EP0671263A1 - Système de transport avec dispositif de maintien électrostatique des feuilles - Google Patents

Système de transport avec dispositif de maintien électrostatique des feuilles Download PDF

Info

Publication number
EP0671263A1
EP0671263A1 EP95300898A EP95300898A EP0671263A1 EP 0671263 A1 EP0671263 A1 EP 0671263A1 EP 95300898 A EP95300898 A EP 95300898A EP 95300898 A EP95300898 A EP 95300898A EP 0671263 A1 EP0671263 A1 EP 0671263A1
Authority
EP
European Patent Office
Prior art keywords
belt loop
belt
transport system
system defined
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP95300898A
Other languages
German (de)
English (en)
Inventor
Manfred R. Kuehnle
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0671263A1 publication Critical patent/EP0671263A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F21/00—Devices for conveying sheets through printing apparatus or machines
    • B41F21/005—Electrostatic holding down devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H5/00—Feeding articles separated from piles; Feeding articles to machines
    • B65H5/004—Feeding articles separated from piles; Feeding articles to machines using electrostatic force
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2404/00—Parts for transporting or guiding the handled material
    • B65H2404/20—Belts
    • B65H2404/25—Driving or guiding arrangements
    • B65H2404/251—Details of drive roller

Definitions

  • This invention relates to a transport system. It relates more particularly to a transport system with electrostatic substrate retention for printing presses and other apparatus requiring accurate positioning registration.
  • Printing is not the only area in which the accurate transport of articles through successive workstations is of concern. For example, in integrated circuit manufacturing processes, semiconductor wafers have to be transported very precisely to successive exposure, masking, etching and lead frame attaching stations in order to create the finished products. Any mispositioning of the wafers results in wastage which can be quite costly to the manufacturer. Mail sorting is another application of interest.
  • the substrate carrier may be a belt or a cylinder.
  • the carrier may even be a so-called moving floor type of conveyor in which one carrier section reciprocates relative to a stationary section with the latter section preventing any back sliding of the conveyed article during rearward motion of the moving section.
  • belt-type transports are usually not used to advance the paper or other printing substrate from one printing station to the next because the belts tend to wander laterally. It would be desirable to be able to provide a belt-type transport system which can achieve good positioning registration accuracy at the printing or other work stations served by the transport.
  • Another object of the invention is to provide a transport system of this type which uses non-mechanical means to retain the substrate to the transport carrier.
  • a further object of the invention is to provide a transport system which is able to safely and reliably transport a variety at different articles including thin and fragile substrates.
  • Another object of the invention is to provide a transport system which is particularly applicable to color printing applications.
  • Another object of the invention is to provide a transport system which is quiet and efficient in that it requires only a minimum amount of power.
  • Still another object of the invention is to provide a transport system which, while using a driven belt carrier, can transport articles through successive work stations and achieve accurate positioning registration at the work stations.
  • my transport system comprises a movable carrier for conveying a substrate through successive of work stations at which various operations are performed at selected positions on the substrate.
  • a transport system incorporated into a printing press for printing in color on a printing substrate such as paper transported through the press. It should be understood, however, that various aspects of the system may be used in other applications that require accurate positioning of a substrate or other planar article. Also, we will dwell primarily on a transport system incorporating a belt-type carrier. However, various features of the invention can also be applied to transports utilizing drum-type carriers or reciprocating (moving floor) carriers.
  • the belt-type carrier in the form of a flexible belt loop, is stretched between a pair of rollers, at least one of which is rotated by suitable motor drive.
  • the upper stretch of the belt loop passes through a plurality of work stations.
  • the work stations consist of a succession of printing stations which are arranged to apply different color printing to a substrate supported by the carrier.
  • the belt loop incorporates an electrostatic hold down grid. This is provided by a pattern of interlaced electrodes which are embedded in the belt. An electrical potential is applied to adjacent ones of these electrodes thereby forming powerful electrostatic fields between the electrodes.
  • the field lines extend above the surface of the belt and interact with the substrate by inducing a capacitive charge in the substrate which, in turn, produces a powerful electrostatic attraction of the substrate for the belt.
