[0001] Credentials include identification cards, driver's licenses, passports, and other documents. Credential manufacturing devices process substrates, such as plastic card substrates using one or more processing devices form credential products. Common processes performed by such devices on substrates include printing processes, laminating processes, data reading and writing processes, for example.

[0002] Printing processes performed by credential manufacturing devices generally operate to print information, such as a photo, account numbers, identification numbers, and other personal information to the substrate. Such printing processes generally use a thermal print head and a print ribbon. The print ribbon generally includes a series of colored dye panels (e.g., yellow, cyan and magenta) and a black resin or fusible pigment panel (hereinafter "black resin panel"). The print head includes a line of resistive heating elements, each of which is selectively activated to heat a corresponding portion of one of the panels of the print ribbon and transfer a pixel of print material (i.e., dye or resin) from the panel to the surface of the substrate. A wide range of colored pixels may be formed by overlaying pixels of the various colored dyes. An image is printed to a surface of the substrate by aligning one of the panels of the print ribbon with the substrate, advancing the panel and the substrate past the print head, and heating portions of the panels to transfer pixels of print material to the surface using the print head. These steps may be repeated for other panels of the print ribbon to complete the printing of the desired image on substrate.

[0003] When an image is printed using the black resin panel, a negative of the image remains on the black resin panel due to the removal of the black resin. Such residual images may contain confidential information. As a result, it is desirable to obscure or erase residual images in the black resin panels to eliminate the risk of such information being accessed after the used print ribbon is discarded.

SUMMARY

[0004] Embodiments of the invention are generally directed to methods of obscuring residual images formed in resin print panels of print ribbons. In some embodiments, a credential manufacturing device is provided that comprises a print head and a print ribbon. The print ribbon includes a print panel comprising a resin or fusible pigment. A first image is printed within an image area on a surface of a substrate by transferring resin pixels of a plurality of resin pixel lines from the print panel to the image area using the print head. A second image is then printed on the substrate by transferring remaining resin pixels from a plurality of the resin pixel lines used to print the first image from the print panel to a residual resin area of the substrate using the print head.

[0005] In some embodiments, the second image comprises a bar. In some embodiments, the image area has a width and the second image has a width that substantially matches the width of the image area. In some embodiments, the second image has a length that is substantially less than the length of the image area.

[0006] In some embodiments, the residual resin area is adjacent the image area. In some embodiments, the residual resin area does not overlap the image area.

[0007] In some embodiments, the image area is located on a first surface of the substrate and the residual resin area is located on a second side of the substrate that is opposite the first side. In the method, the substrate is inverted prior to printing the second image.

[0008] In some embodiments, at least 50% of the remaining resin pixels within a print area of the print panel corresponding to the image area are transferred to the residual resin area of the substrate using the print head. In some embodiments, at least 75% of the remaining resin pixels within the print area are transferred to the residual resin area of the substrate using the print head. In accordance with another embodiment, 90-100% of the remaining resin pixels within the print area are transferred to the residual resin area of the substrate using the print head. In some embodiments, approximately 100% of the remaining resin pixels within the print area are transferred to the residual resin area of the substrate using the print head.

[0009] In some embodiments, the transference of the remaining resin pixels from the print panel to the residual resin area of the substrate comprises heating portions of the panel containing resin pixels and portions of the panel corresponding to resin pixels that were transferred during the printing of the first image.

[0010] In some embodiments, the transference of the remaining resin pixels to the residual resin area of the substrate comprises repeatedly printing a second image over the residual resin area a limited number of times using different portions of the print panel. In some embodiments, the areas of the print panel used for the prints of the second image are selected to obscure the residual image by printing the second image over the residual resin area a minimal number of times.

[0011] In another embodiment of the method, a credential manufacturing device is provided that comprises a print head and a print ribbon including a print panel comprising resin. A first image is printed within an image area on a surface of a substrate by transferring resin pixels of a plurality of resin pixel lines from the print panel to the image area using the print head. A residual image is formed on the print panel responsive to the printing of the first image. The residual image is obscured by transferring remaining resin pixels from the print panel to a residual resin area of the substrate using the print head.

