FR2777828A1 - Making thermotransfer materials available at point of image production, useful for improving productivity when making polychrome and offset images - Google Patents

Abstract

Each cassette (9) contains a narrow thermotransfer ribbon (8) mounted on winding and reserve spools (5,4) and guided by cylinders (6a,6b,7a,7b). A laser (2) mounted on a translation plate (3) focusses light on to the ribbon held adjacent to a substratum (1a) mounted on a drum (1). The cassettes (9) having the correct characteristics are automatically loaded on to the translation plate using attached bar coding, integrated circuit or by electromagnetic emission

Description

The present invention relates to the manufacture of prints, in

  particular of polychrome prints or forms of offset printing, by thermotransfer with use

  a narrow strip as a transfer sheet.

  The present invention relates to a method which optimizes the provision of thermotransfer material and in addition, correctly provides different materials for the purpose

  respective at the correct time respectively.

  The thermotransfer process has been known for years.

  In principle, a substrate which can be the final substrate or an intermediate support, is brought into contact with a layer of color ink which is applied to a support and which is transferred onto the substrate, by point and in accordance with the image. ,

under the effect of heat.

  Using sheets of different colors, several colors can also be applied successively and a full color printing can be achieved. If the substrate is an intermediate support, the finished polychrome image is then transferred in another step to the target substrate. In addition, a print form can also be coated with a layer according to the image, using a suitable polymer. If, for example, the base of the print form is hydrophilic and thus does not absorb color, the elements forming the image are transferred by heat transfer as positive on this print form and are then

  hydrophobic, therefore absorb color.

  DE 44 30 555 discloses an elegant process which can be used for this. In this process, the heat transfer sheet is made in the form of a narrow strip. The problem in this method is that the heat transfer tape must be replaced after each image formation respectively after some image formation. In addition, it is not explained how thermotransfer bands designed from different materials can be used.

  choice for various requirements as would be desirable.

  The object of the present invention is to provide a method in accordance with the genre and a device such that there is a simple availability of the transfer tape and that this availability can be guaranteed in a simple way for several image formations and that in addition, different materials for thermotransfer strips can be accessible at the same time, as is for example necessary

  1 0 when printing in full color.

  The object is solved according to the present invention by a method characterized in that several heat transfer bands are produced respectively in a cassette, in that the cassettes are managed using a control device which provides the means management and control so that each cassette can describe itself with regard to different states or can give information about itself and identify itself, and by a device for carrying out the process, characterized in that several heat transfer strips produced respectively in a cassette are collected inside a storage device, in that there is provided a device for receiving the cassettes which can approach the storage device and which is in an active relationship with an imaging unit and in that there is further provided a control device for the management and control of the cassettes in function tion of an order of

image formation.

  The thermotransfer strip is produced in a cassette.

  A superior control device provides management and control means, for example in the form of a software program which can manage several cassettes, together with the knowledge concerning the requirement relating to the type of thermotransfer strip in function of the respective use, the management and control means having access to the storage means which make available a certain number

  of cassettes with thermotransfer strips.

  The management of the cassettes produced can be done by means of bar codes applied to the respective cassette or by an electronic chip attached to the respective cassette. The control device can be of a higher type but also more decentralized. Thus, for example, a superior control device can operate over the Internet. A bar code which has just been read calls up information coming from a manufacturer's database for thermotransfer tapes / cassettes so that an automatic identification of the thermotransfer tapes respectively used becomes possible. In this way, for

  each transfer band, it is possible to obtain a self-

  - information on the state of the operating means, thermotransfer strip (empty or full), degree of wear, suitability of the material for the respective use (printing of different substrates such as paper, anodized aluminum , sheets

  PET (for example, in the case of a soluble offset without water) and the like.

  Thus a higher control / adjustment through the manufacturer of the heat transfer bands is possible since all the usage data (for example, durability, date

  there, etc.) are present and can be called.

  This can also be obtained by means of the electronic chip which has been added and which can be precisely described and therefore updated after any training.

2 5 of images.

  When using the microchip, a superior control device is not absolutely necessary; this could also be arranged in a decentralized manner, that is to say a control device by printing machine should be sufficient to manage the self-information of the cassettes of

thermotransfer strips.

  However, the identification of the heat transfer bands produced respectively in a cassette can also be done without contact. So for example, an electromagnetic transmission (microwave, infrared, light, etc.) is conceivable as it is already the case for a card

identification for ski lifts.