  • provision may be made for deactivating the electrodes at selected locations along the belt loop path so that the substrate is no longer attracted to the belt at those locations. For example, as the electrodes approach the exit end of the belt loop, they may be deactivated to allow the substrate to be discharged from the carrier or handed off to another conveyor, rather than being carried around to the underside of the belt loop.
  • belt-type carriers are generally not used to transport the printing substrate through the press because the belt tends to wander laterally and the speed of the belt may also vary for one reason or another.
  • the present transport system while using a belt-type carrier, avoids these problems by forminq in the belt, along with the aforementioned electrodes, a cluster of fine longitudinal parallel lines which extend all around the belt loop preferably near an edge thereof.
  • the two signals are fed to a controller which thereupon 1) controls the position of the belt to some extent, by means of a unique variable geometry roller to be described and 2) adjusts minutely the lateral and longitudinal positions of the work members at the various work stations so that they all operate at precisely the correct locations on the substrate being transported by the belt.
  • the present system after electrostatically holding the substrate firmly in place on the belt or other carrier, maintains accurate position registration for the substrate as it arrives at the successive workstations.
  • the system tracks the motion of the belt or other carrier and applies signals to the various workstations so that the work member at each workstation is located precisely at the correct location relative to the substrate when the substrate arrives at that workstation.
  • the system is thus able to provide "predictive positioning" and the precise conjunction of the substrate position with the work member position to an accuracy of less than ⁇ 5 ⁇ m.
  • the drift of the belt as it wanders laterally can be predicted because of the inherent periodicity of the control mechanism which adjusts the belt continuously as it moves. Accordingly, the position of the write head at each printing station, which head operates in conjunction with a print cylinder at that station, is continuously adjusted in anticipation of the arrival of a print dot from the preceding station so that the next dot will always be superimposed precisely on the preceding dot.
  • the print heads at the various print stations of the press are in continuous microscopic motion, shifting laterally as they write images on the respective print cylinders at those stations in accordance with calculations made by the system controller which integrates the knowledge of belt motion and its periodicity of adjustment with that of the necessary timing and location of the successive print heads.
  • FIG. 1 shows my transport system incorporated into a three color printing press. It should be understood however, that essentially the same transport may be used in a four or five color press or in other applications in which planar substrates have to be moved to successive work stations at which various position-sensitive operations are performed on the substrate.
  • the transport system includes a flexible belt loop 10 made of a suitable strong, resilient, tear resistant material such as a reinforced rubber or plastic material.
  • Belt 10 is stretched between a pair of rollers 12 and 13, one of which rollers, i.e., roller 13, may be rotated by a suitable motor 14 under the control of a system controller 15.
  • Spaced along the belt loop 10 are similar print stations 16 a , 16 b and 16 c capable of printing three different colors on substrates S supported on the upper stretch 10 a of the belt loop.
  • the print stations 16 a to 16 c may print the subtractive colors cyan, magenta and yellow, respectively.
  • the belt loop 10 When the press is in operation, the belt loop 10 is rotated in the clockwise direction as indicated by the arrow A in FIG. 1.
  • Substrates S e.g., paper sheets, are deposited successively onto the upper stretch 10 a of the belt loop by a suitable feeder (not shown).
  • a suitable feeder not shown
  • images in different colors are printed on the substrate.
  • these colors are cyan, magenta and yellow.
  • these three printed images represent the three color components or separations of an original color document or image so that it is critical that the images be printed in exact registration on each substrate S.
  • the present system assures this first, by holding each deposited substrate fast to the belt loop 10 as that substrate is transported through the successive printing stations 16 a to 16 c and second, by controlling the printing operation carried out at each printing station to account for any wanderings, or variations in speed, of the belt loop 10.
  • the belt loop 10 incorporates an electrostatic hold-down grid shown generally at 32 which grips each substrate S as the substrate is deposited on the left end of the belt loop, holds the substrate flat against the belt as it is transported through the press and releases the substrate when the substrate reaches the exit or right hand end of the belt loop.
