CH622365A5 - Method for reproducing an image on a transfer medium - Google Patents

Description

The present invention relates to a method for reproducing an image on a transfer medium from an electrophotographic film forming part of an endless ribbon.

The offset plates are produced photographically by complicated methods requiring the use of silver halide films or photoresists, and the processing of images for incorporation on plates suitable for use on printing presses.

In recent years, electrostatic techniques have been used for the production of such plates, but their quality was so much lower than the quality of the plates produced photographically that this technique has been used only rarely.

The object of the invention is to remedy this drawback.

This object is achieved by the means claimed in claims 1 and 11.

The drawing represents, by way of example, several embodiments of the subject of the invention.

Fig. 1 is a perspective view, with partial section, of an embodiment of a transfer device.

Fig. 2 is a diagram of the device of FIG. 1 showing the main parts of it and their construction.

Fig. 3 is a chronological diagram illustrating the operation of the device.

Fig. 4 is a perspective diagram of a second embodiment of such a device.

Fig. 5 is a diagram of the embodiment of FIG. 4.

Fig. 6 is an enlarged diagram of the tacking application station of FIG. 4.

Fig. 7 is a diagram of another embodiment of a tacking application station, and FIG. 8 is a side elevation view of a pipe for applying the tacker.

The offset printing plates are produced by a technique which requires that the image to be incorporated therein be photographed. The cameras that are used for this purpose are specialized for this purpose and begin the process by exposing a silver halide film contained in cartridges which are attached to the back of the camera. in the image plane of it. The present device is intended to replace the silver halide film cartridges and can be used with cameras for the graphic arts.

The electrophotographic film used is capable of being provided with images of such good quality and gray scale,

if not better, than those produced by photographic techniques, and whose solution is better than the latter. This film comprises an inorganic coating of microcrystalline material which is bonded to a polyester substrate with the interposition of an ohmic layer helping to load the film. The film-like material comprises a coating of radio frequency pulverized cadmium sulfide, the thickness of which is between 2000 Å and 2 n, and which is placed on a layer of 300 to 500 µm thick indium or zinc oxide which, in turn, is arranged on a sheet of stable polyester plastic, about 125/1000 mm thick. Such a film is described in US Patent No. 4,025,339.

Figs. 1 and 2 illustrate an embodiment of the device 10. The camera is only represented diagrammatically by a lens 12.

The device 10 comprises a series of stations comprising a charging station 14, an exposure station 16, a tacking application station 18 and a transfer station 20, which can be followed by an optional cleaning station 22. An endless ribbon 24 rotates in these stations, this ribbon forming an electrophotographic film on which the image can be projected and from which it is transferred. The tape 24 must only contain an electrophotographic film large enough to cover the area which must be provided with the image in the exposure station 16; however, the tape 24 can also be entirely made of electrophotographic film. An electrophotographic film which can be used in the present case is the film mentioned above, described in US Patent No. 4025339.

In operation, a starting point of the ribbon 24 is chosen, such as a point of the edge of the ribbon 24 which can be a metallic piece or a mark 26. This mark 26 can be observed optically or magnetically when the ribbon 24 passes through the different stations to control the operations and the cycle. A second mark 27 can be provided on the opposite edge of the ribbon 24 which can be observed by sensors located on the opposite face of the ribbon. The device can be timed by a clock or a counter without the use of sensors and marks.

The general operation of the device 10 will be described before the details of the different stations in order to present the environment thereof. The device 10 is actuated by passing the ribbon 24 through the different stations. When the film to be exposed reaches the charging station 14, it is charged by a corona source, either during its movement, the corona source being stationary, or by stopping the ribbon, the corona source being displaced relative to the film. Once the film is loaded, the ribbon is rotated until the film is in the exposure station 16 where it is stopped and exposed by the camera through the lens 12. The film is then brought into the tack application station 18 where the tack is applied to the image which has been projected onto the film. The ribbon 24 continues to rotate until

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that it reaches the transfer station 20 where the image provided with a tacker is transferred to a plate or other transfer medium. Once the image has been transferred, the tape 24 continues to rotate and passes through a cleaning station 22 where all remains of tack or any other material is cleaned on both sides of the tape 24, the latter then turning completely. to return to its starting position, ready for the next image and its transfer. The cleaning station 22 is optional since the transfer device 10, when applied to a perfectly receptive transfer medium and in good conditions of use, eliminates all the tack of the film, leaving it ready for be recycled for the next image production operation without the cleaning station having to intervene.

