GB2250951A - Thermal transfer printed identification card - Google Patents

Abstract

A method of manufacture of an identification card made of plastics material (11, 12) and which comprises application of a photographic image (15) of the user to a surface portion of the card, said image being first applied by a thermal transfer printer to an intermediate shoot (14), the shoot being then applied to the card in order to transfer the image from the intermediate shoot to said surface portion of the card by the action of heat and pressure provided by polished metal plates (10). The intermediate sheet (14) may be polycarbonate or polyester film. The plastics material of the card may be polycarbonate or PVC. A magnetic strip (13) can be applied to the opposite face of the card at the same time as the image is transferred to the card. <IMAGE>

Description

IDENTIFICATION CARD This invention relates to an identification card, and to a method of manufacture of such a card.

Identification cards are used widely, and usually are made from plastics sheet, and on which is provided any required identification data. Personal identification cards are used in many European countries, although they have not yet been introduced for general use in Great Britain.

Cheque cards issued by banks, and credit cards are typical examples of identification cards with which the invention is concerned, and which comprise a backing strip on which a magnetic strip is provided which bears machine readable data corresponding to the personal data of the intended authorised user of the card, and which usually has the personal details also made visible e.g. name, bank or credit account, by printed or embossed information. The card also usually has a strip to bear an indelible signature applied by the user before first use of the card.

With a view to reduce fraudulent use of cards, it would be desirable to provide a card which can bear a photographic image or "portrait" of the authorised user in a tamper-proof manner, and this is possible to achieve by existing techniques, but which are expensive.

Thus, printing of any required information onto cards can be carried out by well known silk screen printing techniques, and this is acceptable for information which has to be produced on a mass production basis on all cards e.g. general information of the type suitable to describe a particular type of card (American Express, Access or Visa for example), but is not a commercial proposition for oneoff information unique to each authorised card user, such as a reproduction of a signature and / or a photographic image.

Relatively unsophisticated identification cards can incorporate a positive photographic strip which is bonded to the card, and / or encapsulated in the card, but this is difficult to manufacture on a mass production basis, and may be liable to tampering by replacement of the photographic strip by one appropriate to a person wishing to make fraudulent use of the card.

It is also known to form printed images by use of a thermal transfer printer using a three colour dry ink transfer ribbon, and one example of such a printer comprises a video printer made by Mitsubishi or Hitachi.

This type of printer may be used to form high quality reproduction of the portrait of a person, but the machine necessarily involves the generation of a substantial amount of heat, and which renders the printer unsuitable for the direct printing of an image onto the usual material from which credit and bank cards are made, namely PVC (polyvinylchloride). The temperatures developed in a thermal printer are such that unacceptable deformation would take place of a PVC card, and which card would not be capable of regenerating its undeformed shape upon cooling of the card. The deformation would render the card unacceptable in appearance to a customer, would probably interfere with machine reading of information on the card, and would also cause unacceptable deterioration in the quality of the portrait displayed.

The invention has therefore been developed primarily with a view to providing a means whereby a portrait, signature or other data unique to a particular authorised card user (or other data if required) may be applied to a card by a process which involves the use of a thermal transfer printer, and despite the fact that the card may be made of a material which could not tolerate exposure to the levels of heat generated within the thermal printer.

According to one aspect of the invention there is provided a method of manufacture of an identification card made of plastics material, and which comprises application of an image bearing required visible data to a surface portion of the card, said image being first applied by a thermal transfer printer to an intermediate sheet and such sheet being then applied to the card in order to transfer the image from the intermediate sheet to said surface portion of the card.

One example of an image which may be applied to the card by this indirect transfer technique comprises a portrait e.g. a photographically derived image of the head of the intended authorised user of the card. In this way, a durable and high quality photographically derived image of a person can be applied to a predetermined surface portion of the card. to correspond with the personal details. Other card details also may be applied by the same off-set technique, or may be applied to the card by any of existing techniques used in mass production of credit and bank cards and the like e.g. silk screen printing techniques or by lithoprinting.