  • the hold down grid 32 comprises a series of spaced apart, interlaced, finger-like electrodes 34 and 36 which extend across the belt loop 10, the electrode series extending all around the belt loop.
  • Corresponding ends of the electrodes 34 are connected to a common electrode or bus 34 a which extends all around the belt loop adjacent to the left hand edge thereof.
  • a similar common electrode or bus 36 a connects the electrodes 36 near the right hand edge of the belt loop.
  • the electrodes are situated under a high coefficient of friction film 38, e.g., neoprene or silicon rubber, applied to at least the entire outer surface of the belt loop 10.
  • This film 38 not only enhances the holding power of the belt loop 10 for the substrate S, but also protects the electrodes from chemical erosion or the effects of condensation which may be present during certain operating conditions. Film 38 also insulates the electrodes and prevents direct manual contact with those electrodes.
  • a power supply 42 supplies a potential difference of about 1000 volts to busses 34 a and 36 a .
  • the power supply may be connected to those electrodes by brushes 44 a and 44 b as shown in FIG. 1 or by appropriate rolling contacts. Those connections can also be achieved by "capacitive coupling", whereby charges are induced into the hold down grid by the displacement of electrons and holes using capacitor plates (not shown) located in close proximity to the grid at some convenient location such as at the end of the belt loop where it turns around the roller 12 or 13.
  • the electrodes 34 and 36 When the electrodes 34 and 36 are energized, they produce powerful electrostatic fields between themselves all along their lengths.
  • the field lines E reach above the surface of the film 38 and interact with the substrate S deposited on the belt loop 10 so as to induce a capacitive charge in the substrate.
  • This gives rise to a powerful electrostatic attraction of the substrate for the belt.
  • This attraction is, however, effective only at short distances from the belt such as the thickness of the substrate and is effective only when the substrate is in intimate planar contact with the belt. This characteristic is useful, for example, when the transport is being used to route or sort articles such as mail, signatures in a bindery, etc., because it prevents the double feeding of two documents.
  • the electrostatic hold down grid 32 coupled with the high friction film 38 firmly fixes the positions of the substrates S deposited on the belt loop 10. Furthermore, the electrostatic hold down feature is effective over the entire area of the substrate, and is, in fact, proportional to that area.
  • the substrate can be peeled readily from the belt 10 because the resistance forces against peeling are effective only at a line-area which is smaller than e because the width of the line is less than the unit area.
  • a substrate S can be removed easily in a departure path, which, in most cases, will be tangential to the roller 14. In most cases, therefore, it suffices to have the substrate S possess the stiffness of a normal sheet of paper which will cause it not to be carried around the belt roller 14, but rather to be ejected in a straight line direction off the exit end of the belt loop 10 as shown in FIG. 1.
  • a flimsy substrate has no inherent rigidity. Therefore, it could be carried around the roller 14 together with the belt and move to a possibly undesirable position under the belt loop.
  • the hold down grid 32 may be shut off by disconnecting the appropriate electrodes 34 and/or 36. In the illustrated apparatus, this is accomplished by connecting each electrode 36 to its bus 36 a by way of a small photoelectric resistor 46. The resistance of the resistor is inversely proportional to the intensity of light incident on the resistor. Thus, each resistor 46 essentially disconnects its electrode 36 from bus 36 a in the absence of light.
  • the illustrated electrostatic hold-down grid 32 is disabled at a selected location or zone along the belt path by shielding the photo- resistors 46 from light at that location.
  • a light shield 48 may be positioned underneath and around the ends of the belt path as shown in FIGS. 1 and 3, allowing the substrate S to be picked up and released by the belt loop 10.
  • timing track 52 consisting of a series of opaque timing or clock marks 52 a spaced along the belt loop preferably at an edge thereof.
  • the track 52 may be laid down on the belt loop at the same time as the grid 32.
  • Track 56 consists of a cluster of narrow, spaced apart parallel opaque lines 56 a which extend all around the belt loop 10. In the illustrated system, there are five such lines 56 a in track 56. These lines are sensed by a measuring detector 58 mounted to the machine frame just beyond roller 12. Detector 58 may be a grating type detector similar to the one in U.S. Patent 3,584,015, whose contents are hereby incorporated by reference herein, which receives an image corresponding to the track 56 pattern and which, therefore, also has the structure of a grating.
