Patent Description:
High speed printing systems have been developed for printing on a substrate, such as a web of shrinkable polymeric film. Such a material typically exhibits both elasticity and plasticity characteristics that depend upon one or more applied influences, such as force, heat, chemicals, electromagnetic radiation, etc. These characteristics must be carefully taken into account during the system design process because it may be necessary: <NUM>. ) to control material shrinkage during imaging so that the resulting imaged film may be subsequently used in a shrink-wrap process, and <NUM>. ) to avoid system control problems by minimizing dynamic interactions between system components due to the elastic deformability of the substrate.

Also, a flexible web is subject to the formation of wrinkles therein, resulting in poor or even unacceptable print quality. A further issue is encountered in a print system using inkjet printheads to apply inks to a flexible web. A splice or wrinkle passing an inkjet printer during high speed production can damage one or more of the printheads of the printer, resulting in expensive downtime and the need to replace the damaged printheads, entailing significant replacement costs.

<CIT> discloses a system for printing on clear polymeric film web, comprising: a first stationary inkjet print unit having first ejection nozzles that span a width of the clear polymeric film web; a second stationary inkjet print unit having second ejection nozzles that span the width of the clear polymeric film web; a web transport adapted to convey the clear polymeric film web past the first and second stationary inkjet print units; a first print controller adapted to operate the first stationary inkjet print unit to deposit drops of a first material on the clear polymeric film web at a first resolution; and a second print controller adapted to receive the bitmap data and in response operate the second stationary inkjet print unit to deposit drops of a second material on the clear polymeric film web at a second resolution in accordance with the bitmap data, wherein the first and second resolutions are different. Similar systems are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

According to one aspect of the invention, a system for printing on clear polymeric film according to claim <NUM> is disclosed.

According to another aspect of the invention, a method for printing on a clear polymeric film web according to claim <NUM> is disclosed.

Other aspects and advantages will become apparent upon consideration of the following detailed description and the attached drawings wherein like numerals designate like structures throughout the specification.

This brief description of the invention is intended only to provide a brief overview of subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.

So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:.

<FIG> shows an exemplary system <NUM> for printing content (e.g., images and/or text) on a substrate, such as a shrinkable plastic film used in food grade applications. According to the invention, the system is used for printing on clear polymeric film, however, according to examples not according to the invention, the system may be used for printing on other flexible material that is dimensionally stable or unstable during processing for any application, e.g., other than food grade. The system <NUM> preferably operates at high-speed, e.g., on the order of zero to about <NUM>/s or more (<NUM> or more feet per minute (fpm)) and even up to about <NUM>/s (<NUM> fpm), although the system may be operable at a different speed, as necessary or desirable. The illustrated system <NUM> is capable of printing images and/or text on both sides of a substrate (i.e., the system <NUM> is capable of duplex printing) although this need not be the case. In the illustrated embodiment, a first side of a substrate is imaged by a sequence of particular units during a first pass, the substrate is then turned over and the other side of the substrate is imaged by all of the particular units or only by a subset of the particular units during a second pass. First portions of one or more of the particular units may be operable during the first pass and second portions of one or more of the particular units laterally offset from the first portions may be operable during the second pass. Also, one or more of the particular units may be capable of simultaneously treating and/or imaging both sides of the substrate during one pass, in which case such unit(s) need not be operable during the other pass of the substrate. In the illustrated embodiment, the first portions are equal in lateral extent to the second portions, although this is not necessarily the case. Thus, for example, the system may have a <NUM> (<NUM> inch) width, and may be capable of duplex printing up to a <NUM> (<NUM> inch) wide substrate. Alternatively, a <NUM> (<NUM> inch) wide (or smaller) substrate may be printed on a single side (i.e., simplex printed) during a single production run. If desired, additional imager units and associated dryer and web guide units may be added in line with the disclosed imager units and other units so as to obtain full-width (i.e., <NUM> (<NUM> inch) in the disclosed embodiment) duplex printing capability. Still further, a substrate having a different width, such as <NUM> (<NUM> inches) (or larger or smaller width) may be accommodated.

Further, the illustrated system <NUM> may comprise a fully digital system that solely utilizes inkjet printers, although other printing methodologies may be utilized to image one or more layers, such as flexographic printing, lithographic offset printing, silk screen printing, intaglio printing, letterpress printing, etc. Inkjet technology offers drop on demand capability, and thus, among other advantages, allows high levels of color control and image customization.

In addition to the foregoing, certain ink jet heads are suitable to apply the high opacity base ink(s) that may be necessary so that other inks printed thereon can receive enough reflected white light (for example) so that the overprinted inks can adequately perform their filtering function. Some printhead technologies are more suitable for flood coating printing, like printing overcoat varnish, primers, and white, and metallic inks.

On the other hand, printing high fidelity images with high resolution printheads achieves the best quality. Using drum technology and printing with ink jet is the preferred way to maintain registration, control a flexible/shrinkable film substrate, and reproduce an extended gamut color pallet.

The system disclosed herein has the capability to print an extended gamut image. In some cases the color reproduction required may need a custom spot color to match the color exactly. In these cases, an extra eighth channel (and additional channels, if required) can be used to print custom color(s) in synchronization with the other processes in the system.

Printing on flexible/shrinkable films with water-based inks has many challenges and require fluid management, temperature control, and closed loop processes. Thus, in the present system, for example, the ability to maintain a high quality color gamut at high speed is further process controlled by sensor(s) that may comprise one or more calibration cameras to fine tune the system continually over the length of large runs.

As used herein, the phrase "heat-shrinkable" is used with reference to films which exhibit a total free shrink (i.e., the sum of the free shrink in both the machine and transverse directions) of at least <NUM>% at <NUM> (<NUM>°F), as measured by ASTM D2732. All films exhibiting a total free shrink of less than <NUM>% at <NUM> (<NUM>°F) are herein designated as being non-heat-shrinkable. The heat-shrinkable film can have a total free shrink at <NUM> (<NUM>°F) of at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, or at least <NUM>%, as measured by ASTM D2732. Heat shrinkability can be achieved by carrying out orientation in the solid state (i.e., at a temperature below the glass transition temperature of the polymer). The total orientation factor employed (i.e., stretching in the transverse direction and drawing in the machine direction) can be any desired factor, such as at least 2X, at least 3X, at least 4X, at least 5X, at least 6X, at least 7X, at least 8X, at least 9X, at least 10X, at least 16X, or from <NUM>. 5X to 20X, from 2X to 16X, from 3X to 12X, or from 4X to 9X.