The components of the various stations and their detailed operation will be described below: the charging station 14 comprises a corona voltage source 28 which contains one or more corona wires 30. The corona voltage source 28 can be fixed to charge the film when 'it scrolls past the corona source and the wire 30, as it can also oscillate to produce an equal distribution of load on the film. The film as used below is the part of the tape 24 which is chosen to be exposed in the exposure station 16. The film can also be stopped and the corona source 28 be moved transversely relative to the film to produce a equal load distribution thereon. The corona source 28 will preferably be supplied with a current of around 6000 V.

Once the film is loaded at 8 x 10 ~ 7 C / cm2 or 30 V equivalent, the loaded film is brought into the exposure station 16. This comprises an exposure plate 32 which is arranged above ribbon 24 with a smooth lower flat surface 34 disposed under the unstretched strand of ribbon 24 between the rollers 36 and 38. The plate can be chamfered at each of its ends to facilitate the passage of the ribbon over it, its surface 34 being placed in the image plane of the camera and the lens 12. Thus, the tape 24 is held tightly and gently on the bottom surface 34 so that a smooth, non-pleated surface is presented to the camera. taking pictures and with the lens 12. To further facilitate the passage of the ribbon 24 along the plate 32, the latter will preferably be provided with a series of unrepresented passages which pass through it and which open on its lower surface 34 and which are connected to a source of positive fluid not shown presented. The pressure source is supplied when the ribbon 24 moves, but is deactivated when the ribbon is stopped in the exposure station 16 so that the film is then pressed against the smooth surface 34 of the plate 32.

Once the film has been exposed, it rotates on an ohmic roller 38 and between director rollers 40 and 42 to reach the application station of the tacker 18. The tape 24 is stretched between the director rollers 40 and 42 to form a smooth flat strand, a free space remaining between the film and the application plate of the tacker 44. The tacker is in liquid or dry form and is applied in this free space. Preferably, the tacker in liquid form is brought in by at least one pair of distributors 46 and 48 (FIG. 8). Preferably also the distributor 46 is used in conjunction with the distributor 48 to produce a laminar, non-turbulent flow of tacker in the free space provided between the application plate 44 of the tacker and the film. A tack polarization is preferably applied electrically between the tack plate 44 and the tape 24 to assist the tack particles to adhere to form an image on the film.

The application plate 44 of the tacker has an upper flat surface 50 located between the rollers 40 and 42 to maintain the clearance between the film and the application plate of the tacker. An upper shoe 51 has a lower planar surface 52 arranged parallel to the surface 50. The surface 52 holds the film between the rollers 40 and 42 so that the play is kept precisely. The polarization of the tacker can be produced by a negative current of 5 to 25 V, preferably 11 V. The free space can be of the order of 125/1000 to 1 mm, preferably 3/10 of mm. The upper surface 50 of the application plate 44 of the tacker is polished in such a way that the tacking particles and the fluid 5 flow without turbulence on this surface and do not adhere to any particular point thereof.

Any excess tack is removed from the film by an extractor roller 53 when the film passes over it. The extractor roller 53 is placed at a distance from the strip 24, this distance possibly being less than 150/1000 mm, but preferably 100/1000, and it is electrically polarized so that the tack particles which do not adhere are eliminated. firmly on the film with the image. The polarization can be obtained by a negative voltage of 20 to 250 V, preferably 135 V. The particles of tack and liquid are removed from the extractor roller by a squeegee 54. The tacker which is not used and the tacker charges are collected in a tank 56 located below the other elements of the tacker application station 18.

