Holographic Overlaminate


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    Join date : 2011-12-04

    Holographic Overlaminate

    Post  zeusk on Sun Jul 08, 2012 4:25 pm

    The present invention includes a process that prints a clear layer or layers over a YMCK composite printer layer on an identification card by using the overlayers as a printable surface. These overlayer panels (OP) are known in dye sublimation printing. They are typically used to protect the dyes that have been sublimated into a substrate from UV degradation. Because the OP has an UV blocking component which causes the OP layer to fluoresce in UV light, when a pattern printed in the OP layer is bathed in UV light, the entire printed pattern (whether a logo, writing or other computer generated design) will fluoresce. Different OP layers have different formations for UV protection. Ribbons with OP layers are available from Dai Nippon of Tokyo, Japan have characteristics ranging from brightly fluorescent to absorbent. Combining more than one OP layer would give the fluorescing printing changes in intensity and hue.

    If the OP layer or layers are used for printing images rather than laid down on the identification card as a full sheet, the sublimated dye not covered by the image would be unprotected against UV degradation. Since the OP layers themselves are very thin, even with the OP layer being laid down on the card as a full sheet, the durability of the image is problematic. Additional overlaminate material can be laminated onto the card, increasing the durability and longevity of the card. This second overlaminate material can be the holographic material or clear material such as PolyGuard (sold by FARGO Electronics, Inc. of Eden Prairie, Minn.).

    If the OP layer is printed over the dye or resin, it does not sublimate into the card but sits on top of the card. When the second overlaminate material is laminated on top of the image printed on the OP layer, a series of ridges with refracting angles are created by the printed image of the OP layer underneath the second overlaminate. By modulating the printed pattern at a high frequency, this process can create something similar to a diffractive grating where sharp angles are embossed into the reflective surface to create more refractive angles to refract light. In one form, the process causes the printed edges to refract the light so that angling the card from a light source will bring the outline of the clear printed image into view when the angle of the refracted light aligns with the viewer.

    When more printed OP layers are used, then one OP layer can be used to protect the YMCK dye printing and the additional OP layer can be used for security imaging. By putting more OP layers on the card, especially when the OP layers have different refractive properties or different UV absorbing or fluorescing properties, additional security features can be devised.

    The overlaminate, which is laminated onto the identification card in a second step, can be scored by the laminating print head of the identification card printer. This scoring would take the form of reflectively compatible angle grooves. Each groove further enhances the OP layer's refractive properties, creating a diffraction grating like image to appear as the card is moved away from a horizontal plane and light reflects accordingly.

    The diffraction grating type image which previously had to be embossed into the overlaminates now can be simulated by printing the OP layers and using the second overlaminate which will reduce costs, time to manufacture, and enable accurate targeting of the image. In addition, if the printed overlaminate is modulated by either printing or special overlaminate manufacturing, more reflective edges are created to enhance the security image.

    Identification card ribbons (FIG. 1) consist of a series of panels (in the case of FIG. 1, consisting of yellow dye (1), cyan dye (2), magenta dye (3), black resin or black dye (4), and a clear overlaminate (5) thus being known as a "YMCKO" ribbon, each of which are coated with dye sublimation ink or resin ink. Each ribbon can be configured with different ink panels depending on the specifications desired. Thus, the ribbon in FIG. 1 could eliminate the black resin panel, thus becoming a "YMCO" ribbon, or the overlaminate could be eliminated, thus becoming a "YMCK" ribbon. All combinations of ribbons that are able to print in full color require the yellow, cyan, and magenta panels. The ribbons are rolled onto circular cores (6) which fit into the printer. The ribbon is situated between the print head and the blank identification card. The printer then receives instructions from a computer that is connected to printer as to the digital images and heating instructions to heat the print head to place such images onto the identification card (7) (FIG. 2).

    FIG. 3 shows the carrier ribbon (Cool and the overlaminate material (9). The overlaminate material is designed so that it would completely cover an identification card when heat from the print head is applied to the entire overlaminate material. The overlaminate has a laminating material coated on the exposed side (which is face down when run through the printing process) of the laminate. When heat is applied, this coating material bonds the lamination material and the identification card together.