As shown in <FIG>, the illustrated system <NUM> includes a first pull module <NUM> that unwinds a web of plastic web <NUM> from a roll <NUM> that is engaged by a nip roller <NUM> at the beginning of a first printing pass through the system <NUM>. The web <NUM> may comprise a flattened cylinder or tube of plastic film comprising two layers having sides 24a, 24b (see <FIG>) joined at side folds 24c, 24d, although the web <NUM> may instead simply comprise a single layer of material, if desired and as referred to above. Once unwound by the module <NUM>, the web <NUM> may be processed by a surface energy modification system, such as a corona treatment unit <NUM> of conventional type, that increases the surface energy of the web <NUM>. The corona treatment addresses an imaging condition that may be encountered when a large number of closely spaced drops are applied to a low surface energy impermeable material, which, if not compensated for, can result in positional distortion of the applied inks due to coalescence effects. The corona treatment module may be capable of treating both sides of the web <NUM> simultaneously. A first web guide <NUM> of conventional type that controls the lateral position of the web <NUM> in a closed-loop manner then guides the corona-treated web <NUM> a first imager unit <NUM>. A first dryer unit <NUM> is operated to dry the material that is applied to the web <NUM> by the first imager unit <NUM>. The material applied by the first imager unit <NUM> may be deposited over the entirety of the web <NUM> or may be selectively applied only to some or all areas that will later receive ink.

A second pull module <NUM> and a second web guide <NUM> (wherein the latter may be identical to the first web guide <NUM>) deliver the web <NUM> to a second imager unit <NUM> that prints a material supplied by a first supply unit <NUM> on the web <NUM>. A second dryer unit <NUM> is operable to dry the material applied by the second imager unit <NUM>.

Thereafter, the web <NUM> is guided by a third web guide <NUM> (again, which may be identical to the first web guide <NUM>) to a third imager unit <NUM> that applies material supplied by a second supply unit <NUM> thereon, such as at a location at least partially covering the material that was deposited by the second imager unit <NUM>. A third dryer unit <NUM> is operable to dry the material applied by the third imager unit <NUM> and the web <NUM> is then guided by a fourth web guide <NUM> (that also may be identical to the first web guide <NUM>) to a fourth imager unit <NUM> comprising a relatively high resolution, extended color gamut imager unit <NUM>.

The imager unit <NUM> includes a drum <NUM> around which are arranged inkjet printheads for applying primary process color inks CMYK to the web <NUM> along with secondary process color inks orange, violet, and green OVG and an optional spot color ink S to the web <NUM> at a relatively high resolution, such as <NUM> dots/mm (<NUM> dpi) and at a high speed (e.g., <NUM>/s - <NUM>/s ( <NUM>-<NUM> fpm)). The extended gamut printing is calibrated at the high printing speed. The drop sizes thus applied are relatively small (on the order of <NUM>-<NUM> pL). If desired, the imager unit <NUM> may operate at a different resolution and/or apply different drop sizes. The inks are supplied by third and fourth supply units <NUM>, <NUM>, respectively, and, in some embodiments, the inks are of the water-based type. The process colors comprising the CMYK and OVG inks enable reproduction of extended gamut detailed images and high quality graphics on the web <NUM>. A fourth dryer unit <NUM> is disposed downstream of the fourth imager unit <NUM> and dries the inks applied thereby.

Following imaging, the web <NUM> may be guided by a web guide <NUM> (preferably identical to the first web guide <NUM>) and coated by a fifth imager unit <NUM> comprising an inkjet printer operating at a relatively low resolution and large drop size (e.g., <NUM> dots/mm (<NUM> dpi), <NUM>-<NUM> pL size drops) to apply an overcoat, such as varnish, to the imaged portions of the web <NUM>. The overcoat is dried by a fifth dryer unit <NUM>. Thereafter, the web is guided by a web guide <NUM> (also preferably identical to the first web guide <NUM>), turned over by a web turn bar <NUM>, which may comprise a known air bar, and returned to the first pull module <NUM> to initiate a second pass through the system <NUM>, following which material deposition/imaging on the second side of the web <NUM> may be undertaken, for example, as described above. The fully imaged web <NUM> is then stored on a take-up roll <NUM> engaged by a nip roll <NUM> and thereafter may be further processed, for example, to create shrink-wrap bags.

While the web <NUM> is shown in <FIG> as being returned to first the pull module <NUM> at the initiation of the second pass, it may be noted that the web may be instead delivered to another point in the system <NUM>, such as the web guide <NUM>, the first imager unit <NUM>, the pull module <NUM>, the web guide <NUM>, or the imager unit <NUM> (e.g., when the web <NUM> is not to be precoated), bypassing front end units and/or modules, such as the module <NUM> and the corona treatment unit <NUM>.

Further, in the case that the web <NUM> is to be simplex printed (i.e., on only one side) the printed web <NUM> may be stored on the take-up roll <NUM> immediately following the first pass through the system <NUM>, thereby omitting the second pass entirely.

The web <NUM> may be multilayer and may have a thickness of <NUM> or less, or a thickness of from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM>,<NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils), or from <NUM> to <NUM> (<NUM> to <NUM> mils). The web <NUM> may have a film percent transparency (also referred to herein as film clarity) measured in accordance with ASTM D <NUM>-<NUM> "Standard Test Method for Transparency of Plastic Sheeting", published April, <NUM>, of at least <NUM> percent, or at least <NUM> percent, or at least <NUM> percent, or at least <NUM> percent.