To assist in removing excess tack particles from the film, a spray bar 58 is disposed above the pull roller 53 and sprays the tack in the free space between the tape 24 and the pull roller 53 to producing a carrier for the tacker particles and an electric field between the extractor roller and the film, which allows excess tacker particles to be removed.

The ribbon and the film continue to rotate from the application station of the tacker 18 on a guide or directional roller 60 to reach the transfer station 20. The transfer station is preferably provided with a transfer support 62. The support 62 is placed in a first corridor 64 which directs it beyond a point where it is tangent to the strip 24, but located at a distance from the latter. The ribbon 24 passes over another roller 66 in the transfer station 20 which determines the position of the ribbon and of the film when the latter passes through the transfer station. A transfer roller 68, 35 which is free to rotate, is arranged so as to be able to move away from or closer to the ribbon 24. The transfer support, such as a piece of paper, extends between the two rollers 66 and 68 , but is not in contact with the strip 24. Preferably, the support 62 will extend in a discharge passage 72 so that its position is determined precisely. When the front edge of the part provided with the image arrives in the transfer station 20, the transfer roller 68 is brought by pivoting against the support 62 to bring the latter in the immediate vicinity of the ribbon 24 and allow the transfer of the image on the support 62 which rotates 45 with the ribbon 24 between the rollers 66 and 68. A transfer bias can be applied between the roller 68 and the ribbon 24, which can be a negative current voltage of 250 to 1200 V. The transfer polarization must be just sufficient to ensure a complete transfer of any image provided with a tacker and will preferably be at a negative voltage of 500 V. The roller 68 can bring the support 62 directly against the film or can leave a slight play to avoid mechanical friction of the image if the support 62 does not absorb the fluid surrounding the tack particles on the film. This game can be from 0 to 4 (i.

ss The tape 24 then moves to reach the cleaning station 22 where it passes over another roller 74 and over a foam cleaning brush 76 which removes any firmly attached tack particles or other material which has not been removed by the transfer operation. The ribbon 24 then passes opposite a spray bar 78 which sprays a cleaning fluid against the film which is cleaned by an air brush or by a squeegee 80 which produces a gentle flow of air over the entire width of the film and may have a baffle for the fluid such as 46 or 48. The nozzle of the air brush 80 is coated with a non-abrasive material; however, the tape and the film thereof will preferably not be touched by the air brush itself due to the air flow escaping from the nozzle. The cleaning solution and excess tack particles are collected in a tank 82

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housed at the bottom of the cleaning station 22. The back or the internal face of the tape 24 is cleaned by a sweep 84 when it passes over the adjustable ohmic guide roller 36. The ohmic roller 36 is provided with a device adjustment at each end 86, one of which is shown, for driving the ribbon around the set of rollers without excessive lateral movement thereof. The ribbon 24 then continues to circulate in the other stations without these being activated and returns to its initial or stop position, ready for another cycle. As mentioned above, with suitable polarizations and correct conditions for application of the tacker and transfer, the cleaning station 22 could be eliminated.

Fig. 3 represents a time diagram for the device 10. However, it should be noted that the time factor between each of the times To to Tio is not decisive and that these times may vary for particular operations, dimensions of components, etc. . The operation will be explained by means of the time diagram using the sensors Ai to An which feel the metallic marks 26 and 27 along the edges of the ribbon 24.

At time To, the commissioning mechanism is actuated, which starts a drive motor 88 producing the rotation of the ribbon, the activation of the pressure valve in the exposure plate 32, the rotation of the extractor roller 53 and the application of a polarization to the extractor roller. At time T2, when feeling the mark 26 by the sensor Ai, the corona voltage source 28 is activated and the load is applied to the film until time T3 when the mark 26 is felt by the sensor A2. At time T3, the drive motor stops, the corona voltage source is deactivated, the pressure valve and the exposure plate 32 are deactivated, pressing the film against the surface of the plate 34. The extractor roller 53 also stops rotating because it is driven by the motor 88; however, it can be kept rotating by a separate drive if desired. The film is then exposed through the lens 12 by opening a diaphragm to project a bright image on the film.

