixture is then transferred to an S-1 attritor device equipped with 3/16 inch carbon steel media and pigment is added to the material in the attritor.
  • the mixture is diluted with Isopar L to about a 12-16% solids ratio, depending on the viscosity of the material and is ground without cooling until the temperature rises to about 60 degrees C. Cooling, which reduces the temperature to about 30 degrees, is then commenced and grinding is continued for a total of 24 hours.
  • the mixture is removed from the device and diluted with Isopar L to 1.5% by weight solids concentration.
  • the particles in the resultant toner concentrate had an average diameter of 2.5 microns.
  • Charge director as known in the art, is added to give the final liquid developer.
  • the charge director of Example 1 the above referenced PCT publication WO 90/14617 is added to give the final liquid developer.
  • Appropriate colored pigments known in the art of liquid developer manufacture for example the list given in U. S. Patent 4,794,561 can be used.
  • Other suitable pigments are Sico Fast Yellow D1350 (BASF), Lithol Rubin D4576 (BASF), Lyonol Blue FG7351 (TOYO) and Lyonol Yellow 7G1310 (TOYO). in amounts and combinations depending on the color and intensity required.
  • Aluminum Stearate can be added in small amounts.
  • other grinding media such as zirconia may be used.
  • These developers are used to form the individual color liquid toner images on photoreceptor surface 16 which comprise a relatively high concentration of toner particles in carrier liquid.
  • Photoreceptor surface 16 is preferably formed of selenium.
  • Intermediate transfer member 40 is preferably formed of a cylindrical aluminum core coated with a 1 mm thick layer of very soft polyurethane having a hardness of 20-25 Shore A. This layer is covered by an offset printing blanket, preferably a KYNIO AIRTACK offset blanket, which is much harder than the polyurethane.
  • a thin conducting layer of conducting acrylic covers this layer and is covered in turn by a 0.1 mm layer of polyurethane of shore A Hardness 20. This layer is overcoated by a thin layer of Syl-Off type 291 or 294 silicone release coating.
  • Liquid developer prepared in accordance with the method described above is used in the equipment of Fig. 1.
  • the temperature of the intermediate transfer layer should be less than about 50 degrees C.
  • Heating intermediate transfer member 40 improves image transfer to intermediate transfer member 40.
  • Intermediate transfer member 40 is preferably heated to a temperature somewhat below that at which back transfer begins to occur.
  • the improvement in first transfer when the intermediate transfer member is heated may be a consequence of partial solvation of carrier liquid by the pigmented toner particles in the image.
  • the pigmented toner particles contained therein solvate the carrier liquid at elevated temperatures. It is believed that there is a partial solvation of the carrier liquid in the toner particles during first transfer to heated intermediate transfer member 40 which may cause the particles to partially coalesce and form a film during first transfer. Coalesced toner is believed to transfer better than uncoalesced toner particles.
  • the toner material solvates some of the carrier liquid, the toner particles separate from the unsolvated carrier liquid. It is believed that this separated carrier liquid forms a film between the toner image and the photoreceptor which reduces the adhesion of the image to the photoreceptor, aiding complete transfer of the image to the intermediate transfer member.
  • the heating of the image before and/or during final transfer insures the complete or nearly complete transfer of the image from the intermediate transfer member to the final substrate.
  • this image heating comes solely by conduction from the paper, it has been found experimentally that the paper should be at a temperature of at least about 70 degrees C. Higher temperatures such as 80 or 90 degrees can also be used, but substantially lower temperatures do not tackify the image enough to assure complete transfer from intermediate transfer member 40 to paper 42.
  • the precise temperatures used for particular configurations and combinations are a function of the material properties of the toner particles and the carrier liquid as well as of the quality of the release layer on the intermediate transfer member.
  • Back transfer occurs due to the tackiness of the image, but is also influenced by the relative adhesion of the image to the release layer on the intermediate transfer member and to the photoreceptor. It would be possible to increase the temperature of the intermediate transfer member if the release properties of the surface of the intermediate transfer member were poorer. This however would also result in poorer transfer to the final substrate.
  • the following temperatures are used.
  • the intermediate transfer member is heated to a surface temperature of 100 degrees C and the paper is not heated. Calculations show that the image is at a temperature of 52 to 63 degrees C during first transfer. During the interval between first and second transfer the image temperature rises to the intermediate transfer member's temperature of 100 degrees C, and the image is cooled during second, final transfer to paper to a temperature of 73 to 78 degrees C.
  • the intermediate transfer member is heated to 50 degrees C and backing roller 43 is heated to 120 degrees C.
  • the image temperature on first transfer is approximately 43 degrees C and on second transfer it is 75 to 78 degrees C.
  • the temperatures shown in figure 7 are also representative of values suitable for single image transfer.
  • the first transfer temperature must be low enough to assure that no back transfer takes place.

