EP0819269B1 - Doppelseitige bilderzeugung - Google Patents

Doppelseitige bilderzeugung Download PDF

Info

Publication number
EP0819269B1
EP0819269B1 EP95920301A EP95920301A EP0819269B1 EP 0819269 B1 EP0819269 B1 EP 0819269B1 EP 95920301 A EP95920301 A EP 95920301A EP 95920301 A EP95920301 A EP 95920301A EP 0819269 B1 EP0819269 B1 EP 0819269B1
Authority
EP
European Patent Office
Prior art keywords
substrate
image
imaging
images
transfer region
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
EP95920301A
Other languages
English (en)
French (fr)
Other versions
EP0819269A1 (de
Inventor
Benzion Landa
Ishaiau Lior
Yossi c/o Indigo N.V. ROSEN
Boaz Tagansky
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
Hewlett Packard 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 Hewlett Packard Indigo BV filed Critical Hewlett Packard Indigo BV
Publication of EP0819269A1 publication Critical patent/EP0819269A1/de
Application granted granted Critical
Publication of EP0819269B1 publication Critical patent/EP0819269B1/de
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
    • G03G15/232—Arrangements for copying on both sides of a recording or image-receiving material using a single reusable electrographic recording member
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—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
    • G03G15/101—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/0088—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge removing liquid developer
    • 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
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00443—Copy medium
    • G03G2215/00451—Paper
    • G03G2215/00455—Continuous web, i.e. roll