Preferably, the system <NUM> includes a first tension zone between the roll <NUM> (which is a driven roll) and the pull module <NUM>, a second tension zone between the pull module <NUM> and the imager unit <NUM>, a third tension unit between the imager unit <NUM> and the pull module <NUM>, a fourth tension zone between the pull module <NUM> and the imager unit <NUM>, a fifth tension zone between the imager unit <NUM> and the imager unit <NUM>, a sixth tension zone between the imager unit <NUM> and the drum <NUM>, a seventh tension zone between the drum <NUM> and the imager unit <NUM>, and an eighth tension zone between the imager unit <NUM> and the take-up roll <NUM> (which is a driven roll). One or more tension zones may be disposed between the imager unit <NUM> and the pull module <NUM> and/or at other points in the system <NUM>. Each of the elements defining the ends of the tension zones comprises, for example, a driven roll (which, in the case of the imager units <NUM>, <NUM><NUM>, <NUM>, and <NUM>, comprise imager drums) with a nip roller as described in greater detail hereinafter. Preferably, all of the tension zones are limited to about <NUM> (<NUM> feet) or less in length. The web tension in each tension zone is controlled by one or more tension controllers such that the web tension does not fall outside of predetermined range(s).

The nature and design of the first, second, and third imager units <NUM>, may vary with the printing methodologies that are to be used in the system <NUM>. For example, in a particular embodiment in which a combination of flexographic and inkjet reproduction is used, then the first imager unit <NUM> may apply a composition comprising a clear primer and a dispersion of a white colorant, such as titanium dioxide, in a flood-coated fashion to the web <NUM>. The second imager unit <NUM>, which may comprise an ink jet printer or a flexographic unit, may thereafter deposit one or more metallic ink(s) onto the web at least in portions that received material from the first imager unit <NUM>. In such an embodiment, the third imager unit <NUM> is not required, and the imager unit <NUM> and dryer unit <NUM> and web guide <NUM> associated therewith may be omitted.

In a further embodiment, the first imager unit <NUM> comprises a flexographic unit that applies a white pigmented ink to the web <NUM>, the second imager unit <NUM> comprises an ink jet printer or a flexographic unit that applies one or more metallic inks, and the third imager unit <NUM> comprises an ink jet printer or flexographic unit that applies a clear primer to the web <NUM>.

In yet another embodiment that uses ink jet technology throughout the system <NUM>, the first imager unit <NUM> comprising an inkjet printer may apply a composition comprising a clear primer and a dispersion of a white colorant, such as titanium dioxide, to the web <NUM>. The second imager unit <NUM>, which comprises an inkjet printer, may thereafter deposit one or more metallic ink(s) onto the web at least in portions that received material from the first imager unit <NUM>. In such an embodiment, the third imager unit <NUM> is not required, and the imager unit <NUM> and dryer unit <NUM> and web guide <NUM> associated therewith may be omitted.

In a still further embodiment, the first imager unit <NUM> comprises an inkjet printer that applies a white pigmented ink to the web <NUM>, the second imager unit <NUM> comprises an ink jet printer that applies one or more metallic inks, and the third imager unit <NUM> comprises an ink jet printer that applies a clear primer to the web <NUM>.

Any one or more of the imager units <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be omitted or the functionality thereof may be combined with one or more other imager units. Thus, for example, in the case where a combined primer and white pigmented material are applied, the combination may be printed by one of the imager units <NUM> or <NUM> and the other of the imager units <NUM>, <NUM> may be omitted.

In some embodiments each of the first, second, and third imager units <NUM>, <NUM>, <NUM> comprises a <NUM> dots/mm (<NUM> dpi (dots per inch)) inkjet printer that applies relatively large drops (i.e., at least <NUM>-<NUM> picoliters (pL)) each using piezoelectric inkjet heads, although the imager units <NUM>, <NUM>, and/or <NUM> may operate at a different resolution and/or apply different sizes of drops. Thus, for example, a printhead designed for use with metallic and precoating inks in the present system may have a resolution of <NUM> dots/mm (<NUM> dpi) and drop volume of <NUM>-<NUM> pL. The pre-coating material, white, and metallic inks have relatively heavy pigment loading and/or large particle sizes that are best applied by the relatively low resolution/large drop size heads of the imager units <NUM>, <NUM>, <NUM>.

In alternative embodiments, one or more of the primer, white, and coating imager units may operate at a relatively high resolution and/or small drop size, such as <NUM> dots/mm (<NUM> dpi)/<NUM>-<NUM> pL.

The primer renders at least a portion of the surface of the web <NUM> suitable to receive later-applied water-based inks. It is preferable (although not necessary) to apply the primer just before the process and spot color inks are applied by the fourth imager unit <NUM> so that the such colors are directly applied to the dried primer.

Preferably, the fourth imager unit <NUM> comprises the above-described ink jet printer so that drop-on-demand technology may be taken advantage of, particularly with respect to print-to-print variability, high resolution, and the ability to control registration precisely.

The fifth imager unit <NUM> also preferably comprises an inkjet printer that operates at least at <NUM> dots/mm or <NUM> dots/mm (<NUM> dpi or 2400dpi), although it may instead be implemented by a different printing methodology, such as a flexographic unit.

As noted in greater detail hereinafter, a supervisory or global control system <NUM> is responsive to sensors (not shown in <FIG>) and is responsible for overall closed-loop control of various system devices during a production run. A further control system comprising a print management control system <NUM> controls the various imager units also in a closed-loop fashion to control image reproduction as well as color correction, registration, correct for missing pixels, etc..

Also in the illustrated embodiment, each dryer unit <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> is controlled by an associated closed-loop dryer management system (not shown in <FIG>) during printing to, among other things, minimize image offsetting (sometimes referred to as "pick-off"), which can result in artifacts that may result from improper or insufficient drying of ink deposited on the web causing undried ink/coating to adhere (i.e., offset) to one or more system handling components, such as idler roller(s) or other component(s), and be transferred from such system handling component(s) to other portions of the web.

In the case of a partially or completely inkjet implemented system, the printheads used by the first through fifth imager units <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> may be of the same or different types, even within each printer, and/or, as noted previously, different printing methodologies could be used to apply inks/coatings. In any event, the global control system <NUM> and/or the print management control system <NUM> is (are) programmed to convert input data representing the various layers, such as data in a print-ready source format (e.g., Adobe Portable Document Format or PDF) to bitmaps by a ripping process or other page representation(s) during pre-processing taking into account the operational characteristics of the various printhead types/printing methodologies (such as the resolution(s) and drop size(s) to be deposited) and properties of the web (such as shrinkage when exposed to heat).

In addition to the foregoing, one or more additional control systems may be provided, for example, to track and control the web <NUM> as the web <NUM> is conveyed through the system <NUM> and as described further hereinafter. The various control systems may be implemented together or separately by one or more suitable programmable devices, input sensors, and output control devices, as appropriate or desirable.