[0012] Other features and benefits that characterize embodiments of the invention will be apparent upon reading the following detailed description and review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a simplified diagram of a portion of an exemplary credential manufacturing device in accordance with embodiments of the invention.

[0014] FIG. 2 is a simplified top plan view of an exemplary print ribbon in accordance with embodiments of the invention.

[0015] FIG. 3 is a simplified top plan view illustrating the transference of pixels of print material from a print ribbon to a surface of a substrate.

[0016] FIGS. 4 and 5 respectively are top plan views of a substrate with an image printed thereon, and a resin print panel of a print ribbon used to form the image in FIG. 4.

[0017] FIG. 6 is a flowchart illustrating a method in accordance with embodiments of the invention.

[0018] FIG. 7 is a top plan view of a substrate having first and second images printed thereon.

[0019] FIGS. 8 and 9 are simplified top plan views of a substrate, print ribbon and a print head (phantom lines) illustrating printing steps in accordance with embodiments of the invention.

[0020] FIGS. 10-13 are simplified side views of a substrate, print ribbon and print head illustrating printing steps in accordance with embodiments of the invention. [0021] FIGS. 14 and 15 are top plan views of a print panel of a print ribbon after a residual image in the panel has been obscured in accordance with embodiments of the invention.

DETAILED DESCRIPTION

[0022] The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing one or more exemplary embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims.

[0023] Sufficient details are given in the following description to provide those of ordinary skill in the art with a thorough understanding of the embodiments. Well-known and understood components, circuits, processes and techniques may be illustrated in block diagram form or not shown in the drawings in order to avoid obscuring disclosed embodiments in unnecessary detail.

[0024] Also, it is noted that individual embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in a figure or described herein. Further, it is understood that embodiments of disclosed process steps include the performance of the process step through the execution of program instructions stored in a tangible medium by one or more processors.

[0025] FIG. 1 is a simplified diagram of a portion of an exemplary credential manufacturing device 100 that may be used to perform method steps in accordance with embodiments of the invention. In some embodiments, the device 100 includes a direct-to- substrate print section 102 that is configured to print an image directly to a substrate 104 delivered along a processing path 106 by a substrate transport mechanism 108. The print section 102 generally includes a print head 110 and a print ribbon 112. In some embodiments, the print ribbon 112 is supported between a supply roll 114 and a take up roll 116. [0026] The print head 110 can be any suitable conventional print head comprising a line of heating elements that may be selectively activated to transfer pixels of print material from the ribbon 112 to the surface 118 of the substrate in accordance with conventional techniques. In some embodiments, the device 100 includes a conventional print head lift mechanism configured to move the print head 110 relative to the processing path 106.

[0027] The exemplary transport mechanism 108 is configured to feed individual substrates 104 along the processing path 106. Embodiments of the substrate 104 include substrates that form the final credential product, such as plastic card substrates, paper substrates, or other substrate that will form a credential product. Thus, as used herein, the term "substrate" does not include a transfer film used in reverse-image transfer printing processes.

[0028] The transport mechanism 108 may receive individual substrates 104 from a supply of substrates (not shown) in accordance with conventional designs. In some embodiments, the transport mechanism 108 drives the substrates 104 along the processing path 106 using motorized pinch rollers 120 in a feed direction 122.

[0029] FIG. 2 is a simplified top plan view of an exemplary print ribbon 112 in accordance with embodiments of the invention. In some embodiments, the print ribbon 112 includes a black resin or fusible pigment print panel (K) formed in accordance with conventional resin print panels. In some embodiments, the print ribbon 112 includes colored dye panels such as, for example, a yellow dye panel (Y), a magenta dye panel (M), and a cyan dye panel (C). In some embodiments, the panels extend in a repeatable series.

[0030] In some embodiments, the device 100 includes a controller 124 that is configured to control the components of the device 100 and carry out method steps described herein. In some embodiments, the controller 124 represents one or more processors and memory containing instructions that are executable by the one or more processors to perform the method steps. For instance, the controller 124 controls the feeding of individual substrates 104 along the processing path 106 through the control of the motors responsible for driving the feed rollers 120. Similarly, the controller 124 controls the feeding of the print ribbon 112 through the control of the motors responsible for rotating the supply spool 114 and the take up spool 116. The controller 124 also controls the activation of the individual heating elements of the print head 110 to print an image in accordance with conventional techniques. The controller 124 may also control other components of the device 100, such as a lift mechanism for the print head 110, and other substrate processing devices 126, such as a laminator, a data encoder, a substrate inverter, or other processing device.