The intermediate sheet will be made of any suitable material which is capable of withstanding (without deterioration or deformation) the heat to which it will be exposed when introduced into the thermal printer, and which can receive a high quality image on its surface, but can permit substantially the entire image to be removed and transferred to the surface portion of the card without any unacceptable loss in quality of the applied image.

One preferred material which has been found in tests to be very satisfactory comprises the proprietary polyester f-ilm supplied by Mitsubishi or Hitachi for use in their video printers. This material has a higher melting point than the usual material (PVC) from which cards are made (PVC is the preferred material from which the cards of the invention are made), and also has a sufficiently smooth surface to perform the dual function of: (a) accepting a high quality image applied thereto by the thermal printer and (b) enabling this image to be transferred substantially without loss of quality from the intermediate sheet to the card.

The intermediate sheet may therefore be applied "image downwardly" onto the card, and then the assembly may be compressed and heated in a press in order to effect transfer of the image from the intermediate sheet to the card. This may take place as a lamination technique i.e.

by compression between opposed pressing plates, and then upon removal from the press the intermediate sheet can be peeled-off, leaving the image on the card.

As indicated above, polyester film is the preferred means for effecting indirect transfer of an image from a thermal printer to the card, but other materials may be found to be suitable, and including polycarbonate film of the type sold under the trade name Makrofol and made by Bayer.

According to a further aspect of the invention there is provided an identification card made of plastics material. and which has an image applied thereon by transfer from an intermediate sheet on which the image has been applied by a thermal transfer printer.

It is also envisaged that, while PVC card is not particularly suitable for direct application of an image from a thermal printer, there may be other suitable plastics card forming materials which may be able to receive a satisfactory image from a thermal transfer printer, and in particular it is believed that polycarbonate sheets may be capable of this direct application of an image e.g. a reproduction of a photographic image. The invention therefore includes manufacture of a card of plastics material having an image applied thereon directly by a thermal transfer printer.

The invention will now be described in detail, by way of example only, with reference to the accompanying drawings which show a preferred embodiment of method steps which may be utilised in order to carry out the invention, and in which: Figure 1 illustrates a batch of identification cards each bearing portraits applied thereon by indirect transfer; and, Figure 2 is a schematic illustration of a lamination process utilised in effecting transfer of the image onto the cards.

The invention may be applied in the production of any required type of identification card, including bank cheque cards, credit cards and security cards. These cards are usually made of PVC. which has sufficient durability for the anticipated life of the card, and the major part of the information applied to the cards may be carried out by well known techniques, including particularly silk screen printing techniques.

Figure 1 of the drawings shows a typical batch of cards which may be produced. and Figure 2 shows schematically a lamination process used in effecting transfer of photographically derived images to the cards.

The production of colour cards and identity cards has to conform to ISO 2894-1980, and the method of production disclosed herein permits PVC cards to be made which conform to this standard, and utilising computer generated data together with a direct print transfer technique. One preferred use of cards produced by this method comprises personal identity cards incorporating a card holder's portrait and, if required, the signature of the card holder.

Origination of the required image information to be transferred may be achieved by the use of a personal computer, together with a range of data acquisition devices including video and ccd cameras, digitising pads, document scanners and others. Data assimilated by the computer via these input devices is assembled into the required format for output by a system programme which is specifically designed for this application. This programme has the facility to combine text and pictorial data in such a way as to provide a mirror image of the required finished card image for output to a print mechanism to be used in the method of the invention. and as described in more detail below.

A preferred batch production technique may comprise production of the print image as an eight up image i.e.

eight card images are produced on one single printed sheet as shown in Figure 1, although this is not mandatory, and is described and illustrated by way of example only.

The image printing is achieved by taking the data output from the personal computer system and which converts this into a printed image by the use of a thermal transfer printer (video printer) which is commercially available from Mitsubishi or Hitachi, and which uses a three colour dry ink transfer ribbon. A polyester film comprises an intermediate sheet for use in the invention, and which is used as the medium to which the printed image is applied.

this film being supplied as A-4 size sheets by Mitsubishi or Hitachi for use in their video printer.

The polyester film is able to withstand the heat generated within the thermal transfer printer, and receives a high quality image, but in a readily removable form.