Referring next to <FIG>, an exemplary embodiment of the print management control system <NUM> is illustrated in generalized form, it being assumed that the first imager unit <NUM> applies pre-coating material over a selected portion of or over the entire web <NUM> so that control of such imager unit <NUM> is straightforward and therefore not illustrated. The exemplary print management control system <NUM> takes in pages <NUM> in a print-ready format, such as PDF or another print-ready or non-print-ready format, and divides each page into data representing layers that are to be imaged by the imager units <NUM>, <NUM>, <NUM>, and <NUM>. More particularly, using the illustrated page <NUM> as an example, a processing unit <NUM> divides the data defining the page <NUM> into layer data representing four layers 150a, 150b, 150c, and 150d to be printed in white, silver, process colors (with an optional spot color), and overcoat, respectively, color corrects the layer data as needed taking into account the particular inks and web material, and converts the color corrected layer data into four layer bitmaps using a raster image processing (RIP) technique (block <NUM>). The processing unit <NUM> then determines registration parameters that are used in conjunction with the layer bitmaps to control the individual imager units <NUM>, <NUM>, <NUM>, and <NUM> (block <NUM>) such that the layer images are accurately printed atop one another on the web <NUM>.

The processing unit <NUM>, which may comprise a suitably programmed computer or server or other programmable device, is responsive to feedback signals developed by sensors including a position encoder <NUM> and, optionally, a camera <NUM> that sense web position and the printed image so that the processing unit <NUM> and/or other controls can operate in a closed-loop manner during start up, shutdown and steady state operation.

The pull module <NUM>, the web guides <NUM>, <NUM>, <NUM>, and <NUM>, and the rollers described above provide a web transport that conveys the web <NUM> past the imager units <NUM>, <NUM>, <NUM>, and <NUM>. In some embodiments, each of imager units <NUM>, <NUM>, and <NUM> comprises a inkjet print unit <NUM>, <NUM>, and <NUM>, respectively, and a print unit controller <NUM>, <NUM>, and <NUM>, respectively. Each inkjet print unit <NUM>, <NUM>, and <NUM> is adapted to selectively deposit a particular material substantially along the width of the web <NUM>. In particular, each inkjet print unit <NUM>, <NUM>, and <NUM> includes a sufficient number inkjet printheads so that the ejection nozzles of such inkjet printheads substantially span a width of the web <NUM>. In some embodiments, if the inkjet print unit <NUM>, <NUM>, or <NUM> includes a plurality of inkjet printheads (rather than just one web-wide inkjet printhead), such plurality of inkjet printheads are disposed abutting one another end-to-end in linear fashion to span the web <NUM>. In other embodiments, such plurality of inkjet printheads may be disposed in a carrier (not shown) in a two-dimensional array of inkjet printheads so that the ejection nozzles of the inkjet printheads (and of the inkjet print unit <NUM>, <NUM>, or <NUM> comprising such inkjet printheads) span the width of the web <NUM>.

Further, the imager unit <NUM> includes a plurality of inkjet printing units 228a-<NUM> disposed around a circumference of the drum <NUM>. Each inkjet printing unit 228a-<NUM> includes a sufficient number of inkjet printheads such that the ejection nozzles of the inkjet printheads substantially span the width of the web <NUM>. The inkjet printhead(s) that comprise(s) each inkjet printing unit 228a-<NUM> is/are adapted deposit a particular material along substantially along the width of the web <NUM>. For example, the inkjet printhead(s) that comprise(s) the inkjet print unit 228a are disposed so that such inkjet printhead(s) may deposit a cyan ink substantially along the width of the web <NUM>. Similarly, the inkjet printhead(s) that comprise(s) the inkjet print unit 228b-<NUM> are disposed such inkjet printhead(s) may deposit magenta, yellow, black, orange, violet, green, and a spot color ink, respectively.

Similar to the arrangement of the inkjet printheads of the inkjet print units <NUM>, <NUM>, and <NUM>, the inkjet printheads that comprise each inkjet print unit 228a-<NUM> may be disposed abutting one another end-to-end in linear fashion or in a two dimensional array such that the ejection nozzles of the inkjet printheads of each inkjet print group <NUM> span the width of the web <NUM>.

Each inkjet print unit <NUM>, <NUM>, <NUM>, and 228a-<NUM> is associated with a print unit controller <NUM>, <NUM>, <NUM>, and 196a-<NUM>, respectively. Each print unit controller <NUM>, <NUM>, and <NUM> receives, from the print management control system <NUM>, layer data 150a, 150b and 150d to be printed by the print unit <NUM>, <NUM>, and <NUM>, respectively, associated therewith and position information of where such layer data 150a, 150b, and 150d should be printed. Each print unit controller <NUM>, <NUM>, and <NUM> controls the inkjet print units <NUM>, <NUM>, and <NUM>, respectively, to cause the nozzles of such print unit to eject ink (or other material) onto the web <NUM> in accordance with such layer data 150a, 150b, and 150d and position data.

Further, the print management control system <NUM> provides layer data 150c, representing all of the color bitmaps to be printed using process color inks to the print unit controllers 196a-<NUM> and position information of where on the web <NUM> to print such layer data 150c. In some embodiments, the layer data 150c is provided in its entirety to all of the print unit controllers 196a-<NUM>. In response, the print unit controller <NUM> selects the color bitmap from the layer data 150c that is associated with the color of ink to be printed by the inkjet print unit <NUM>, and generates signals to cause the inkjet printheads of such print unit <NUM> to deposit drops of such color of ink in accordance with the selected bitmap and position data. In other embodiments, the print management control system <NUM> provides the bitmap from the layer data 150c that is associated with the color of ink that is printed by the inkjet print unit <NUM> to the print unit controller <NUM> associated with such inkjet print unit.

In some embodiments, to support printing at high speeds, the positions of all of the inkjet print units (and the inkjet printheads) that comprises the imager units <NUM>, <NUM>, <NUM>, and <NUM> are fixed (i.e., stationary) during printing as the web <NUM> is transported thereby.

As discussed above, the imager units <NUM>, <NUM>, <NUM>, <NUM>, and thus the inkjet print units <NUM>, <NUM>, and <NUM>, respectively, thereof, may be operated to deposit drops of ink or other material having different volumes and at different resolutions.