  • the position of the grating-shaped image of track 56 relative to the grating-shaped detector 58 produces a signal from the detector that is indicative of the lateral position of the belt relative to a reference position such as the machine centerline.
  • the detector output is accurate to less than 1 ⁇ m.
  • the signal from detector 58 is applied to controller 15 and is used not only to minimize the lateral wanderings of the belt, but also, as will be described, to control the printing on the substrates S by the printing stations 16 a to 16 c so that those stations print in exact registration on the substrates S which, as noted above, are pinned to the belt loop stretch 10 a .
  • the present system incorporates a unique roller 12 which can grow in diameter at one end of the roller and shrink in diameter at the other end, or vice versa to shift the belt 10 laterally.
  • the system is able to achieve a minute conical deformation of roller 12 which induces an immediate lateral shift of the belt 10 as it moves around the semi-circumference of roller 12.
  • the lateral drift of the belt is continuously monitored and a servo-system adjusts the conicalness of the roller 12 to maintain the belt at a desired position, e.g., the machine centerline.
  • roller 12 comprises a cylindrical central body 62 having shafts 64 projecting axially from opposite ends of that body.
  • a reduced diameter end 64 a of each shaft 64 is journalled in the machine frame 65.
  • a shaft segment 64 b just in board the machine frame is threaded.
  • Slidably supported on each shaft 64 is an annular roller end member 66.
  • Each member 66 has a base 66 a slidably received on the corresponding shaft 64 and which butts against the adjacent end of body 62.
  • each end member 66 has the same outside diameter as the roller body 52 and thus forms a variable diameter extension thereof.
  • the roller body 62 and end members 66 are covered by a sleeve 70 of a resilient material such as rubber.
  • the inner wall 72 of end member section 66 b is tapered to form a conical surface whose radius decreases with the distance from the end of the roller 12.
  • Slidably positioned on each shaft 64 for engagement with surface 72 is an annular wedge 74 having a conically shaped exterior surface 74 a whose cone angle corresponds to that of surface 72.
  • a spur gear 76 having a threaded axial opening 78 is threaded onto each shaft segment 62 b between wedge 74 and the machine frame 65.
  • Each gear 76 may be rotated in one direction or the other on its shaft 64 by a meshing gear 86 which rotates with the shaft 88 a of a synchronous pulsed reversible servo motor 88 mounted to the machine frame 65.
  • Each motor 88 may rotate its gear 76 faster or slower than roller 12 which will move the corresponding wedge 74 in or out to adjust the conicalness of the corresponding end of roller 12.
  • the end member 66 b is shaped and positioned on its base 66 a such that when the asscciated wedge 64 is retracted outward, the resilient roller sleeve 70 will shrink so that the corresponding end of the roller 12 may have a smaller diameter than the mid portion of the roller.
  • the opposite end segments of the roller can each be controlled to have a diameter which is smaller, equal to or greater than the diameter of the middle segment of the roller.
  • the conicalness of the roller as a whole may be varied in one axial direction or the other.
  • the motors 88 that adjust the conicallness of roller 12 are controlled by a standard servo circuit in controller 15 (FIG. 1) in accordance with the output signals from the detector 58 which monitors the lateral drift of belt stretch 10 a .
  • the servo tends to maintain the belt at a selected lateral position, e.g., the machine centerline, within very close tolerances.
  • controller 15 controls one or both of the motors 88 to move the wedges 74 in or out to adjust the conicallness of roller 12 by just the required amount to return the belt to its center position.
  • the printing stations 16 a to 16 c are all the same except that they print using different color inks, e.g., the subtractive color inks cyan, magenta and yellow.
  • Each printing station includes a print cylinder 92 disposed above belt stretch 10 a and an anvil cylinder 94 located parallel to cylinder 92 below belt stretch 10 a . All of the cylinders 92, 94 are rotatably supported by the machine frame parallel to the belt rollers 12 and 14 such that the upper stretch 10 a of the belt loop 10 is in rolling contact with the cylinder couple at each print station.
  • Each print station also includes a print head 96 supported very close to the cylindrical surface of cylinder 92 by a lead screw 98 rotatably mounted to the machine frame such that it is parallel to the cylinders 92, 94.
  • the lead screw 98 may be rotated in one direction or the other by a reversible step motor 102 which receives drive signals from controller 15.
  • the print head, print cylinder and printing controller may be of the types described in my patent 4,792,860 (the contents of which are hereby incorporated by reference herein.) or in my above-referenced patent application.
  • controller 15 issues print signals to the print heads 96 causing the print heads to write electronic images on the associated print cylinders 92 corresponding to the primary color components or separations of an original document or image, the images being written line by line as the print cylinders 92 rotate.