Landscapes

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

Claims (14)

  1. Procédé d'impression d'images sur les deux côtés d'un substrat, comprenant :
    (a) la formation d'une première image sur une première surface ;
    (b) le transfert de la première image de la première surface vers une troisième surface ;
    (c) le transfert de la première image de la troisième surface vers la seconde surface ;
    (d) la formation d'une seconde image sur la première surface ;
    (e) le transfert de la seconde image de la première surface vers la troisième surface ; et
    (f) le transfert simultané des première et seconde images des seconde et troisième surfaces vers les deux côtés du substrat.
  2. Procédé selon la revendication 1, dans lequel au moins l'une des première et seconde images comprend une image multicolore formée d'une pluralité d'images monochromes.
  3. Procédé selon la revendication 2, dans lequel la pluralité d'images monochromes sont formées séparément sur la première surface et transférées successivement vers la troisième surface.
  4. Procédé selon la revendication 3, dans lequel la première image est une image multicolore formée d'une pluralité d'images monochromes qui sont transférées ultérieurement de la troisième surface vers la seconde surface.
  5. Procédé selon la revendication 4, dans lequel la pluralité d'images monochromes qui composent la première image sont transférées ensemble de la troisième surface vers la seconde surface.
  6. Procédé selon la revendication 4, dans lequel la pluralité d'images monochromes qui composent la première image sont transférées successivement de la troisième surface vers la seconde surface.
  7. Procédé selon l'une quelconque des précédentes revendications, dans lequel la température de la seconde surface est supérieure à celle de la troisième surface.
  8. Procédé selon l'une quelconque des précédentes revendications, dans lequel les seconde et troisième surfaces sont électrisées à des tensions différentes, ce qui améliore le transfert de la première image entre elles.
  9. Procédé selon l'une quelconque des précédentes revendications, dans lequel les première et seconde images sont transférées sur le substrat par chaleur et pression.
  10. Procédé selon l'une quelconque des précédentes revendications, dans lequel les première et seconde images sont des images à l'encre.
  11. Procédé selon la revendication 10, dans lequel les images à l'encre sont des images à l'encre liquide.
  12. Procédé selon l'une quelconque des précédentes revendications, dans lequel les première et seconde images sont formées électrostatiquement sur la première surface
  13. Procédé selon la revendication 12, dans lequel les première et seconde images sont transférées électrostatiquement depuis la première surface.
  14. Procédé selon l'une quelconque des précédentes revendications, dans lequel le transfert simultané des première et seconde images sur le substrat comprend :
    la formation d'un point de contact entre les seconde et troisième surfaces ; et
    le passage du substrat à travers le point de contact.
EP96202488A 1990-12-13 1990-12-13 Methode de formation d'images à élément de transfert intermédiaire Expired - Lifetime EP0753797B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE1990633709 DE69033709T2 (de) 1990-12-13 1990-12-13 Bilderzeugungsmethode mit Zwischenübertragungselement
EP96202488A EP0753797B1 (fr) 1990-12-13 1990-12-13 Methode de formation d'images à élément de transfert intermédiaire

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP94200966A EP0609966B1 (fr) 1989-01-04 1990-12-13 Système de formation d'images avec un élément de transfert intermédiaire
EP91901324A EP0515378A1 (fr) 1989-01-04 1990-12-13 Systeme d'imagerie a element intermediaire de transfert
EP96202488A EP0753797B1 (fr) 1990-12-13 1990-12-13 Methode de formation d'images à élément de transfert intermédiaire

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
EP94200966.3 Division 1990-12-13
EP94200966A Division EP0609966B1 (fr) 1989-01-04 1990-12-13 Système de formation d'images avec un élément de transfert intermédiaire

Publications (3)

Publication Number Publication Date
EP0753797A2 EP0753797A2 (fr) 1997-01-15
EP0753797A3 EP0753797A3 (fr) 1997-05-07
EP0753797B1 true EP0753797B1 (fr) 2001-02-28

Family

ID=26130407

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96202488A Expired - Lifetime EP0753797B1 (fr) 1990-12-13 1990-12-13 Methode de formation d'images à élément de transfert intermédiaire

Country Status (1)