In one embodiment, the imager unit <NUM> deposits a white (or other) colorant onto the clear web <NUM> to create a backing (or silhouette) onto which subsequent colorants may be deposited. Because the white colorant includes particles such as titanium dioxide, a relatively large drop volume (e.g., between about <NUM> pico-liters and <NUM> pico-liters/drop) is required to accommodate such particles. Further, because the silhouette comprises an image that has a substantially identical intensity level throughout, the silhouette may be formed at a relatively low resolution, for example, <NUM> dots/mm (<NUM> dots-per-inch). Such large drop size and low resolution may also allow the drops of the material to coalesce and form a consistent layer of colorant to form the silhouette.

As discussed above, the imager unit <NUM> deposits a metallic ink on top of the colorant deposited by the imager unit <NUM>. Like the colorant deposited by the imager unit <NUM>, the metallic ink typically includes colorants and other materials having a relatively large particle size and the metallic ink is deposited to form a printed image that has little variability in intensity. Thus, the image using the metallic ink may be formed using drops of relatively large volume (e.g., from about <NUM> pico-liters/drop to <NUM>-pico-liters/drop) and at a relatively low resolution (e.g., about <NUM> dots/mm (<NUM> dots-per-inch)).

The imager unit <NUM> forms a high-resolution color image on the web. Therefore, the imager unit <NUM> forms an image using each print unit <NUM> with drops of ink having a relatively low volume (e.g., between about <NUM> pico-liters/drop and about <NUM> pico-liters/drop) and at a high resolution (e.g., <NUM> or more dots/mm (<NUM> or more dots-per-inch)). Such low drop volume and high resolution form an image that has intensity variability throughout to reproduce the page <NUM> with fine detail therein.

In some embodiments, the layer data 150a-150d generated by the ripping and color correction process (block <NUM>) is screened bitmap data and the inkjet print units <NUM>, <NUM>, <NUM>, and <NUM> are controlled by the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM>, respectively, to place drops of material on the web <NUM> in accordance with such screened bitmap data. In other embodiments, the bitmap data generated by the ripping and color correction process (block <NUM>) is not screened and the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM> screen the bitmap data provided by the ripping and color correction process (block <NUM>) and drive the print units <NUM>, <NUM>, <NUM>, and <NUM> to deposit drops of material on the web <NUM> in accordance with the screened data developed by the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM>.

In some embodiments, the data used to drive the low-resolution inkjet print units <NUM> and <NUM> is screened in accordance with a conventional halftone (e.g., amplitude modulated) screening pattern. Further, the data used to drive the high-resolution inkjet print units <NUM> and <NUM> is screened in accordance with a frequency modulated screening pattern. It would be appreciated by one who has ordinary skill in the art that using the frequency modulated screening pattern allows reproduction of greater detail printed using such pattern. Other screening methods apparent to one who has ordinary skill in the art may be also be used.

In some embodiments, the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM> operated on one or more computer processors separate from computer processors used to implement the print management control system <NUM>. In other embodiments, one or more of the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM> may operate as processes on the computer processors used to implement the print management control system <NUM>.

As noted above, in some embodiments, the imager unit <NUM> is used to deposit a coating material onto the image printed by the imager unit <NUM>. To ensure that a thin layer of coating is deposited, such imager unit also prints at high resolution using a relatively small drop volume.

It should be apparent to one who has ordinary skill in the art that using inkjet printheads that print at a relatively low resolution using large drop sizes when possible may be more cost effective than using inkjet printheads that print at high resolution with small drop sizes. Further, one having ordinary skill in the art would appreciate that the amount of data that has to be transmitted between the print unit controllers <NUM> and <NUM> and the inkjet print unit <NUM> and <NUM>, respectively, that print at low resolution/large drop size may be substantially less than the amount of data that has to be transmitted from the inkjet print controller <NUM> and the inkjet print unit <NUM> that prints at high-resolution/small drop size, and thus the costs of implementing the print unit controllers <NUM> and <NUM> may be less than the cost of implementing the inkjet print controller <NUM>.

Referring once again to <FIG>, a camera <NUM> may be disposed following the image unit <NUM> that, when used, images the entire width of the web <NUM> (<NUM> (<NUM> inches) in the illustrated embodiment) and allows the print management control system <NUM> (or any of the other control systems of the system <NUM>) undertake color-to-color registration and color calibration, detect and correct for missing pixel(s) and stitching errors (gaps or alignment errors between portions of an image printed by adjacent heads), and undertake printhead normalization across the web.

In some embodiments, the print management control system <NUM> undertakes a distortion correction process (block <NUM>) prior to undertaking the ripping and color correction process (block <NUM>). As described in greater detail below, the distortion correction process (block <NUM>) adjusts the dimensions of the page <NUM> (or elements thereof) to compensate for shrinking of the portion of the web <NUM> on which such page <NUM> is printed when the portion of the web <NUM> is used in a shrink wrap application.

<FIG> illustrates the dimensional compensation performed by the distortion correction process (block <NUM>) undertaken of the print management control system <NUM>. In the example shown in <FIG>, assume that after printing, the web <NUM> is to be used to produce a shrink-wrapped package <NUM> (i.e., after the web <NUM> is shrunk) having a first image <NUM> having dimensions (x, y) and a second image <NUM> having dimensions (w, z) printed thereon. The print management control system <NUM> undertakes distortion correction (block <NUM>) and determines that to compensate for the shrinking of the film, the first image <NUM> should be printed having dimensions (x', y') and the second image should be printed having dimensions (w', z').

The distortion correction process (block <NUM>) also determines dot gain changes that may result in each of the images <NUM> and <NUM> as a result shrinking the portions of the web <NUM>, where such images are printed for example, because the distance between the dried drops of ink on the web decreases when such portions are shrunk. Thereafter, the distortion correction process (block <NUM>) adjusts the image data to be printed to compensate for such dot gain changes prior to providing such image data to the ripping and color correction process (block <NUM>).