  • the image written on each print cylinder 92 is developed by applying electrostatic thermoplastic ink to the surface of the cylinder from an ink source 106 at an inking station. As described in my patent and parent application, the ink adheres only to the surface areas of the cylinder 92 that were charged by the print head 96. When the inked portions of a rotating cylinder 92 encounter a substrate S passing through the corresponding inking station, the ink is transferred to that substrate.
  • the position of the image written on each print cylinder 92 is coordinated with the position of the substrate S on the substrate carrier such that the image printed on the substrate is located at the correct position on the substrate.
  • the print head when printing using an electronic print head 96 like the ones described in my prior application, the print head is invariably stationary. In accordance with this invention, however, the print head is movable laterally on lead screw 98 to account for any residual lateral drift of the belt loop 10 that may occur due to any lead or lag in the servo circuit controlling belt position. More particularly, the output signal from the detector 58 together with the signal from a second similar detector 58 a both of which monitor belt position are used to shift each print head 96 to compensate for any such drift.
  • the controller 15 which receives the output signals from detectors 58 and 58 a calculates the vector movement of the belt 10 in the direction of travel and applies appropriate drive signals to the step motors 102 which rotate the lead screws 98. Rotations of the lead screws shift the positions of the corresponding print heads 96 laterally so that the electronic image dots being written on the print cylinders 92 are repositioned laterally to compensate for the belt drift. At the same time, the timings of the writings by print head 96 of the image dots on the cylinders 92 are adjusted to compensate for any speed variations of the belt loop 10 as detected by the clock track detector 54.
  • successive substrates S are fed to the upper belt stretch 10 a at the entrance end of belt loop 10 to which they firmly adhere due to the high friction film 38 on the belt and the electrostatic hold down grid 32.
  • the controller 15 coordinates the feeding of each substrate onto the belt loop with the printing operations being carried out at the printing stations 16 a to 16 c so that the images are centered properly on the substrate.
  • controller 15 controls the print head 96 at station 16 a so that it writes an electronic image on the print cylinder 92 at that station which image is inked by the cyan ink source 106 so that when the substrate S reaches the printing station 16 a , the inked image will be transferred to the substrate as the substrate passes between the cylinders 92 and 94 at that station.
  • the controller 15 receives signals from detectors 54, 58 and 58 a indicating the lengthwise position and lateral position of the belt stretch 10 a .
  • the controller determines if the image being written onto the print cylinder 92 has to be shifted axially or circumferentially on the cylinder in order to compensate for any belt position or speed changes. If the belt has drifted laterally, the controller computes the amount of the drift and the longitudinal belt position and delivers a drive signal to step motor 102 to shift the print head 96 in one direction or the other to compensate for that drift.
  • the controller 15 controls the timing of the writing operation carried out by the print head to adjust the circumferential positions of the image dots on the print cylinder 92 to compensate for the belt speed changes.
  • a cyan image will be printed at the proper location on the substrate S despite unwanted belt movements between the time that the substrate is deposited on the belt and the time that the substrate is processed by the print station 16 a .
  • the system continues to monitor the belt movements and to adjust the position and/or timing of the print head 96 at the latter station so that by the time a particular print dot or pixel on the substrate reaches the print station 16 b , the print head 96 at that station will have been adjusted position-wise and timing-wise so that the print head writes the corresponding magenta image dot at the proper location on the print cylinder 72 at station 16 b so that it will be superimposed on the cyan print dot on substrate S when that print dot reaches the print station 16 b .
  • each write head 96 which operates in conjunction with the associated print cylinder 92 may be adjusted continuously in anticipation of the arrival of a print dot so that the next dot will always be superimposed exactly onto the preceding dot.
  • the controller 15 calculates the speed of the belt, the distance of travel of each print dot as well as the position of the dot being written on the print cylinder so that the two can converge simultaneously at the correct location on the substrate.
  • the writing heads are in continuous microscopic motion shifting laterally as they deposit their signals on the respective print cylinders in accordance with the calculations from the controller.