Definitions

  • the substrate is provided in sheets having predetermined dimensions adapted for a given page layout, it is possible to image both sides of each sheet by, first, feeding the sheet with a first surface interfacing the imaging device and, then, refeeding the sheet with the second, opposite, surface facing the imaging device. This method is not available for web-fed imaging.
  • WO 94/27193 describes an electrographic printing device designed to print on recording media shaped as tapes of various widths.
  • WO 94/27193 discloses an image forming apparatus for double-sided imaging on a continuous-web substrate, having first and second surfaces on opposite sides of the substrate, comprising: an imaging device comprising an image bearing surface moving in a given direction and having selectively formed thereon first and second images.”
  • a first surface of a continuous substrate is fed to the imaging device by a controlled feeding mechanism and at least one image is formed on the first surface of the substrate. Then, by guiding the continuous substrate through an inverter mechanism, a second, opposite, surface of the substrate is controllably fed to the imaging device and at least one image is formed on the second surface of the substrate.
  • the controlled feedings of the first and second surfaces of the substrate are preferably synchronized so as to control the relative locations of the images formed on the first and second surfaces.
  • the web-feeder system includes a substrate advance mechanism operative for advancing the continuous substrate through the first and second impression regions.
  • the web-feeder system further includes a controller which controls the advance of the continuous substrate through the first and second impression regions, in accordance with the predetermined imaging sequence, by controlling the operation of the substrate advance mechanism.
  • the controller preferably also controls the engagement and disengagement of the first and second substrate surfaces with the toner-image bearing surface, in accordance with the predetermined imaging sequence, by controlling the position of the first and second impression members relative to the toner-image bearing surface.
  • the advancing mechanism rewinds a preselected length of the continuous substrate through the first impression region following each first surface imaging cycle.
  • the continuous substrate is accelerated to a surface velocity comparable with that of the toner-image bearing surface before each first surface imaging cycle.
  • a method for double-sided imaging on a continuous-web substrate, having first and second substrate surfaces, using an electrostatic imaging device including an image transfer member having an toner-image bearing surface the method including:
  • the method includes detecting the post image marks on the first substrate surface ahead of the first impression region.
  • the method also includes triggering the transferring of each first toner image in response to the post-image mark of the preceding first toner image.
  • the method includes detecting the post image marks on the first substrate surface between the first and second impression regions.
  • the method also includes triggering the transferring of each second toner image in response to the post-image mark of the preceding first toner image.
  • the imaging method further includes cutting the continuous substrate at the spaces between the first images on the first substrate surface.
  • the method further includes detecting the post image marks on the first substrate surface downstream of the second impression region.
  • cutting the continuous substrate includes cutting the continuous substrate in response to detection of post-image marks.
  • the imaging method further includes monitoring the position of the continuous substrate relative to the first impression region.
  • detecting the post-image marks on the continuous substrate ahead of the first impression region includes detecting the post-image marks only within preset, first, detection time windows.
  • the imaging method includes setting the time gaps between the first detection time windows in accordance with the monitored position of the continuous substrate relative to the first impression region.
  • portions of the spring comprises a low friction material contacting the squeegee roller at said second portion.
  • the wire comprises a low friction material, preferably, teflon.
  • a cleaning device for removing residual toner from a toner-bearing surface comprising:
  • the first roller is biased to a voltage which attracts residual toner particles on said toner-bearing surface to said conductive surface.
  • FIG. 1 illustrates imaging apparatus constructed and operative in accordance with a preferred embodiment of the present invention.
  • the apparatus of Fig. 1 comprises a drum 10 arranged for rotation in a direction generally indicated by arrow 14.
  • Drum 10 preferably has a cylindrical photoconductive surface 16, made of selenium, a selenium compound, an organic photoconductor or any other suitable photoconductor known in the art.
  • Photoconductive surface may be in the form of a photoreceptor sheet and may use any suitable arrangement of layers of materials as is known in the art. However, in the preferred embodiment of the invention, certain of the layers of photoreceptor sheet 16 are removed from the ends of the sheet to facilitate its mounting on drum 10.
  • photoreceptor sheet and preferred methods of mounting it on drum 10 are described in a copending application of Belinkov et al., IMAGING APPARATUS AND PHOTORECEPTOR THEREFOR, filed September 7, 1994, assigned serial number 08/301,775 and corresponding applications in other countries, the disclosure of which is incorporated herein by reference.
  • photoreceptor 16 may be deposited on drum 10 and may form a continuous surface.
  • drum 10 rotates and photoconductive surface 16 is charged by a charger 18 to a generally uniformly pre-determined voltage, typically a negative voltage on the order of 1000 volts.
  • Charger 18 may be any type of charger known in the art, such as a corotron, a scorotron or a roller.
  • charger 18 is a double scorotron including a housing and two corona wire segments 218.
  • the voltage between wires 218 and surface 16 should preferably be as high as possible, the actually obtained voltage is generally not higher than 7000-7500 Volts, typically 7300 Volts, due to discharging between wires 218 and housing 33.
  • the present invention provides a method for raising the voltage between wire segments 218 and surface 16.
  • housing 33 is electrically insulated from other elements of the imaging device and is charged to a relatively high voltage, preferably on the order of 1500 Volts. This enables charging of wires 218 to a voltage on the order of 9000 Volts, maintaining the voltage difference between wires 218 and housing 33 within a safe range.
  • developer roller 22 rotates in a direction opposite that of drum 10, as shown by arrow 13, such that there is substantially zero relative motion between their respective surfaces at the point of contact.
  • Surface 21 of developer roller 22 is preferably composed of a soft polyurethane material, preferably made more electrically conductive by the inclusion of conducting additives, while the core of developer roller 22 may be composed of any suitable electrically conductive material.
  • drum 10 may be formed of a relatively resilient material, and in such case surface 21 of developer roller 22 may be composed of either a rigid or a compliant material.
  • Developer roller 22 is preferably charged to a negative voltage of approximately 300 - 600 volts, desirably approximately -400 volts.
  • surface 21 is coated with a very thin layer of concentrated liquid toner, preferably containing 20-50% charged toner particles, more preferably 25% solids or more.
  • the layer is preferably between 5 and 30 pm, more preferably between 5 and 15 pm, thick.
  • Developer roller 22 itself is charged to a voltage that is intermediate the voltage of the charged and discharged areas on photoconductive surface 16.
  • liquid toner similar to the toner described in Example 1 of U.S. Patent 4,794,651 , the disclosure of which is incorporated herein by reference, is used although other types of toner are usable in the invention.
  • carbon black in the preferred toner is replaced by colored pigments as is well known in the art.
  • the liquid toner is preferably maintained in a toner reservoir 65 which is associated with development assembly 23.
  • the transfer of the concentrated layer of toner is much less mobility dependent than in normal electrophoretic development, the process described above occurs at a relatively high speed. Also, since the layer already has a high density and viscosity, there is no need to provide for metering devices, rigidizing rollers and the like which would otherwise be necessary to remove excess liquid from the developed image to attain the desired density of toner particles of the developed image.
  • the present invention is described in the context of a BID (Binary Image Development) system in which the concentrated layer of liquid toner is completely transferred to photoconductor surface 16 during development.
  • BID Binary Image Development
  • the present invention is also compatible with a partial BID system in which only a portion of the thickness of the concentrated toner layer is transferred to surface 16 by appropriately adjusting the development voltages.
  • a preferred partial BID system of this type is described in PCT publication WO 94/16364 , the disclosure of which is incorporated herein by reference.
  • the latent image developed by means of the process described above may then be directly transferred to a desired substrate in a manner well known in the art.
  • the developed image is transferred to the desired substrate via an intermediate transfer member 40, which may be a drum or belt, in operative engagement with photoconductive surface 16 of drum 10 bearing the developed image.