At time T4, before the end of the exposure and the re-rotation of the ribbon 24, the tack pump, not shown, is actuated to circulate the tack in the distributors 46 and 48, and the extractor jet is actuated to fill the space between the extractor roller 53 and the tacking tape 24 so that the extractor roller can function properly. At time T5, when the film has been suitably exposed, for a time of 1 to 10 s, the drive motor 88, the pressure valve in the plate 32, the tack polarization on the plate 44 and the drive of the extractor are activated. The film then moves through the application station of the tacker 18 and is felt by the sensor A3 at time Tô, indicating that the film has passed through the application station of the tacker. This disables the tack pump and tack polarization; the film is then transported to the transfer station 20 during the period of time from Tß to T7.

At time T7, when the mark 26 is probed by the sensor A4, the drive motor 88 increases its speed for the transfer operation because it has been discovered that the application operation of the tacker takes place more favorably at a slower speed than the transfer operation. The tape 24 can move in the tacking application station at approximately 125 mm / s and can be transferred at a speed of approximately 200 mm / s. When the front edge of the film reaches the transfer station 20, the mark 27 is felt by the sensor A5 at time Ts, which activates the polarization of the transfer roller 68 at the same time as it is actuated to move towards the support 62 and press the latter against the ribbon 24 so that this support 62 is intimately applied against the film of the ribbon 24 when the latter passes between the rollers 66 and 68. The first time that the mark 26 is felt by the sensor Aö, at time T9, it activates the components of the cleaning station 22. The tape 24 then rotates in each of the stations so that the residual materials are eliminated. When the sensor Aö marks the mark 26 a second time, at time T10, all the systems and stations are deactivated and the ribbon 24 is stopped, ready for the next image production and the transfer thereof.

Referring to fig. 4 and 5, in a second embodiment, the charging station 14 and the exposure station 16 remain as described above; however, the cleaning station 22 has been eliminated and a different tack application station 18 'as well as a different transfer station 20' are also used. The basic operation, with the exception of the cleaning operation, remains the same as that described above. The different rollers of fig. 1 and 2 have been replaced by two main support rollers 90 and 92, at least one of which is actuated by the motor to frictionally drive the ribbon 24, as before. A third adjustable steering roller 94 cooperates with one end of the ribbon 24 to ensure correct alignment of the ribbon in a similar fashion to that of the adjustable roller 36. The roller 94 is connected to an articulated bar 96 which is fixed so as to pivot adjustable around a hinge pin 98 to properly adjust the tension of the tape 24. The pin 98 could, of course, be replaced by two or more points, adjustable at the outer ends of the articulated bar 96, as described previously.

The film of the ribbon 24 is again loaded and exposed as before; however, the tacker is applied by a tacking feed roller 100 which picks up the tacker by adhesion from a tacking tank 56 and applies it uniformly over the entire width of the tape film 24. As mentioned above , the application plate 44 of the tacker and the upper shoe 51 can be arranged so as to maintain the optimal free space between the tape 24 and this application plate 44 of the tacker. The tacker application stations 18 and 18 'are, of course, interchangeable, if desired.

Once the film has been provided with a tacker, it continues to move around the roller 94 to the transfer station 20 '. The film is driven until its front edge is located towards the end of the transfer station 20 '. The ribbon 24 is then stopped and the support 62 is brought in the immediate vicinity of the ribbon 24 for the transfer operation. The film is brought in close proximity to the support 62 by a reciprocating transfer roller 102 which is arranged parallel and below the tape 24.