  The different requirements for thermotransfer tapes can be: different colors when performing a polychrome print (for example, successively, cyan, magenta, yellow and black) or various polymer chemicals for the use of the form printing in different areas of editing (for example, tape for a small print with simple successive deletion of the image for reuse or tape for a large print with no possibility of reuse or with a long duration for the realization of - possibility of re-use or with different color systems (for example, mineral oil colors or colors

1 5 curable in UV).

  The present invention is explained more precisely below.

  after using the preferred embodiments and figures.

  The figures show: Figure 1: a side view of a device for thermotransfer for the execution of the thermotransfer process with a tape guiding mechanism, Figure 2: a side view of a device for the execution of the thermotransfer process thermotransfer with the functional components according to a perspective view, FIG. 3: a global embodiment with a device for carrying out the thermotransfer process with the use of a cassette at the same time as a storage unit for cassettes, Figure 4: an embodiment for the multiple use of a

  transfer tape which is housed in a cassette.

  Figure 1 shows a substrate cylinder 1 on the surface of which is applied a substrate la. A belt transport mechanism comprising a reserve cylinder 4 and a winding cylinder 5 (the identification of the reserve cylinder 4 and the winding cylinder 5 is significant only for a direction of travel of the heat transfer sheet 8 in the form of a strip, in the opposite direction, this would of course be the reserve cylinder 5 and the winding cylinder 4), two adjusting cylinders 6a, 6b and two guide cylinders 7a, 7b guide a thermotransfer sheet 8 in strip form, hereinafter called transfer strip, near the substrate cylinder 1 respectively in contact with the substrate la. A laser writing head 2 concentrates one or more rays on the strip

transfer.

  The laser writing head 2 and the tape guiding mechanism 4, 5, 6, 7 are arranged together in the preferred embodiment on the cross unit 3 by which they

  can be moved across the width B of the substrate cylinder 1.

  At least the winding cylinder and the

  - reserve are housed in a cassette 9.

  Figure 2 shows this embodiment with the functional components in a perspective view. The winding motors 10a, 10Ob form with the base plate 11il the mechanical parts of the cassette receiving station. For the provision of the tape, the cassette is placed on the receiving station and the tape is extracted with appropriate means (not shown) and positioned by

  through the return rollers 6a, 6b.

  FIG. 3 shows a global embodiment for

  the execution of the method according to the present invention.

  The cassette receiving device 12 cooperates with a storage device 18 in which are stored tape cassettes 9 of the most diverse materials intended for the most diverse uses for printing different substrates or with different colors. The cassette receiving device 12 is mounted at the same time as the image forming unit 2 on the cross unit 3. This is used to drive the cassette receiving device 12 near the storage device 18 A cassette 9 already loaded on the cassette receiving device 12 is removed using the clips of the storage device 18. Conversely, a cassette located in the storage device is first positioned, then the cassette receiving device 12 approaches the storage device 18 and the

  cassette is received by the latter.

  In this preferred embodiment, an image forming cycle takes place as follows: An image formation order is predefined from the outside, for example, the image formation of a print form. This implies that a form of printing is made available, for example an anodically preoxidized aluminum plate is fixed as substrate 1a on the substrate cylinder 1. These operations are known from the relevant publications on imaging on plate and for this reason are not shown here. A control device which manages the cassettes 9 and the tapes 8, now checks in its storage unit (database) whether a suitable transfer tape is present in the storage device 18. If so, the latter is brought to the transfer point for reception by the cassette receiving device. It is then taken care of by the latter. The imaging station then goes with the tape

on the starting position.

  During this process, the strip is not yet mounted on the substrate. The transfer tape must possibly be wound up in the correct position in the case where, for example, the tape admits several image formations one behind the other. The management device knows the state of the tape and causes the execution of this process. When the substrate is ready, the cycle

image formation begins.

  The cylinder and the strip are accelerated to a theoretical speed, the strip is brought to the substrate cylinder 1 at least by the two adjusting cylinders and the imaging

begin.

  After imaging, the transfer tape can be wound up in a defined position. It is preferably a position from which another imaging cycle can start directly. Then the cassette is again

returned to the storage unit.

  If no suitable tape is present in the storage unit, a cassette is requested by the operator with an appropriate transfer tape according to the parameters and the product specification. The operator then engages said cassette at a transfer point and thus loads the unit

  storage. Then the process continues as described.