  • Intermediate transfer member 40 rotates in a sense opposite to that of photoconductive surface 16, as shown by arrow 43, providing substantially zero relative motion between their respective surfaces at the point of image transfer.
  • Intermediate transfer member 40 is operative for receiving the toner image from photoconductive surface 16 and for transferring the toner image to a final substrate 42, such as paper.
  • Final substrate 42 which is preferably continuously fed as described below, is urged against the image bearing surface of ITM 40 by either a first impression roller 39 or a second impression roller 41, in accordance with a predetermined imaging sequence, as described in detail below.
  • the transfer of the toner image from ITM 40 to substrate 42 is preferably electrostatically assisted by charging impression rollers 39 and 41 to an appropriate voltage, which is adapted to counteract the electrostatic attraction of the toner image to ITM 40.
  • substrate 42 engages ITM 40 at a first impression region 239, when urged by roller 39, and at a second impression region 241, when urged by roller 41.
  • Impression rollers 39 and 41 form part of a web-feeder system 100 which is described below with reference to Fig. 5 .
  • intermediate transfer member 40 Disposed internally of intermediate transfer member 40 there may be provided a heater 45, to heat intermediate transfer member 40 as is known in the art. Transfer of the image to intermediate transfer member 40 is preferably aided by providing electrification of intermediate transfer member 40 to provide an electric field between intermediate transfer member 40 and the image areas of photoconductive surface 16.
  • Intermediate transfer member 40 preferably has a conducting layer 44 underlying an elastomer layer 46, which is preferably a slightly conductive resilient polymeric layer.
  • Intermediate transfer member (ITM) 40 may be any suitable intermediate transfer member, for example, as described in U.S. Patents 4,684,238 and 4,974,027 or in PCT Publication WO 90/04216 , the disclosures of which are incorporated herein by reference.
  • ITM 40 has a multilayered transfer portion such as those described below or in U.S. Patents 5,089,856 and 5,047,808 , or in U.S. Patent application S.N. 08/371,117, filed January 11, 1995 and entitled IMAGING APPARATUS AND INTERMEDIATE TRANSFER BLANKET THEREFOR and corresponding applications in other countries, the disclosures of all of which are incorporated herein by reference.
  • Member 40 is maintained at a suitable voltage and temperature for electrostatic transfer of the image thereto from image bearing surface 16.
  • the single color image is transferred to intermediate transfer member 40.
  • Subsequent images in different colors are sequentially transferred in alignment with the previous image onto intermediate transfer member 40.
  • the complete multi-color image is transferred from transfer member 40 to substrate 42.
  • Impression rollers, 39 or 41 produce operative engagement between intermediate transfer member 40 and substrate 42 at regions 239 or 241, respectively, when transfer of the composite image to substrate 42 takes place.
  • the invention is not limited to the specific type of image forming system used and the present invention is also useful with any suitable imaging system which forms a liquid toner image on an image forming surface, such as that shown in the above referenced Patent Application S.N. 08/371,117, and, for some aspects of the invention, with powder toner systems. Furthermore some aspects of the invention are suitable for use with offset printing systems as are well known in the art. The specific details given above for the image forming system are included as part of a best mode of carrying out the invention, however, many aspects of the invention are applicable to a wide range of systems as known in the art for electrostatic and offset ink printing and copying.
  • cleaning station 49 which may be any cleaning station known in the art. However, in a preferred embodiment of the invention, cleaning station 49 is an improved cleaning station which also functions as a cooling station, as described below with reference to Fig. 3 .
  • cleaning station 49 includes a casing 81 which is associated with a carrier liquid inlet 90 and a carrier liquid outlet 92.
  • Carrier liquid inlet 90 preferably includes a perforated nozzle 191 which disperses the supplied carrier liquid.
  • Fresh and, preferably, cooled carrier liquid is preferably pumped from a carrier liquid reservoir (not shown) to inlet 90 which scatters the liquid in the direction of a wet cleaning roller 88.
  • Wet cleaning roller 88 is preferably formed of a relatively rigid material, such as metal, and is mounted juxtaposed with surface 16 of drum 10, preferably with a gap of 120 to 150 micrometers from surface 16.
  • the toner on surface 16, which is now diluted in the wetting carrier liquid, is carried by surface 16 of drum 10 towards a sponge roller 82 which is urged against surface 16, such that the surface of roller 82 is deformed inwardly by approximately 1.5 millimeters.
  • Sponge roller 82 which is preferably constructed of an approximately 4 millimeter layer of open-cell polyurethane around a metal core having a diameter of approximately 14 millimeters, absorbs the diluted toner and scrubs it off surface 16.
  • sponge roller 82 preferably rotates in the same sense as that of drum 10, such that their respective surfaces move in opposite directions at their region of contacts.
  • a squeezer roller 84 which is urged deeply into sponge roller 82, preferably to a depth of approximately 2 millimeters from the original surface of roller 82, squeezes used carrier liquid out of roller 82.
  • Squeezer 84 which is preferably a metal roller having a diameter of approximately 16 millimeters, is preferably an idler roller, i.e. rotates in response to the rotation of sponge roller 82.
  • a scraper 56 preferably a resilient blade urged against surface 16 next to sponge roller 82, completes the removal of any residual toner on surface 16 which may have not been removed by sponge roller 82.
  • Blade 56 is preferably formed of polyurethane and has a thickness of approximately 3 millimeters.
  • Fluid guide 86 which separates the relatively warm and soiled carrier liquid from the fresh carrier liquid supplied by inlet 90, back to the liquid toner reservoir via carrier liquid outlet 92.
  • Fluid guide 86 is preferably resiliently urged against the surface of roller 88 via a, preferably spongy, sealing pad 87.
  • Fluid guide 86 is preferably formed of metal and sealing pad 87 is preferably formed of closed-cell polyurethane.
  • a lamp 58 completes the imaging cycle by removing any residual charge, characteristic of the previous image, from photoconductive surface 16, if necessary.
  • lamp 58 may be omitted and surface 16 is discharged only by discharge device 28, as described above with reference to Fig. 1 and Fig. 2 .
  • the liquid toner concentrate which is transferred to drum 10 has substantially the same toner particle concentration as the image when it is transferred from drum 10. This is in contrast to traditional liquid development where the liquid developer has a comparatively low concentration of particles before development and where excess liquid is removed from the image before transfer from the photoconductor. It is also in contrast to U.S. Patent 4,504,138 , in which the toner supplied to the drum is more concentrated, but where excess liquid must still be removed from the image before transfer to the final substrate.
  • the toning material developed onto drum 10 is at a solids concentration substantially equal to that of the image transferred from the drum. Since the toner supplied during development to surface 21 of developer roller 22 is generally not sufficiently concentrated, the toner on surface 21 is further concentrated before contact with drum 10, for example by mechanical and electrical squeegeeing as described below with reference to Fig. 4 .
  • Fig. 4 schematically illustrates the construction and operation of developer assembly 23.
  • Developer assembly 23, including developer roller 22 and other elements described below, may be a fixed component within the imaging apparatus or, alternatively, assembly 23 may take the form of a replaceable cartridge (not shown) which is readily inserted into the housing of the imaging apparatus and removed therefrom when the supply of liquid toner concentrate has been depleted.
  • the conductive lacquer preferably includes three parts H322 (Lord Corporation, U.S.A.) and 1 part ethyl acetate, however, other conductive lacquers may be suitable.
  • the conductive layer is preferably coated with an additional layer of polyurethane, preferably having a Shore A hardness of 20-25 and a resistivity on the order of 1•10 8 ⁇ •cm.
  • roller 22 protrudes somewhat from the opening of housing 60 such that, when assembly 23 is installed in the imaging apparatus, surface 21 of roller 22 is in contact with photoconductive surface 16 of drum 10.
  • roller 22 is electrically charged, preferably to a negative voltage of 300-600 volts, for example -400 volts, and is rotated in the direction indicated by arrow 13.
  • a layer of highly concentrated liquid toner is deposited on surface 21 of roller 22, as described below, and thus, roller 22 functions as a developer roller with regard to latent images formed on photoconductive surface 16 of drum 10, as described above with reference to Fig. 1 .
  • the pressurized toner received via inlet 62 is deposited on developer roller 22 by a depositing electrode 70 which forms one wall of inlet chamber 63.
  • the opposite wall 72 of inlet chamber 63' is preferably formed of an insulating material, for example a plastic insulator, and is juxtaposed with surface 21 by a distance of approximately 0.5 millimeters.
  • Electrode 70 which is preferably charged to a negative voltage of 900-2000 volts, for example -1400 volts, is preferably situated juxtaposed with a portion of developer roller 22, preferably at a distance of approximately 400 micrometers therefrom.
  • the large difference in voltage between electrode 70 and developer roller 22 causes toner particles to adhere to developer roller 22, while the generally neutral carrier liquid is generally not affected by the voltage difference.