Country Link
EP (1) EP0753797B1 (fr)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2557317B1 (fr) * 1983-12-22 1986-04-18 Rhone Poulenc Syst Procede de reproduction electrophotographique, avec developpement inverse, sur un support conducteur a l'aide d'une poudre de developpement magnetique monocomposant et dispositif pour la mise en oeuvre du procede
JPH0229217B2 (ja) * 1984-11-13 1990-06-28 Konishiroku Photo Ind Zokirokuhoho
US4688925A (en) * 1985-12-06 1987-08-25 Eastman Kodak Company Electrographic reproduction apparatus capable of producing duplex copies
US4690539A (en) * 1986-05-27 1987-09-01 Xerox Corporation Transfer apparatus
GB8823256D0 (en) * 1988-10-04 1988-11-09 Spectrum Sciences Bv Imaging apparatus

Also Published As

Publication number Publication date
EP0753797A2 (fr) 1997-01-15
EP0753797A3 (fr) 1997-05-07

Similar Documents

Publication Publication Date Title
EP0577597B1 (fr) Systeme d'imagerie muni d'elements de transfert intermediaires
US5276492A (en) Imaging method and apparatus
EP0609966B1 (fr) Système de formation d'images avec un élément de transfert intermédiaire
EP0725322B1 (fr) Procédé pour le développement à sec avec toner liquide
US5017967A (en) Method and apparatus for forming images including a toner transporting member having an insulating layer
US5347353A (en) Tandem high productivity color architecture using a photoconductive intermediate belt
US6496676B1 (en) Liquid developer system employing a pretransfer station
US5572274A (en) Liquid developer imaging system and method utilizing an intermediate transfer member
US5570173A (en) Color printer using liquid developer
JPH09179417A (ja) 転写定着部材
US5815783A (en) Method and apparatus for printing on both sides of a substrate
US6487389B2 (en) Refreshing a sticky cleaner for a fuser
WO1992017825A1 (fr) Systeme d'imagerie muni d'elements de transfert intermediaires
JP3263069B2 (ja) 結像方法および装置
US8023846B2 (en) Segmented roller for flood coating system
EP0753797B1 (fr) Methode de formation d'images à élément de transfert intermédiaire
US20060039715A1 (en) Electrostatographic apparatus with cleaning device for controlling release oil transfer
DE69030271T2 (de) Bilderzeugungssystem mit Zwischenübertragungselement
DE69033709T2 (de) Bilderzeugungsmethode mit Zwischenübertragungselement
US5576817A (en) Dual zone development for liquid developers
JP5030636B2 (ja) 湿式画像形成装置
JPH07210019A (ja) 定着方法
JPH03164762A (ja) 湿式現像のカラー画像形成方法
JPH03185471A (ja) 湿式現像のカラー画像形成方法
JP2004012559A (ja) 液体現像電子写真のための溶融転写方法及び装置

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

AC Divisional application: reference to earlier application

Ref document number: 609966

Country of ref document: EP

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT

RIN1 Information on inventor provided before grant (corrected)

Inventor name: PINHAS,HANNA

Inventor name: LAVON,AMIRAN

Inventor name: LANDA,BENZION

Inventor name: LIOR,ISHAIAU

RIN1 Information on inventor provided before grant (corrected)

Inventor name: PINHAS,HANNA

Inventor name: LAVON,AMIRAN

Inventor name: LANDA,BENZION

Inventor name: LIOR,ISHAIAU

RIN1 Information on inventor provided before grant (corrected)

Inventor name: PINHAS,HANNA

Inventor name: LAVON,AMIRAN

Inventor name: LANDA,BENZION

Inventor name: LIOR,ISHAIAU

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19970825

17Q First examination report despatched

Effective date: 19990311

RTI1 Title (correction)

Free format text: IMAGING METHOD WITH INTERMEDIATE TRANSFER MEMBER

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

RIC1 Information provided on ipc code assigned before grant

Free format text: 7G 03G 15/00 A, 7G 03G 15/23 B, 7G 03G 13/23 B

RTI1 Title (correction)

Free format text: IMAGING METHOD WITH INTERMEDIATE TRANSFER MEMBER

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AC Divisional application: reference to earlier application

Ref document number: 609966

Country of ref document: EP

Ref document number: 515378

Country of ref document: EP

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

ITF It: translation for a ep patent filed
ET Fr: translation filed
REF Corresponds to:

Ref document number: 69033709

Country of ref document: DE

Date of ref document: 20010405

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20070125

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20070228

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20071229

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20071217

Year of fee payment: 18

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20071213

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20071213

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20090831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081213