Referring also to <FIG>, the distortion correction process (block <NUM>) comprises a distortion corrector process (block <NUM>), a page analyzer process (block <NUM>), a distortion loader process (block <NUM>), and a database <NUM>. <FIG> shows a flowchart <NUM> of the steps undertaken by the distortion correction process (block <NUM>). Referring to <FIG>, at step <NUM>, the distortion corrector process (block <NUM>) loads a page file to print and printing parameters including the inks (or other materials) to be deposited by the imager units <NUM>, <NUM>, <NUM>, and <NUM>, the material of the web <NUM> to be printed on, a final product that the web <NUM> will be formed into (by shrinking), and the like.

At step <NUM>, the distortion loader process (block <NUM>) queries the database <NUM> for distortion information data in accordance with the job parameters. In particular, such distortion information data includes information regarding dimensional changes different portions of the material of the web <NUM> undergoes when shrunk. For example, a portion of the web <NUM> proximate an outer edge of the web may shrink more (or less) compared to a portion of the web <NUM> proximate a central portion of the web. In some embodiments, such dimensional change information includes changes that occur when the web is shrunk to positions of a grid of equally spaced horizontal and vertical lines on an unshrunk web <NUM>. The equally spaced horizontal and vertical lines define a two-dimensional array of cells that comprise the grid. Each cell of the grid is associated with a portion of the web <NUM> on which an image may be printed and represents a predetermined area of contiguous pixels of such image. For example, each cell of the grid may represent a portion of an image that is <NUM> pixels wide by <NUM> pixels high. It should be apparent to one who has ordinary skill in the art that each cell may represent portions of the image having other dimensions. Each cell of the grid is associated with distortion information that includes how a portion of an image that is to be printed on the portion of the web <NUM> associated with the cell is to be modified to compensate for distortion that may occur to such printed portion of the image due to shrinkage of the web after printing.

The distortion information associated with each cell includes horizontal vertical scale factors by which the dimensions of the portion of the image to be printed on the portion of the web <NUM> associated with cell should be adjusted. In addition, the distortion information associated with each cell also includes information regarding adjustments that should be made to color values of pixels of the portion of the image associated with the cell to compensate for dot gain changes that may result from shrinking of the web <NUM> to dried drops of each type of ink (or other material) deposited on the web <NUM>.

Further, the distortion information data may identify portions of the web <NUM> on which scannable elements (e.g., barcodes, QR codes, and the like) should not be printed because, for example, such portions may become too distorted or even occluded when the web <NUM> is shrunk around a product disposed therein. The distortion information may also identify alternate locations of the web <NUM> where such scannable elements should be repositioned if they happen to fall on a portion of the web <NUM> on which scannable elements should not be printed.

At step <NUM>, the page analyzer process (block <NUM>) selects from the page file loaded at step <NUM> a page element that is to be printed. Such page element may include an image, a scannable element, a text block, and the like. At step <NUM>, the distortion corrector process (block <NUM>) determines the position on the web <NUM> the selected page element is to be printed, uses the distortion information loaded at step <NUM> and such position to determine dimensional changes to apply to the selected page element, and adjusts the dimensions (e.g., by resampling an image, adjusting font metrics, and the like) of the selected page element to develop an adjusted page element. The distortion corrector process (block <NUM>) may also, at step <NUM>, adjust the start position where adjusted page element is to be printed on the unshrunk web <NUM> in accordance with the distortion data.

At step <NUM>, the distortion corrector process (block <NUM>) checks if the selected page element is a scannable element and the adjusted start position would place the printed scannable element on a portion of the web <NUM> where such scannable element should not be printed. If so, the distortion corrector process (block <NUM>) proceeds to step <NUM>, otherwise the distortion corrector proceeds to step <NUM>.

At step <NUM>, the distortion corrector process (block <NUM>) adjusts the position of scannable element (as adjusted at step <NUM>) to an alternate location (e.g., as identified in the distortion data loaded as step <NUM>) and proceeds to step <NUM>.

At step <NUM>, the distortion corrector process (block <NUM>) adjusts values of pixels of the adjusted page element to compensate for dot gain changes that may occur because of shrinking the web <NUM>. Alternately, for example, if the page element is not an image, the distortion corrector process (block <NUM>) adjusts color values specified by print commands in the page file associated with the page element, as would be apparent to one who has ordinary skill in the art.

At step <NUM>, the distortion corrector process (block <NUM>) adds the adjusted page element that results from dot gain compensation applied at step <NUM> to an output page file and printing commands to cause the page element to be printed at a position on the web <NUM> determined at steps <NUM> or <NUM>.

At step <NUM>, the page analyzer process (block <NUM>) determines if there any additional page elements that have not been processed and, if so, returns to step <NUM> to select another page element. Otherwise, at step <NUM>, the distortion loader process (block <NUM>) adds the output page file to an input queue associated with the ripping and color correction process (block <NUM>, <FIG>) or otherwise provides the output page file to such process. Thereafter, the distortion correction block <NUM> exits.

Referring once again to <FIG> and <FIG>, the distortion correction process (block <NUM>) includes an on-press distortion analyzer process (block <NUM>), an in-plant distortion analyzer process (block <NUM>), and a customer site distortion analyzer process (block <NUM>) that develop and adjust the distortion information stored in the database <NUM>.

<FIG> is a flowchart <NUM> of steps undertaken by the on-press distortion analyzer process (block <NUM>) to monitor distortion during a production run.

Referring to <FIG>, the on-press distortion analyzer process (block <NUM>), at step <NUM>, loads parameters of a production job including the page <NUM> to be printed on the web <NUM>, the material that comprises the web <NUM>, and the like.

At step <NUM> the on-press distortion analyzer process (block <NUM>) selects from the database <NUM> the distortion information in accordance with the parameters of the production job.

At step <NUM>, the on-press distortion analyzer process (block <NUM>) waits for the production job to begin.

At step <NUM>, the on-press distortion analyzer process (block <NUM>) receives from a camera (not shown) disposed along a path of the web <NUM> between the dryer unit <NUM> and the take up roll <NUM> an image of a page printed on the web <NUM>. In some embodiments, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) determines when a page will be in the field of view of the camera and directs the camera to acquire the image. In other embodiments, the camera acquires images of all pages printed on the web at a predetermined rate in accordance with the web speed and page size being printed. Other ways of operating the camera to acquire the image of the printed page apparent to one who has ordinary skill in the art may be used.

At step <NUM>, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) analyzes the image of the printed page relative to the page data <NUM> (<FIG>) used to generate the printed page to estimate distortion that has occurred during printing.