[0031] Images are printed to the surface 118 of the substrate 104 by the print section 102 in accordance with conventional direct-to-substrate printing techniques. In general, the transport mechanism 108 delivers a substrate 104 along the processing path 106 to the print section 102. A head lift mechanism may move the print head 110 toward the processing path 106 such that the print head presses the print ribbon 112 against the substrate 104 that is supported by a print platen 128, as shown in FIG. 1.

[0032] FIG. 3 is a simplified top plan view illustrating the transference of pixels of print material from the print ribbon 112 to the surface 118 of the substrate 104. Initially, one of the panels of the print ribbon 112 is aligned with the substrate 104 such that the panel covers an image area 130 of the substrate 104 where an image is to be printed, as shown in FIG. 3. The resistive heating elements of the print head 110, which extend in a line across the width of the substrate 104, are generally aligned with a leading edge 132 of the image area 130. The heating elements of the print head 110 are selectively activated to transfer a pixel line 134 from the print panel to the substrate 104. The pixel line 134 comprises pixels 136 of print material corresponding to the activated heating elements and portions 138 corresponding to deactivated heating elements that do not contain print material. As the substrate 104 and the print ribbon are fed together in the feed direction 122 past the print head 110, the print head 110 prints additional pixel lines 134 within the image area 130. Additional color layers of pixels may be formed within the image area 130 by, for example, displacing the print head 110 from the processing path 106, aligning another color panel of the print ribbon 112 with the image area 130 of the substrate 104, and feeding the print ribbon 112 and the substrate 104 along the processing path relative to the print head 110 as the print head 110 selectively transfers pixel lines 134 from the print panel to the image area 130 of the substrate 104. This may be repeated until the desired image is formed within the image area 130.

[0033] The delivery of ink or dye from the colored dye panels (Y, M, C) of the print ribbon 112 do not generally leave behind a traceable record of the printed image on the panels of the print ribbon 112. However, the transference of the resin from the black panel K, leaves behind a record of the printed image. This is illustrated in FIGS. 4 and 5. FIG. 4 is a top plan view of a substrate 104 with an image printed on the surface 118, and FIG. 5 is a top plan view of a resin print panel 142 of the print ribbon 112 used to form the image 140. In some embodiments, the image 140 was formed using the print head 110 as discussed above with reference to FIG. 3, by transferring resin pixel lines 134 comprising resin pixels 136 from the print panel 142 to the surface 118 using print head 110. The transference of the resin pixels from the panel 142 to the surface 118 produces a residual image 144 on the print panel 142 that is a negative of the image 140 printed to the card substrate 104, as shown in FIG. 5. As a result, the information printed in the image 140 may be obtained through a review of the print panel 142 used to print the image 140. This creates a potential security risk when image 140 contains sensitive or confidential information.

[0034] Embodiments of the invention are directed to methods of obscuring residual images on resin print panels to prevent the release of information contained therein. In some embodiments, the image area 130 of the substrate 104, in which the image 140 is printed, corresponds to a print area 146 of the resin print panel 142, as shown in FIGS. 4 and 5. In some embodiments, the residual image 144 on the print panel 142 is obscured by printing a second image to the substrate 104 using portions of the print area 146, as described below.

[0035] FIG. 6 is a flowchart illustrating a method in accordance with embodiments of the invention. At 150, a credential manufacturing device 100 is provided, such as that described above, comprising a print head 110 and a print ribbon 112. The print ribbon 112 includes a print panel 142 comprising a resin, such as black resin or fusible pigment, for example. At 152, an image 140 is printed within an image area 130 on a surface 118 of a substrate 104 using the print head 110 and the print panel 142, as shown in the top plan view of FIG. 7. The printing of the image 140 results in the formation of the residual image 144 on the print panel 142. At step 154, the residual image 144 is obscured on the print panel 142 by printing a second image 156, shown in FIG. 7, to a residual resin area 158 of the substrate 104 using the print area 146 of the print panel 142.