  • belt stretch 10 a should drift to the left as it is transporting the substrate S from print station 16 a to station 16 b , its drift would be detected by detector 58 and passed on to controller 15.
  • the controller which knows the position of the belt stretch 10 a from the signals provided by detectors 54, 58 and 58 a will compute the amount by which the print head 96 at the printing station 16 b has to be moved leftward in order to write a corresponding magenta image dot I m on cylinder 92 which will be superimposed on the print dot P c that was printed on the substrate at station 16 a .
  • the print station 16 b would write an image dot I' m on cylinder 92 which would print to the right of the print dot P c on substrate S.
  • the print head 96 is shifted to the left by the same amount as the belt drift so that the image dot I m which corresponds with the print dot P c will be superimposed on the latter dot.
  • the electrostatic transport of this invention greatly exceeds, in the area of color printing, the presently attainable accuracies of print registration which are typically only in the order of ⁇ 100 ⁇ m.
  • the belt-type transport described above with an electrostatic hold down grid can also be used to facilitate printing on both sides of a substrate.
  • two such transports can be arranged in series as shown in FIG. 4 such that the upper stretch of one belt loop lies in the same plane as the lower stretch of the other belt loop.
  • a substrate S deposited on the belt loop 10 of the left hand transport may be conveyed by that belt loop through a first press which prints on the upper side of the substrate as described above. At the end of that belt loop, this substrate will be handed off to the right hand transport whose belt loop 10' carries an electrostatic hold down grid similar to grid 32 in FIGS. 1 and 2.
  • the grid is activated in the zone at the underside of the belt loop so that the substrate will be suspended from the lower stretch of that belt loop and carried past a second press which can print on the other side of the substrate.
  • the substrate may be handed off to a suitable inclined tray T.
  • a switchable electrostatic hold down grid may also be incorporated into the cylindrical surface of a paper drum or cylinder in order to pick up and let off a substrate from the drum or cylinder in the same manner described above in connection with belt loop 10.
  • FIG. 5 illustrates a reciprocating or moving floor-type transport incorporating my electrostatic hold-down grid.
  • This transport includes a pair of spaced apart, parallel, stationary side plates 116 a and 116 b which incorporate electrostatic hold-down grids 118 a and 118 b .
  • Slidably positioned between the side plates 116 a and 116 b is a reciprocatable plate 122 which also carries an electrostatic hold-down grid 124.
  • Plate 122 is reciprocated back and forth parallel to plates 116 a and 116 b by a linear actuator 126 whose armature is 126 a is connected to one end of plate 122.
  • the stationary hold-down grids 118 a and 118 b are electrically connected in parallel to a voltage source v1 by way of one terminal of a double throw switch 128.
  • the other terminal of switch 128 connects the grid 124 on the movable plate 122 to that same voltage source.
  • the actuator 126 is connected to a second voltage source v2 by way of a second switch 129, the positions of both switches 128 and 129 being controlled by a relay coil 130.
  • the relay 130 actuates the switch 128 so that it connects the hold-down grid 124 on the moving plate 122 to the voltage source V1 and disconnects the hold-down grids 118 a and 118 b on plates 116 a and 116 b from that voltage source. Therefore, a substrate S positioned on the transport is adhered to the moving plate 122 and is caused to advance with that plate.
  • relay 130 when relay 130 is de-energized, switch 129 opens thereby de-energizing the actuators so that plate 122 moves leftward toward its retracted or home position. At the same time, relay 130 moves switch 128 to its other position so that it disconnects the hold-down grid 129 from the voltage source V1 and connects the grids 118 a and 118 b to that voltage source.
  • the substrate S is released from plate 122 and pinned to plates 116 a and 116 b so that it stays in its advanced position.
  • Subsequent reciprocations of the movable plate 122 coupled with the 180° out-of-phase switching on and off of the movable and stationary hold-down grids continue to advance the substrate S toward the right in FIG. 5.
  • a reciprocating-type transport that moves over much smaller distances can be envisioned which uses piezoelectric vibrators or benders to move the movable member(s) of the transport.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Delivering By Means Of Belts And Rollers (AREA)
  • Control Of Conveyors (AREA)
  • Color, Gradation (AREA)
  • Paper Feeding For Electrophotography (AREA)
  • Structure Of Belt Conveyors (AREA)
  • Feeding Of Articles By Means Other Than Belts Or Rollers (AREA)
  • Handling Of Cut Paper (AREA)
EP95300898A 1994-02-14 1995-02-14 Système de transport avec dispositif de maintien électrostatique des feuilles Withdrawn EP0671263A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US19527994A 1994-02-14 1994-02-14
US195279 1994-02-14