    FIG. 5 shows the process of laminating. The ribbon core (6) has been mounted onto the core holder (12) and the ribbon (13) has been pulled through the print head mounting assembly (14) and is pinched between the print head (15) and the identification card (7), which is held tightly by a pinch roller (16). The used ribbon is re-wrapped around a take up roll (not shown). The identification card is fed into the printer by a series of pinch rollers (17) from an input hopper (not shown). The identification card (7) moves with the ribbon panel, and then is pulled in the reverse direction from which it was fed to have the next panel printed upon it. Thus the card moves forward and backwards depending upon its location and the ribbon panel location. The pinch rollers are capable of moving bi-directionally while the print head and print head mechanism remain stationary. Once printed and laminated, the identification card is moved from the print head area by a series of pinch rollers (18).

    In FIGS. 4A through 4D, the results of the bonding can be seen. The identification card (7) has been printed on, and the overlaminate layer (9) has been applied over the full length and width of the identification card. FIG. 4B is a cross-section of the bonded identification card (7). The overlaminate (9) cove's the entire width of the identification card. If the cross-section was lengthwise rather than through the width of the card, the overlaminate would stretch the entire length of the card. The clear feature of the overlaminate allows the printing on the card to be completely visible. The dye sublimation (10) have sublimated into the card, remaining below the surface of the identification card (11) so that the surface is still flat until the overlayer is applied. When and where the overlayer is applied, the card's thickness is increased. Resin ink sits on top of the surface and also provides ridges.

    The overlayer can be supplemented with an additional lamination at a separate station. Identification card printers such as the Cheetah II or the Pro-L (available from Fargo Electronics, Inc. of Eden Prairie, Minn.) incorporate a second lamination station for an overlaminate that is thicker and more durable than the overlaminate layer applied at the printing station. This thicker and more durable overlaminate such as PolyGuard sold by FARGO is on a separate roll from the YMCKO ribbon. These overlaminates are suitable for having a holographic type image embossed therein. In FIG. 4C, the results of applying the thicker overlaminate can be seen. The identification card (7) has the sublimated dyes or resins (10) which have become part of the card. The overlaminate layer (9) has been laid down in a full sheet to cover the entire card, and the thicker overlaminate layer (19) has been laminated on top of the first overlaminate to create a sandwich effect.

    In FIG. 6, the overlayer panel (9) is printed on (20), rather than being laid down as a full sheet. The printed image can be any graphic image created on a computer FIG. 4D shows the cross-section of the card (7) with the overlayer (20) being printed as a clear printed layer rather than as an unbroken sheet. When the thicker overlayer (19) is applied in FIG. 4E, the effect is to create ridges on the thicker overlaminate sheet rather than a smooth surface as was shown in FIG. 4C. When these ridges are created, light reflects from the edges of the underlying overlaminate (20) creating a ghosting image when the card is moved from a horizontal plane.

    In some cases, application of the overlaminate is not a viable option because of the cost of the overlaminate and the price of the printer required to laminate the card. In that case, a similar methodology can be utilized that achieves a similar result. In FIG. 6, the overlay materials is laid down as a first pass, with the heavier overlaminate materials being applied in the second operation, utilizing a hot roller. To achieve a similar result, the first thin overlaminate is applied in reverse, i.e., the entire overlaminate panel is applied except for the image. Instead of a raised surface on the card, the image is actually lower than the overlay material on the card. The ridges that are created are inverted, sot hat the eye can still see the image, since the image is the area where the overlay was not printed. Since there is no overlaminate coating in this embodiment, the image can be seen, otherwise the application of the second, heavier overlaminate would cover and fill in the nonprinted area. Since the non printed area has no protection from UV rays, over time the image (as this is the non printed area) will appear since the dye sublimation inks will fade from exposure to UV light.

    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, other types of overlaminate, over lamination techniques, or techniques for creating ridges in an overlaminate layer can be sued when implementing the present invention. For simplicity, a preferred species is disclosed. However, the invention includes the gnus and the invention should not be limited to any particular species when interpreting broad steps or elements of the invention.

      Current date/time is Tue Feb 19, 2019 6:31 am