Referring to the time diagram in fig. 3, it can be seen that the sensors A4 and A5 are replaced by a single sensor, that the times T7 and Ts coincide, that the motor 88 stops, stopping the rotation of the ribbon, and that the transfer polarization is applied to the support 62 and not with the roller 102. The latter is activated and is placed in position 104 illustrated in dashed lines during a back-and-forth movement through the film, then to bring this film in the immediate vicinity or in contact with the support 62 over the entire length thereof. The roller 102 is then returned to its initial position away from the ribbon 24.

A common method of determining the position of the support 61 parallel to the upper strand of the ribbon 24 consists in using a vacuum plate 106. This vacuum plate 106 occupies a first open or load position 108 which has a lower flat surface 110 pierced with passages for a suction fluid. The paper or plate material 62 such as aluminum is placed on the plate 106 in the loading position 108 and the vacuum source not shown is actuated to press this support 92 against the plate 106 which is then pivoted in the station transfer 112. The plate 106 may contain other means for fixing the support 62 to the surface 110 and can be suitably moved between its loading position 108 and its receiving position 112 by pivoting around a pivot 114. The polarization transfer plate is then applied to the plate 106 and, when the transfer roller 102 has returned to its starting position at time T9, the plate 106 moves from its

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receiving position 112 to its charging and discharging position 108 and the cycle is stopped, ready for a new medium 62 to be loaded and the next image and the next transfer operation to take place.

The application station of the tacker 18 'is best illustrated in FIG. 6. The feed roller of the tacker 100 rotates with its underside immersed in the tacking fluid 116 which is kept agitated by a tacking stirrer 118 to keep the tacking particles in suspension and without depositing them in the bottom. tank 56. The top of the tack feed roller is about 5 to 10 percent away. from the lower surface of the tape 24. The tacking particles adhere to the periphery of the roller 100 during the rotation of the latter in the fluid 116 and are attracted in their upper position on the film portion of the tape 24. The fluid excess tacker is removed from the tape 24 when it leaves the application plate 44 of the tacker by an extractor roller 53 which is kept clean by sweeping 54. The play between the surfaces 50 and 52 is also more clearly illustrated and is of preferably from 125/1000 to 1 mm, the clearance of the extractor roller being approximately 100/1000 to 150/1000 mm.

Fig. 7 illustrates a third embodiment of the tacker application station 18 ". In this embodiment, a flexible sheet 120 is connected to a pair of drive rollers 122 and 124. The rollers 122 and 124 are driven in tandem to rotate the sheet from the roller 122 around a pair of guide rollers 126 and 128 on the second drive roller 124 to apply the tacker to the film when it passes through the station 18 "tacking application. The application plate 44 of the tacker, the upper shoe 51 and the guide rollers 40 and 42 have been shown simply by way of illustration. The flexible sheet 120 or the tacking application station of the type of that of FIG. 7 can also be used in the embodiment shown in FIG. 4 with or without tacker application plate 44 and upper shoe 51, depending on the tension and position of the tape 24. Once the film has passed through the 18 "tacking application station, the drive rollers 122 and 124 turn in the opposite direction and rewind the flexible sheet 120 on the roll 122. The tacker can be picked up by the sheet when it unwinds from the roll 122 or can be applied by a pipe such as the pipe 46 in Fig. 1 and 2 after it has passed on roller 126.

The tackle distributors 46 and 48 and the air knife or air brush 80 are most clearly illustrated in FIG. 8 where the distributor 46 is shown in section. The air or tacking fluid is applied by a pump to one or more openings 130 connected to a plurality of passages 132 which direct the fluid into the first chamber 134. The chamber 134 as each of the following chambers and baffles extend over the width of the dispenser which is substantially equal to the film, provided with the image, of the tape 24. When the fluid has filled the first chamber 134, it flows through a narrow passage 136 into the second chamber 138, following a serpentine path, and from the second chamber 138, through a passage 140, into a third chamber 142 and, similarly, from the third chamber 142 through a narrow passage 144 towards an outlet slot or nozzle 146, in a non-turbulent laminar flow, through the nozzle 146 ensuring a substantially constant flow of tacking over the width of the strip 24. The distributor 46 may be in one piece or may be formed by an upper part 148 assembled with a lower part 150 for train pa wsages and the rooms between them.