  • the deposited liquid toner is carried by surface 21 of roller 22 in the direction indicated by arrow 13.
  • the layer of liquid toner deposited on surface 21 is preferably at a concentration of 15-17 percent as described below.
  • assembly 23 includes a squeegee roller 66 and a cleaning roller 74 which are mounted within housing 60 in contact with the surface of developer roller 22.
  • Rollers 66 and 74 are composed of any suitable electrically conducting material, preferably metal, having a smooth surface.
  • the diameters of squeegee roller 66 and cleaning roller 74 are preferably significantly smaller than that of developer roller 22. Thus, if the diameter of roller 22 is approximately 3 centimeters, the diameters of rollers 66 and 74 are preferably approximately 10 millimeters.
  • rollers 66 and 74 are electrically charged and are caused to rotate in a sense opposite that of roller 22, as indicated by arrows 67 and 73, while being urged against the resilient surface of roller 22.
  • squeegee roller 66 is charged to a negative voltage of 400-800 volts, preferably approximately -600 volts
  • cleaning roller 74 is preferably charged to a negative voltage of 0-200 volts.
  • Squeegee roller 66 is preferably urged against roller 22, at a pressure of approximately 100 grams per centimeter of length, by means of a leaf spring 68, preferably extending along substantially the entire length of the squeegee roller and having a, preferably teflon, tip which engages the surface of roller 66.
  • the tip is preferably formed with grooves in the direction of motion of the surface of roller 66 which prevent accumulation of toner between roller 66 and spring 68 by allowing draining of the toner therefrom.
  • the leaf spring includes a wire, preferably of a low friction material such as teflon, wrapped around the leaf as around a core to form a flat coil with an axis along the length of the squeegee roller.
  • the wires are spaced in the winding direction so that they contact the squeegee roller only along discrete portions or points along its length so that the above described draining of toner may occur.
  • the spring is formed with spaced winding grooves to position the wire and stabilize its position.
  • Squeegee roller 66 is operative to squeegee excess carrier liquid from surface 21 of developer roller 22, thereby to further increase the concentration of solids on surface 21. Because of the squeegee action at the region of contact between resilient surface 21 and the surface of squeegee roller 66, a large proportion of the carrier liquid contained within the toner concentrate is squeezed out of the layer, leaving a layer having a solids concentration of 20 percent or more as described below. The excess carrier liquid, which may include a certain amount of toner particles, drains towards toner outlet 64.
  • the ends of squeegee roller 66 and roller 22 are formed with matching chamfered ends to reduce the effects of end overflow.
  • chamfered rollers are described more fully in a PCT application titled “Squeegee roller for Imaging Systems” which corresponds to Israel application 111441, filed October 28, 1994 . This PCT application, which is incorporated herein by reference, is filed on the same day as the present application.
  • Cleaning roller 74 by virtue of the relatively low voltage to which it is charged, is operative to remove residual toner from surface 21 of developer roller 22.
  • the toner collected by roller 74 is then preferably scraped off roller 74 by a, preferably resilient, cleaning blade 76 which is urged against the surface of roller 74.
  • the scraped toner is preferably absorbed by a sponge roller 78, which is urged against roller 74 so as to be slightly deformed thereby, preferably by approximately 1.5 millimeters radially.
  • Sponge roller 78 rotates in the same sense as that of roller 74, such that the surfaces of rollers 74 and 78 move in opposite directions at their region of contact.
  • Sponge roller 78 also absorbs some of the excess liquid toner from the deposition region between electrode 70 and roller 22, mainly including carrier liquid, which is drained along the external surface of insulator wall 72 of chamber 63.
  • Roller 78 preferably has a diameter of approximately 20 millimeters and is preferably formed of open-cell polyurethane surrounding a metal core having a diameter of approximately 8 millimeters.
  • squeezer roller 80 is preferably an idler roller which rotates in response to the rotation of sponge roller 78.
  • the layer deposited on surface 21 of roller 22 has a very high solids concentration, preferably greater than about 15 percent and typically between 15 and 17 percent, depending on which color toner is deposited. This concentration is much higher than the initial concentration of solids supplied to inlet 62 from reservoir 65, which concentration is generally lower than 8 percent solids and typically between 1.8 and 2 percent solids. Squeegeeing of the deposited layer of toner by squeegee roller 65, as described above, further increases the concentration of solids in the toner layer to approximately 20-50 percent solids, depending on the color of the toner. This high concentration has been found to be almost dry to the touch, non-flowing and crumbly in texture.
  • roller 22 continues to rotate and interfaces the latent-image-bearing surface of drum 10, portions of the layer of the dry to the touch liquid toner concentrate are selectively transferred to surface 16 of drum 10, thereby developing the latent image as explained above.
  • Resilient blade 76 which is preferably anchored to housing 60, scrapes off the remaining portions of the toner layer from the surface of roller 74, as described above.
  • toners are suitable for the present invention, the following toner materials and toner production methods are preferred:
  • the mixture is ground for approximately 20 hours at a temperature of approximately 40 ⁇ 3°C.
  • the magnetically treated toner is placed in a vacuum nutcha, such as a Buchner Funnel, having a polypropylene cloth support, and is concentrated using a vacuum pump.
  • the toner concentration exceeds 22% solids after approximately 4 hours of pumping.
  • the concentrated toner is placed in a planetary mixer.
  • a predetermined amount of charge director is added, preferably approximately 9 milligrams charge director per gram of toner solids.
  • the toner concentration is adjusted, using Isopar-L, to approximately 20% solids.
  • the toner is then pumped into 380 gram containers using a gear pump system.
  • a variety of charge directors known in the art are operative in this embodiment of the invention.
  • a preferred charge director for the present invention preferably utilizing lecithin, BBP and ICIG3300B, is described in U.S. Patent Application 07/915,291 and in P.C.T. Publication W.O. 94/02887 .
  • Fig. 5 schematically illustrates a preferred embodiment of web-feeder system 100
  • Fig. 6 schematically illustrates, in block diagram form, a preferred circuit for controlling the operation of web-feeder system 100.
  • Fig. 8 schematically illustrates a preferred sequence of operation of web-feeder system 100.
  • web-feeder system 100 includes first and second impression rollers 39 and 41 which are alternatively applied to support final substrate 42 against the surface of ITM 40 at regions 239 and 241, respectively.
  • a first surface 101 of substrate 42 engages ITM 40 when roller 39 is urged against the ITM
  • a second, opposite surface 103 of substrate 42 engages ITM 40 when roller 41 is urged against the ITM.
  • This arrangement enables imaging on both surfaces 101 and 103 of substrate 42 using a single imaging apparatus, wherein ITM 40 engages surfaces 101 and 103 in accordance with a predetermined imaging sequence, as described below.
  • Rollers 39 and 41 are driven by impression motors 158 and 160, the operation of which is controlled by a controller 150.
  • Substrate 42 which may be formed of paper or any other suitable material, is preferably a continuous web supplied from a web-dispenser roll 102, through a substrate input arrangement which preferably includes input roller 104 and 105. Input rollers 104 and 105 are preferably driven by an input motor 152, the operation of which is controlled by controller 150 as described below. It should be appreciated that first surface 101, as defined above, is the top surface of continuous substrate 42 when the substrate is between rollers 104 and 105.
  • the dispensed continuous web 42 is guided to a first free-loop arrangement 107, having maximum height detectors 106 and minimum height detectors 108 associated with controller 150.
  • Detectors 106 are activated when the loop of substrate 42, dispensed into arrangement 107, is above a predetermined maximum height, while detectors 108 are activated when the loop of substrate 42 in arrangement 107 is below a predetermined minimum height.
  • controller 150 activates motor 152 so as to dispense more of web 42 from dispenser 102 into loop arrangement 107, thereby to lower the loop in arrangement 107.
  • controller 150 deactivates motor 152 so as to stop dispenser 102 from dispensing web 42 into loop arrangement 107, thereby to raise the loop in arrangement 107. In this manner, the length of substrate 42 in loop arrangement 107 is maintained within a predetermined length range which allows sufficient timing flexibility during imaging.
  • Continuous web 42 is pulled out of free loop arrangement 107, via a support roller 110, by a collection arrangement which preferably includes tension rollers 112 and 113.
  • Rollers 112 and 113 are preferably driven by a tension motor 154 which is controlled by controller 150.
  • Motor 154 is preferably a torque motor operative for maintaining a substantially constant tension in web substrate 42, downstream of rollers 112 and 113, during operation of the web-feeder system.
  • web 42 is accelerated by motor 156 and by an indexing motor 158 which is described below, until the velocity of surface 101 is comparable with the surface velocity of ITM 40.