[0036] In some embodiments of the printing step 152, resin pixels 136 of a plurality of resin pixel lines 134 are transferred from the print panel 142 to the image area 130 using the print head 110, generally as described above with reference to FIG. 3. In some embodiments of the printing step 152, a leading edge 170 of the image area 130 is aligned with the print panel 142, or a leading edge of the print area 146 that overlays the image area 130, as shown in the simplified top plan view of FIG. 8, in which the print head 110 is shown in phantom lines. The print head 110 then selectively activates one or more of the resistive heating elements to heat one or more resin pixels of a resin pixel line of the print panel 142. The heated resin pixels are then transferred to the image area 130 of the substrate 104. The substrate 104 and the print panel 142 are advanced in the feed direction 122, and the steps of heating one or more resin pixels of one or more resin pixel lines of the print panel 142 and transferring the heated resin pixels to the image area 130 are repeated until the printing of the image 140 is completed.

[0037] In some embodiments of step 154, remaining resin pixels from a plurality of the resin pixel lines used to print the image 140 are transferred from the print panel 142 to the residual resin area 158 of the substrate 104 using the print head 110 to print the second image 144. In some embodiments of the printing step 154, the second image 144 is repeatedly printed over the residual resin area 158 a limited number of times using different portions of the print area 146 of the resin print panel 142. Embodiments of this process are generally illustrated in the simplified side views of FIGS. 10-13. In some embodiments, a leading edge 172 of the print area 146 of the print panel 142 is aligned with a leading edge 174 of the residual resin area 158, as shown in FIG. 10. A leading edge 172 of the print area 146 is also aligned with the print head 110. The print head 110 then selectively activates its heating elements to heat remaining resin pixels in the pixel line corresponding to the location of the print head 110. The heated remaining resin pixels are then transferred to the residual resin area 158 of the substrate 104. The substrate 104 and the print panel 142 are then advanced in the feed direction 122 as the heating and transferring steps are repeated until a trailing edge 176 of the residual resin area 158 reaches the print head 110, as shown in FIG. 11. The substrate 104 is then advanced in the direction 178 relative to the print head 110 to reposition the leading edge 174 of the residual resin area 158 at the print head 110, as shown in FIG. 12. This may involve the displacement of the print head 110 from the processing path 106, in accordance with conventional printing techniques. In some embodiments, the print panel 142 is not moved relative to the print head 110 as the leading edge 174 of the residual resin area 158 is realigned with the print head 110. The second image is then re-printed over the residual resin area 158, in the manner discussed above with regard to FIGS. 10 and 11, followed by the realignment of the leading edge 174 of the residual resin area with the print head 110 (FIG. 12), until the trailing edge 180 of the print area 146 reaches the print head 110, as shown in FIG. 13. This repeated printing of the second image to the residual resin area 158 using portions of the print area 146 used to print the image 140 to the image area of the substrate 104 operates to obscure the residual image 144. [0038] In some embodiments, the residual resin area 158 is adjacent the image area 130, as shown in FIG. 7. In some embodiments, the residual resin area 158 does not overlap the image area 130.

[0039] The image area 130 has a width 160 and the second image 156 has a width 162, which are measured in a direction that is substantially perpendicular to the feed direction 122. In some embodiments, the width 162 substantially matches the width 160 of the image area 130, as shown in FIG. 7. This ensures that the printing of the second image 156 will include portions that fully overlap the print area 146 and, therefore, the residual image 144.

[0040] In some embodiments, the second image 156 has a length 164, measured in the feed direction 122, that is substantially less than a length 166 of the image area 130, as shown in FIG. 7.

[0041] In some embodiments, the residual resin area is located on the side of the substrate 104 that is opposite the surface 118. In accordance with this embodiment, following the printing of the image 140 on the surface 118 (printing step 152), the substrate is fed to the substrate processing device 126 in the form of a substrate inverter, shown in FIG. 1. The substrate inverter 126 flips the substrate in accordance with conventional techniques and the substrate is fed back to the print section 102 where the second image 156 is repeatedly printed to the residual resin area 158 in accordance with step 154. This embodiment allows the image area 130 to substantially cover the surface 118. Additionally, the residual resin area 158 could be formed larger than that illustrated in FIG. 7.