The tacker will not be applied, preferably, over the entire width of the tape 24 so that the rear part of the tape remains dry so that the motor 88 can drive it frictionally by one or more rollers. Preferably, the roller 74 is driven when the ribbon 24 makes a 180 ° turn around it. Each of the rollers will preferably be made of metal and of suitable size to ensure ohmic contact by the rollers 36 and 38.

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Claims (28)

622,365 CLAIMS 1. Method for reproducing an image on a transfer medium from a part forming an electrophotographic film of an endless ribbon, characterized in that the ribbon is rotated to pass it sequentially through a series of stations, we load the film in a charging station, we locate and stop the film against a flat surface in an exposure station, we apply a constant amount of tack through the lower strand of the film in a station application of a tacker, and an image of the film is transferred to a support in a transfer station. 2 s 2. Method according to claim 1, characterized in that the rotator is rotated in the immediate vicinity of the film. 3 622,365 and position the ribbon and the film when the latter passes through the transfer station, a corridor (64-72) to bring the adjacent support, but at a distance from the ribbon on the anterior face of it and a transfer roller ( 68) opposite the roller (66) which is actuated by the drive means to press on the support, move it and bring it in close proximity to the film to allow the transfer of an image on the support. 3. Method according to claim 1 or 2, characterized in that the application of tacker comprises the fact of forming a smooth and flat strand of film when it passes through the application station of the tacker and of placing a surface d application of smooth and level tacker parallel to the strand and at a distance therefrom. 4. Method according to one of claims 1 to 3, characterized in that the application of tacker comprises the fact of electrically polarizing the surface relative to the film. 5. Method according to one of claims 1 to 4, characterized in that the transfer operation comprises bringing the support in the immediate vicinity but away from the ribbon and moving the support to bring it close film immediately when it passes through the transfer station. 6. Method according to one of claims 1 to 4, characterized in that the transfer operation comprises the fact of holding the support against a flat surface, of forming a flat strand of the film when the latter passes through the station transfer, moving the support parallel to the planar strand, stopping the film in the planar strand and then bringing the film in the immediate vicinity of the support. 7. Method according to one of claims 1 to 6, characterized in that the film is cleaned in a cleaning station after it has passed through the transfer station. 8. Method according to one of claims 1 to 7, characterized in that the transfer operation comprises the fact of electrically polarizing the support relative to the film. 9. Method according to one of claims 1 to 8, characterized in that the application of tackifier comprises the fact of applying a liquid tackifier, in the form of laminar flow and not turbulent, to the film. 10 10. Method according to one of claims 1 to 8, characterized in that a pressure is applied against the tape in the exposure station to move the tape away from the flat surface when it rotates in the exposure station . 11. Device for implementing the method according to claim 1, characterized in that it comprises an endless rotating ribbon (24) comprising an electrophotographic film, the ribbon and the film comprising an anterior exposure side and a rear side, drive means (88) for rotating the ribbon and passing it sequentially through a charging station (14) adjacent to the front face of the ribbon and which comprises means producing a corona effect (28, 30 ) for loading the film, by an exposure station (16) comprising means (32, 34) for locating and stopping the film in an exposure plan, by a pointer application station (18) comprising means (44, 46, 48, 50, 51, 52; 100, 53; 120,122, 124, 126, 128) for applying a substantially constant amount of tacker transversely to the front side of the film and by a transfer station (20) comprising means (64, 66, 68, 70, 72; 106) for transferring an image of the fi lm on a support and means for bringing the support and the anterior face of the film in close proximity to one another during the transfer. 12. Device according to claim 11, characterized in that the tacker (116) is liquid, and in that the tacking application station comprises means for supplying the tacker in a laminar and non-turbulent flow on the face film. 13. Device according to claim 11 or 12, characterized in that the tacking application station comprises a tacking application plate (44) having a smooth flat surface (50) located at a distance from the front face, and by the fact that the means for supplying the tacker comprise at least a first conduit (46) having at least a first baffle connected to a longitudinal outlet (146) to allow the tacker to flow on the film. 14. Device according to one of claims 11 to 13, characterized in that the exposure station comprises a plate (32) disposed opposite the rear face of the tape and having a flat surface (34) placed in the plane under the stretch of the ribbon to press the film against the flat surface. 