  • This allows position controlled, slip-free, engagement between surface 101 and ITM 40 during imaging on the first surface.
  • a preselected post-image mark is imprinted on surface 101 immediately following each image printed thereon. This mark is detectable by first detector 114 and by second and third detectors, 128 and 144, as described in detail below.
  • web 42 is partially rewound, preferably by reverse operation of motors 154, 156 and 158, after each first surface imaging cycle. This provides a length of web as necessary for subsequent reacceleration of web 42 for the next first surface imaging cycle.
  • Correct positioning of a given first surface image is enabled by detection of the post-image mark of the preceding first surface image.
  • detector 114 is preferably operative only within preset detection time windows, during which time controller 150 queries for a detection signal. The time gaps between consecutive detection time windows are preferably set in accordance with the page layout of the respective first surface images.
  • the first surface images are reproduced with a minimal spacing, preferably not more than a few millimeters, whereby the post-image marks are imprinted within the boundaries of the spacings.
  • the images on ITM roller 40 are preferably bottom-justified, such that a substantially constant spacing is maintained between images. It should be appreciated, however, that in an alternative embodiment of the invention pre-image marks may be used rather than post-image marks and, in such an embodiment, the images on the surface of ITM 40 are preferably top-justified.
  • Web 42 bearing images on first surface 101 thereof, then passes through indexing rollers 116 and 117 which are, preferably, driven by first indexing motor 158.
  • Indexing motor 158 communicates with controller 150 and is operative, together with motor 156, to advance web 42 in accordance with the first surface imaging cycles, i.e. for a specified length of web 42 after each First Image Trigger signal generated by controller 150.
  • the velocity and relative position of web 42 during each first surface imaging cycle are preferably monitored by controller 150 through an encoder which is preferably associated with rollers 116 and 117.
  • Detectors 118 are activated when the loop of substrate 42 dispensed into arrangement 119 is above a predetermined maximum height, while detectors 120 are activated when the loop of substrate 42 in arrangement 119 is below a predetermined minimum height.
  • controller 150 activates a second tension motor 160 which drives second tension rollers 124 and 125, downstream of loop arrangement 119, to collect web 42 from loop arrangement 119 thereby to raise the loop in arrangement 119.
  • controller 150 deactivates motor 160 so as to stop tension rollers 124 and 125 from collecting web 42 from loop arrangement 119, thereby to lower the loop in arrangement 119. In this manner, the length of substrate 42 in loop arrangement 119 is maintained within a predetermined length range which allows sufficient imaging timing flexibility.
  • Motor 160 is preferably a torque motor which maintains a substantially constant tension in web substrate 42, downstream of rollers 124 and 125, during operation of the web-feeder system.
  • Web 42 is preferably collected from second loop arrangement 119 via a support roller 122 similar to support roller 110.
  • substrate 42 is "folded" three times, about three respective axes.
  • substrate 42 may be folded, first, about a 45 degree axis 170, then, about an axis 172 parallel to the advance of substrate 42 and, finally, about another 45 degree axis 174.
  • triple "folding" of substrate 42 by inverter 130 results in an inverted substrate 42 whose direction of motion is generally parallel to the original direction but has second surface 103 as its top surface.
  • Folding at the above specified axes is preferably performed by providing elongated rollers 171, 173 and 175, having preselected diameters, along axes 170, 172 and 174, respectively.
  • rollers 171, 173 and 175 are preferably appropriately separated, as shown schematically in Fig. 7B , such that substrate 42 is folded by less then 180 degrees at each axis.
  • inverter 130 may be equally suitable for inverting the surfaces of substrate 42 as described above, for example a Mobius belt arrangement wherein the substrate is inverted by being gradually rotated about its longitudinal axis while being advanced.
  • Figs. 7A and 7B has been found to be effective in operation and economic in space.
  • impression roller 41 Downstream of inverter mechanism 130, web 42 is directed around a support roller 126 towards impression roller 41, passing a second detector 128 which is operative for detecting the post-image synchronization marks imprinted between the images on surface 101.
  • Impression roller 41 is driven by a second impression motor 162, which is activated by controller 150 in accordance with the predetermined imaging sequence.
  • impression roller 41 is urged against the surface of ITM 40 only when second surface 103 of web 42 is to be imaged according to the imaging sequence.
  • each period of engagement between surface 103 with ITM 40 i.e. each second surface imaging cycle, is initiated by a Second Image Trigger signal from controller 150.
  • web 42 is accelerated by motor 162 and by a second indexing motor 164 which is described below, until the velocity of surface 103 is comparable with the surface velocity of ITM 40. This allows position controlled, slip-free, engagement between surface 103 and ITM 40 during imaging on the second surface.
  • web 42 is rewound, preferably by reverse operation of motors 160, 162 and 164, after each second surface imaging cycle. This provides the length of web necessary for subsequent reacceleration of web 42 for the next second surface imaging cycle. Correct positioning of a given second surface image is enabled by detection of the post-image mark of the preceding first surface image, so as to accurately position the given second surface image opposite its corresponding image on surface 101.
  • Web 42 which now bears a series of images on first surface 101 and a corresponding series of images on opposite surface 103, is guided by a roller 132 and then passes through a second indexing rollers 134 and 135 which are preferably driven by second indexing motor 164.
  • Indexing motor 164 communicates with controller 150 and is operative together with motor 160, to advance web 42 in accordance with the second surface imaging cycles, i.e. for a specified length of web 42 after each Second Image Trigger signal generated by controller 150.
  • the velocity and relative position of web 42 during each second surface imaging cycle are preferably monitored by controller 150 through an encoder which is preferably associated with rollers 134 and 135.
  • Detectors 136 are activated when the loop of substrate 42 dispensed into arrangement 137 is above a predetermined maximum height, while detectors 138 are activated when the loop of substrate 42 in arrangement 137 is below a predetermined minimum height.
  • controller 150 activates an output motor 166 which drives output rollers 142 and 143, downstream of a support roller 140, to collect web 42 from loop arrangement 137 thereby to raise the loop in arrangement 137.
  • controller 150 deactivates motor 166 so as to stop output rollers 142 and 143 from collecting web 42 from loop arrangement 137, thereby to deepen the loop in arrangement 137. In this manner, the length of substrate 42 in loop arrangement 137 is maintained within a predetermined length range which allows sufficient imaging timing flexibility.
  • the double-sided image bearing substrate 42 exiting output rollers 142 and 143 is then cut between images by a cutter 146, as known in the art.
  • a third detector 144 is provided between rollers 142 and 143 and cutter 146 for detecting the post-image marks imprinted between the images on surface 101.
  • the position of substrate 42 relative to cutter 146 is adjusted by controlled operation of output motor 146 based on the detection signals from third detector 144 to controller 150.
  • detector 144 is preferably operative only within preset detection time windows, during which time controller 150 queries for a detection signal therefrom.
  • the time gaps between consecutive detection time windows are preferably the same as those of the respective first and second surface images. These time gaps are preferably calculated by controller 150 based on the substrate length of the corresponding images, as measured by the encoders associated with indexer rollers 134 and 135.
  • motors 152-164 are brushless servo-motors driven by a plurality of corresponding digital servo-drivers (not shown), as known in the art.
  • the predetermined imaging sequence may be as follows. First, a predetermined number of images are reproduced on first surface 101 to account for the length of continuous substrate 42 separating between first impression roller 39 and second impression roller 41. Then, ITM 40 is alternatingly engaged by surfaces 101 and 103 such that each first surface imaging cycle is followed by a second surface imaging cycle.
  • the present invention provides an initiation procedure for synchronizing between the first surface imaging cycles, the second surface imaging cycles and the cutting of substrate 42.
  • controller 150 The length of substrate 42 between regions 239 and 241 is monitored by controller 150 by subtracting the length measured at indexers 134 and 135 from the length measured at indexer 116 and 117. Based on this information, controller 150 synchronizes between the detection time windows of the first surface imaging cycles and the corresponding detection windows of the second surface imaging cycles.
  • controller 150 Based on this information, controller 150 synchronizes between the detection time windows of the imaging cycles and the corresponding detection windows which are used for timing the cutting at cutter 146.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Counters In Electrophotography And Two-Sided Copying (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Wet Developing In Electrophotography (AREA)