At step <NUM>, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) determines if the amount of distortion (either in dimensions of the printed page or in dot gain) determined at step <NUM> exceeds a predetermined acceptable level of distortion, and, if so, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>), at step <NUM>, generates an error to the print management control system <NUM> to stop the production run because of excessive distortion and exits.

Otherwise, at step <NUM>, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) adjusts the distortion information in the database <NUM> associated with the parameters of the production run in accordance with the distortion determined at step <NUM>.

At step <NUM>, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) determines if the production run has completed, and if so exits. Otherwise, the on-press distortion analyzer on-press distortion analyzer process (block <NUM>) proceeds to step <NUM> to receive another image.

The in-plant distortion analyzer process (block <NUM>) analyzes an image of a representative bag formed from a web <NUM> to develop distortion information used by the distortion corrector process (block <NUM>) and the on-press distortion analyzer on-press distortion analyzer process (block <NUM>). In some embodiments, a model of a product that is to be placed in bags formed from web <NUM> may be placed in the representative bag and the representative bag may be shrunk therearound. <FIG> illustrates a flowchart <NUM> of the steps undertaken by the in-plant distortion analyzer process (block <NUM>).

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) loads the job parameters used to print the web <NUM> that was used to form the bag.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) initializes new distortion information that is associated with the job parameters.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) receives an image of the representative bag after the bag has been formed and heat shrunk.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) identifies in the received image a printed page element printed on the bag and selects a page element in the page <NUM> that corresponds to the printed page element, by for example, comparing the contents and position of the printed page element to the specification of the page element in the page <NUM>. In addition, the in-plant distortion analyzer process (block <NUM>) undertakes image processing operations such as edge detection, thresholding, and the like to isolate in the received image the printed page element from other portions of the received image.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) determines the dimensional and position distortion between the printed page element identified at step <NUM> and the page element in the page <NUM> corresponding thereto.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) updates the distortion information created at step <NUM> with the dimensional and position distortion determined at step <NUM> and associates such distortion with the position on the unshrunk web <NUM> where the page element was printed (as specified in the page <NUM>).

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) determines if all of the printed page elements in the image received at step <NUM> have been analyzed, and, if so, proceeds to step <NUM>. Otherwise, the in-plant distortion analyzer process (block <NUM>) proceeds to step <NUM> to identify another printed element.

At step <NUM>, the in-plant distortion analyzer process (block <NUM>) stores the distortion information developed in steps <NUM>-<NUM> in the database <NUM>, and then exits.

Referring once again to <FIG>, the customer-site distortion analyzer process (block <NUM>) is used to update distortion information stored in the database <NUM> in accordance with information received after a product has been place in the bag created from the web <NUM>, and the bag is shrunk around the product.

<FIG> shows a flowchart <NUM> of steps undertaken by a bag loading system to prepare data for use by the customer-site distortion analyzer process (block <NUM>). At step <NUM>, a product is placed in a bag produced from the printed web <NUM>.

At step <NUM>, the bag having the product therein in shrunk (e.g., in a heated water bath or other method apparent to one who has ordinary skill in the art).

At step <NUM>, a scannable print element on the shrunk bag is scanned.

At step <NUM>, data (e.g., a SKU or other identifying information) that results from scanning the scannable print element and an image of the scannable print element are stored on a computer (not shown). The computer may be at the production facility where the customer-site distortion analyzer process (block <NUM>) operates, on a computer in the cloud, or at any other location accessible to the customer-site distortion analyzer process (block <NUM>).

At step <NUM>, a bag loading system determines if additional bags remain to be loaded with product and scanned, and if so, proceeds to step <NUM>. Otherwise, the bag loading system exits.

Periodically, for example, after a predetermined number of production runs to produce bags in which a particular type of product is to be disposed, the customer-site distortion analyzer process (block <NUM>) operates to determine if distortion errors are causing scanning errors at step <NUM> (<FIG>).

<FIG> is a flowchart <NUM> of steps undertaken by the customer-site distortion analyzer process (block <NUM>) to update distortion information to reduce scanning errors. At step <NUM>, the customer-site distortion analyzer process (block <NUM>) selects images of scannable page elements that are associated with mis-scans. Such scannable page elements may have encoded therein information regarding when and where the web <NUM> from the bag imprinted was printed with the scannable page element, a sequence code, and the other production information.

At step <NUM>, the customer-site distortion analyzer process (block <NUM>) loads the job parameters, the page <NUM>, and the distortion information associated with the job during which the printed scannable item that resulted in the mis-scan was printed on the web <NUM>.

At step <NUM>, the customer-site distortion analyzer process (block <NUM>) analyzes each image selected at step <NUM> with respect to the scannable page element in the page <NUM> to determine the distortion present in the selected image.

At step <NUM>, the customer-site distortion analyzer process (block <NUM>) updates the distortion information loaded at step <NUM> and associated with the job parameters in accordance with the distortion determined at step <NUM>. At step <NUM>, the customer-site distortion analyzer process (block <NUM>) stores the updated distortion in the database <NUM> for use with subsequent jobs having job parameters identical to those loaded at step <NUM>.

Thereafter, the customer-site distortion analyzer process (block <NUM>) exits.

<FIG> graphically illustrates an example of how dimensional distortion information may be developed at step <NUM> (<FIG>), step <NUM> (<FIG>), and step <NUM> (<FIG>).

Referring to <FIG>, a first two-dimensional array <NUM> of cells <NUM> is created wherein each cell spans a predetermined number of pixels of an element to be printed. For clarity, the reference number <NUM> associated with each cell of grid is shown in <FIG> with only a few such cells.

Preferably, each cell <NUM> of the first two-dimensional array <NUM> spans an equal number of pixels horizontally and vertically. An image element <NUM> in the page <NUM> to be printed is associated with the two-dimensional array of cells <NUM> to determine the number of cells <NUM> spanned by the image element <NUM>. In the example shown in <FIG>, the image <NUM> spans an area of <NUM> cells horizontally and <NUM> cells vertically.

Referring to <FIG>, after the image element <NUM> is printed on the web <NUM>, an image <NUM> of the printed page element is acquired after the web <NUM> has been shrunk and formed into a bag. The acquired image is aligned with a second two-dimensional array <NUM> of cells <NUM>. Initially, the dimensions of each cell <NUM> is identical to the dimension of each cell <NUM>.