Publications (1)

Publication Number Publication Date
EP0671263A1 true EP0671263A1 (fr) 1995-09-13

Family

ID=22720777

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95300898A Withdrawn EP0671263A1 (fr) 1994-02-14 1995-02-14 Système de transport avec dispositif de maintien électrostatique des feuilles

Country Status (6)

Country Link
EP (1) EP0671263A1 (fr)
JP (1) JPH07285698A (fr)
CN (1) CN1071264C (fr)
DE (1) DE671263T1 (fr)
SG (1) SG48706A1 (fr)
TW (1) TW339028U (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0738680A2 (fr) * 1995-04-20 1996-10-23 Heidelberger Druckmaschinen Aktiengesellschaft Système digital précis de positionnement

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001353863A (ja) * 2000-06-16 2001-12-25 Noritsu Koki Co Ltd 画像出力装置
JP4968324B2 (ja) * 2009-12-29 2012-07-04 ブラザー工業株式会社 媒体搬送装置及び記録装置
US10632740B2 (en) 2010-04-23 2020-04-28 Landa Corporation Ltd. Digital printing process
US11104123B2 (en) 2012-03-05 2021-08-31 Landa Corporation Ltd. Digital printing system
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
US9498946B2 (en) 2012-03-05 2016-11-22 Landa Corporation Ltd. Apparatus and method for control or monitoring of a printing system
US9643403B2 (en) 2012-03-05 2017-05-09 Landa Corporation Ltd. Printing system
CN104271356B (zh) 2012-03-05 2016-10-19 兰达公司 数字印刷工艺
BR112014021786B1 (pt) 2012-03-05 2021-06-08 Landa Corporation Ltd estruturas de película de tinta
JP6393190B2 (ja) * 2012-03-15 2018-09-19 ランダ コーポレイション リミテッド 印刷システムのためのエンドレスフレキシブルベルト
GB201401173D0 (en) 2013-09-11 2014-03-12 Landa Corp Ltd Ink formulations and film constructions thereof
JP6207391B2 (ja) * 2013-12-27 2017-10-04 株式会社島精機製作所 裁断機の排出案内装置
GB2536489B (en) 2015-03-20 2018-08-29 Landa Corporation Ltd Indirect printing system
CN104738902B (zh) * 2015-03-26 2017-02-08 温州欧卓服饰有限公司 一种制鞋用的循环输送系统
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
DE112018004530T5 (de) 2017-10-19 2020-07-09 Landa Corporation Ltd. Endloses flexibles band für ein drucksystem
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
WO2019102297A1 (fr) 2017-11-27 2019-05-31 Landa Corporation Ltd. Système d'impression numérique
US11707943B2 (en) 2017-12-06 2023-07-25 Landa Corporation Ltd. Method and apparatus for digital printing
JP7273038B2 (ja) 2017-12-07 2023-05-12 ランダ コーポレイション リミテッド デジタル印刷処理及び方法
IL279556B2 (en) 2018-06-26 2024-06-01 Landa Corp Ltd Part for intermediate transfer to a digital printing system
CN108820947A (zh) * 2018-06-29 2018-11-16 安徽轩扬包装科技有限公司 一种用于印刷机的走纸装置
US10994528B1 (en) 2018-08-02 2021-05-04 Landa Corporation Ltd. Digital printing system with flexible intermediate transfer member
WO2020035766A1 (fr) 2018-08-13 2020-02-20 Landa Corporation Ltd. Correction de distorsions en impression numérique par implantation de pixels factices dans une image numérique
JP7246496B2 (ja) 2018-10-08 2023-03-27 ランダ コーポレイション リミテッド 印刷システムおよび方法に関する摩擦低減手段
DE102018127658A1 (de) * 2018-11-06 2020-05-07 Asm Assembly Systems Gmbh & Co. Kg Elektrostatisches Aufspannen von Elektronikplatten
EP3902680A4 (fr) 2018-12-24 2022-08-31 Landa Corporation Ltd. Système d'impression numérique
JP2023505035A (ja) 2019-11-25 2023-02-08 ランダ コーポレイション リミテッド Ｉｔｍ内部に埋め込まれた粒子によって吸収された赤外線放射を使用したデジタル印刷におけるインクの乾燥
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
CN112309913A (zh) * 2020-09-28 2021-02-02 晶澳（扬州）太阳能科技有限公司 一种用于湿法刻蚀的带液滚轮及湿法刻蚀方法
CN115502127B (zh) * 2022-11-22 2023-03-10 苏州方普智能装备有限公司 一种笔记本电脑键盘清洁设备

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2222846A5 (en) * 1973-03-19 1974-10-18 Honeywell Bull Soc Ind Automatic high speed printing head - comprises memory units for characters and sequences with matrix control cct.
WO1983000658A1 (fr) * 1981-08-25 1983-03-03 Hyllberg, Bruce, E. Rouleau d'impression presentant des caracteristiques electriques reglables et son procede de fabrication
JPS61124455A (ja) * 1984-11-16 1986-06-12 Ekuseru Kogyo Kk 静電吸着ゴムベルト
US5121170A (en) * 1989-05-12 1992-06-09 Ricoh Company, Ltd. Device for transporting sheet members using an alternating voltage
US5246099A (en) * 1992-09-23 1993-09-21 Xerox Corporation Belt steering roller mechanism and steering roll construction
US5295571A (en) * 1991-02-20 1994-03-22 Rollin S.A. Method for continuously controlling an endless band and machine for carrying out this method
JPH06194951A (ja) * 1992-11-20 1994-07-15 Ricoh Co Ltd 電子写真記録装置の現像器