Claims (57)

  1. Bilderzeugende Vorrichtung zur doppelseitigen Bilderzeugung auf einer durchgehenden Bahn als Träger (42) mit einer ersten und zweiten Fläche (101, 103) auf entgegengesetzten Seiten des Trägers (42), umfassend:
    eine Bilderzeugungseinheit, bei der ein Zwischenübertrager (40) eine bildtragende Fläche umfasst, die sich in eine Richtung bewegt und auf der selektiv erste und zweite mehrfarbige Bilder gebildet werden;
    einen Trägerwender (130), der dazu vorgesehen ist, den Träger (42) zwischen dem ersten und zweiten Übertragungsbereich (239, 241) zu wenden; und
    ein Bahnzuführungssystem (100), das die erste und zweite Trägerfläche (101, 102) selektiv mit der bildtragenden Fläche in Wirkberührung bringt, um darauf die ersten beziehungsweise zweiten mehrfarbigen Bilder gemäß einer vorgewählten Bilderzeugungssequenz zu übertragen, wobei ein erstes Druckelement (39) den Träger (42) gegen die bildtragende Fläche drückt, so dass die erste Trägerfläche (101) die bildtragende Fläche an einem ersten Übertragungsbereich (239) berührt, und ein zweites Druckelement (41) den Träger (42) gegen die bildtragende Fläche drückt, so dass die zweite Trägerfläche (103) die bildtragende Fläche an einem zweiten Übertragungsbereich (241) berührt,
    dadurch gekennzeichnet, dass
    der zweite Übertragungsbereich (241) vom ersten Übertragungsbereich (239) in Bewegungsrichtung der bildtragenden Fläche versetzt ist.
  2. Vorrichtung nach Anspruch 1, wobei die vorbestimmte Bilderzeugungssequenz Zyklen zur Bilderzeugung an der ersten Fläche, während derer die ersten Bilder auf die erste Trägerfläche (101) übertragen werden, und Zyklen zur Bilderzeugung an der zweiten Fläche, während derer die zweiten Bilder auf die zweite Trägerfläche (103) übertragen werden, umfasst.
  3. Vorrichtung nach Anspruch 2, wobei die vorbestimmte Bilderzeugungssequenz mehrere aufeinanderfolgende Bilderzeugungszyklen an der ersten Fläche umfasst, die von abwechselnden Bilderzeugungszyklen an der ersten Fläche (101) und der zweiten Fläche (103) gefolgt werden.
  4. Vorrichtung nach Anspruch 3, wobei das erste Druckelement (39) den durchgehenden Träger (42) während jedes Zyklus zur Bilderzeugung an der ersten Fläche gegen die bildtragende Fläche drückt und das zweite Druckelement (41) den durchgehenden Träger (42) während jedes Zyklus zur Bilderzeugung an der zweiten Fläche gegen die bildtragende Fläche drückt.
  5. Vorrichtung nach Anspruch 4, wobei das Bahnzuführungssystem (100) einen Materialvorschubmechanismus (116, 117, 134, 135) umfasst, der zum Vorwärtsbewegen des durchgehenden Trägers (42) durch den ersten und zweiten Übertragungsbereich (239, 241) dient.
  6. Vorrichtung nach Anspruch 5, wobei das Bahnzuführungssystem (100) weiterhin eine Steuerung (150) umfasst, die die Vorwärtsbewegung des durchgehenden Trägers (42) durch die ersten und zweiten Übertragungsbereiche (239, 241) gemäß der vorbestimmten Bilderzeugungssequenz durch Steuerung des Betriebs des Materialvorschubmechanismus (116, 117, 134, 135) steuert.
  7. Vorrichtung nach Anspruch 6, wobei die Steuerung (150) die Berührung und Nichtberührung der ersten und zweiten Trägerflächen (101, 103) durch die bildtragende Fläche gemäß der vorbestimmten Bilderzeugungssequenz durch Steuerung der Position des ersten (39) und zweiten (41) Druckelements relativ zu der bildtragenden Fläche steuert.
  8. Vorrichtung nach Anspruch 6 oder Anspruch 7, wobei die ersten Bilder mit einem vorgewählten Zwischenraum auf der ersten Trägerfläche (101) gebildet werden.
  9. Vorrichtung nach Anspruch 8, wobei die Bilderzeugungseinheit auf dem Zwischenraum nach jedem ersten Bild auf der ersten Trägerfläche (101) eine Nachbild-Markierung erzeugt.
  10. Vorrichtung nach Anspruch 9, wobei der Vorschubmechanismus (116, 117, 134, 135) nach jedem Bilderzeugungszyklus an der ersten Fläche eine vorgewählte Länge des durchgehenden Trägers (42) durch den ersten Übertragungsbereich (239) zurückspult.
  11. Vorrichtung nach Anspruch 10, wobei der durchgehende Träger (42) vor jedem Bilderzeugungszyklus an der ersten Fläche auf eine Flächengeschwindigkeit beschleunigt wird, die mit der der bildtragenden Fläche vergleichbar ist.
  12. Vorrichtung nach Anspruch 10, wobei das Bahnzuführungssystem (100) weiterhin vor dem ersten Übertragungsbereich (239) einen mit der ersten Trägerfläche (101) assoziierten ersten Markierungsdetektor (114) umfasst, der die Nachbild-Markierungen auf der ersten Trägerfläche (101) detektiert und in Antwort darauf erste Detektionssignale erzeugt.
  13. Vorrichtung nach Anspruch 12, wobei die Steuerung (150) jeden Bilderzeugungszyklus an der ersten Fläche in Antwort auf das erste Detektionssignal der vorangehenden Nachbild-Markierung auslöst.
  14. Vorrichtung nach einem der Ansprüche 10 - 13, wobei der Vorschubmechanismus (116, 117, 134, 135) nach jedem Bilderzeugungszyklus an der zweiten Fläche eine vorgewählte Länge des Trägers (42) durch den zweiten Übertragungsbereich (241) zurückspult.
  15. Vorrichtung nach Anspruch 14, wobei das der durchgehende Träger (42) vor jedem Bilderzeugungszyklus an der zweiten Fläche auf eine Flächengeschwindigkeit beschleunigt wird, die mit der der bildtragenden Fläche vergleichbar ist.
  16. Vorrichtung nach Anspruch 15, wobei das Bahnzuführungssystem (100) weiterhin vor dem zweiten Übertragungsbereich (241) einen mit der zweiten Trägerfläche (103) assoziierten zweiten Markierungsdetektor (128) umfasst, der die Nachbild-Markierungen auf der ersten Trägerfläche (101) detektiert und in Antwort darauf zweite Detektionssignale erzeugt.
  17. Vorrichtung nach Anspruch 16, wobei die Steuerung (150) jeden Bilderzeugungszyklus an der zweiten Fläche in Antwort auf das zweite Detektionssignal der vorangehenden Nachbild-Markierung auslöst.
  18. Vorrichtung nach einem der Ansprüche 10 - 17, wobei das Bahnzuführungssystem (100) weiterhin eine mit dem in Bewegungsrichtung hinter dem zweiten Übertragungsbereich (241) liegenden durchgehenden Trägers (42) assoziierte Schneidevorrichtung (146) umfasst, die den durchgehenden Träger (42) in den Zwischenräumen zwischen den ersten Bildern auf der ersten Trägerfläche (101) schneidet.
  19. Vorrichtung nach Anspruch 18, wobei das Bahnzuführungssystem (100) weiterhin vor der Schneidevorrichtung (146) einen mit der ersten Trägerfläche (101) assoziierten dritten Markierungdetektor (144) umfasst, der die Nachbild-Markierungen auf der ersten Trägerfläche (101) detektiert und als Antwort darauf dritte Detektionssignale erzeugt.
  20. Vorrichtung nach Anspruch 19, wobei die Steuerung (150) die Schneidevorrichtung (146) in Antwort auf die dritten Detektionssignale aktiviert.
  21. Vorrichtung nach einem der Ansprüche 10 - 20, wobei das Bahnzuführungssystem (100) weiterhin wenigstens eine Freilauf-Anordnung umfasst, welche eine variable Länge des durchgehenden Trägers (42) enthält.
  22. Vorrichtung nach Anspruch 21, wobei die wenigstens eine Freilauf-Anordnung eine erste Freilauf-Anordnung (107) vor dem ersten Übertragungsbereich (239) umfasst.
  23. Vorrichtung nach Anspruch 21 oder Anspruch 22, wobei die wenigstens eine Freilauf-Anordnung eine zweite Freilauf-Anordnung (119) zwischen dem ersten Übertragungsbereich (239) und dem zweiten Übertragungsbereich (241) umfasst.
  24. Vorrichtung nach Anspruch 23, wobei das Bahnzuführungssystem (100) weiterhin eine dritte Freilauf-Anordnung (137) zwischen dem zweiten Übertragungsbereich (241) und der Schneidevorrichtung (146) umfasst, welche eine variable Länge des durchgehenden Trägers (42) enthält.
  25. Vorrichtung nach einem der Ansprüche 10 - 24, wobei das Bahnzuführungssystem (100) weiterhin einen ersten Längendetektor (108) umfasst, der mit dem durchgehenden Träger (42) zwischen dem ersten und zweiten Übertragungsbereich (239, 241) assoziiert ist, und der ein elektrisches Ausgangssignal in Antwort auf die Position des durchgehenden Trägers (42) relativ zum ersten Übertragungsbereich (239) erzeugt.
  26. Vorrichtung nach Anspruch 25, wobei der erste Längendetektor (108) einen Kodierer umfasst.
  27. Vorrichtung nach Anspruch 25 oder Anspruch 26, wobei die Steuerung (150) den ersten Markierungdetektor (114) nur innerhalb vorbestimmter erster Detektionszeitfenster anspricht und wobei die Zeitlücken zwischen den ersten Detektionsfenstem gemäß dem Ausgangssignal des ersten Längendetektors (108) gesetzt sind.