15 15. Device according to claim 14, characterized in that the plate comprises fluid pressure means arranged through the flat surface and which are actuable when the ribbon moves to facilitate the passage of the latter in the station exposure beyond the surface of the stage. 16. Device according to one of claims 11, 12, 14 or 15, characterized in that the tacker application station comprises a roller (100) for tacking feeder arranged parallel and adjacent to the front face of the tape for feeding the film with tacking device, and a tray (44) for applying the tacking device adjacent to the feed roller comprising a flat smooth surface located at a distance from the front face of the tape. 17. Device according to claim 16, characterized in that the tacking application station comprises polarization means for electrically polarizing the film with respect to the tacking application plate through the space between them, for assist in the application of the tacker. 18. Device according to one of claims 11 to 16, characterized in that the tacking application station comprises a shoe (51) having a flat smooth surface (52) disposed against the front face, parallel to the flat surface of the tacker application plate to form a free space between the film and the tacker application plate. 19. Device according to one of claims 11,12,14 or 15, characterized in that the application station of the tacker comprises a curtain for applying the tacker comprising a flexible sheet (120) having a first strand arranged in parallel on the anterior face of the film to constitute a free space therewith when the latter passes through the tacking application station, the latter comprising means (122,124, 126,128) for driving the sheet from a tacking post located beyond the anterior side of the film to apply tacking to it. 20 20. Device according to one of claims 18 or 19, characterized in that the application station of the tacker comprises polarization means for electrically polarizing the film with respect to the application plate of the tacker through the space free to help with the application of the tacker. 21. Device according to claim 19 or 20, characterized in that the tacking application station comprises a tacking application plate (44) having a smooth flat surface disposed against the flexible sheet in the first strand thereof. this on the opposite side of the film to maintain free space. 22. Device according to claim 21, characterized in that the application station of the tacker comprises a shoe (51) comprising a smooth flat surface disposed against the rear face parallel to the flat surface of the tacking application plate for maintain free space. 23. Device according to one of claims 11 to 22, characterized in that the transfer station comprises a support roller (66) disposed against the rear face to support 24. Device according to claim 23, characterized in that the transfer station comprises polarization means for electrically polarizing the film with respect to the support and with respect to the transfer roller to aid in the transfer operation. 25. Device according to one of claims 11 to 22, characterized in that the transfer station comprises a load plate (106) having a planar surface comprising means for holding the support against the planar surface, and by the fact that the drive means comprise means for moving the surface of the load plate from a first loading and unloading position, in which it is located at a distance from the strip, to a second transfer position, in which it is brought closer of, but not in contact with, the front side of the tape and parallel to it, and a roller (102) adjacent to the back side of the tape, but prevented from coming into contact with it, parallel to the surface of the plate to bring the film in the immediate vicinity of the support to transfer an image thereon. 25 30 35 40 45 50 55 60 65 26. Device according to claim 25, characterized in that the transfer station comprises polarization means for electrically polarizing the film with respect to the support and with respect to the plate to aid in the transfer operation. 27. Device according to one of claims 11 to 26, characterized in that it comprises a cleaning station (22) following the transfer station and which comprises means (76, 78, 80, 84) for ridding the tape and film of any excess tack. 28. Device according to claim 27, characterized in that the transfer station comprises polarization means for electrically polarizing the film with respect to the support to aid in the transfer operation.