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2222846A5 (en) * 1973-03-19 1974-10-18 Honeywell Bull Soc Ind Automatic high speed printing head - comprises memory units for characters and sequences with matrix control cct.
WO1983000658A1 (fr) * 1981-08-25 1983-03-03 Hyllberg, Bruce, E. Rouleau d'impression presentant des caracteristiques electriques reglables et son procede de fabrication
JPS61124455A (ja) * 1984-11-16 1986-06-12 Ekuseru Kogyo Kk 静電吸着ゴムベルト
US5121170A (en) * 1989-05-12 1992-06-09 Ricoh Company, Ltd. Device for transporting sheet members using an alternating voltage
US5295571A (en) * 1991-02-20 1994-03-22 Rollin S.A. Method for continuously controlling an endless band and machine for carrying out this method
US5246099A (en) * 1992-09-23 1993-09-21 Xerox Corporation Belt steering roller mechanism and steering roll construction
JPH06194951A (ja) * 1992-11-20 1994-07-15 Ricoh Co Ltd 電子写真記録装置の現像器

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 010, no. 270 (M - 517)<2326> 13 September 1986 (1986-09-13) *
PATENT ABSTRACTS OF JAPAN vol. 010, no. 315 (M - 529) 25 October 1986 (1986-10-25) *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0738680A2 (fr) * 1995-04-20 1996-10-23 Heidelberger Druckmaschinen Aktiengesellschaft Système digital précis de positionnement
DE19610953A1 (de) * 1995-04-20 1996-10-24 Heidelberger Druckmasch Ag Digitales Präzisionspositioniersystem
EP0738680A3 (fr) * 1995-04-20 1997-11-05 Heidelberger Druckmaschinen Aktiengesellschaft Système digital précis de positionnement

Also Published As

Publication number Publication date
SG48706A1 (en) 1998-05-18
TW339028U (en) 1998-08-21
DE671263T1 (de) 1996-09-19
CN1121033A (zh) 1996-04-24
CN1071264C (zh) 2001-09-19
JPH07285698A (ja) 1995-10-31

Similar Documents

Publication Publication Date Title
EP0671263A1 (fr) Système de transport avec dispositif de maintien électrostatique des feuilles
US5774153A (en) Digital precision positioning system
EP3271178B1 (fr) Système d&#39;impression indirecte
EP0211562B1 (fr) Plieuse à lame
US5121170A (en) Device for transporting sheet members using an alternating voltage
US4607834A (en) Adjustable sheet guide
ES2107750T3 (es) Impresora electrostatografica de secciones multiples de una sola pasada.
US20020092735A1 (en) Device for conveying printed products through a printing-related machine
US6267225B1 (en) Sheet-conveying device for machines used in the printing technology field
US6676123B2 (en) Device for improving the alignment accuracy of sheet-like material
JPH02198952A (ja) 画像形成装置の用紙搬送装置
EP0491087B1 (fr) Méthode de production d&#39;une image en couleurs
US20070228307A1 (en) Method and apparatus for recording an image of an edge of a moving object
EP0689915A2 (fr) Dispositif pour une alimentation synchronisée de carreaux de céramique dans une machine rotative de décoration et d&#39;émaillage
US5337123A (en) Belt supporting member for a color image forming apparatus
JP2001253049A (ja) 印刷機における引渡し誤差の補償
JP2000351467A (ja) 用紙の送り装置
US4797714A (en) Master and master transport assembly registration system
EP1111476B1 (fr) Système de contrôle pour imprimante
US4793255A (en) Electrostatic pick-up onto and retention of permanent master on a flexible web
EP0924087A2 (fr) Appareil d&#39;impression directe de type tandem
EP0924088A2 (fr) Appareil d&#39;impression directe de type tandem et méthode d&#39;alignement d&#39;une image composite
JPH0758407B2 (ja) 転写型画像形成装置
EP3581382B1 (fr) Commande de positionnement longitudinal d&#39;une bande de film utilisée dans un procédé d&#39;impression
JPH09123415A (ja) 印刷機、および印刷しようとする基体と複数のインキ移し装置との間の圧着力を形成する方法

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): CH DE ES FR GB LI NL SE

EL Fr: translation of claims filed
17P Request for examination filed

Effective date: 19960206

DET De: translation of patent claims
17Q First examination report despatched

Effective date: 19970502

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19980901