[0042] The second image 156 can take on many different forms. In some embodiments, the term "second image" refers to the image printed to the residual resin area 158 during a single pass by the print head 110 (FIGS. 10-11). In some embodiments, each of the second image printings can comprise the attempt to print the same second image. That is, the heating pattern applied to the panel 142 by the print head 110 is identical in each printing pass. In some embodiments, the second image printings comprise the application of two or more distinct heating patterns to the panel 142 during the printing passes.

[0043] In some embodiments, the second image 156 is in the form of a bar, as shown in FIG. 7. Here, the print head activates substantially all of the heating elements extending across the print area 146 to ensure that all remaining resin pixels in the resin pixel line are transferred to the residual resin area 158. When this second image 156 is repeated across the entire print area 146, the residual image 144 is erased from the print panel 142, as shown in FIG. 14.

[0044] In some embodiments, the residual resin area 158 includes dark portions of a design element formed on the substrate 104. Such design elements include, for example, images that are repeated through a series of substrates 104, such as background images or logos, that are printed on the substrate 104 prior to processing the substrate 104 using the device 100. In some embodiments, the dark portions are black. In some embodiments, the second image 156 takes the form of the dark portions of the design element, or parts of the dark portions of the design element.

[0045] In some embodiments, the residual resin area 158 includes dark portions of the image 140. In some embodiments, the dark portions of the image 140 are black. In some embodiments, the second image 156 takes the form of at least parts of the dark portions of the image 140.

[0046] Instead of using a continuous bar, the second image can also take the form of dark portions of printed design elements (which are preferably repeated through full series of cards like logos or or background pictures) and can be used as residual resin areas. The condition is that these portions of printed elements are dark enough such as the plurality of print remain undetectable.

[0047] In some embodiments, the print panel 142 is advanced a short distance when the substrate 104 is repositioned relative to the print head 110 to realign the leading edge 174 of the residual resin area 158 with the print head 110. This results in a portion of the residual image 144 remaining on the print panel 142, as shown in FIG. 15. The distance that the print panel 142 is advanced is selected such that the remaining residual image 144 on the print panel 142 is obscured such that it is unlikely that sensitive information in the image 144 can be obtained. One advantage to this embodiment is that the residual image 144 can be obscured in fewer printings of the second image than is necessary to completely erase the residual image 144 from the print panel 142. Additionally, this embodiment results in a reduced amount of resin buildup in the residual resin area 158 of the substrate 104.

[0048] Other embodiments of the second image 156 include a pattern that is printed within the residual resin area 158. In some embodiments, rather than repeatedly heating entire pixel lines across the print area 146, the print head 110 only heats portions of the resin pixel lines such that a dashed, or other patterned line of the resin, would transfer to the residual resin area 158 if all of the resin pixels remained in the pixel line, for example. Such a pattern can further reduce the amount of resin transferred to the residual resin area 158 while still obscuring the residual image 144.

[0049] In some embodiments, the areas of the print panel used for the printings of the second image 156 are selected to obscure the residual image 144 by printing the second image 156 over the residual resin area 158 a minimal number of times. In other words, the portions of the print area 146 of the print panel that are heated by the print head 110 are selected to substantially minimize the time required to obscure the residual image 144 on the print panel 142.

[0050] In some embodiments of the printing step 154, at least 50% of the remaining resin pixels within the print area 146 of the print panel 142 corresponding to the image area 130 are transferred to the residual resin area 158 of the substrate 104 using the print head 110. In accordance with another embodiment, at least 75-90% of the remaining resin pixels within the print area 146 are transferred to the residual resin area 158 of the substrate 104 using the print head 110. In accordance with another embodiment, 90-100% of the remaining resin pixels within the print area 146 are transferred to the residual resin area 158 of the substrate 104 using the print head 110.

[0051] In some embodiments, the residual resin area 158 may comprise multiple areas on the substrate 104. For instance, a pair of residual resin areas 158 may be positioned on the leading and trailing sides of the image 144 relative to the feed direction 122.

[0052] 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 instance, although embodiments of the credential device are illustrated as performing a process (e.g., printing) on a bottom surface of a substrate, it is understood that the device can be configured to perform the process on a top surface of the substrate.