Thus, the polyester film holding the required printed image is applied with the printed image facing down to the PVC sheets that make up a particular card. This is shown in Figure 2, in which a laminating press has a pair of opposed pressing plates 10, and into which is introduced a batch of cards built-up from standard first and second card core sheets 11 and 12, and which usually will be made of PVC.

For illustration purposes, a magnetic strip 13 is shown, which may bear machine readable information corresponding with the particular identity of the cards concerned.

Figure 2 also shows intermediate polyester film sheet 14, bearing images which have been applied thereon by the thermal transfer printer, and shown generally by reference 15.

The stack of PVC sheets may be pre-printed, or plain, and the complete pack of polyester intermediate film and the PVC sheets are heat bonded together by a series of spot welds to one edge, to ensure maintenance of registration.

The complete pack is then laminated between polished metal plates (10) at a temperature of 1600C for 110 seconds, and then cooled to room temperature over a period of approximately 5 minutes, with adequate pressure being applied to the card material throughout the laminating cycle.

The temperatures and cycle times may vary between different types of laminating press, and these figures are given by way of example only.

On completion of the lamination cycle, the polyester sheet 14 can then be peeled from the surface of the uppermost PVC sheet 12, which thereby leaves the image 15 firmly adhereing to the surface of PVC sheet 12 by an offset printing technique. It will be appreciated that the printed image will now be a true image. rather than a mirror image.

The individual cards can then now be die-cut from the laminated assembly.

The above described technique will provide credit cards having exposed portraits thereon, but it may be desirable to provide a protective cover for the printed image. Preferably, this cover is a protective PVC cover, and which may be produced by a modification to the lamination cycle described above.

Thus, the lamination cycle may be reduced to 60 seconds at operating temperature of 1350C, and upon completion of the lamination cycle, the polyester intermediate sheet is peeled-off as described above. A 3.8 micron thick clear PVC sheet is now secured over the offset produced printed image, and this sheet is shown by reference 16 in Figure 2. The pack is then laminated for a second time at a temperature of 1600C for 100 seconds. The pack is then removed from the press and the individual cards die-cut from the laminated sheet assembly.

The invention involves the use of a thermal transfer printer, in conjunction with a specially developed programme. The assimilation of data through digital computing techniques allows for the creation of the printed image (and any other data as desired e.g. specially designed logos) in mirror image form through software control, taking into consideration the required end results. The thermal transfer printer applies this image to the intermediate transfer sheet (the polyester film), and this is then used to create an off-set applied image to a PVC substrate through lamination or partial lamination techniques.

The cards produced by the method therefore incorporate digitised pictorial images and other computer generated images, in colour for preference, and to a PVC card conforming to the physical properties. characteristics and dimensions of the standard ISO 2894-1980.

Claims (9)

1. A method of manufacture of an identification card made of plastics material. and which comprises application of an image bearing required visible data to a surface portion of the card. said image being first applied by a thermal transfer printer to an intermediate sheet and such sheet being then applied to the card in order to transfer the image from the intermediate sheet to said surface portion of the card.

2. A method according to Claim 1. in which the intermediate sheet is made of polyester film of such a nature that it has a sufficiently smooth surface to perform the dual function of: (a) accepting a high quality image applied thereto by the thermal printer and (b) enabling this image to be transferred substantially without loss of quality from the intermediate sheet to the card.

3. A method according to Claim 1 or 2, in which the intermediate sheet is applied "image downwardly" onto the card, and then the assembly is compressed and heated in a press in order to effect transfer of the image from the intermediate sheet to the card.

4. A method according to Claim 3, in which the assembly is compressed between opposed pressing plates, and then upon removal from the press the intermediate sheet is peeled-off, leaving the image on the card.

5. A method according to Claim 1. in which the intermediate sheet is made of polycarbonate film.

6. An identification card made of plastics material, and which has an image applied thereon by transfer from an intermediate sheet on which the image has been applied by a thermal transfer printer.

7. An identification card according to Claim 6, in which the card is made of polycarbonate sheet of a type capable of receiving an image applied directly thereto.

8. A method according to Claim 1 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

9. An identification card according to Claim 6 and substantially as hereinbefore described with reference to.

and as shown in the accompanying drawings.