  28. Vorrichtung nach einem der Ansprüche 25 - 27, wobei das Bahnzuführungssystem (100) weiterhin einen zweiten Längendetektor (118) umfasst, der mit dem Endlosmaterial (42) assoziiert ist, das in Bewegungsrichtung hinter dem zweiten Übertragungsbereich (241) liegt, der ein elektrisches Ausgangssignal in Antwort auf die Position des durchgehenden Trägers (42) relativ zum zweiten Übertragungsbereich (241) erzeugt.
  29. Vorrichtung nach Anspruch 28, wobei der zweite Längendetektor (118) einen Kodierer umfasst.
  30. Vorrichtung nach Anspruch 28 oder Anspruch 29, wobei die Steuerung (150) den zweiten Markierungdetektor (128) nur innerhalb vorbestimmter zweiter Detektionszeitfenster anspricht und wobei die Zeitlücken zwischen den zweiten Detektionsfenstern gemäß den Ausgangssignalen des ersten (108) und zweiten (118) Längendetektors gesetzt sind.
  31. Vorrichtung nach einem der Ansprüche 28 - 30, wobei die Steuerung (150) den dritten Markierungdetektor (144) nur innerhalb vorbestimmter dritter Detektionszeitfenster anspricht und wobei die Zeitlücken zwischen den dritten Detektionsfenstem gemäß dem Ausgangssignal des zweiten Längendetektors (118) gesetzt sind.
  32. Vorrichtung nach einem der vorherigen Ansprüche, wobei die bildtragende Fläche eine entwickelte Bilderzeugungsfläche umfasst.
  33. Vorrichtung nach Anspruch 32, wobei die Bilderzeugungsfläche eine Photorezeptorfläche umfasst.
  34. Vorrichtung nach einem der vorherigen Ansprüche, wobei die Bilder Tonerbilder umfassen.
  35. Verfahren zur doppelseitigen Bilderzeugung auf einer durchgehenden Bahn als Träger (42) mit einer ersten und zweiten Fläche (101, 103) auf entgegengesetzten Seiten des Trägers (42), unter Verwendung einer Bilderzeugungseinheit mit einem Zwischenübertrager (40), der eine bildtragende Fläche umfasst, die sich in eine Richtung bewegt, wobei das Verfahren umfasst:
    Bereitstellen einer Serie von ersten mehrfarbigen Bildern auf der bildtragenden Fläche;
    Übertragen jedes Bildes der Serie von ersten Bildern von der bildtragenden Fläche auf die erste Trägerfläche (101);
    Bereitstellen einer Serie von zweiten mehrfarbigen Bildern auf der bildtragenden Fläche; und
    Übertragen jedes Bildes der Serie von zweiten Bildern von der bildtragenden Fläche auf die zweite Trägerfläche (103),
    wobei keines der Bilder in der Serie der ersten Bilder gleichzeitig mit einem der Bilder in der Serie der zweiten Bilder übertragen wird;
    Bereitstellen der Serie von ersten Bildern und der Serie von zweiten Bildern, was zunächst aufeinanderfolgendes Bilden mehrerer erster Bilder und dann abwechselndes Bilden erster und zweiter Bilder umfasst; und
    Übertragen jedes Bildes aus der Serie von ersten Bildern, was das Übertragen der Bilder in der Serie von ersten Bildern auf einen ersten Übertragungsbereich (239) umfasst, wobei ein erstes Druckelement (39) eines Bahnzufizhrungssystems (100) den Träger (42) gegen die bildtragende Fläche drückt; und
    Übertragen jedes Bildes aus der Serie von zweiten Bildern, was das Übertragen der Bilder in der Serie von zweiten Bildern auf einen zweiten Übertragungsbereich (241) umfasst, wobei ein zweites Druckelement (41) des Bahnzuführungssystems (100) den Träger (42) gegen die bildtragende Fläche drückt; und
    wobei der zweite Übertragungsbereich (241) vom ersten Übertragungsbereich (239) in Bewegungsrichtung der bildtragenden Fläche versetzt ist, und ein Trägerwender (130) bereitgestellt wird, um den Träger (42) zwischen dem ersten und zweiten Übertragungsbereich (239, 241) zu wenden.
  36. Bilderzeugungsverfahren nach Anspruch 35, wobei das Bereitstellen und Übertragen gemäß einer vorbestimmten Bilderzeugungssequenz durchgeführt wird und weiterhin das Vorwärtsbewegen des durchgehenden Trägers (42) durch den ersten und zweiten Übertragungsbereich (239, 241) gemäß der vorbestimmten Bilderzeugungssequenz umfasst.
  37. Bilderzeugungsverfahren nach einem der Ansprüche 35 - 36, wobei das Übertragen jedes Bildes der Serie von ersten Bildern auf die erste Trägerfläche (101) das Übertragen der Bilder mit einem vorbestimmten Zwischenraum umfasst.
  38. Bilderzeugungsverfahren nach Anspruch 37, das weiterhin Erzeugen einer Nachbild-Markierung auf dem Zwischenraum nach jedem ersten Bild umfasst.
  39. Bilderzeugungsverfahren nach Anspruch 38, das weiterhin nach dem Übertragen jedes ersten Bildes das zurückspulen einer vorgewählten Länge des durchgehenden Trägers (42) durch den ersten Übertragungsbereich (239) umfasst.
  40. Bilderzeugungsverfahren nach Anspruch 39, das weiterhin vor dem Übertragen jedes ersten Bildes das Beschleunigen des durchgehenden Trägers (42) auf eine Flächengeschwindigkeit umfasst, die mit der der bildtragenden Fläche vergleichbar ist.
  41. Bilderzeugungsverfahren nach Anspruch 40, das weiterhin das Detektieren der Nachbild-Markierungen auf der ersten Trägerfläche (101) vor dem ersten Übertragungsbereich (239) umfasst.
  42. Bilderzeugungsverfahren nach Anspruch 41, das weiterhin das Auslösen des Übertragens jedes ersten Bildes in Antwort auf die Nachbild-Markierung des vorangehenden ersten Bildes umfasst.
  43. Bilderzeugungsverfahren nach einem der Ansprüche 39 - 42, das weiterhin nach dem Übertragen jedes zweiten Bildes das Zurückspulen einer vorbestimmten Länge des durchgehenden Trägers (42) durch den zweiten Übertragungsbereich (241) umfasst.
  44. Bilderzeugungsverfahren nach Anspruch 43, das weiterhin vor dem Übertragen jedes zweiten Bildes das Beschleunigen des durchgehenden Trägers (42) auf eine Flächengeschwindigkeit umfasst, die mit der der bildtragenden Fläche vergleichbar ist.
  45. Bilderzeugungsverfahren nach Anspruch 44, das weiterhin das Detektieren der Nachbild-Markierungen auf der ersten Trägerfläche (101) zwischen dem ersten Übertragungsbereich (239) und dem zweiten Übertragungsbereich (241) umfasst.
  46. Bilderzeugungsverfahren nach Anspruch 45, das weiterhin das Auslösen des Übertragens jedes zweiten Bildes in Antwort auf die Nachbild-Markierung des vorangehenden zweiten Bildes umfasst.
  47. Bilderzeugungsverfahren nach einem der Ansprüche 39 - 46, das weiterhin das Schneiden des durchgehenden Trägers (42) in den Zwischenräumen zwischen den ersten Bildern auf der ersten Trägerfläche (101) umfasst.
  48. Bilderzeugungsverfahren nach Anspruch 47, das weiterhin das Detektieren der Nachbild-Markierungen auf der ersten Trägerfläche (101) in Bewegungsrichtung hinter dem zweiten Übertragungsbereich (241) umfasst.
  49. Bilderzeugungsverfahren nach Anspruch 47 oder Anspruch 48, wobei das Schneiden des Endlosmaterials (42) das Schneiden des Endlosmaterials (42) in Antwort auf das Detektieren der Nachbild-Markierungen umfasst.
  50. Bilderzeugungsverfahren nach einem der Ansprüche 39 - 49, das weiterhin das Überprüfen der Position des durchgehenden Trägers (42) relativ zum ersten Übertragungsbereich (239) umfasst.
  51. Bilderzeugungsverfahren nach Anspruch 50, wobei das Detektieren der Nachbild-Markierungen auf dem durchgehenden Träger (42) vor dem ersten Übertragungsbereich (239) das Detektieren der Nachbild-Markierungen nur innerhalb vorbestimmter erster Detektionszeitfenster umfasst.
  52. Bilderzeugungsverfahren nach Anspruch 51, das weiterhin das Setzen der Zeitlücken zwischen den ersten Detektionszeitfenstern gemäß der überprüften Position des durchgehenden Trägers (42) relativ zum ersten Übertragungsbereich (239) umfasst.
  53. Bilderzeugungsverfahren nach einem der Ansprüche 50 - 52, das weiterhin das Überprüfen der Position des durchgehenden Trägers (42) relativ zum zweiten Übertragungsbereich (241) umfasst.
  54. Bilderzeugungsverfahren nach Anspruch 53, wobei das Detektieren der Nachbild-Markierungen auf dem durchgehenden Träger (42) zwischen dem ersten und zweiten Übertragungsbereich (239, 241) das Detektieren der Nachbild-Markierungen nur innerhalb vorbestimmter zweiter Detektionszeitfenster umfasst.
  55. Bilderzeugungsverfahren nach Anspruch 54, das weiterhin das Setzen der Zeitlücken zwischen den zweiten Detektionszeitfenstern gemäß der überprüften Position des durchgehenden Trägers (42) relativ zum zweiten Übertragungsbereich umfasst.
  56. Bilderzeugungsverfahren nach einem der Ansprüche 35 - 55, wobei die bildtragende Fläche eine Bilderzeugungsfläche umfasst, auf welcher ein latentes Bild entwickelt wurde.
  57. Bilderzeugungsverfahren nach Anspruch 56, wobei die Bilderzeugungsfläche eine Photorezeptorfläche umfasst.
EP95920301A 1995-04-03 1995-06-06 Doppelseitige bilderzeugung Expired - Lifetime EP0819269B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IL11323595 1995-04-03
IL113235A IL113235A (en) 1995-04-03 1995-04-03 Double sided imaging
PCT/NL1995/000199 WO1996031809A1 (en) 1995-04-03 1995-06-06 Double-sided imaging