Thereafter, the dimensions of the cells <NUM> are adjusted so that the acquired image <NUM> spans an identical number of cells <NUM> spanned by the image <NUM> (i.e., 5x5). The number of horizontal pixels spanned by the adjusted cell <NUM> divided by the number of horizontal pixels spanned by the cell <NUM> provides a horizontal scaling factor. Similarly, the number of vertical pixels spanned by the adjust cell <NUM> divided by the number of vertical pixels spanned by the cell <NUM> provides a vertical scaling factor. Such horizontal and vertical scaling factors are stored in the distortion information in the database <NUM>.

As discussed above, each cell <NUM> is associated with a predetermined area of pixels of a portion of the image <NUM>. The changes to such portion of the image associated with each cell may be analyzed as described above to determine the dimensions of each adjusted cell <NUM>. Horizontal and vertical scale factors may be calculated from such determined dimensions to and stored as distortion information associated with each cell <NUM>. Similarly, changes to image density (i.e., dot-gain) due to shrinking of the web <NUM> may be analyzed to determine the dot-gain adjustment needed to compensate for such changes and also stored as distortion information associated with each cell <NUM>.

It should be apparent to those who have skill in the art that any combination of hardware and/or software may be used to implement the system print management control system <NUM> and print unit controllers <NUM>, <NUM>, <NUM>, and <NUM> described herein. It will be understood and appreciated that one or more of the processes, sub-processes, and process steps described in connection with <FIG>, <FIG>, and <FIG> may be performed by hardware, software, or a combination of hardware and software on one or more electronic or digitally-controlled devices. The software may reside in a software memory (not shown) in a suitable electronic processing component or system such as, for example, one or more of the functional systems, controllers, devices, components, modules, or sub-modules schematically depicted in <FIG>, <FIG>, and <FIG>. The software memory may include an ordered listing of executable instructions for implementing logical functions (that is, "logic" that may be implemented in digital form such as digital circuitry or source code, or in analog form such as analog source such as an analog electrical, sound, or video signal). The instructions may be executed within a processing module or controller (e.g., the print management control system <NUM> and the print unit controllers <NUM>, <NUM>, <NUM>, and <NUM>), which includes, for example, one or more microprocessors, general purpose processors, combinations of processors, digital signal processors (DSPs), field programmable gate arrays (FPGAs), or application-specific integrated circuits (ASICs). Further, the schematic diagrams describe a logical division of functions having physical (hardware and/or software) implementations that are not limited by architecture or the physical layout of the functions. The example systems described in this application may be implemented in a variety of configurations and operate as hardware/software components in a single hardware/software unit, or in separate hardware/software units.

The executable instructions may be implemented as a computer program product having instructions stored therein which, when executed by a processing module of an electronic system, direct the electronic system to carry out the instructions. The computer program product may be selectively embodied in any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as an electronic computer-based system, processor-containing system, or other system that may selectively fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, computer-readable storage medium is any non-transitory means that may store the program for use by or in connection with the instruction execution system, apparatus, or device. The non-transitory computer-readable storage medium may selectively be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. A non-exhaustive list of more specific examples of non-transitory computer readable media include: an electrical connection having one or more wires (electronic); a portable computer diskette (magnetic); a random access, i.e., volatile, memory (electronic); a read-only memory (electronic); an erasable programmable read only memory such as, for example, Flash memory (electronic); a compact disc memory such as, for example, CD-ROM, CD-R, CD-RW (optical); and digital versatile disc memory, i.e., DVD (optical).

It will also be understood that receiving and transmitting of signals or data as used in this document means that two or more systems, devices, components, modules, or sub-modules are capable of communicating with each other via signals that travel over some type of signal path. The signals may be communication, power, data, or energy signals, which may communicate information, power, or energy from a first system, device, component, module, or sub-module to a second system, device, component, module, or sub-module along a signal path between the first and second system, device, component, module, or sub-module. The signal paths may include physical, electrical, magnetic, electromagnetic, electrochemical, optical, wired, or wireless connections. The signal paths may also include additional systems, devices, components, modules, or sub-modules between the first and second system, device, component, module, or sub-module.

In summary, a printing system <NUM> for printing on a clear polymeric film web <NUM> is disclosed in which a plurality of imager units <NUM>, <NUM>, <NUM>, and <NUM> have inkjet print units <NUM>, <NUM>, <NUM>, and <NUM>. Such inkjet print units are operated to deposit material on the web <NUM> at a particular resolution and drop size selected in accordance with the type of material being deposited by such inkjet print unit and content being reproduced thereby. In addition, a distortion corrector <NUM> determines adjustments to the dimensions and position on the web <NUM> of a page element prior being printed to compensate for distortion of the printed page element that results from heat shrinking of a bag manufactured from the web <NUM> around a product disposed therein.

The invention is however defined by the appended claims.

Claim 1:
A system (<NUM>) for printing on clear polymeric film web, comprising:
a first stationary inkjet print unit (<NUM>) having first ejection nozzles that span a width of the clear polymeric film web;
a second stationary inkjet print unit (<NUM>) having second ejection nozzles that span the width of the clear polymeric film web;
a web transport adapted to convey the clear polymeric film web past the first and second stationary inkjet print units (<NUM>, <NUM>);
a distortion corrector adapted to adjust dimensions of a page element to be printed in accordance with predetermined distortion data to develop an adjusted page element, wherein the dimensions are adjusted to compensate for expected shrinking of the clear polymeric film in a shrink wrap application after printing, the distortion corrector being further adapted to determine dot gain changes as a result of the shrinking and to adjust image data of the adjusted page element to compensate for such dot gain changes;
a raster image processor adapted to rasterize printing commands associated with the adjusted page element to generate bitmap data;
a first print controller (<NUM>) adapted to receive the bitmap data and in response operate the first stationary inkjet print unit (<NUM>) to deposit drops of a first material on the clear polymeric film web in accordance with the bitmap data at a first fixed resolution; and
a second print controller (<NUM>) adapted to receive the bitmap data and in response operate the second stationary inkjet print unit (<NUM>) to deposit drops of a second material on the clear polymeric film web in accordance with the bitmap data at a second fixed resolution,
wherein the first and second fixed resolutions are different.