  A planned loading of the storage unit can take place at any time, even at the same time as imaging. It would be possible to choose for example as a criterion, the state in which the image formation which is in progress is the last possible without changing cassettes or the state in which the number of possible image formations is lower to the preset number. To generate a full color image, image formation on the substrate must take place for each color with a transfer tape which has a coating of the corresponding color in order to generate, in known manner, a full color impression. In order to achieve, for example, a four-color image with black, cyan, magenta and yellow, the respective color selections must be subjected successively to the image formation process and the cycle described will therefore be carried out four times with the bands.

corresponding transfers.

  The method includes the use of a training unit

  image and tape transport device.

  The principle is shown in FIG. 4. The transfer tape 8 may not be reused in the places which have already been transferred during an image formation, and thus on all the trace of the image formation 14a 14b 14c , as in the case

  carbon tape in a traditional typewriter.

  Multiple use of the transfer tape cannot be

  achieved only by providing unused traces.

  This is done so that the strip has a width which is a multiple of the width t of the imaging with respectively a safety margin a. The transfer tape 8 is now divided into image traces 14a 14b 14c and during each image formation, a trace is made available. For this, the transfer band 8 must be able to be moved in a defined manner with respect to the laser beam (s) L, as shown by the arrow 15. In total, during image formation, the device of course passes through always the width of the substrate cylinder synchronously to the laser imaging unit and writes a trace 16 at each cylinder rotation until the entire forming surface

image is scanned.

  During imaging, the tape unwinds from the reserve cylinder 4 and is wound on the take-up cylinder 5. After imaging, the transfer tape is then rewound in a position without contact of the transfer tape 8 and of the substrate 1a respectively of the substrate cylinder 1, is moved onto an unused track and is then ready for the next

image formation.

  The management of traces and the request for new tapes, ie the change of cassettes comprising tapes used by new tapes must take place again by means of the management and control means. In addition, in the storage unit, depending on the capacity, several cassettes of the same color can be placed there to allow a greater number of images to be formed without

  manual intervention, ie without changing the cassette.

  In addition, the process for generating impressions is not limited to the usual color selections such as cyan, magenta, yellow and black. We can manufacture transfer bands which have special colors, a second chromatic range such as for example, the SWOP chromatic range in addition to the Euro chromatic range or a chromatic range with more than four colors such as the seven-color range according to the teacher. K ppers or the six-color range from Pantone. Depending on the capacity of the storage unit, these may be available at the same time in the system or only by replacing the cassettes. The arrangement shown in the embodiment is of course only one arrangement among others which can be used in a modified manner by a specialist during the execution of the method. The cassettes can be held for example on a wheel of the storage unit so that the transfer positions for the operator and the transfer position for 1 o image formation are accessible just as well with all the others positions. Embodiments as used in jukeboxes for the management of magnetic tapes or in other alternative data carriers in

IT is possible.

Claims (10)

  1. Method for providing a thermotransfer material for the formation of images by thermotransfer with the use of a narrow strip of thermotransfer, characterized in that several strips of thermotransfer (8) are produced respectively in a cassette (9 ), in that the cassettes (9) are managed using a control device which makes the management and control means available so that each cassette (9) can describe itself in regarding different states or can give   information about herself and identify herself.   2. Method according to claim 1, characterized in that a superior control device is provided by means of which the manufacturer's databases can be accessed via the Internet and in that, a control / adjustment   cassettes (9) of the most different materials are executed.   3. Method according to claim 1, characterized in that a decentralized control device is provided by machine   print to manage the self-information of the cassette (9).   4. Method according to claim 1, characterized in that the self-shaping of the cassette (9) is carried out using bar codes.   5. Method according to claim 1, characterized in that the self-shaping of the cassette (9) is carried out by means of a   electronic chip added and can be described.   6. Method according to claim 1, characterized in that the self-shaping of the cassette (9) is carried out without contact,   by means of an electromagnetic transfer.   7. Device for carrying out the method according to claim 1, characterized in that several heat transfer strips (8) produced respectively in a cassette (9) are collected inside a storage device (18), in what is provided a cassette receiving device (12) which can approach the storage device (18) and which is in an active relationship with an imaging unit (2) and in that there is further provided a control device for the management and control of the cassettes (9) according to an order image formation.   8. Device according to claim 7, characterized in that the control device comprises a database. 9. Device according to claim 7, characterized in that the thermotransfer strip (8) has at least in a cassette (9), a width which is a multiple of the width t of the image formation so that several traces of training   images (14a, b, c) can be separated.   10. Cassette for use in the method according to claim 1 and in the device according to claim 7, characterized in that at least one winding cylinder and a reserve cylinder (4, 5) are provided on which a   heat transfer tape (8) can be rolled up and unwound.