Publications (2)

Publication Number Publication Date
EP0819269A1 EP0819269A1 (de) 1998-01-21
EP0819269B1 true EP0819269B1 (de) 2010-01-20

Family

ID=11067314

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95920301A Expired - Lifetime EP0819269B1 (de) 1995-04-03 1995-06-06 Doppelseitige bilderzeugung

Country Status (6)

Country Link
EP (1) EP0819269B1 (de)
JP (2) JP3685337B2 (de)
AU (1) AU2579595A (de)
DE (1) DE69536043D1 (de)
IL (1) IL113235A (de)
WO (1) WO1996031809A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022263989A1 (en) * 2021-06-15 2022-12-22 Landa Corporation Ltd. Digital printing system and process

Families Citing this family (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU7638696A (en) 1996-12-03 1998-06-29 Indigo N.V. Method and apparatus for cleaning an image transfer member
DE69920771T2 (de) 1999-07-05 2005-10-06 Hewlett-Packard Indigo B.V. Verfahren zum Übertragen eines Tonerbildes
JP3680989B2 (ja) * 2000-12-22 2005-08-10 リコープリンティングシステムズ株式会社 印刷システム
US6795683B2 (en) 2002-01-11 2004-09-21 Hitachi Printing Solutions, Ltd. Tandem type printing system
WO2005029198A1 (en) * 2003-09-25 2005-03-31 Hewlett-Packard Development Company, L.P. Low mass impression cylinder
US7481509B2 (en) * 2003-10-31 2009-01-27 Hewlett-Packard Development Company, L.P. Ink thickness consistency in digital printing presses
DE102009060334B4 (de) * 2009-12-23 2012-02-16 OCé PRINTING SYSTEMS GMBH Vorrichtung zum Entwickeln von auf einem Ladungsbildträger erzeugten Ladungsbildern bei einem elektrophoretischen Druckgerät
US10632740B2 (en) 2010-04-23 2020-04-28 Landa Corporation Ltd. Digital printing process
JP5752318B2 (ja) * 2011-04-29 2015-07-22 ヒューレット−パッカード デベロップメント カンパニー エル．ピー．Ｈｅｗｌｅｔｔ‐Ｐａｃｋａｒｄ Ｄｅｖｅｌｏｐｍｅｎｔ Ｃｏｍｐａｎｙ， Ｌ．Ｐ． プリンター表面から材料を除去するための装置、プリンター、及び方法
US10642198B2 (en) 2012-03-05 2020-05-05 Landa Corporation Ltd. Intermediate transfer members for use with indirect printing systems and protonatable intermediate transfer members for use with indirect printing systems
AU2013229142B2 (en) 2012-03-05 2017-02-02 Landa Corporation Ltd. Ink film constructions
CN104271356B (zh) 2012-03-05 2016-10-19 兰达公司 数字印刷工艺
AU2013229140B2 (en) 2012-03-05 2017-02-02 Landa Corporation Ltd. Ink film constructions
US9643403B2 (en) 2012-03-05 2017-05-09 Landa Corporation Ltd. Printing system
GB2518169B (en) * 2013-09-11 2015-12-30 Landa Corp Ltd Digital printing system
US9902147B2 (en) 2012-03-05 2018-02-27 Landa Corporation Ltd. Digital printing system
US10569534B2 (en) 2012-03-05 2020-02-25 Landa Corporation Ltd. Digital printing system
US9498946B2 (en) 2012-03-05 2016-11-22 Landa Corporation Ltd. Apparatus and method for control or monitoring of a printing system
WO2013136220A1 (en) 2012-03-15 2013-09-19 Landa Corporation Limited Endless flexible belt for a printing system
US10434761B2 (en) 2012-03-05 2019-10-08 Landa Corporation Ltd. Digital printing process
GB201401173D0 (en) 2013-09-11 2014-03-12 Landa Corp Ltd Ink formulations and film constructions thereof
JP6287405B2 (ja) * 2014-03-18 2018-03-07 富士ゼロックス株式会社 液体現像装置及び画像形成装置
US10191416B2 (en) * 2014-08-08 2019-01-29 Hp Indigo B.V. Wet null cycle printing
GB2536489B (en) 2015-03-20 2018-08-29 Landa Corporation Ltd Indirect printing system
GB2537813A (en) 2015-04-14 2016-11-02 Landa Corp Ltd Apparatus for threading an intermediate transfer member of a printing system
JP7144328B2 (ja) 2016-05-30 2022-09-29 ランダ コーポレイション リミテッド デジタル印刷処理
GB201609463D0 (en) 2016-05-30 2016-07-13 Landa Labs 2012 Ltd Method of manufacturing a multi-layer article
JP7206268B2 (ja) 2017-10-19 2023-01-17 ランダ コーポレイション リミテッド 印刷システム用の無端可撓性ベルト
JP7225230B2 (ja) 2017-11-19 2023-02-20 ランダ コーポレイション リミテッド デジタル印刷システム
US11511536B2 (en) 2017-11-27 2022-11-29 Landa Corporation Ltd. Calibration of runout error in a digital printing system
US11707943B2 (en) 2017-12-06 2023-07-25 Landa Corporation Ltd. Method and apparatus for digital printing
WO2019111223A1 (en) 2017-12-07 2019-06-13 Landa Corporation Ltd. Digital printing process and method
IL279556B2 (en) 2018-06-26 2024-06-01 Landa Corp Ltd Part for intermediate transfer to a digital printing system
US10994528B1 (en) 2018-08-02 2021-05-04 Landa Corporation Ltd. Digital printing system with flexible intermediate transfer member
WO2020035766A1 (en) 2018-08-13 2020-02-20 Landa Corporation Ltd. Correcting distortions in digital printing by implanting dummy pixels in a digital image
WO2020075012A1 (en) 2018-10-08 2020-04-16 Landa Corporation Ltd. Friction reduction means for printing systems and method
EP3902680A4 (de) 2018-12-24 2022-08-31 Landa Corporation Ltd. Digitales drucksystem
WO2021105806A1 (en) 2019-11-25 2021-06-03 Landa Corporation Ltd. Drying ink in digital printing using infrared radiation absorbed by particles embedded inside itm
US11321028B2 (en) 2019-12-11 2022-05-03 Landa Corporation Ltd. Correcting registration errors in digital printing
JP2023508513A (ja) 2019-12-29 2023-03-02 ランダ コーポレイション リミテッド 印刷方法およびシステム

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996014605A1 (de) * 1994-11-04 1996-05-17 OCé PRINTING SYSTEMS GMBH Multifunktionale elektrografische druckeinrichtung

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63315451A (ja) * 1987-01-17 1988-12-23 Asahi Optical Co Ltd 電子写真用被記録媒体供給方法
CA2113169C (en) * 1991-07-09 2003-05-27 Benzion Landa Latent image development apparatus
DE59303381D1 (de) * 1992-04-10 1996-09-12 Siemens Nixdorf Inf Syst Elektrofotografische druckeinrichtung zum simultanen beidseitigen bedrucken eines aufzeichnungsträgers
CA2387333C (en) * 1993-01-11 2006-05-16 Indigo N.V. Latent image development apparatus
EP0699315B1 (de) 1993-05-19 1996-10-30 Siemens Nixdorf Informationssysteme AG Elektrografische druckeinrichtung zum bedrucken von bandförmigen aufzeichnungsträgern unterschiedlicher bandbreite

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996014605A1 (de) * 1994-11-04 1996-05-17 OCé PRINTING SYSTEMS GMBH Multifunktionale elektrografische druckeinrichtung

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022263989A1 (en) * 2021-06-15 2022-12-22 Landa Corporation Ltd. Digital printing system and process

Also Published As

Publication number Publication date
JP2005234590A (ja) 2005-09-02
DE69536043D1 (de) 2010-03-11
IL113235A (en) 2006-07-17
JPH11503244A (ja) 1999-03-23
IL113235A0 (en) 1995-07-31
EP0819269A1 (de) 1998-01-21
JP3890348B2 (ja) 2007-03-07
WO1996031809A1 (en) 1996-10-10
JP3685337B2 (ja) 2005-08-17
AU2579595A (en) 1996-10-23

Similar Documents

Publication Publication Date Title
EP0819269B1 (de) Doppelseitige bilderzeugung
US6108513A (en) Double sided imaging
EP0249385B1 (de) Zwischenübertragungsgerät
JP3946237B2 (ja) 無端ウェブを使用した、中間イメージ転写部材から受取部材へのマーキング粒子イメージの転写を容易とする方法および装置
EP2458451B1 (de) Bilderzeugungsvorrichtung
EP0678202B1 (de) Entwicklungsapparat für ein latentes bild
US4362378A (en) Paper feed and image transfer for electrostatographic copiers and duplicators
EP0795799B1 (de) Gerät und Verfahren zur Bilderzeugung
US5140375A (en) Image forming apparatus
JPH06273996A (ja) 画像形成装置
EP0609966A2 (de) Bilderzeugungssystem mit Zwischenübertragungselement
US5600413A (en) Method and apparatus for controlling the potential applied to a contact charger in an image forming apparatus
US5303009A (en) Image forming apparatus with an improved discharger
US5276491A (en) Image forming apparatus
CA2216843C (en) Double-sided imaging
CA2387330C (en) Latent image development apparatus
US5815783A (en) Method and apparatus for printing on both sides of a substrate
US5940665A (en) Liquid immersion development machine having a multiple zone image development and conditioning apparatus
US5693441A (en) Method and apparatus for eliminating residual charge potential in an electrostatographic system
JPH0627757A (ja) トナー像形成装置
US4248518A (en) Electrophotographic copying apparatus
JP3739063B2 (ja) 現像バイアス制御方式
US5646719A (en) Cleaner-brush having a fiberless segment
JP3007845B2 (ja) カラー電子写真装置
EP0753797B1 (de) Bilderzeugungsmethode mit Zwischenübertragungselement

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

17P Request for examination filed

Effective date: 19971003

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

RIN1 Information on inventor provided before grant (corrected)

Inventor name: TAGANSKY, BOAZ

Inventor name: ROSEN, YOSSI

Inventor name: LIOR, ISHAIAU

Inventor name: LANDA, BENZION

17Q First examination report despatched

Effective date: 19990903

RIN1 Information on inventor provided before grant (corrected)

Inventor name: TAGANSKY, BOAZ

Inventor name: ROSEN, YOSSIC/O INDIGO N.V.

Inventor name: LIOR, ISHAIAU

Inventor name: LANDA, BENZION

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: HEWLETT-PACKARD INDIGO B.V.

17Q First examination report despatched

Effective date: 19990903

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69536043

Country of ref document: DE

Date of ref document: 20100311

Kind code of ref document: P

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

Effective date: 20101021

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

Effective date: 20100606

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20110228

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 FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100120

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: 20100630

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: 20100606

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

Ref country code: DE

Payment date: 20140523

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69536043

Country of ref document: DE